Hybrid materials: state of the art and new frontiers

Resume : This work aims at imparting biological functions into polymeric materials. On approach which is discussed, involves the synthesis of polymer-protein conjugates and their self-assembly to form biofunctional membranes. Self-assembled membranes offer a promising alternative for conventional membrane fabrication, especially in the field of nano-filtration. However, recent advances pushing the developments in self-assembled membranes towards thinner membranes with more selectivity are still limited with respect to active permeation area, stability and responsiveness. Here we introduce a new strategy using engineered natural protein channels decorated with polymer chains followed by self-assembly at various interfaces to form ultrathin, permeable and highly selective membranes. This approach diversifies membrane technology since various sizes and shapes of proteins can be used, in addition to different responsive polymers generating a platform for “smart” self-assembled membranes. References [1] N.C. Mougin, P. van Rijn, H. Park, A.H.E. Müller, A. Böker Adv. Funct. Mater. 2011, 21, 2470. [2] P. van Rijn, M. Tutus, C. Kathrein, L. Zhu, M. Wessling, U. Schwaneberg, A. Böker Chem. Soc. Rev., 2013, 42, 6578. [3] P. van Rijn, H. Park, K. Özlem Nazli, N.C. Mougin, A. Böker Langmuir, 2013, 29, 276. [4] P. van Rijn, M. Tutus, C. Kathrein, N.C. Mougin, H. Park, C. Hein, M.P. Schürings, A. Böker Adv. Funct. Mater., 2014, 24, 6762. [5] G. Jutz, P. van Rijn, B. Santos De Miranda, A. Böker Chem. Rev., 2015, 115, 1653. [6] H. Charan, J. Kinzel, U. Glebe, D. Anand, T. Mirzaei Garakani, L. Zhu, M. Bocola, U. Schwaneberg, A. Böker Biomaterials, 2016, 107, 115. [7] H. Charan, U. Glebe, D. Anand, J. Kinzel, L. Zhu, M. Bocola, T. Mirzaei Garakani, U. Schwaneberg, A. Böker Soft Matter 2017, 13, 2866.

Resume : Conventional syntheses of industrially important reagents such as dimethyl carbonate, ethylene carbonate and carbodihydrazide are challenged by low efficiency due to side reactions, use of toxic starting materials, high energy input, and inconvenient reaction conditions. In view of the strategic importance of such compounds, alternative production methods boasting higher productivity and lower cost remain a subject of interest. Urease CLELs were demonstrated to prompt formation of the above products by enforcing reaction between the inexpensive substrate urea, and a non-water nucleophile such as methanol, ethylene glycol or hydrazine. These results lead to assume the general utilization opportunity of similar heterogeneous catalyst systems in organic reactions to afford greener and more economic syntheses of many industrially important commodity compounds. Crosslinked enzyme aggregates (CLEAs) have greatly improved the storage and operational stability of enzyme preparations as well as permitted their easy recovery. Critical breakthrough with CLELs was achieved by enforcing protein aggregation via lyophilization as opposed to conventional CLEA. The subsequent crosslinking of the lyophilizate (yielding a crosslinked enzyme lyophilizate) in a suitable saturated salt solution/anti-solvent led to a much improved crosslinking yield and catalytic activity. Furthermore, urease CLELs have been shown to sustain activity and stability in organic solvents and temperatures nearing 100 oC.

Resume : Coconut leaf sheath-derived nitrogen doped carbon framework is developed and incorporated with nickel and cobalt metal nanoparticles in the carbon matrix by a facile process of growing ZIF-67 metal organic framework particles on the graphitised carbon, followed by annealing it in inert atmosphere. Various parameters, such as the annealing and activation temperature used in the preparation of the samples and amount of nitrogen doped carbon used for loading the nickel cobalt nanoparticles, are modified to obtain three different samples. The samples obtained are then tested for high performance supercapacitors and as an oxygen evolution reaction (OER) catalyst. The optimised sample NiCo-C-1 gave an ultrahigh specific capacitance of 2471 Fg-1 at a current density of 1 Ag-1 in a 2 M KOH electrolyte. An asymmetric supercapacitor assembly prepared from NiCo-C-1 as the positive electrode and the nitrogen doped carbon as the negative electrode, exhibited an energy density of up to 31.8 WhKg-1 for a high power density of 6.2 kWKg-1 over a potential window of 0 to 1.55 V. The two of our best samples were also tested for OER, giving good water oxidation kinetics, revealed by their lower Tafel slopes in the range of 107 mVdec-1 and a low over potential (η) of around 420 mV at a current density of 10 mA cm−2. The process involves minimum chemicals for the pre/post treatment of the biomass and is very crucial as it yields an unprecedented performance for a material majorly developed and modified from biomass. The process involves minimum chemicals for the pre/post treatment of the biomass and is comparable to a ZIF-derived Ni Co mixed oxide/graphene hydrogel system which we developed previously. Hence, this work opens great avenues for biomass-derived materials for high performance supercapacitors and catalysis.

Resume : In this work, a hybrid solid state electrolyte for lithium ion/metal batteries is presented based on the deep eutectic solvents. The hybrid electrolyte is synthesized in a facile one-pot non-aqueous sol-gel route by the encapsulation of a deep eutectic solvent, rather than a costly ionic liquid, in a porous silica matrix at room temperature. The deep eutectic solvent electrolyte is formed by the mixing of N-methylacetamide and the lithium salt, i.e. LiTFSI, in appropriate molar ratios.[1] The voltage window and ionic conductivity have been characterized by means of voltammetric methods and electrochemical impedance spectroscopy. A beneficial anodic stability limit of up to 4.8 V vs. Li+/Li and ionic conductivity of up to 1.15 mS cm-1 at room temperature have been observed. LiFePO4 (LFP) half-cells were assembled with these hybrid solid state electrolyte membranes/monoliths. These cells display highly reversible capacities of about 110 mAh/g for over 100 cycles (at 0.1C, 16 °C), which are comparable to LFP half-cells assembled with a conventional liquid electrolyte (1M LiPF6, 50/50 vol% EC/DEC, 115 mAh/g at 0.1C). These results have been recently published in Chemistry of Materials. Acknowledgements B. Joos is a PhD fellow of the Research Foundation – Flanders (FWO Vlaanderen). This project receives the support of the ERDF. References [1] A. Boisset, J. Jacquemin, M. Anouti, Electrochimica Acta, 2011, 102, 120-126. .[2] DOI: 10.1021/acs.chemmater.7b03736

Resume : Efficient water oxidation catalysts are required for the development of water splitting technologies. Herein, we report the synthesis of layered hybrid transition metal phosphonate compounds from metal acetylacetonate precursors and various phosphonic acid in benzyl alcohol. The hybrid particles are formed by inorganic layers of divalent transition metals (e.g. Fe, Co, Ni) in distorted octahedra environments separated by bilayers of the organic group. These hybrid materials are used as precursors for water splitting electrocatalysts in two ways. On the one hand, their direct use as anode materials, so as oxygen evolution catalyst, involves their gradual transformation to hydroxide nanosheets during operation. It is found that the hybrid particles template the formation in situ of transition metal hydroxide nanosheets of sizes between 5 and 25 nm and thicknesses between 3 and 10 nm. X-ray absorption spectroscopy measurements suggest that the hybrid acts also as a template for the local structure of the metal sites in the active catalyst, which remain distorted after the transformation. Optimum electrocatalytic activity is achieved with the hybrid compound with a Fe content of 16 %. The combination of the synergistic effect between Ni and Fe with the structural properties of the hybrid results in an efficient catalyst that generates a current density of 10 mA cm^-2 at an overpotential of 240 mV, and also in a stable catalyst that operates continuously at low overpotentials for 160 h. On the other hand, we report that nickel phosphides can be synthesized through thermal treatment of layered nickel phenyl- (NiPh) or methyl-phosphonates (NiMe) that act as single-source precursors. Ni[12]P[5], Ni[12]P[5]-Ni[2]P and Ni[2]P nanoparticles with sizes of ca. 15-45 nm coated with a thin shell of carbonaceous material were produced. Thermogravimetric analysis coupled with mass spectrometry (TG-MS) showed that H[2], H[2]O, P[2] and –C[6]H[5] are the main compounds formed during the transformation of the precursor under argon, while no hazard phosphorous-containing compounds are created, making this a simple and relatively safe route for fabricating nanostructured transition metal phosphides. The H[2] most likely reacts with the –PO[3] groups of the precursor to form H[2]O and P[2], and the latter subsequently reacts with the metal to produce the phosphide. The nickel phosphides nanoparticles efficiently catalyze the hydrogen evolution reaction, with Ni[2]P showing the best performance and generating a current density of 10 mA cm^-2 at an overpotential of 87 mV and exhibiting long-term stability. Co[2]P and CoP NPs were also synthesized following this method. All in all, these approaches may be utilized to explore the rich metal-phosphonate chemistry for fabricating a large variety of nanostructured materials for electrochemical energy conversion and storage applications.

Resume : Energy crisis is one of the most urgent and critical issues in our modern society. To counteract the growing energy consumption demand, there is an urgent need to design sustainable, efficient and low-cost devices for energy production and storage. Novel electrode materials, with a high energy density at high power are urgently needed for realizing high-performance energy storage devices, including supercapacitors for applications in electrical vehicles, portable electronic devices, and power grids, etc. Graphene-based materials have recently attracted a notable attention due to their extraordinary properties, which make them attractive candidates for many technological applications, such as sensing, catalysts and energy storage. The development of functional graphene-based materials combining high stability, large surface areas, ability to act as absorbent of relevant chemical species, and solution processability is of significance for energy applications. A poorly explored approach relies on the controlled nanostructuration of graphene into robust and highly ordered three-dimensional (3D) networks as a route to further leverage the exceptional properties of this unique material. Herein, a simple yet effective and scalable one-step method is developed to prepare graphene-based 3D covalent networks with tunable interlayer distance and specific surface areas, which is used for high performance supercapacitors. Furthermore, we also describe the generation of novel graphene-based functional hybrid architectures by reacting functionalized graphene derivatives with certain photo-/redox active functional molecules. The versatile modular synthetic approach allows the generation of various graphene-based hybrid nanomaterials, which were characterized fully by various spectroscopic and microscopic techniques. These materials are potentially very useful for energy-related applications, such as photoelectrochemical cells and supercapacitors. References: 1. X. Y. Zhang, P. Samorì, ChemNanoMat. 2017, 3, 362-372. 2. X. Y. Zhang, A. Ciesielski, F. Richard, P. Chen, E. A. Prasetyanto, L. De Cola, P. Samorì, Small 2016, 12, 1044 –1052. 3. X. Y. Zhang, L. L. Hou, A. Ciesielski, P. Samorì, Adv. Energy Mater. 2016, 6, 1600671. 4. X. Y. Zhang, L. L. Hou, F. Richard, P. Samorì, submitted.

Resume : Carbon-coated α-MnO2 hybrid nanowires (C-MnO2 NWs) comprised of ~ 1% amorphous porous carbon were prepared by the pyrolysis of a sucrose/α-MnO2 NW blend. Relative to the α-MnO2 NWs, the C-MnO2 NWs exhibited a five-fold increase in conductivity as determined by single-nanowire electronic conductivity measurements and an increase in Mn3 content as determined by XPS/iodometric titration. Despite a decrease in surface area relative to the α-MnO2 NWs, the C-MnO2 NWs exhibited a 13-fold increase in diffusion limited specific activity and a six-fold decrease in charge transfer resistance for the oxygen reduction reaction (ORR) in alkaline electrolyte. The C-MnO2 NWs comprised of ~99 wt. % MnO2 and ~1 wt. % carbon coating also demonstrated an ORR onset potential within 20 mV of commercial 20% Pt/C and chronoamperometric current/stability competitive with 20% Pt/C at high overpotential (0.4 V vs. RHE) and high temperature (60 °C) with no additional conductive carbon. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525

Resume : In recent years, the water splitting process with electrocatalytic and photocatalytic, as one of the next generation energy conversion technology for producing hydrogen and oxygen molecules has been widely considered in solving energy and environmental problems. However, half reaction of oxygen evolution reaction (OER) plays a critical role in improving overall conversion efficiency of the water splitting process because the OER system encounters the bottle-neck of a kinetically sluggish reaction and considerable overpotential value. Precious metal based materials as the superior active catalyst for OER have been used, however, high cost and poor stability these metals hinder widespread practical and technical use. Hence, extensive research activities have focused on inexpensive earth-abundant metal based materials such as multi-composite transition metal (Ni, Fe, Mn, and Co etc.) compounds, as well as hybrid structures with carbon-based materials as candidate catalysts for alternative developed OER electrocatalyst. Herein, we report successful design and fabrication of unique mesoporous CoxN nanocubes (NCs)@N-doped carbon hybrid nanostructures in-situ nitridation and calcination via Prussian blue analogue of Co3[Co(CN)6]2 NC precursors and polydopamine. Unique architectures (mesoporous CoxN and N-doped carbon encapsulation) could assign well dispersed pore, highly active sites, and good durability of CoxN NCs for OER.

Resume : Energy storage is a key technology to enable our ongoing transition to a sustainable energy model. Electrochemical energy storage will be central to this transition but is still far from optimal. Furthermore, many new niches of application are envisioned with specific and varied needs, from wearable electronics to smart grids. That is why there is still plenty of room for new and novel types of materials and devices in this area. Hybrid materials offer opportunities for synergy and improved properties with respect to their components.[1] Those formed by electroactive and conducting compounds are of particular interest for energy storage applications.[2, 3, 10] We have developed a whole line of work dealing with hybrid electroactive (oxides, phosphates[4] polioxometalates[5]) and conductive materials (conducting polymers or carbons) for energy storage applications (Figure 2).[4-9] In this conference we will address the different approaches towards hybridizing energy storage by taking the hybridization concept to a chemical level and will discuss the several multifunctional synergies hybrids provide. In particular, in addition to conductive-electroactive combinations, we will show how hybrids can be designed to take advantage of dual energy storage mechanisms by combining the typical capacitive behaviour of supercapacitors with the characteristic faradaic activities of batteries.[10] [1] P. Gomez-Romero Adv.Mater. 2001, 13(3), 163. [2] P. Gomez-Romero et al. J.Solid State Electrochem. 2010 14(11), 1939 [3] Ait Salah et al. J.Electrochem.Soc. 2006, 153(9), A1692. [4] A. Fedorkova et al. Electrochim.Acta 2010, 55(3), 943 [5] J. Vaillant et al. Progress in Solid State Chemistry, 2006, 34, 147. [6] M. Baibarac and P. Gómez-Romero. J. of Nanoscience and Nanotechnology, 6(2) 2006, 289. [7] M. Baibarac et al. Small 2006, 2(8-9), 1075 [8] V. Ruiz, J. Suárez-Guevara, P. Gomez-Romero Electrochem. Communications 2012, 24, 35. [9] J. Suarez-Guevara, V. Ruiz and P. Gomez-Romero J.Mat.Chem.A, 2014, 2, 1014. [10] D.P. Dubal, V. Ruiz, O. Ayyad and P. Gomez-Romero Chem.Soc.Rev. 2015 44(7):1777-90

Resume : Physical vapor deposition (PVD) is an efficient method of thin film deposition with a variety of advantages over solution processing: the absence of solvents allows depositing easily two or more materials; multilayers can be deposited on the top of each other; layer thickness can be controlled with nanometer precision; absence of solvents and vacuum processing reduces impurities. In this work, thin film deposition using a novel physical vapor methodology is described for a series of relevant materials with photovoltaic applications: lead halide perovskites, organic semiconductors and ionic liquids. [1-3] PVD is optimized based on the volatility of each material, from the mass flow of effusing vapor from Knudsen cells maintained at phase equilibrium conditions. This procedure of vapor deposition presents a high versatility to the fabrication of high purity thin films, multilayers and hybrid materials. References [1] José Costa, Rui Rocha, Inês Vaz, Manuel Torres, Adélio Mendes, Luís Santos; Journal of Chemical & Engineering Data, 60, 3776-3791, 2015. [2] José Costa, João Azevedo, Adélio Mendes, Luís Santos; Journal of Physical Chemistry C, 121, 2080-2087, 2017. [3] José Costa, Ana Coelho, Adélio Mendes, Luís Santos; Applied Surface Science, 428, 242-249, 2018. Acknowledgments The authors thank Fundacão para a Ciência e Tecnologia (FCT), Lisbon, Portugal, for financial support to CIQUP, University of Porto (Projects Pest-C/QUI/UI0081/2013 and NORTE-01-0145-FEDER-000028, Sustainable Advanced Materials) and for financial support to LEPABE, University of Porto (Projects POCI-01-0145-FEDER-006939 and NORTE‐01‐0145‐FEDER‐000005). Dr. José Costa also thank FCT for the award of the Research Grant SFRH/BPD/116930/2016.

Resume : A one-step/one-pot strategy to synthesize phase pure Co2P nanoparticles encapsulated N, P dual-doped carbon nanotubes (denoted as Co2P/CNT) is developed. The method is free of toxic, pyrophoric alkylphosphine as the phosphorus source, does not involve the use of sophisticated instrumentation or expensive precursors and may be extended to other transition-metal phosphides. When the as prepared Co2P/CNTs are applied as an anode for OER in 1 M KOH, a current density of 10 mA/cm2 is achieved at an overpotential of 292 mV which is 36 mV less than that required for the state-of-art OER catalyst RuO2 with a small Tafel slope of ∼68 mV/decade. While applied as a cathode towards HER, Co2P/CNTs exhibit a current density of 10 mA/cm2 at an overpotential of 132 mV with a Tafel slope of 103 mV/dec that compares favourably with the state-of-art HER catalyst, Pt/C. After 15 h of continuous electrolysis for both HER and OER, the electrode material preserves its structure along with its robust catalytic activity which points out to their excellent stability. A total alkaline water electrolyzer constructed by employing Co2P/CNT as catalyst on both anode and cathode delivered a current density of 10 mA/cm2 at around 1.53 V over an extended operational period rivalling the state-of-art combination of Pt/C and RuO2 and is among the best of the bi-functional total-water splitting electrocatalysts reported till date. This remarkable performance of Co2P/CNTs can be attributed to the intrinsic catalytic activity of Co2P nanoparticles fortified with heteroatom doped few layered graphene which results in enhanced electrical conductivity besides providing long-term stability.

Resume : Organic-inorganic hybrid perovskite solar cells received significant attention due to its low-cost facile solution processability and high performances. However, its poor moisture stability has been the bottleneck for commercialization of perovskite solar cell. Recently, several types of research revealed the mechanisms of moisture-induced degradation of perovskite absorption layer. Water molecules penetrate perovskite’s grain boundary, propagating through perovskite layer in the in-plane direction. Several approaches have been tried for moisture resistant enhancement of planar perovskite layer such as the addition of polymers. These inevitably require a complicated structure and fabrication process such as the use of mesoporous TiO2 and expensive polymers. Herein, we present enhanced moisture stability of perovskite absorption layer in planar structure solar cells by adding amino acid salts. By simply introducing amino acid salts (PABA•HI(4-aminobenzoic acid)) into the precursor solution, the cell performance with efficiency of 16% maintains more than 12 h against high humidity condition (relative humidity > 75%). Increased stability of perovskite absorption layer is originated from blocking water molecule penetration to perovskite grain boundaries by forming hydrogen bonds between amino acid salts and halide atoms at perovskite grain surfaces. Our finding on the stability improvement of perovskite layer would facilitate the commercialization of perovskite solar cells.

Resume : Various combinations of conducting polymers and graphene have been fabricated in order to gain synergetic advances: to improve the energy storage capability and cycle life of supercapacitors. Usually, these materials are characterized by electrochemistry and spectroscopy separately, but by combining the techniques, a more fundamental study of potential supercapacitor materials’ performance can be realised. In this work, polyazulene-graphene oxide composite films were electropolymerized in choline-based ionic liquid containing various amounts of graphene oxide (GO). The suitability of the composites as material for an electrochemical supercapacitor electrode was determined by CV and EIS. Successful incorporation and reduction of GO were confirmed by ex situ Raman and FTIR as well as X-ray photoelectron spectroscopy. Changing the concentration of GO had no effect on the polymerization of azulene, but all composites showed improvement in both capacitance and long term cycling performance compared to neat polyazulene. The electronic transport during p-doping was determined by in situ UV-Vis and ATR-FTIR Kretschmann spectroelectrochemistry. As the charging level increased, the IR spectra showed an increase of infrared active vibration bands under 2 000 cm-1 while build-up of two electronic absorption bands above 2 000 cm-1 could be assigned to the formation of polarons and polaron pairs.

Resume : Renewable hydrogen production is key for establishing clean energy systems because hydrogen can be used as a clean energy source in hydrogen fuel cells and a hydrogen-driven society. Recently, we have developed the novel donor-bridge-acceptor type organic molecule for dye-sensitizer with metal oxide semiconducting photocatalyst for photocatalytic hydrogen production. To increase of the production rate of hydrogen from water, high rate of charge separation from light is one of the target. Here, we will introduce of the effects of alcoxychains and anchor group on organic dye molecules for photocatakytic hydrogen production. (i) Alcoxychains can be modified the hydrophobicity of photocatalyst, it makes to protection of the electron leakage from photocatalyst to water medium. The modification of photocatalysts such by hexadecane group could improve of the hydrophobicity than that of methyl group protection of organic dye, therefore hydrogen production as high as 200% was found from no alcoxy chain treatment of organic dye. (ii) In the reaction using carboxylic acid, phosphoric acid, pyridyl group, the pyridyl group showed the highest hydrogen production capacity, thus we found good photo stability (>100 h) and hydrogen productivity (TON = 23557, AQY 420nm = 2.63%) in pyridyl group system under visible light reaction. A suitable anchor group may suppress the dissociation reaction of the dye during the reaction. In addition, when a dimer such as a porphyrin dimer having a pyridyl group was used, the durability was further improved. About 60% of the activity remained after 300 hours.

Resume : This paper firstly presents the possibility of direct and continuous weaving the piezoelectric PVDF-TrFE nanofiber on metal-wire for energy harvesting by electrospinning. Previous many other groups have tried various methods for enhanced flexible energy harvesting properties; incorporation of high piezoelectric inorganic fillers in polymer, organic conducting/piezoelectric polymer core-shell structure, and alignment of piezoelectric polymer nanofiber. In this experiment, we try to make highly efficient flexible piezoelectric nanofiber with both an improved energy density and stability and a self-electrode contained nanofiber direct applicable for electronic devices. PVDF-TrFE nanofiber was continuously electrospun on Cu metal wire (Φ = 200 µm). PVDF-TrFE nanofibers without beads was determined to concentration of PVDF-TrFE in solvent. PVDF-TrFE nanofibers with various diameters were prepared with the flow rate ranging from 1 to 10 µl/min. The other conditions such as needle to substrate (metal wire) distance and needle size were fixed. The metal wire was continuously rotated and moved in axial direction for uniformly depositing PVDF-TrFE nanofiber during electrospinning. To protect PVDF-TrFE nanofibers/metal wire, it was embedded in PDMS before properties measurement. A single PVDF-TrFE nanofibers/metal wire showed a voltage of 0.3 V at the low external pressure of 3.82 kpa. As the number of PVDF-TrFE nanofiber/metal wire increased, the induced voltage was also proportional to the increased number of nanofiber. In case of aligned 42 PVDF-TrFE nanofiber/metal wires, induced voltage was 16 V under 15 kpa. Such a large voltage per unit pressure of about 1 V/kpa corresponds to 3 times enhanced value compared to previously reported ones observed in PVDF-TrFE films or matt type nanofibers. We will discuss the improved energy harvesting properties of the PVDF-TrFE nanofiber/metal wire structure in terms of concentration of PVDF-TrFE, deposition speed, and nano fiber density and some useful applications like wearable energy harvesting devices.

Resume : Recent attention has been increasingly received to prepare anti-corrosive coatings with superhydrophobicity which can significantly suppress the exposure of corrosive species to metal substrates. Herein, superhydrophobic/porous coating with ultra-low water adhesion has successfully been fabricated via a micelle fusion-aggregation assembly method by using a hybrid poly(dimethylsiloxane)-block-polystyrene-block-poly(methacrylolsobutyl POSS) triblock copolymer (PDMS−PS−PiBuPOSSMA). It was found that aggregation behavior in diluted solution and subsequent formation of nano-/microscale hierarchical surfaces in the condensed state were affected by the molar mass of the triblock copolymers, which were evidenced by dynamic light scattering (DLS), SEM, and TEM studies. The pendant massive POSS moieties are able to “bind” the methacrylate polymer chains, with the result of decreasing segment mobility, thus ensuring the stability of polymeric micelles during solvent evaporation. Increasing of PiBuPOSSMA content can significantly increase the roughness of the resulting coatings, leading to an increase of apparent water contact angles from 145.7 ± 1° to 157.3 ± 1.1°. The optimized PDMS−PS−PiBuPOSSMA surface possesses unique nano/microscale hierarchical morphology, large apparent water contact angle (157.3 ± 1.1°), small roll-off angle (∼3°), low contact angle hysteresis (∼0.9°), long-term stability, and good chemical and thermal resistance. An anti-corrosive coating based on the superhydrophobic/porous polymeric assemblies exhibits an excellent performance in preventing corrosive species (ions and water) from the underlying metallic substrate (stainless steel) in 3.5 wt% NaCl aqueous solution with high inhibition efficiency and long-term preservability, which could be attributed to the synergistic effect of superhydrophobic surface and capillary action arising from the underlying porous structure.

Resume : This work presents a first-principles simulation and non-equilibrium Green's function (NEGF) based computational study of a novel monolayer InSe- antimonene van der Waals (vdW) heterostructure deeper nanoscale MOS transistor. With GGA-PBE calculations inclusive of Grimme's DFT-D2 corrections in density functional theory, the structure, electronic properties and spatial carrier distributions in InSe-Sb vdW heterostructure is evaluated. Thereafter with NEGF formalism, the device performance metrics of a 15nm nMOSFET with the InSe-Sb heterostructure channel material are simulated. The InSe-Sb vdW MOSFET is predicted to deliver good drive currents ~800 uA/um, ON/OFF ratio of 4x10^4 and a high transconductance of 2.5 uS/um. The small and isotropic carrier effective mass of ~0.163 and band-gap of ~0.6eV, which are tunable with stacking arrangement, make the device suitable for high frequency applications with a cutoff frequency ~ 2.5 THz.

Resume : We present in-situ growth of an ultrathin layer of MoS2 on self-sensitized carbon nitride (SSCN) microspheres. The resulted MoS2-coated SSCN photocatalyst exhibits excellent visible-light activities for photocatalytic H2 generation. The characterizations and photocatalytic test results suggest that the surface s-triazine dyes on SSCN present synergistic effect with the intimately contacted MoS2 layer, allowing for strong light-harvesting capability with effective generation of photo-electrons which transport to the MoS2 layer for H2 evolution. Our studies provide a new way of future development of low-cost noble-metal-free photocatalysts for efficient solar-driven hydrogen production.

Resume : Calcium indate (CaIn2O4) is an important wideband gap (3.9 eV) semiconductor that can be explored for optical doping such as transition metals and/or rare-earths useful to make light-emitters, optical data storage, and other devices. Here, we synthesize Cr4+ doped CaIn2O4–C hybrid nanostructure (1-10 mol% Cr4+) in tuning visible-light emission and dielectric properties. When grafting a C-sp2 surface layer on Cr4+: CaIn2O4 of small crystallites it yields a core-shell structure of tailored dielectric, optical and other properties. A green route using fresh nectar from aloe vera leaves is used to produce this structure from Cr6+, Ca2+ and In3+ salts. The aloe vera nectar embeds the cations in a gel so as it controls an ionic conversion Cr6+ Cr4+ in the ambient air [1,2]. When self-dried at room temperature, the gel was burnt with camphor (a fuel) in air to yield a hybrid phase. Free carbon could be burnt out by annealing the powder at 400C in air. In 1 mol% Cr4+ doped sample (measured at room temperature), a dielectric permittivity εr ~ 97 lasts at low frequencies near 1 Hz, and it decays progressively on raising the frequency in a fairly steady εr ~ 3 above 1 kHz. At 105 to 106 Hz frequency, the ac conductivity picks-up suddenly by nearly three orders of magnitude, e.g., 34.5x10-7 Scm-1. A semi-circle that appears of the Nyquist plots at small 1 mol% Cr4+ doping converts into a linear path intrinsic of an insulating behavior at higher Cr4+ contents. As-prepared Cr4+:CaIn2O4–C exhibits two bands at 265 nm and 360 nm, which are shifted to at 270 and 370 nm when it is annealed at 400-600 ºC for 2 h. These are the ligand-to-metal O2- Cr4+ charge transfer bands. The light-emission is studied in analyzing migration, transfer and recombination processes of light-induced e--h+ pairs. Upon exciting at a 270 nm wavelength from a xenon lamp, two broad emission bands appear at 395 nm and 680 nm as intense blue and red lights. The intensity decreases in both the bands on annealing the sample as a result of a suppressed e--h+ recombination. The results are described in correlation to a hybrid Cr4+:CaIn2O4–C structure.

Resume : Ever-increasing energy crisis and environmental concerns associated with excessive fossil fuel combustion have aroused intensive search for clean and sustainable alternative energy sources. Highly efficient and cost-effective electrocatalysts for the oxygen evolution reaction (OER) are of paramount importance for renewable energy conversion and storage. Here, we developed a facile approach for integrating two-dimensional zeolitic imidazolate framework-67 (ZIF-67) nanoarrays and Co-Ni-Al layered double hydroxide (CoNiAl-LDH) nanoplatelets to form a hybrid CoNiAl-LDH/ZIF-67 electrocatalyst. Due to the unique hierarchical architecture with largely increased electrochemical active surface area, multi-porous framework, and intimate interfacial coupling effect, as-fabricated CoNiAl-LDH/ZIF-67 electrocatalyst exhibited excellent OER activity with a small overpotential of 303 mV at 10 mA cm-2 and Tafel slope around 88 mV dec-1. Moreover, such electrocatalyst possessed excellent electrochemical durability and structural stability. The present work provides a general strategy for the rational design and synthesis of multi-functional hierarchical catalyst systems, which is expected to exhibit superior performance in a wide range of catalysis, especially in water electrolysis.

Resume : Currently, efficient transform of economical hydrocarbons to corresponding high value-added oxygenates through aerobic oxidations is receiving increasing attention on account of its great importance in fine chemical industry. Here, Zn-Cr layered double hydroxide (ZnCr-LDH)/carbon nanotubes (CNTs) hybrid composite was assembled for this reaction. It was found small-sized ZnCr-LDH nanocrystals could be anchored on the surface of acid-treated CNTs, thus forming strong interactions between them. An excellent catalytic performance was achieved over the ZnCr-LDH/CNTs, with an ethylbenzene conversion of 54.2% and a high acetophenone selectivity of 93.7%, which was better than those of pristine ZnCr-LDH and other most previously reported heterogeneous catalysts in the literature. Highly dispersed active Cr species and strong interactions between ZnCr-LDH and CNTs were attributable to its excellent catalytic performance. Moreover, strong interactions between ZnCr-LDH and CNTs highly restrained the agglomeration and leaching of the active LDH phase species during the reaction, thus giving rise to good stability and reusability of as-assembled ZnCr-LDH/CNTs. It is expected that the present nanocomposite would provide a promising stable and efficient catalyst system for the oxidation of other alkylaromatics.

Resume : With the popularization of portable mobile devices and higher requirement of energy storage devices, the development of high-power energy storage device, especially super capacitor aroused people high attentions. Here, we developed a novel hybrid bimetallic Co-Ni hydroxide/polyaniline-modified graphene (GP) nanocomposite for supercapacitor application. A series of characterizations showed that Co-Ni hydroxide nanosheets were longitudinally grown on the surface of GP substrate, thus forming a hybrid three-dimensional nanostructure. The as-prepared composite exhibited much higher specific capacitance, capacitance retention rate and stability compared with pure Co-Ni hydroxide, Ni(OH)2 and/or Co(OH)2/GP samples. Furthermore, as-assembled Co0.4Ni0.6(OH)2/GP asymmetric supercapacitor possessed a specific capacitance of 2561 Fg-1 at 2 Ag-1 current density, a 93.2% capacitance retention at a current density of 10 Ag-1 after 1000 cycles, and an energy density of 73.78 Whkg-1 at a power density of 354.4 Wkg-1, indicative of excellent supercapacitor property and practicality for energy storage.

Resume : The performance and degradation of polymer electrolyte fuel cells and electrolysers depends on the nanostructure of its components. In working fuel cell electrodes, the ionomer films that encapsulate the Pt/C agglomerates fall within the range of ultrathin films. The quantitative investigation of the nanostructure of fuel cell electrodes, especially the analysis of the correct dimensions of the ionomer component has proven to be exceptionally difficult. Electron beam-based techniques provide a low contrast between ionomer and carbon components and lead to significant shrinkage. Atomic force microscopy (AFM) can work in humid environment and at elevated temperatures, close to operational conditions. Using material-sensitive tapping mode, the high contrast between the ionomer- and the Pt/C phase in adhesion force mapping allows studying the distribution and thickness of the ionomer films that cover the Pt/C agglomerates. In this contribution, the analysis of cross-sections of Nafion- and Aquivion–based fuel cell electrodes will be presented. A thickness distribution of the ionomer films ranging from roughly 4 to 20 nm was retrieved. After operation, significant thinning of the ionomer films depending on location within the membrane-electrode-assembly and preparation was found. Differences of the swelling behavior of the ionomer films prior and after operation were used as a measure for ionomer degradation. A dependence of macroscopic cell degradation rate on initial electrode ionomer film thickness was observed. For further determination of the properties model layers were examined. Significant differences in conductivity for films below 10 nm thickness were detected.

Resume : Alkaline water electrolysis (AWE) is one of the easiest methods for high-purity hydrogen production. Membrane has played a key role in AWE, by providing highly conductive passage of hydroxide ions. As a key component of AWE, Porous composite membrane with good hydroxide ion conductivity, mechanical properties, and thermal and chemical stability are desirable, and many efforts have been concentrated on developing new AWE materials. Porous composite membrane material is generally composed of polymer matrix and inorganic particles. However, the role of hydroxyl group of inorganic materials and the effect of interaction between polymer matrix and inorganic particles on the membrane characteristics has not been studied yet. In this study, we studied the correlation between characteristics of inorganic particles and the performance of the composite membrane. The concentration of hydroxyl group on the inorganic particle was strongly related to an increase in conductivity, wettability, and mechanical properties. The inorganic particle with high hydroxyl group was developed and showed the enhanced performance such as ionic resistance, BP pressure, wettability and mechanical properties.

Resume : For constructing bio-inspired functional films with various superhydrophobic functions including self-cleaning, anti-corrosion, anti-bioadhesion, and oil-water separation, hydrophobic nanomaterials have been widely used as crucial structural components. In general, hydrophobic nanomaterials, however, cannot form strong chemical bond networks in organic-inorganic hybrid composite films because of the absence of chemically compatible binding components. Here, we present bio-inspired design and synthesis of multifunctional hybrid nanomaterials with tunable functionalities of covalent cross-linking and hydrophobicity for constructing three-dimensionally interconnected superhydrophobic composite films via a facile solution-based fabrication at room temperature. The multifunctional hybrid nanomaterials allow the systematic control of functionalities of composite films, as well as the stable formation of covalently linked superhydrophobic composite films with excellent flexibility (a bending radius of 6.5 mm, 1000 cycles) and self-healing ability (water contact angle > 150°, ≥ 10 cycles). The presented strategy can be a versatile and effective route to generating other advanced functional films with covalently interconnected composite networks.

Resume : Since ten years we have used of original rigid poly-functional phosphonic acids to design new metallophosphonate hybrid materials. The tetrahedral geometry of the phosphonic acid and the large number of coordination mode of this group, compare to the one of the carboxylic acid, contribute to produce materials with a great number of original topologies and properties. Our synthetic strategy consists to understand the influence of some pertinent parameters like pH, time, temperature, number and type of reactive functions, shape of the building block on the dimensionality of the final materials (1D, 2D or 3D network). For organic precursors possessing both a phosphonic and carboxylic acid function, we clearly observed a chemoselectivity influenced by the pH media during the synthesis of the hybrid materials. Various coordination polymers or Metal Organic Framework’s materials were synthesised from 3- or 4- phosphonobenzoic acids. Some unexpected results were obtained like the formation of a non-centrosymmetric helical copper-based material with a homochiral structure from a non-chiral ligand, or the synthesis of an europium-based hybrid exhibiting remarkable luminescent properties and an excellent thermal stability (up to 500°C). Moreover, a series of materials obtained from these building blocks produced materials exhibiting distinct capacity to release silver ions and were assessed for their bactericidal action. We will describe the link between the structure and properties of these materials completed by our last results obtained following this strategy to obtain non-centrosymetric materials.

Resume : Exploration of low-cost and efficient catalysts for hydrogen evolution reaction (HER) is of great importance for sustainable hydrogen economy. As one of the most promising alternative candidates for replacement of commercial noble metal catalyst, i.e., Pt catalyst, transition metal dichalcogenide (TMD) nanomaterials play an important role in the electrocatalytic HER in acid medium. However, designing facile and efficient TMD-based electrocatalysts with abundant active sites and great long-term stability for HER still remains challenge. Herein, we report a general and facile method, by combining chemical vapor transport (CVT) and chemical Lithium-intercalated method, for preparation of water-dispersed, ultrasmall-sized, single-layer TMD nanodots with high-density active edge sites and clean surface, including MoS2, WS2, MoSe2, Mo0.5W0.5S2 and MoSSe, which exhibit much enhanced electrochemical HER performances as compared to their corresponding nanosheets. Impressively, the obtained MoSSe nanodots achieve a low overpotential of -140 mV at current density of 10 mA cm-2, a Tafel slope of 40 mV dec-1 and excellent long-term durability. The experimental and theoretical results suggest that the excellent catalytic activity of MoSSe nanodots is attributed to the high-density active edge sites, high-percentage metallic 1T phase, alloying effect and basal-plane Se-vacancy.

Resume : In order to produce a polymer-inorganic composite film in which a high-dielectric inorganic filler is well dispersed, a high dielectric polymer-composite nanofiber was prepared by electrospinning, followed by hot-pressing method. Polyimide and BaTiO3 were used as a polymer matrix and an inorganic filler, respectively. The effects of polyamic acid (as a polyimide precursor) solution concentration and the content of dispersed BaTiO3 nanoparticle on the nanofiber production were investigated by scanning electron microscope. By forming nanofibers through electrospinning, dielectric composite films with very high dispersibility could be produced. As a result, it was possible to produce a composite film having a remarkably low dielectric loss value while maintaining a high dielectric property. The dielectric permittivity of the as-fabricated nanocomposites significantly improved with the increase of BaTiO3 fraction. Dielectric constant and dielectric loss of BaTiO3 80 wt% composite film were measured at 1 kHz and below 25.01 and 0.08, respectively.

Resume : In the 4th industrial revolution, smart devices, artificial intelligence equipment, and self-driving cars are emerging as new industrial fields. The heat dissipation and electromagnetic wave problems of the highly integrated electric circuits in the advanced electric devices are rising, resulting in deterioration of performance, lifetime and efficiency of the equipment. Carbon-based materials, which are widely used as dissipating of heat materials, have excellent thermal conductivity, but also have high electrical conductivity, making them unsuitable as heat protecting and insulating materials. In recent years, hexagonal boron nitride (h-BN) is an emerging material with excellent mechanical and chemical properties. However, h-BN normally has an anisotropic thermal conductivity in horizontal direction and low thermal transfer efficiency due to the high resistance at the particle surface boundary, and expensive material cost, which is not suitable for thermally conductive and electrically non-conductive material in devices. Herein, we report a thermally conductive and electrically insulating cylindrical pillar using glass fiber. h-BN is allowed to grow on the glass fiber surface. A thermal conductivity and an electrical insulating were successfully achieved through powder resistance measurement and LFA test. Especially excellent thermal transfer properties in vertical direction of cylindrical pillar can find commercially applications in a range of electric advanced devices.

Resume : The synthesis of highly efficient electrocatalysts for water splitting has played an important role in developing eco-friendly energy sources. LDHs serves as a catalyst to lower energy consumption in water splitting. Conventional methods for synthesizing these catalysts need a lot of time and harsh reaction conditions. Here, we introduce a simple synthetic method of ZnCo LDHs with a shorter reaction time under a mild condition. Add the Co precursor to the as-synthesized ZnO and stirring it while heating. Using transmission electron microscopy (TEM) and scanning electron microscopy(SEM), the synthesized materials were confirmed to have a sheet structure of several tens of nanometers and a few hundreds of nanometers in size. The onset-potential of the OER reaction is 1.55V, which is similar or better than the ZnCo LDHs synthesized by other methods. In addition, as the proportion of initially added Co increases, the onset-potential decreases because of the replacement of Co and Zn. Moreover, it can be seen that the value at which the current density reaches 1mA/cm2 is considerably close to 1.23V. The graph of the stability of the catalyst is stable even though the polymer does not enter during the reaction. ZnCo LDHs itself can be used as a catalyst, but it can also be used as a support for noble metals such as Pt and Pd.

Resume : We synthesized metal/Fe3O4/TiO2 nanohybrids. They can be applied to the photocatalyst and the catalyst of H2O2 production. The photocatalyst can be applied anywhere with a light. Recently, the subject of the photocatalyst activated under the visible light has attracted great attention. We tried to synthesize nanohybrids by adding metal nanoparticles which were adhered to TiO2 in order that these new nanohybrids can have photocatalytic activity under the visible light too. To easily recover of the nanohybrids after all the reaction is completed, Fe3O4 nanoparticles were adhered to TiO2 as well. Also, Pd/Fe3O4/TiO2 nanohybrids were applied to H2O2 production as the catalyst. The H2O2 production rate was 317.35 H2O2 mmol/gPd·h and it is better than Pd/SiO2. To determine the reason why these nanohybrids have high production rate, we investigated Pd/TiO2, Pd/Fe3O4 and Fe3O4/TiO2. As a result, we found out that Pd/Fe3O4/TiO2 is the most effective catalyst for production of H2O2. Herein we report a simple and mild method for synthesis of metal/Fe3O4/TiO2 nanohybrids in two steps. First, Fe3O4/TiO2 nanohybrids were synthesized with TiO2, polyethylene glycol(PEG), hexylamine, water and Fe(ClO4)2. Secondly, Pd or Pt nanoparticles were adhered to them using a metal precursor. These nanohybrids were analyzed by transmission electron microscope(TEM) and X-ray diffraction(XRD) and measured their photocatalytic properties by UV-vis spectrophotometer.

Resume : Metal organic frameworks (MOFs) consist of an array of metal ions connected by coordinating organic linkers. Depending on the metal ion, organic linkers, the coordination chemistry and the actual crystal structure in which they crystalize, their properties and areas of application will be determined. In 2009, Cheetham et al. for the first time prepared multiferroic MOFs in perovskite dimethyl ammonium metal formate ([(CH3)2NH2]MII(HCOO)3) MOF with metal ion M = Mn, Fe Co, Ni, and Zn. Magnetoelectric coupling has been observed in [(CH3)2NH2]Fe(HCOO)3 (DFeF) by Tian et al. Two magnetic transitions in DFeF crystals at 19 K and 10 K respectively assigned to antiferromagnetic transition (TN) and blocking temperature (TB), indicating presence of metastable states or kinetic arrest, which motivated us to elucidate the magnetic characteristics near transition temperatures for DFeF. In present work we report a first order paramagnetic to antiferromagnetic transition in DFeF MOF crystals showing kinetic arrest. The nature of phase transition have strong dependence on applied magnetic field and temperature. The establishment of metastable state is traced by changing the cooling rates under applied magnetic field. Time measurements (constant magnetic field and Temperature) has been performed in order to find stability of magnetic states in temperature region below TN. The multiferroic character of the material is also revealed through a dielectric transition near 165 K.

Resume : Asymmetric Supercapacitors (ASC) with redox-based pseudocapacitive materials have attracted attention as alternative storage devices owing to their compelling power densities, rapid charge-discharge capability and long-cycling stability. However, to overcome poor conductivity limit of oxide-based pseudocapacitive materials, a novel nanostructured core-shell electrode design is introduced for realizing high-performance ASCs. In the core-shell design, thin shell-layers of highly pseudocapacitive materials provide the platform for surface or near-surface-based faradaic and non-faradaic reactions together with shortens ion-diffusion path facilitating fast-ion intercalation and deintercalation processes. The highly-conducting core serves as highway for fast electron transfer towards current collectors, improving both energy and power performance of the core-shell structure in relation to pristine component materials. With this idea, we have designed ZnO/α-Fe2O3 core-shell nanorod (NR) anode that exhibits improved capacitance and rate capability as compared to its component materials owing to the synergy between pseudocapacitive α-Fe2O3 and highly conductive ZnO. Moreover, besides being served as promising anode material in ASCs, pristine α-Fe2O3 NRs can also be used as conducting scaffold for depositing MnO2 to design a high-performance hybrid cathode material, thus making α-Fe2O3 versatile in electrode designing. Our study demonstrates the potentiality of α-Fe2O3 based hybrid nanostructures in realizing high-performance, cost-effective and environment-friendly ASCs.

Resume : Nickel tungsten oxide (NiWO4)-Tungsten oxide (WO3) composite nanofibers were synthesized by electrospinning technique combined with thermal annealing. Morphologies of synthesized nanofibers were imaged by scanning electron microscopy (SEM), transmission electron microscopy(TEM). Crystalline structures and surface properties were identified by Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Electrospun NiWO4/WO3 composite nanofibers showed rough and porous surface composed of aggregation of many small grains like nanocrystals of NiWO4 and WO3. In addition, the morphology of NiWO4-WO3 composite nanofibers is tube-like that outer diameter of the nanofiber is about 250nm and inner hole diameter is about 100nm. It is expected that NiWO4/WO3 hybrid nanostructures are contributed to changes in the annealing temperature and ratio of precursors. Generally, tungsten oxide has high electrical conductivity due to semiconducting behaviors and its nanostructures have been used for many applications such as photocatalysts and electrochemical materials. High electrical conductivity and thermal sensitivity of nickel oxide has been utilized in various catalyst applications and conductive films. Thus, the composite nanostructures between NiWO4 and WO3 are able to increase electrocatalytic and electrochemical activity than their single phase nanostructures.

Resume : Utilization of renewable biomass for the chemical production has been a growing interest in the current bio-based industries. Furfural has been identified as one of the most promising platform chemical directly derived from biomass, because it is having potential in the productions of value-added chemicals, fuels, and intermediates. One step catalytic conversion of xylan to furfural in presence of acid functionalized catalysts is one of the great importance in the bio-refinery. Many researchers have made considerable efforts to use Brønsted acids instead of Lewis acids as catalysts for catalytic conversion of xylan. In this regards, homogenous acid catalysts are utilized for the furfural production from xylan and C5 sugars, however, these processes faces some limitations such as catalyst separation, environmental issues, toxicity, corrosiveness etc. There are also reports of eco-friendly routes using solid-acid catalysts, but the yields are often low, even if an excess of catalyst is used. Last decade, graphene has attracted much interest because of its outstanding electronic and mechanical properties. Graphene oxide (GO) are graphene sheets that contain high densities of hydrophilic functional groups such as hydroxyl, carboxyl, and epoxy groups. These hydrophilic groups provide means for incorporation of sulfonic acid groups as Brønsted acid sites through sulfonation, and the sulfonated GO could become a promising candidate of solid acid catalyst for xylan decomposition to industrially important chemicals, or other useful chemical reactions. Here, we report that a new SO3H-incorporated GO (GO–SO3H) produced through sulfonation, is one of the best solid acid catalysts for the catalytic conversion of xylan to furfural.

Resume : Nowadays, morphine remains the gold standard for the treatment of pain, but it is also responsible for serious adverse effects. In that sense, the use of cargo is of interest for the drug delivery, and layered double hydroxide structure is known as an appealing choice. Some organic molecules were synthesized by Knoevenagel condensation. Our original approach was to incorporate both directly the guest molecules by exchange reaction (ex situ) between the platelets or in situ through the Knoevenagel reaction in 2D confined space. LDH is found to play the role of molecular sieves because only ionic compounds will be exchanged. Moreover, they should facilitate the controlled release of organic products in vivo. Rather counter intuitively, ex situ-based on topotactic exchange reaction matches the in situ templating reaction in many cases as a function of the dispersion state regardless of the guest organic molecules. This interface between organic and inorganic moieties, using LDH matrices to «protect from» our active molecule seems to be promising for future process.

Resume : Polybutylene succinate (PBS) is one of the most popular biodegradable aliphatic ester and a promising candidate to replace classical petrol-based polymers in the packaging domains. However, it is necessary to improve some of its properties as rapid hydrolysis, low barrier before to be able to meet such application. For this, polybutylene succinate (PBS) nanocomposites have been prepared in the melt compounding process, by the incorporation of inorganic-organic hybrid materials so called layered double hydroxides (LDHs), based on Mg-Al structure and functionalized with amino acids (AA): histidine (HIS) and phenylalanine (PHE), all benign in terms of environmental impact and biocompatibility (regarding food packaging). The organization of the hybrid LDH/AA was characterized and subsequently the parent PBS:LDH/AA composite in terms of dispersion and evaluation of the PBS properties. Indeed the rheological and anti-UV properties were investigated in comparison to pure PBS and MgAl LDH-nitrate as references. Both organo-modified LDHs showed a chain extension effect of PBS and an outstanding increase was observed for PBS:MgAl/PHE LDH. Moreover, HIS and PHE embedded in LDH structure can successfully prevent the chain scission reactions which occur during photo-ageing of PBS under accelerated UV conditions. Altogether these findings demonstrate that AA- modified hydrotalcite can be used to improve PBS polymer processability as well as to act efficiently as UV stabilizer.

Resume : The lack of pure water is one of the major challenge of the contemporary society, especially in the low populated and arid areas of the world. Desalination is an efficient way to produce pure water, and direct solar distillation processes (by solar stills) are the most suitable for rural areas, even though their productivity is low. To increase the productivity of these systems, in this work graphene hydrogels were synthetized to increase water evaporation yield to produce pure water by using solar energy. Graphene nano-powders were successfully dispersed and embedded in thin gum arabic cross-linked gelatin membranes. The very high thermal conductivity of graphene at room temperature, with its higher absorption ability of solar energy, leads water to reach higher temperature compared to pure water. Therefore this light-to-heat conversion process enables an enhancement of evaporation rate and of evaporation efficiency of water by using graphene hydrogels. The advantages of this hybrid material are the enhanced pure water production, the possibility to collect and re-use the membrane several times thanks to its long time stability in water, the simplicity in synthesis. Graphene hydrogels were characterized by means spectroscopy techniques (Raman, XPS), SEM, and the dispersion stability of graphene was studied by spectrophotometry, while evaporation rate and efficiency were evaluated by gravimetric measurements under UV-Visible irradiation (generated by a solar simulator).

Resume : The pulverization of Si during the lithiation process and the continuous growth of a solid-electrolyte interphase (SEI) at the surface of Si are primary causes of chronic capacity fading of Si based Li-ion battery (LIB) anodes. Here, we report the fabrication of few-layer graphene grown Si nanoparticles (FLG-Si NPs) for LIBs with high energy density. The CVD-grown few layer-graphene anchored onto the Si surface accommodate the volume expansion of Si via a sliding process between adjacent graphene layers.[1,2] In addition, stable SEI layers can be formed on the surfaces of FLG-Si NPs by ionic liquid electrolytes, and these layers can significantly suppress capacity loss.[3] When combined with an ionic liquid electrolytes, an anode containing 75% FLG-Si NPs (Si:graphene:binder = 68:7:25) delivered a reversible capacity of 1770 mAh g-1 (92.8% retention) at a current density of 2 mAh cm-2 after 200 cycles. When paired with a commercial lithium cobalt oxide cathode, the FLG-Si NPs anode allows the full cell to reach volumetric energy densities of 972 and 700WhL-1 at first and 200th cycle, respectively, 1.8 and 1.5 times higher than those of current commercial LIBs. The results of our studies demonstrate that the few-layer graphene coating may lead Si to commercially viable material. References [1] I. H. Son and J. H. Park et. al. Nat. Commun. 2015, 6, 7393. [2] I. H. Son and J. H. Park et. al. Small 2016, 12, 658. [3] J. H. Park et. al. J. Phys. Chem. C 2017, 121, 26155.

Resume : The hydrogels have been extensively investigated in tissue engineering, biosensor and so on due to their hydrophilic and biocompatible properties. Moreover, core/shell type hydrogel beads have advantages such as encapsulation of specific materials and easy control of shell properties for application in various fields. This work describes recent studies of the alginate/chitosan, chitosan/alginate, alginate/((2-hydroxyehtyl methacrylate)(HEMA) + (2-(Methacryloyloxy)ethyl trimethylammonium chloride)(MAETC)), (HEMA+MAETC)/alginate, HEMA/(HEMA+MAETC) as core/shell type hydrogel beads. These beads were fabricated by using dip-coating or electro-spraying methods. Their mechanical properties, water content and cell affinities were surveyed with all types of core/shell type hydrogel beads. Among these, the HEMA/(HEMA+MAETC) hydrogel beads were successfully fabricated via electro-spraying method using photo-polymerization in one step method. Their surface charges of beads were controlled by the amount of MAETC. The increased MAETC composition in shell resulted in much more positive surface charges and enhanced attachment of negative-charged bacteria onto the beads. The HEMA/(HEMA+MAETC) core/shell type hydrogel beads are expected to be effectively applied to future biotechnology.

Resume : Amino acid is a naturally occurring organic molecule can be mass-synthesized and has been manufactured commercially. As a basic unit of proteins, amino acid is nontoxic and can be absorbed in vivo, which has led to its application in many fields. Therefore, if amino acid molecules can be used as building blocks to combine with specific metal ions, the novel functional nanomaterials should have great applications in many fields. Terbium-aspartic acid (Tb-Asp) nanocrystals with chirality-dependent tunable fluorescent properties can be synthesized through a facile synthesis method through the coordination between Tb and Asp. Asp with different chirality (dextrorotation/D and levogyration/L) changes the stability of coordination center following fluorescent absorption/emission ability difference. Compared with L-Asp, D-Asp can coordinate Tb to form more stable center, following the higher quantum yield and longer fluorescence life. Fluorescent intensity of Tb-Asp linearly increases with increase ratio of D-Asp in the mixed chirality Tb-Asp system, and the fluorescent properties of Tb-Asp nanocrystals can be tuned by adjusting the chirality ratio. Tb-Asp nanocrystals possess many advantages, such as high bio-compatibility, without any color in visible light irradiation, mono-dispersion with very small size, long fluorescent life. Those characteristics will bring its great potential in many application fields, such as low-cost anti-fake markers and advertisements using ink-jet printer or mold molding when dispersed in PDMS. In addition, europium (Eu) can also been used to synthesize Eu-Asp nanoparticles. Importantly, the facile, low cost, high yield and mass-productive “green” synthesis approach opens a new door for synthesis and application of the new generation fluorescent nanocrystals, which will have great impact in nanomaterial technology. (Baojin Ma, et al. ACS nano 11.2 (2017): 1973-1981) Further, other metal-amino acid nanocrystals are being synthesized and will be applied in many fields according their unique properties. Through structure design and property optimization, it can be believed that the novel metal-amino acid nanocrystals with multi-functions will have very important and wide applications.

Resume : Development of hydrogen evolution catalysts based on non-precious metals is essential for the practical application of water-splitting devices. Here, we report the synthesis of Co9S8-MoS2 hierarchical nanoboxes (HNBs) as efficient catalysts for hydrogen evolution reaction (HER). The surface of the hollow cubic structure was organized by CoMoS4 nanosheets formed by the reaction of MoS42- and Co2+ released from the Co-zeolite imidazole framework (ZIF-67) templates under reflux condition. The formation of CoMoS4 HNB structures was characterized by TEM images obtained at various reaction temperatures. The amorphous CoMoS4 hierarchical nanoboxes were converted by sequential heat treatments to CoSx-MoS2 and Co9S8-MoS2 HNBs. Owing to their unique chemical compositions and structural features, Co9S8-MoS2 HNBs have high specific surface area (124.6 m2 g-1) and superior electrocatalytic performances for HER. The Co9S8-MoS2 HNBs exhibit a low overpotential (η10) of 106 mV, a low Tafel slope of 51.8 mV dec-1 and long-time stability in an acidic medium. The electrocatalytic activity of Co9S8-MoS2 HNBs is superior to the recently reported values and proves to be a promising candidate for HER.

Resume : Hollow nanostructured semiconducting materials have been emerging as an important field of energy storage and conversion, due to their unique electronic properties which can be tuned by the size, shape and composition. Iron diselenide (FeSe2) is a p-type semiconductor with band gape of 1.0 eV, studied in photovoltaics and fuel cells. Here, highly uniform carbon coated FeSe2 yolk-shell spheres (C@FeSe2 YSs) with average size of 100 nm were synthesized. First, polydopamine (PDA) coated Fe2O3 nanospheres were synthesized, then annealed in N2 atmosphere and further etched to obtain C@Fe3O4 yolk-shell hollow spheres. The C@FeSe2 YSs were obtained via selenization C@Fe3O4. The obtained C@FeSe2 has exhibit specific surface area. Electrochemical studies reveals, C@FeSe2 YSs has exhibit electrocatalytic activity for hydrogen evolution reaction (HER) and delivered overpotential of (η10) 137 mV, Tafel slope value of 58.2 mV dec-1 and long-time stability in alkaline medium. The HER activity of C@FeSe2 YSs is superior to the recently reported values, suggesting a promising candidate for alkaline water splitting.

Resume : There are growing interests to explore alternative, sustainable strategies for the synthesis of 3D nanomaterials for various applications including batteries, biosensing, supercapacitors and catalysis. Recently, bio-inspired approaches have attracted attention due their mild synthesis conditions and their abilities to produce a variety of unique 3D structures. For instance, well-controlled morphologies and chemical compositions of these inorganic nanomaterials can be produced by engineering specific interactions between biomolecules and the metallic precursors. In our laboratory, we have developed a variety of bio-inspired strategies for the preparation of 3D nanomaterials including metal oxides, fluorides, sulphides, phosphates etc. It is also possible to produce nanomaterials with hollow profiles, or with complex stoichiometric chemistries using bio-inspired methods. More importantly, we showed that the as-prepared nanostructured materials possess excellent electrochemical properties when evaluated as electrodes in metal-ion batteries. Taken together, the bio-inspired approach is a promising strategy for nanomaterial synthesis.

Resume : Nowadays, the demand for wearable device is increased. Then the desire for continuous and reliable power supply is also becoming a hot issue. Recently the self-powered thermoelectric module using body temperature has been studied in the world. To use thermoelectric modules with body temperature, it should be flexible to fit a body shape and generate reliable and efficient electric power. When a thermoelectric module is worn on the body, they are exposed to a lot of damages from outside. So, when thermoelectric materials are broken, we should repair the damaged part easily. In this study, we synthesized polydimethylsiloxane(PDMS)-based photo-curable resins, which were used as 3D printer resins to make flexible substrate. Inorganic thermoelectric materials (N-type: bismuth telluride, P-type: antimony telluride) were used for electric power generating sources. . This thermoelectric module was modularized easily by inserting block-shaped thermoelectric materials into a flexible substrate, and the output power was easily adjusted by modeling the substrate design through 3D printing method. As a result, we confirmed the energy generation potential by measuring the thermoelectric characteristics according to the number of P type and N type couples or temperature differences and showing the case of easy replacement of damaged thermoelectric materials.

Resume : Silica-modified magnetite powders synthesized in forms of nano- and micro-sized grains have been tested in magnetorheological fluids (MRF), which are used as dampers in a wide range of applications. The materials were prepared by spray pyrolysis using sols of magnetite (Fe3O4) and silica (SiO2) with 8 wt. % of SiO2. The sols were obtained by hydrolysis of Fe(II) and Fe(II) salts with NH3, and by hydrolysis of TEOS in the presence of HCl, correspondingly. The mixture of sols was transformed into aerosol state with an ultrasonic atomizer and directed to the reaction zone (300 C) with a flow of N2. The resultant powders have a size of 0.5–1.5 mkm. To prepare nano-sized particles (30–50 nm), an inert component (NaCl) was added to the reactant mixture. In this case, the generated powder was washed with distilled water to remove NaCl and disaggregate the oxide nano-particles. The magnetic measurements indicate that micro-sized Fe3O4/SiO2 samples are characterized by greater specific magnetization and coercivity values (63 A•m2/kg and 6.5 A/m) as compared to the nano-sized powders (54 A•m2/kg and 4.2 A/m). This leads to a greater magnetorheological effect (increase in viscosity under applied magnetic field) of suspensions with 15 wt. % of micro-sized magnetite τ/τ0 ~ 4.5 vs. τ/τ0 ~ 2 for the corresponding nano-sized powders. However, the small grains, along with the presence of SiO2, could possess a stronger stabilizing effect when used as a modifier of MRF based on carbonyl iron.

Resume : A three-phase polymer composite with a ferroelectric phase (BaTiO3) and conductive core-shell polypyrrole@polyimide (PPy@PI) nanoparticles embedded in a polyimide (PI) matrix was prepared by using a simple direct mixing and solution casting process. PPy@PI nanoparticles as the conductive filler were synthesized to obtain homogeneous dispersion in the PI matrix. The dependence of the dielectric behavior on the BaTiO3 and PPy@PI contents was studied over a wide frequency range from 10 kHz to 1 MHz. The incorporation of low loading levels of PPy@PI nanoparticles to the PI/BaTiO3 system led to a significant enhancement in the dielectric constant with suppressed loss. The dielectric constant (Dk) of the PI/BaTiO3/PPy@PI (25/75/5) hybrid was 58.53 at 10 kHz, i.e., three times higher than that of the PI/BaTiO3 (25/75) nanocomposite without PPy@PI. The fairly improved dielectric properties were due to the synergistic enhancement of the ferroelectric ceramic filler, BaTiO3, and conductive filler, PPy@PI nanoparticles, as well as due to homogeneous dispersion. Such polymer composites have the potential for use in fabricating embedded capacitors, and specimens with various shapes can be easily obtained owing to the flexibility of the nanocomposite.

Resume : The growing interest in hybrid organic-inorganic devices and materials creates a need for development of methods for their characterization. High-resolution chemical imaging using secondary ion mass spectrometry (SIMS) in combination with focused ion beam (FIB) milling is a promising method to study buried interfaces in hybrid materials. However, there is a lack of guidance for analysts to achieve reliable and reproducible FIB-SIMS measurements. In this study, we fabricate a reference sample with well-defined organic and inorganic regions that enables reliable measurements of damage, sputtering rate change and distortion artefacts. The reference sample consists of a microchannel plate with a regular honeycomb array of 10 µm diameter tubes filled with polystyrene or poly(methyl methacrylate). This is suitable for evaluating the lateral resolution, repeatability, reproducibility and reconstruction accuracy in FIB-SIMS measurements. The FIB is able to mill both inorganic and organic materials but the milled organic surface is molecularly damaged. The damage is localised to the near surface (< 10 nm) and can be cleaned by sputtering with a gas cluster ion beam (GCIB). We show how the signal recovery is dependent on key parameters related to the beam used to generate the damage, as well as to the dose, energy, and size of the argon clusters used to clean up the damage. The study provides valuable understanding for optimising FIB cutting of hybrid materials for molecular analysis.

Resume : The synthesis, structure, and photocatalytic water splitting performance of two new titania (TiO2)/gold(Au)/Bombyx mori silk hybrid materials are reported. All materials are monoliths with diameters of up to ca. 4.5 cm. The materials are macroscopically homogeneous and porous with surface areas between 170 and 210 m2/g. The diameter of the TiO2 nanoparticles (NPs) – mainly anatase with a minor fraction of brookite - and the Au NPs are on the order of 5 and 7-18 nm, respectively. Addition of poly(ethylene oxide) to the reaction mixture enables pore size tuning, thus providing access to different materials with different photocatalytic activities. Water splitting experiments using a sun simulator and a Xe lamp show that the new hybrid materials are effective water splitting catalysts and produce up to 30 mmol of hydrogen per 24 h. Overall the article demonstrates that the combination of a renewable and robust scaffold such as B. mori silk with a photoactive material provides a promising approach to new monolithic photocatalysts that can easily be recycled and show great potential for application in lightweight devices for green fuel production.

Resume : This work reports for the first time, the preparation of photocatalysts based on hybrid clay materials and the fast degradation of AMP on the surface of as prepared TiO2/ZnWO4 photocatalysts. The materials also show a great potential for the simultaneous removal of other class of water contaminants, while degrading the pharmaceuticals without a major effect on its photocatalytic potentials. The as-synthesized photocatalysts were characterized with X-ray diffraction, (XRD); scanning electron microscopy (SEM) equipped with energy dispersive X-ray (EDX) and Transmission Electron Microscopy (TEM); Attenuated Total Reflectance-Fourier transformed infrared (ATR-FTIR) spectroscopy and UV-VIS diffuse reflectance spectroscopy (DRS) and other analyses.

Resume : Calcium phosphate is one of the most important biominerals, because it is one of the components of bones and teeth. Osteoporosis and tooth degradation are only two examples of damage typical of an ageing society. As a result new materials for the replacement of bones or teeth are necessary. Often hydrogels are being used. In this research we focus on hydrogels based on polyelectrolytes. Of great interest is here the investigation of the structure, the behavior of the resulting hydrogel and its mineralization. On the one hand methods for structure elucidation such as solid state nuclear magnetic resonance spectroscopy, small angle x-ray scattering, dynamic light scattering and one the other hand stability measurements such as thermogravimetric analysis and mechanical studies were carried out. Subsequent to this the influence of the matrix on calcium phosphate mineralization was analyzed. For the analysis of the hybrid material mainly the optical microscope and the X-ray diffraction were used. Furthermore the testing of the biocompatibility is also in the scope of this research. As a simple model system the Dictyostelium discoideum (amoeba) was selected for the first evaluation via fluorescence microscopy. This work is merely the beginning of the research on new hydrogels for the use as an organic matrix for controlled mineralization. It is suitable for fundamental research and maybe for application in the biomedical field. As the poster will show this system has a high potential in the field of biomaterials chemistry.

Resume : 3D printing of biocompatible polymers has become a big subject in the development of new materials for bone replacement. One of the most important polymers is polylactic acid (PLA) which is widely used in 3D printing and is also biodegradable. The PLA was used as a scaffold for a hydrogel as matrix for the mineralization of calcium phosphate. Gelatin or Chitosan were used for the hydrogel formation and crosslinked with glutaraldehyde. The mineralization was realized with an alternate soaking method of the hydrogel in aqueous solutions of Ca(NO3)2 and Na2HPO4. Mineralized samples were analyzed using IR-spectroscopy, SEM, EDXS, and XRD.

Resume : Arising from the demand of high-performance energy storage, the search for a practical hybrid material that can give high energy densities to a full-cell energy storage is one of the most challenging issues. Also, the method of producing a hybrid material is also a difficult problem. Herein, we report a hierarchical graphene pliable pocket (GPP) that can provide the internal compartment to accommodate active materials. In addition, Metal_encapsulated GPPs (M_GPPs) have been fabricated by the instant polymerization of ester along with the subsequent stacking of graphene upon metal nanoparticles within an hour, which is also extended to a scalable mass production by simply increasing the batch size. Moreover, electrochemical energy storage performances of Si_GPPs as anodes in half-cell and full-cell configurations demonstrate that allows excellent rate capability at various current densities along with > 99 % in initial Coulomb efficiency by minimizing the irreversible reactions at a full-cell configuration. Furthermore, the full-cell configurations using Si_GPP anodes with representative cathodes of LiCoO2, LiMnO2, and LiFePO4 are proven to give the highest gravimetric and volumetric energy densities close to 500Wh/Kg and 1370Wh/l, exceeding those of full-cells using commercial anodes. The hybrid structure we have developed and its synthesis method could pave a novel route to realize a new class of full-cell energy storage devices with high energy densities along with robust cycle life.

Resume : We successfully synthesized transition metal hydroxide (Ni(OH)2 and Co(OH)2) nanoplates in an aqueous solution. These nanoplates have a hexagonal shape with 45nm and 500nm size for Ni(OH)2 and Co(OH)2, repectively, from the scanning electron microscopy(SEM) and the transmission electron microscopy(TEM) images. Also, we checked the main growth direction of Ni(OH)2 and Co(OH)2 by using the X-Ray diffraction(XRD) results. In addition, we could synthesize platinum/nickel hydroxide hybrid nanostructures (Pt/Ni(OH)2) in an aqueous solution. The TEM studies of the Pt/ Ni(OH)2 hybrid nanostructures revealed that a number of 3 nm-sized Pt nanoparticles were well dispersed on the surface of each Ni(OH)2 nanoplate. The ratio of Pt and Ni(OH)2 could be readily controlled by using different amount of Pt precursor. We measured the zeta potential values of Ni(OH)2 to demonstrate the grow mechanism of Pt nanoparticles on the surface of Ni(OH)2. The Pt/Ni(OH)2 hybrid nanostructures exhibited enhanced electrocatalytic properties due to synergetic effect of Ni(OH)2 and Pt. After catalytic reaction, the TEM image and energy dispersive spectroscopy(EDS) of the Pt/Ni(OH)2 hybrid nanostructures showed unchanged morphology of Ni(OH)2 nanoplates with Pt nanoparticles, indicating stable materials under electrocatalytic atmosphere.

Resume : Alkaline niobate-based piezoelectric ceramics are recognized as substitutions of conventional lead-based counterparts because of their excellent ferroelectric property, piezoelectric property, high curie temperature and environmental protection concern. (K0.5Na0.5)NbO3 (KNN) locates around a morphotropic phase boundary (MPB) between two orthorhombic phases, which is very sensitive to piezoelectric properties. Piezoelectric coefficient of the KNN-based system lie within the range d33 = 80–160 pC/N. On the other hand, P(VDF-TrFE) is the best known and most widely used ferroelectric polymer because of its relatively high polarization value, large piezoelectric coefficient, low dielectric loss, temperature stability and flexibility. In order to form a new type of lead-free piezoelectric ceramic-polymer flexible material, KNbO3 (KN) and NaNbO3 (NN) micron-size particles were synthesized by hydrothermal process, then the equimolar KN and NN were sintered into (K0.5Na0.5)NbO3. KNN particles were mixed with P(VDF-TrFE) matrix to form KNN/P(VDF-TrFE) composite flexible materials. After the composite samples are polarized, piezoelectric coefficient and other electrical properties of the samples have been measured. Based on the lead-free, flexible and thermal stability, KNN/P(VDF-TrFE) ceramic-polymer composite is a promising material for piezoelectric application.

Resume : Density functional theory (DFT) calculation has been commonly adopted in the field of computational materials discover. Aflow and The Materials Project collected lots of calculation results and provided easy-to-use informatics infrastructure. As a result, mining information from these data repositories has recently attracted huge attention in the material society. In the present work, we describe a practicable material design framework for the prediction of formation energy of High Entropy Alloy (HEA). Low-level (Intrinsic properties, such as mass, lattice structure… et al.) and High-level features (such as, chemical characteristic or thermodynamic properties) are selected for the model training. Several machine learning models, such as Kernel Ridge Regression (KRR), Support Vector Machines (SVM) and Deep Neuron Network (DNN) are adopted in the supervised learning. Furthermore, the true positive rate (TPR) between these models are also compared.

Resume : In an organic molecule with a D-π-A arrangement, intramolecular charge-transfer (ICT) from the donor (D) to the acceptor (A) occurs and the molecule constitutes a dipole. Such push–pull systems are investigated as active molecules for nonlinear optics (NLO). Recently, we have demonstrated that such properly substituted organic push-pull molecules undergo smooth intercalation into inorganic layered materials [1, 2]. Such inorganic-organic hybrid systems combining advantages of both materials constitute efficient NLO-active material. Whereas the organic CT-chromophore brings the nonlinear response, inorganic matrix serves as thermally stable and robust carrier and assures polar order of the chromophore. In this contribution, intercalates of 4-aminopyridine, 4-dimethylaminopyridine, 4-diphenylaminopyridine, di(pyridin-4-yl)amine, N-phenyl-(N-pyridine-4-yl)pyridine-4-amine, and tri(pyridin-4-yl)amine with alpha-zirconium and gamma titanium hydrogen phosphates and zirconium sulfophenylphosphonate were prepared. The influence of the number of protonable atoms in the molecule and its shape on the amount of the guest molecules intercalated, their arrangement and especially on optical properties of the intercalates is discussed. References: 1. K. Melánová et al: Dalton Trans. 2014, 43, 10462 - 10470. 2. F. Bureš et al.: J. Mater. Chem. C 2016, 4 (3), 468-478. This work was supported by the Czech Science Foundation (grant number 17-10639S).

Resume : Boron Neutron Capture Therapy (BNCT) is potentially a promising and powerful anti-cancer therapy which is based on the selective accumulation of a stable isotope of boron (10B) in the tumor, followed by irradiation with low energy neutrons. Several classes of BNCT agents have been designed and synthesized including boron-containing amino acids, biochemical precursors of nucleic acids, DNA-binding molecules, and carboranes. Recently, carborane derivatives containing suitable functional groups (-SH, -COOH) were intercalated into ZnAl and MgAl layered double hydroxides [1, 2]. In this contribution, intercalation of decaborate and dodecaborate anions, p-carborane-l,l2-dicarboxylic, m-carborane-1,7-dicarboxylic and m-carborane-1-carboxylic acids into ZnAl-LDH and zinc hydroxide nitrate is described. The intercalates prepared were characterized by powder XRD, ICP and EDX microanalysis, thermogravimetry and IR spectroscopy. The decaborate, dodecaborate and p-carborane-l,l2-dicarboxylate anions form a monolayer in the interlayer space, a bilayer arrangement is presumed for m-carborane-1-carboxylate anions. The m-carborane-1,7-dicarboxylate anions form a bilayer in which the guests are bonded alternately to the upper and lower host layers and are strongly interdigitated. This work was supported by the Czech Science Foundation (grant number 17-10639S). References 1. J. H. Choy et al: US patent 7572458B2, 2009. 2. A. Nedim Ay et al: Dalton Trans. 46 (2017) 3303–3310..

Resume : Na-ion based energy systems are slowly emerging out of the shadow of their more illustrious Li-ion counterparts and proving themselves as greener and cost effective replacements. We will present novel synthesis strategy to stabilize microstructures of porous NaFePO4 microspheres, which can be used as a hybrid material in both supercapacitor and battery technologies. It is further shown that, using simple modifications, nanoparticles of NaFePO4 can be formed with solid, porous, hierarchical or even hollow morphologies. It is observed that the hollow and porous particles have much higher electrochemical response as compared to other morphologies under investigation. This observation can be explained by considering the increased surface area, efficient transport channels and higher redox sites, which becomes available in porous or hollow particles. The performance of these electrode materials were also investigated in presence of different electrolytes and specific capacitances > 115 F/g could be easily obtained. This value is much higher than these reported till date for this material. The porous and hollow particles are also found to have higher cyclability, which makes them useful for industrial applications. We will also present the electrochemical performance of these materials at non-ambient temperatures for showing their usefulness in hybrid vehicles.

Resume : Hydrogels are cross-linked hydrophilic polymer networks that can absorb water up to thousand percent. Poly (2-hydroxyethyl methacrylate) (poly(HEMA))-based hydrogels have been studied for application in various fields because of their hydrophilic properties and relatively good mechanical properties. However, there are some problems associated with relatively poor water content and cell attachment. To solve these problem, in this work, poly ((2-hydroxyethyl methacrylate)-(2-(methacryloyloxy) ethyl trimethylammonium chloride solution)) (poly (HEMA-MAETC)) hydrogel beads were successfully fabricated via electro-spraying method using photo-polymerization, a process that is easy to control. With the addition of MAETC as a cationic monomer, the swelling behavior was enhanced with a maximum of 2500 (%)-equilibrium water content, which is 20 (%) higher than that for poly (HEMA). Additionally, the elastic modulus was also 3-fold enhanced from 130 to 630 (kPa). Also, the cell affinity was also enhanced by interaction between the positively charged poly (HEMA-MAETC) beads and negatively charged cells. These charge controlled beads were used as a sensor for TNT detection with a green fluorescent protein (GFP)-producing Escherichia coli (E. coli) which is reactive to the material.

Resume : Rational architectural design of highly active and stable electrochemical materials is desirable for sustainable energy technologies but remains great challenges. Herein, inspired by inherent anisotropic structure for high-efficient ions transport in natural wood, we use basswood as precursor and present a low-tortuosity, multichannel, mesoporous carbon framework for both supercapacitor and oxygen reduction reaction (ORR) applications. With initial heteroatom embedment, followed by ammonia activation, surface functionalities, porous structures and specific surface areas of the wood carbons are simultaneously optimized. Accordingly, the as-prepared materials deliver a high specific capacitance (704 F g-1 at 0.2 A g-1) with an outstanding cycling stability (negligible decay after 10000 cycles) as self-supported supercapacitor electrodes. Simultaneously, the resultant wood carbons also exhibit superior ORR performance with a half-wave potential of 0.86 V (vs. reversible hydrogen electrode) in alkaline media, in conjunction with superb methanol cross-over tolerance and long-term stability, which then served as suitable and durable air-cathode catalysts for Zn-air battery. The results of this work open up new avenues for facile and rational design of structure-featured carbon materials from earth-abundant biomass for practical energy storage and conversion utilizations.

Resume : Titanium and its alloys are extensively employed in the field of tissue engineering for their excellent physical, chemical and biocompatible properties; the most important feature of Ti is the formation of the natural oxide layer on its surface, which provides resistance to corrosion. For the success of an implant, it is of primary importance to improve the osseointegration, as to minimize the risk of implant loosening over time and consequently implant failure. Infections around the implant are another cause of implant failure: the implant surface can be easily covered with antibiotic-resistant bacteria that form a biofilm. Considering these two important issues, the surface features of the titanium play a crucial role. Many attempts to modify the titanium surface are proposed in the literature to improve the integration between the metal implant and tissue. Among the surface modifications, the immobilization of biomolecules on the Ti surface is one of the most effective strategies. Covalent grafting allows the deposition of a robust layer of bioactive molecules and the orientation and density control of the bonded molecules. Among others, Self Assembling Peptides (SAPs) are able to promote osseointegration, and Chitosan has biocide properties; moreover, both biomolecules exhibit nontoxic, osteogenic, biocompatible and biodegradable properties. With the aim to obtain an innovative bioactive material able on one hand to promote osseointegration, and on the other hand to avoid infections, we produced an innovative high-tech hybrid material obtained by chemically anchoring a mixed layer of SAP and Chitosan on Ti surface. The effectiveness of Ti surface functionalization was probed at each step by surface-sensitive spectroscopies as XPS, NEXAFS and IRRAS.

Resume : Electrospinning is one of the most facile methods to fabricate nanofibers from a mixed metal solution of precursors. We successfully synthesized Vanadium Pentoxide (V2O5) nanorods on Tungsten trioxide (WO3) nanotubes by combination of electrospinning process and thermal annealing using precursors of V2O5 and WO3. The hierarchically driven nanostructures of V2O5 nanorods and WO3 nanotubes were characterized by scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) spectrum, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and high resolution transmission electron microscopy (HRTEM). Results indicate that the length of V2O5 nanorods is approximately 150-180nm with diameter of about 5-10nm while WO3 nanotubes have uniform outer diameters around 280nm with full of small protuberances. Generally, tungsten oxide has been widely studied for diverse applications because of photocatalytic, intrinsic catalytic, and eletrocatalytic properties. And as a transition metal, Vanadium is known for high electrochemical performance and also has the possibility to catalyze the water splitting. Thus, we further investigated the electrocatalytic activities for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) through synthesized V2O5-WO3 composite nanostructure depending on different atomic ratio of Vanadium and Tungsten and the calcination temperature toward future high performance electrocatalysts.

Resume : We prepared graphene oxides (GO) to have controlled surface chemistry by modifying with amine moieties such as ammonia, 1,3-diaminopropane and 1,6-diaminohexane. The X-ray photoelectron spectroscopy showed the successful formation of C-O and C-N bonds in amine modified GOs (GNs). Light scattering electrophoresis analysis showed that the zeta potential changed from negative (~ -45 mV) to positive (~ 33 mV) values upon amine modification at physiological pH of 7.4 and the positive charge intensified with increasing alkyl chain of amine moieties In order to evaluate interaction between proteins and GOs depending on their surface chemistry, we investigated both protein adsorption isotherms by Bradford assay and protein denaturation/aggregation by fluorescence quenching assay utilizing human serum albumin, human serum gamma-globulin, human serum fibrinogen and human whole plasma. It was confirmed that GO can interact with plasma proteins mainly through surface adsorption; however, the degree of agglomeration among proteins was not significant. The protein quenching ratio was determined to increase with increasing surface positive charge of GO or GNs. The quartz crystal microbalance (QCM) showed that surface adsorbed human serum albumin consisted of an irreversibly adsorbed fraction and a reversibly adsorbed fraction. Quantitative analyses on QCM exhibited that irreversibly adsorbed fraction increased upon surface negativity of GO or GNs.

Resume : Core- shell systems, such as oxide nanoparticles (NP) functionalized with chained phosphonic acid derivatives (PA), are applicable in various contexts. By a careful choice of the PA derivative the NPs solubility or reactivity [1] can precisely be adjusted. The NPs surface properties, respectively zeta potential and solubility change upon interactions with complementary amphiphiles that is for example the interaction between hexadecylphosphonic acid (C16-PA) bound to an oxide NP and dodecylbenzenesulfonate (SDBS). Hereby, a “second shell” is formed through noncovalent interactions between C16-PA and SDBS [2]. This toolbox is applied for the precise tuning of the optical properties of functionalized oxide NPs. Therefore, fluorescent polyaromatic hydrocarbons are linked to aluminum oxide NPs as PA derivatives. Their aggregation behavior is controlled by functionalizing NPs with a mixture of optical active and “spacing” PA or by forming a “second shell”, corresponding to the nature of the “spacing” PA. The optical behavior is influenced by the chemical nature of the “spacing” PA (e.g. alkyl-, glycol-, fluorinated chains) by providing a distinctive chemical environment to the chromophore. The changed solubility of the NPs, upon “second shell” formation, allows the maintenance of optical features corresponding to e.g. an alkyl environment in e.g. an aqueous solution. [1] S.H. Etschel, et al., Langmuir (2016), 10604–10609 [2] L. Zeininger, et al., Chemistry (2015), 14030-14035

Resume : Microwave (MW) absorbers have attracted tremendous attention of research community because of unprecedented surge in communication equipments and their requirement in defence related applications (stealth technology). In modern technological applications, a material with high magneto-dielectric loss is primarily required to attain the wide bandwidth of MW absorption. Bi3+-Zn2+ substituted U-type hexaferrite samples, of varying particle sizes, were prepared through one-pot chemical route at different optimized temperatures. Le Bail refinement of XRD patterns of prepared samples were used to confirm the formation of U-type hexaferrite phase and to calculate the lattice parameters ?a? and ?c?. Scanning electron microscopy (SEM) was used to study the microstructure of prepared samples and showed the variation in average particle size from 70 nm to 0.6 ?m. The complex permittivity and permeability spectra, measured using Naito and Suetake model and transmission line theory on vector network analyser (VNA), were explored in the determination of reflection loss. The single layer absorber shows a minimum reflection loss of -40.2 dB (99.99% MW absorption) at 11.9 GHz frequency along with 5.5 GHz bandwidth for reflection loss of -10 dB (90% MW absorption) or less. On the other hand, dual-layer absorber, designed with the combination two U-type hexaferrite samples of varying particles size, showed the broad bandwidth of 9 GHz, over X- to Ku-band, for the reflection loss of -10 dB or less.

Resume : The new hybrid materials (HM) are based on the phosphors used in OLED technology in inorganic PbF2-containing matrices: nanopowders PbF2 and low melting PbF2-based oxyfluoride glasses, were synthesized. We used highly effective thermostable phosphors: β-diketone complexes of Eu, 8-hydroxyquinoline complexes with metals I, II and III group of Periodic table. HM (nanopowders PbF2 phosphor) obtained by coprecipitation from aqueous solutions. The effect of organic molecules or molecular fragments on the size and morphology of precipitated PbF2 particles, the luminescence properties of HM both directly after precipitation and drying, and after calcination of powders were investigate. The change in the photoluminescence spectra after the heat treatment of the powders is caused by the passage of the exchange reaction between the metal complex and the matrix with the formation of Pb-complexes of different coordination is shown. HM (glasses PbF2-B2O3, PbF2-B2O3-SiO2 or PbF2-B2O3-SiO2-ZnO phosphor) were obtained by the melt process, the phosphor powder was introduced into the melt of the pre-synthesized glasses. The influences of the matrix composition, the concentration of residual water and OH-groups in the glass on the luminescence efficiency of HM were studied. The research was supported by the Russian Science Foundation by grant 14-13-01074П.

Resume : Next generation of sensors will have to fulfil challenging requirements such as high sensitivity, high specificity, easiness, durability and rapidity to process. In this context, we report here on the design of hierarchical hybrid SPR sensors based on a gold substrate covered with iron oxide nanoparticle assemblies bearing bioreceptor molecules at their surface. Iron oxide nanoparticles were hierarchically assembled onto a gold thin film and were easily functionalized by biomolecular receptors by using an original two step copper catalyzed alkyne-azide cycloaddition (CuAAC) “click” reaction. This building strategy allow us preparing highly stable and robust nanostructured biosensor. We selected the very-well known biotin-streptavidin couple to demonstrate the efficiency of our strategy toward the enhancement of the detection of biomolecules without using any labelling of the target molecules. High refractive index nanoparticles were demonstrated to enhance markedly the sensitivity to detection of streptavidin by increasing the accessibility of biotin groups (reduction of steric hindrance) and the sensitivity factor of the gold thin film.

Resume : Direct magnetoelectric (ME) coupling was measured on bilayered multiferroic composites. As a piezoelectric phase (PE), bidomain LiNbO3 Y 127o-cut single crystals with a “head-to-head” (HH) or a “tail-to-tail” (TT) macrodomain structure were used. Amorphous Metglas 2826 MB alloy was selected as the magnetostrictive (MS) layer. The measurements were carried out in two regimes: with a free fixation of the samples in the center by two spring-loaded bronze contacts and as cantilevers clamped at one end. Low-frequency ME coefficients of up to 440 V/(cm•Oe) were obtained at 244 Hz at resonance and 7.2 V/(cm•Oe) in the quasi-static mode at 173 Hz in the cantilever regime. Limit of detection (LOD) measurements were performed at quasi-static and resonant conditions using AC magnetic fields. The LOD at resonance drops to 420 fT/Hz^1/2 in the free fixation mode at 3300 Hz. The quasi-static LOD in an AC magnetic field for two regimes (free fixation and cantilever mode) yielded at 173 Hz values down to 50 pT/Hz^1/2 and 140 pT/Hz^1/2, respectively. To clarify and confirm the experimental results, performed numerical simulations were performed using a finite element method and a 1D model. The experimental and simulated data are in good agreement. Thus, we have shown that such systems may be used in simple and sensitive low-frequency magnetic sensors, which will be passive and stable. The sensor performance is competitive for medical applications.

Resume : Transition metal dichalcogenide monolayers (TMDC) consist of spin-splitting of both valence bands and conduction bands under the influence of spin-orbital coupling and reversion symmetry. The exciton-hole pair which arises from transition of energy states with opposite spin are named dark exciton. The in-plane photon decoupled nature of dark exciton and unconservative spins of transition contributes its less interaction with income photon. It causes a challenging measurement of such quantum states. We now present the experimental determining of the energy of those excitonic dark states in WS2 through coupling exciton with a gold core and silver shell nanocuboid. The resonance interaction between the plasmonic cavity and bright exciton demonstrates temperature varying which couple strength has significant changes. By fitting the couple strength with two level Boltzmann distribution, we observe a lower energy dark states should be exists to cause the variation. The energy of the dark state has energy 60.1meV lower than the bright exciton state. To comparing the result with literature, we conclude the dark state is dark excitonic state. By understanding the existence of the dark state, we might also predict the Rabi splitting is possibility to achieve in only certain temperature range. It is expected that the finding of the rule of dark exciton in plasmon-exciton interaction clarifies behaviors of similar system under different working temperature environment. It helps to achieve thermal control photonics device in the future.

Resume : For the first time, phase-engineered type-II metal-selenide heterostructures were demonstrated by directly selenizing indium–tin oxide (ITO) to form multi-metal selenides in single step. The utilization of a plasma system to assist selenization facilitated the low-temperature process and resulted in large-area films with high uniformity. Compared to single-metal-selenide-based photodetectors, our multi-metal-selenide photodetectors exhibited obviously improved performance, which can be attributed to the Schottky contact at the interface for tuning the carrier transport, as well as the type-II heterostructure that was beneficial to the separation of electron–hole pairs. The multi-metal-selenide photodetectors exhibited response to light over a broad spectrum from ultraviolet (UV) to visible light with a high responsivity of 0.8 AW^−1 and an on/off-current ratio of up to 10^2. More interestingly, all-transparent photodetectors were successfully produced in this work. Moreover, we also demonstrated the possibility of fabricating devices on flexible substrates with sustainable performance, high tolerance of strain, and high durability in bending tests.

Resume : In the field of the synthesis and functionalization of inorganic nanoparticles (NPs) for biomedical applications, most researches aim at developing multifunctional theranostic NPs which can both identify disease states and deliver therapy and allow thus following the effect of therapy by imaging. The current challenge for iron oxide based NPs is the design of NPs able to combine in one nano-object both magnetic hyperthermia (MH) and MRI with the best efficiency in order to reduce the dose injected in the patient. IONPs are already commercially used as T2 contrast agent for MRI. The use of MH as therapy for cancer is closer to be a reality thanks to the positive results achieved by the clinical trials carried out by MagforceTM(Germany). Nonetheless, there is currently a need of improving NPs for MH. On that basis, NPs with different shapes were prepared by thermal decomposition of home-made iron stearate, functionalised with dendron ligands to achieve aqueous suspensions and proved suitable for in vivo injection. MH performance was found to be shape-dependent with octopod-shaped NPs exhibiting the highest SAR values. At the same time, their performance in MRI was investigated leading to relaxivity values, which were superior to those of commercial products like Resovist®. Cell response was studied as a function of NP concentration and morphology, as well as under MH treatment. The in vivo MRI and MH experiments have allowed evaluating their targeting potential, their biodistribution and their therapeutic properties. A start-up company is currently under construction.

Resume : We present a preparation of an Ag/LiF nanocomposite films by a high-pressure magnetron sputtering. Localized surface plasmon resonance (SPR) in metallic nanoparticles can induce a significant enhancement of electromagnetic field in the nanoparticle's vicinity. The high-intensity electromagnetic field is essential for luminescence processes such as down-conversion or up-conversion. Energy transfer rates and photoemission rates can also be affected by SPR. For these reasons, this can be a promising method to fabricate efficient light conversion layers. Silver nanoclusters are created in an aggregation chamber exploiting gas condensation. The aggregation chamber with a magnetron head is separated from the main chamber by an orifice with the diameter of 4 mm. The pressure in the aggregation chamber is increased by an Ar flow. Silver nanoclusters are transported through the orifice into the main chamber. An evaporation boat in this chamber enables a deposition of a fluoride matrix. Homogeneous Ag/LiF nanocomposite coatings can be prepared using this method. The height and lateral size of silver nanoparticles deposited on silicon for various magnetron-orifice distances were estimated by AFM and SEM. Nanoparticles were also embedded in a very thin layer of CaF2 deposited on a NaCl crystal for a HRTEM analysis. Optical properties of the Ag/LiF nanocomposite were studied using spectrophotometry and spectral ellipsometry. Computer simulations were carried out using Mie model.

Resume : We present the results of the study of completely new photoelectric material based on size-ordered Ni nanocluster thin film. A key feature of this system is that spatially inhomogeneous distribution of metallic nanoparticle size leads to a spatial charge redistribution in such a system induced by the size dependences of the Fermi energy. It means that in the conductive system of metal nanoparticles being in contact with each other, with the average size varying monotonically in a selected direction, a potential difference is to be registered in the same direction. Nanocluster film is prepared with Nanogen-50 (Mantis Deposition) nanocluster source. The obtained film is sensitive to light of wide wavelength range from IR to visible light. The value of photo electromotive force (EMF) and short circuit current was measured while irradiation of the film with green laser (532 nm, 300 mW). We measured the maximum photo EMF to be 2.8 mV for nanocluster thin film with average nanocluster size of 5 nm. The electro physical properties of the films obtained were measured. We found that the studied films have the ohmic-type conductivity. We discuss the possible mechanisms of the observed effect.

Resume : Waste management systems are of prime concern now-a-days to reach the sustainable development goals. Reduce, reuse and recycle-these three `R´ factors are the building blocks towards managing waste products not only of the industries but also from households. Obviously, carbon based materials are the lion´s share of such waste products as well as of the raw materials. Here, waste carbon from cooking oven has been directly percolated into polyaniline (PANI), via in-situ polymerization procedure, without any prior chemical purification or modification. The excellent properties of π-electron delocalization at the backbone of conjugate polymer like PANI can be initiator of charge transfer mechanism with the incorporated carbon nanoparticles resulting tunibility of electronics dynamics within the composites. Aim of our work is to develop novel strategies for recycling biowaste-derived carbon after functionalizing with PANI via simple cost-effective techniques towards multifunctional applicability. Based on the charge transfer mechanism between PANI matrix and waste carbon particles, composites have been used for next-generation charge trapping memory device, microelectrodes for supercapacitors, sensitive ion (Fe+3) detectors etc. Such kind of advanced multifunctional materials derived from waste carbon-polyaniline by a cheap and eco-friendly process, having unique synergy in their physicochemical properties, can surely enrich the green technology towards sustainability.

Resume : A series of organic-anorganic hybrid nancomposites were obtained starting from aqueous suspensions containing different ratios of graphite oxide (GO) - obtained by modified Hummer method from graphite flakes - and natural halloysite aluminosilicate short nanotubes (HNTs). Then, pyrrole solutions at different pH and concentrations were added with mixing to the GO-HNTs suspensions, followed by oxidative polymerization using APS ((NH4)S2O8).The resulted dispersions were filtered, washed with water and ethanol in order to remove the inorganic salt and pyrrole oligomers, and finally dried. The obtained naocomposite powders were characterized by various techniques: XRD, FT-IR, Raman, UV-Vis, TEM, SEM, XPS and TGA. Also, their electrochemical and electrical behavior was analyzed using cyclic voltammetry and resisitivity measurements, respectively. Depending on precursors concentations, the inorganic halloysite nanotubes were coated/embedded with/in the organic shells/matrices in the resulted nanocomposites. These hybrid materials deserve to be tested for applications in different fields, from aqueous toxic metal ions decontamination to supercapacitors.

Resume : Metal nanoparticles growth induced by electron beam is a hot research topic, due to great advances on the in situ growth phenomena observation and to the improvements on the generation of hybrid micro-nano materials. Silver tungstate (Ag2WO4) is a semiconductor with several possible technological applications. To date, the growth process of Ag nanoparticles (Ag-NP) on the most common morphology of α-Ag2WO4, by exposition to an electronic microscope (TEM or SEM), is well known. However, morphological variations of the same material are composed by different combinations of the clusters, resulting in different exposed terminations on each surface, which can influence several properties. In this work, we compare the silver NP growth into a SEM and a TEM on two different α-Ag2WO4 morphologies: the most common hexagonal rod-like and the ideal (less explored), cuboid-like morphology. Both were obtained by simple adapted controlled-precipitation methods. Techniques such as XRD analysis, FT-IR, FT-Raman, UV-Vis, and photoluminescence emission are employed to disclose the structural and electronic properties of both α-Ag2WO4. First-principles calculations have been also performed. The differences in the Ag-NP growth for each morphology, like distribution and size of nanoparticles, as well as the shape of the crystals, are believed to occur due to the presence of different surfaces on each morphology, which is a consequence of the particular organization of the atoms in the clusters.

Resume : Hybrid polymer/inorganic nanocapsules, cross-linked with the zirconium oxocluster Zr4O2(methacrylate)12 and enclosing the fluorescent dye Nile red, are prepared by free radical copolymerization in miniemulsion. Because of the different low critical solution temperature (LCST) displayed, N-isopropylacrylamide (NIPAM) and N-isopropylmethacrylamide (NIPMM) are used as organic comonomers, endowing the resulting nanocapsules with thermoresponsive properties. The encapsulation of Nile red allows for triggering an “on–off” switching behavior of its fluorescence, according to the temperature of the dispersing medium.

Resume : We have presented a development of low temperature-curable organometal-based electrically conductive pastes for flexible substrates. Electrically conductive pastes are composed of a novolac epoxy resin and a trimodal metallic mixture of micron-sized silver flakes, silver microspheres, and silver nanoparticles, followed by curing of epoxy resin and sintering of silver nanoparticles at relatively low temperatures. The conductive silver fillers made the pastes electrically conductive due to their metal-to-metal bonding, whereas the epoxy resins used for an improvement of a processability and adhesion between the metal surface and conductive pastes. Silver nanoparticles were also used as a supplementary filler to improve the metallurgical adhesion between conductor traces into the epoxy matrix. In this study, our strategy is to add reactive organosilver complex to form the good metallic network of the conductive materials and reduce curing temperatures of the conductive pastes. As a result, we found that volume resistivity and electric conductivity of our epoxy-based conducting pastes containing the reactive organosilver complex exhibited high values of 2.5 X 10^-5 Ωcm and 4.0 X 10^4 S/cm, respectively, even at a low curing temperature of 150 °C. The resulting high conductivity may be used for a fabrication of various electronic devices, which require low temperature process.

Resume : Abstract Air cathode direct urea fuel cell (DUFC) appears as a promising candidate for sustainable urea removal and power production from urea reach wastewater. The efficiency of DUFC mainly depends on the anodic urea oxidation reaction (UOR) and cathodic oxygen reduction reaction (ORR) kinetics. The design and development of efficient economic electrocatlysts for UOR and ORR remains a key for practical implementation of DUFC. Herein, we demonstrate a single step hydrothermal synthesis of NiWO4 NPs/rGO composite for catalyse both UOR and ORR. The as synthesized NiWO4 NPs/rGO composite catalyse UOR efficiently with a high oxidation current (210 mA/cm2) and exhibits less catalyst poisoning. Moreover, the NiWO4 NPs/rGO composite shows a quasi 4 electron (n= 3.94) reduction path for molecular oxygen electroreduction. Oxygen reduction performance of the present composite is found comparable to the state-of-the-art Pt/C catalyst. In addition, the bifunctional electrocatalytic behavior of the NiWO4 NPs/rGO composite is found superior as compared to pristine NiWO4 NPs, physical mixture of NiWO4 NPs and rGO, mixture of NiO and WO3, pristine NiO and WO3. The improved electrocatalytic efficiency of the NiWO4 NPs/rGO composite originates from the synergetic physiochemical properties of NiWO4 NPs and rGO which facilitates analytes diffusion, reduces charge transfer resistance, and offers a greater number of active sites for the catalytic reactions. Present of Ni and Win a single block improve the catalyst stability for UOR catalysis. Keywords: Urea electro oxidation, oxygen reduction, nanoparticles, fuel cell, reduced garphene oxide

Resume : The high efficient water splitting system should involve the reduction of high overpotential value, which was enhanced the electrocatalytic reaction efficiency of catalysts, during the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) reaction, respectively. Transition metal nitride based nanostructures with enhanced the electrical conductivity and improved corrosion-resistance such as composition (Ni3N, CoxN, CoMoNx, and NixFeyN), morphologies-engineering (porous nanosheets and wires) and their composites with carbon materials (N-doped graphene and CNT) have been consistently studied as the OER and HER catalysts due to the superior intrinsic conductivity, large specific reaction sites and synergistic electrical coupling effect. Despite great achievements and their promising performances toward OER, one of the challenging issues for excellent efficient OER electrocatalyst is design and control of the morphology and shape including highly opened reaction sites and enhanced cycling performance.

Resume : Transitional metal sulfides, hydroxides, and oxides have special physical and chemical properties. Among the various transition metal sulfides, nickel sulfides have drawn much attention with the advantages of high redox activity, high electrical conductivity, low cost and ease of fabrication. However, these metal sulfides are susceptible to mechanical degradation which makes them lose their cycling performance. Herein, a core-shell structure of nitrogen-doped carbon on nickel sulfide particles (NC@NiS) is prepared with a simple coating of polydopamine on metallic nickel followed by annealing and hydrothermal synthesis. The nitrogen doped carbon shell protects degradation as well as aggregation of the nickel sulfide core giving rise to higher stability during electrochemical charging-discharging processes. Additionally, the carbon casing can participate in electrochemical double layer capacitance while the nickel sulfide contributes to pseudocapacitance. When used as a supercapacitor electrode, the NC@NiS displayed outstanding specific capacitance of 1033 F g -1 (at 0.5 A g -1) and maintained 90.7 % (at 6 A g -1) of its initial capacitance after 4600 charge-discharge cycles owing to the unique core-shell structure. An asymmetric supercapacitor device using NC@NiS and activated carbon electrodes exhibited high power and energy density with remarkable cycling stability maintaining 89.2 % of its initial capacitance after 5000 cycles.

Resume : Accelerating sustainably oxygen reduction reaction (ORR) kinetics is the largest challenge for polymer electrolyte membrane fuel cells (PEMFC) to be used as alternative energy sources to fossil fuels. In particular, active research is ongoing to find less expensive catalysts than the rare and high-cost platinum-based systems [1], such as non-noble metal nanoparticles or molecular based solids [2]. Metal Organic Frameworks (MOFs) have been recently proposed as promising electrocatalysts [3], yet the exact nature of the mechanisms in play has not been deeply addressed. Metalloporphyrins form part of the active oxygen reduction sites in terminal oxidases in nature [4]. They catalyze the reduction of oxygen to water utilizing electrons derived from oxidative catabolism. Therefore, structuring porphyrins in crystalline porous materials such as Metal Organic Frameworks (MOFs) or Covalent Organic Frameworks (COFs)[5] offers the opportunity to precisely tune the porphyrin environment. In this manner the influence of the arrangement of catalytic sites on the electrochemical properties can be carefully rationalised. By studying the electrocatalysis for both the MOF and the corresponding free metalloligand, we investigated the nature of the catalytic sites, their redox states, the electron transfer pathways and gained insight on the effect of structuration of the catalytic centres on the ORR mechanism[6]. 1. M. Shao, Q. Chang, J.-P. Dodelet, R. Chenitz, Chemical Reviews 2016, 116, 3594-3657. 2. S. Dresp, F. Luo, R. Schmack, S. Kuhl, M. Gliech, P. Strasser, Energy & Environmental Science 2016, 9, 2020-2024. 3. A. Morozan, F. Jaouen, Energy & Environmental Science 2012, 5, 9269-9290. 4. S. Ferguson-Miller, G. T. Babcock, Chemical Reviews 1996, 96, 2889-2908. 5. a.)G. Lu, H. Yang, Y. Zhu, T. Huggins, Z. J. Ren, Z. Liu, W. Zhang, Journal of Materials Chemistry A 2015, 3, 4954-4959; b)S. Sohrabi, S. Dehghanpour, M. Ghalkhani, ChemCatChem 2016, 8, 2356-2366. 6. M. Lions, J.-B. Tomasino, R. Chattot, B. Abeykoon, N. Guillou, T. Devic, A. Demessence, L. Cardenas, F. Maillard, A. Fateeva, Chem. Commun., 2017,53, 6496-6499.

Resume : Two major obstacles limiting the manufacturing of renewable and cost-effective polymer solar cell are low efficiency and poor stability. Introducing metallic or semiconducting nanoparticles into the polymeric surface-grafted brushes opens new pathways for the engineering of composite nanostructures which thus may exhibit unique mechanical, electrical, or optical properties. Surface-grafted polymer brushes may also serve as templates for guided synthesis of inorganic nanomaterials in the interchain confined environment. Creating new systems combining polymer brushes and nanoparticles may be a promising solution to problems associated with the effectiveness of solar cells. However, due to relatively high conformational freedom of the chains such composites often suffer from low packing density of the dispersed nanoparticles, their non-uniform size and spatial distribution. In this report we present synthesis and characterization of hybrid systems, based on polymer brushes with embedded superparamagnetic iron oxide nanoparticles (SPION) or quantum dots (QD). Polymeric brushes were obtained by grafting from the surface of silica support using atom transfer radical polymerization (ATRP) using two monomers: thermally-responisve - N-isopropylacrylamide (NIPAM) and cationic acrylamide derivative. The nanoparticles were either synthesised first and introduced into the brushes (SPION) or formed inside the brushes (QD, SPION). The nanocomposites were characterized using i.a. scanning electron microscopy (SEM), atomic force microscopy (AFM), magnetic force microscopy (MFM) and spectroscopic methods. Based on AFM measurements it was found that nanoparticles were successfully incorporated into polymer brushes. Magnetic properties were also preserved for SPION. Distribution of NPs was investigated in the systems of various brushes lenghts and surface-grafting densities. Stability of nanoparticles in the obtained polymeric systems was studied as well. Due to the combination of specific physicochemical properties of polymer brushes and magnetic nanoparticles used the development of magneto-responsive surface coatings with wide range of possible applications, starting from controlled adsorption to an energy conversion was possible.

Resume : We present an innovative surgical instrument with Au, Ag or Au-Ag nanostructured surfaces employed for in vivo assessment of tumour margins in veterinary surgery [1] through label free surface enhanced Raman scattering. The associated in vivo studies make a start towards the translation into clinics of both instrument and technique for applications in veterinary and human diagnosis. The noble metal/alloy coatings have been produced by direct imprint on stainless steel surgical blades and underwent an adequate postdeposition annealing to enhance adhesion and allow for typical temperature sterilization processes. The surfaces roughness lays between 3 and 11nm depending on the material. The blades were used to perform the incisions around the tumour allowing for an appropriate margin for each animal patient (dogs and cats with therapeutic mastectomy). Traces left on the blades were analyzed by surface enhanced Raman spectroscopy using a 632 nm excitation source in the range 100-4000 cm-1 to enable accessing lines from fatty molecules (above 2200 cm-1) and interfacial water (above 3000 cm-1) known as possible markers in human in vitro research [2]. Following tumour excision direct ex vivo SERS analyses were performed. Spectra of margins and tumours were compared immediately and the results were paralleled to later histopathology outcomes with a 97% match. The studies involved 70 pet patients. An analysis of the performance of the nanostructured surfaces in terms of enhancement of the Raman signal shows that Ag provides the highest amplification, followed by the alloy and gold. We show that label free SERS with 632nm Raman excitation can provide fluorescence-free spectra of fresh samples when the nanostructured blades are employed.In vivo assessment of surgical margins in veterinary oncologic surgery using nanostructured blades and SERS can be a step forward in comparative oncology. Acknowledgements: CORE Programme Romania [1] I. A. Birtoiu, C. E. A. Grigorescu*, et al., INTERFACE FOCUS - Vol. 6; No. 6; pp 1-11; 6 December 2016, DOI: 10.1098/rsfs.2016.0067 [2] H. Abramczyk et al., Spectrochim. Acta Part A, 129 609–623, 2014

Resume : Access to clean water, suitable for human consumption and domestic uses, is increasingly becoming the most important issue facing people around the world. For countries with plenty of solar light and scarce water, direct solar energy use for desalination is the most appropriate for a large exploitation by non-industrial communities. Nanomaterials, graphene in particular, are increasingly gaining interest in this field, thanks to their peculiar electronic, thermal and optical properties. In this work, graphene and oxide-graphene hybrid suspensions in saline water were tested for their ability to increase the light-to-heat conversion and water evaporation efficiency. The hybrid materials were developed by means of radio-frequency sputtering of oxides (Nb2O5 and SiO2) onto graphene powder. A positive effect of graphene on saline water evaporation rate, measured under a 1 sun solar simulator, was observed, while the presence of the oxides was found to improve the graphene dispersion in water. The samples were characterized by means of X-ray photoelectron and Raman spectroscopies. UV-Vis spectrophotometry and contact angle measurements were employed to characterize the treated powder suspension stability in water.

Resume : Electrodes in electrochemical reactors – in particular batteries, electrolyzers and fuel cells -for energy conversion need to fulfill several functionalities that often lead to materials problems. In general, a combined electronic and ionic conductivity is needed with adequate gas or mass transport (porosity) properties as well as chemical and mechanical stability in aggressive environments. These conflicting properties are rarely achieved with homogeneous materials and therefore a hybrid material approach is quite common in electrochemical energy conversion. Hybrid materials are often a nanometer dispersed combination of metal or metal oxides with polymeric materials, e.g. ionomers with ionic conductivity or polymeric binders. This contribution will present selected examples for electrolyzers, fuel cells and lithium batteries and discuss how technological driven approaches can help to design electrodes with superior performance and stability. Characterization to evaluate performance structure relationships will be discussed with respect to the following hybrid configurations: • Electrodes for oxygen evolution reaction with amorphous IrOx and electroceramic supports with ionomer • Ceramic perovskites/Ni anode materials as alternative solid oxide fuel cell anodes • Cathode composites with sulfur, carbon and polymer • Gas diffusion electrodes for metal air and polymer electrolyte fuel cells

Resume : We have developed a versatile colloid-based approach allowing for the synthesis of a new family of hybrid organic-inorganic nanocomposites with a high level of control of the texture and morphology [1]. This approach combines the self-assembly properties of polysaccharide chitin nanorods - bundles (L ~ 260 nm, D ~ 23 nm) of monocrystals (D ~ 3 nm) - extracted from shrimp shells with the flexibility of sol-gel processes involving inorganic precursors like siloxane oligomers (Dh ~ 4 nm). The stable ethanolic co-suspensions of the two colloids posses similar liquid-crystal properties of the aqueous suspensions of solely chitin nanorods. This allows the formation of aligned textures over millimeters during solvent evaporation across the sol-gel transition [1,2]. Besides, microparticles are obtained using spray-drying processes, thin films using spin-coating, and fibers by electrospinning. We showed that the characteristics of the silica-chitin nanocomposites (morphology, texture, birefringence) can be transferred to their mesoporous counterpart (Dpore: 5-20 nm) [1,3], with specific surface areas up to 500 m2.g-1. More recently, mesoporous SiO2-TiO2 materials have been designed as efficient catalysts through a controlled dispersion of Ti sites [4,5]. Further, our approach is adapted to the synthesis of highly porous alumina microparticles with defined and elongated mesopores using Al oxohydroxo clusters (Al13, Al30) simply added to aqueous chitin nanorods' suspensions [6]. In addition, replacing the chitin nanorods by cellulose nanorods leads to new insights on the role of the polysaccharide surface chemistry and the interactions between organic and inorganic moieties [7]. These latest results will be presented. 1. B. Alonso and E. Belamie, Angew. Chem. Int. Ed., 81, 8201 (2010). 2. M. Yu Boltoeva, I. Dozov, P. Davidson, K. Antonova, L. Cardoso, B. Alonso and E. Belamie, Langmuir, 29, 8208 (2013). 3. E. Belamie, M. Yu. Boltoeva, K. Yang, T. Cacciaguerra and B. Alonso, J. Mater. Chem., 21, 16997 (2011). 4. A. Sachse, V. Hulea, K. L. Kostov, N. Marcotte, M. Yu. Boltoeva, E. Belamie and B. Alonso, Chem. Commun., 48, 10648 (2012). 5. A. Sachse, V. Hulea, K. L. Kostov, E. Belamie and B. Alonso, Catal. Sci. Technol., 5, 415 (2015). 6. A. Sachse, L. Cardoso, K.L. Kostov, C. Gérardin, E. Belamie and B. Alonso, Chem. Eur. J., 21, 3206 (2015). 7. L. Cardoso, T. Cacciaguerra, P. Gaveau, L. Heux, E. Belamie and B. Alonso, New J. Chem., 41, 6014 (2017).

Resume : The renewable green and clean energy sources are in high demand to fulfill the requirement of ever increasing world population and environmental pollution generated by using energy derived from conventional fossil fuels. The electrochemical energy devices are considered to be one of the most suitable candidates which have great ability to accomplish the energy requirements. For the advancement of electrochemical energy conversion and storage devices, the catalysts derived from transition metal oxides are very important. The development of highly efficient and durable electrocatalysts for the oxygen reduction reaction (ORR) is highly desirable for the commercialization of energy devices derived from it such as fuel cell and metal-air batteries which are considered to be a potential energy generation devices. Moreover, the futuristic catalysts for these applications need to be cost effective in order to ensure a competitive edge for these devices in the energy market. The present study is based on the preparation of a cost-effective and efficient electrocatalyst for the ORR. The mentioned work is focused on supporting transition metal based CoMn alloy oxide nanoparticles over N-doped porous graphene using a simple and scalable microwave irradiation method. During the synthesis process, the microwave irradiation was found to be very crucial for the fast creation of pores in the graphene framework along with a simultaneous formation of the CoMn alloy oxide nanoparticles. Among the prepared catalysts by varying the Co:Mn ratio, the catalyst designated as CoMn/pNGr(2:1) displayed remarkably close ORR activity to the state-of-the-art (Pt/C) catalyst in 0.1 M KOH solution. The prepared catalyst has shown a ∼60 mV potential shift with a low Tafel slope of 74 mV/decade, which is comparable to that derived from the commercial Pt/C catalyst. The observed higher activity from the CoMn/pNGr(2:1) catalyst has been credited to the cooperative effect coming from the metal entities in alloy oxide nanoparticles and the defects present in the N-doped porous graphene. Finally, the prepared catalyst was employed for the real system-level demonstration by using as cathode catalyst in single-cells of an anion-exchange membrane fuel cell (AEMFC) and a primary Zn-air battery. The fabricated devices were successfully demonstrated the efficiency of the catalyst to facilitate ORR in real integrated systems of the single-cell assemblies. Reference: S. K. Singh, V. Kashyap, N. Manna, S. N. Bhange, R. Soni, R. Boukherroub, S. Szunerits and S. Kurungot, ACS Catal., 2017, 7, 6700-6710.

Resume : Major disasters in the handling of crude oil and its products, e.g. the Deepwater Horizon explosion, result in a vast release of hydrocarbons (HCs) and thus, lead to a dramatic impact to the environment [1]. SotA response includes dispersion and in situ burning of the HCs [2]. These methods are of enormous ecological impact. We have developed a nanoparticle (NP) based system for the efficient removal of HCs from the water surface. Magnetite NPs are functionalized with a hydrophobic and oleophilic phosphonic acid (PA) self-assembled monolayer (SAM) allowing the highly selective adsorption of HCs. A high surface area to volume ratio and the magnetic core feature high extraction rate and easy collection of the adsorbed HCs by a magnetic field. Due to the stability of PA on oxide surfaces, the functionalized NPs show very good reusability over several cycles for the extraction of single components as well as different crude oils. By fine-tuning the chemical structure of the SAM molecules with different PAs, the collection of specific HC groups may be improved. The commercial availability of the magnetic nanoparticles as well as of suitable PAs and the simple and fast functionalization process [3], in combination with the eminent, selective HC extraction make this system a cheap and competitive HC cleanup agent [4]. [1] 10.17226/10388 [2] 10.3844/ajessp.2011.423.440 [3] 10.1021/am501155r [4] Thanks to ?Engineering of Advanced Materials ? EXC 315?, DFG for financial support

Resume : We report a light, flexible, and low-power poly(ionic liquid)/alumina composite CO2 sensor. We monitor the direct-current resistance changes as a function of CO2 concentration and relative humidity and demonstrate fast and reversible sensing kinetics. Moreover, on the basis of the alternating-current impedance measurements we propose a sensing mechanism related to proton conduction and gas diffusion. The findings presented herein will promote the development of organic/inorganic composite CO2 gas sensors. In the future, such sensors will be useful for numerous practical applications ranging from indoor air quality control to the monitoring of manufacturing processes.

Resume : Multiferroic materials have potential for many applications such as actuators, magnetic field sensors or new types of electronic memory devices. As magneto-electric effect (ME), first observed in inorganic single crystals was weak, the use of composite materials is appealing to overcome this limitation. In this context, we developed new flexible multiferroic hybrid materials through a smart tailoring of the hybrid interface between a ferroelectric polymer and ferromagnetic and magnetostrictive nanoparticles (NPs). This presentation is focused on the synthesis of polyol-made cobalt ferrite CoFe2O4 NPs larger than 10 nm. Interestingly, we show that despite their reduced size, these NPs are ferrimagnetic at room temperature with non-zero remanence and coercivity, and a close to bulk saturation magnetization value (90 emu/g). Furthermore, we accurately controlled their composition and report on Co0.7Fe2.3O4 and CoFe2O4 NPs whose surface was finally functionalized to increase their miscibility in PVDF. The microstructure of the resulting hybrids, melt-processed at 80-100 °C was investigated with a special emphasis on the crystallinity and polymorphism of PVDF. This ferroelectric phase of PVDF could also be stabilized by suitable tensile tests performed by stress-induced self-crystallization, coupled to X-ray diffraction (XRD) for monitoring the crystalline phase modifications, while microstructural changes were observed by near-field microscopy.

Resume : In the silk industry, a large fraction of raw or waste silk is left underexploited. These natural fibers offer untapped hierarchical structures organization, to template the formation of functional groups. Accessing the part of these organized structures has been a major challenge. In this work we demonstrate that selective impregnation using supercritical carbon dioxide (scCO2) and sonication of Bombyx mori (commercial silkworm) silk fibers could impart multi functionality. In a first step, scCO2 was used to impregnate pyrrole monomers into Bombyx mori silks fibers, followed by iron chloride oxidative polymerization at atmospheric pressure and 4˚C. Under supercritical condition, fiber swelling and pyrrole increased solubility drove pyrrole enrichment in the fibers by diffusion. Upon return to atmospheric conditions, the fibers contracted back with the pyrrole monomer organized and ready for an oxidative polymerization. The resulting scCO2 treated fibers had six times higher conductivity for a lower mass increase in polypyrrole, compared to fibers treated and polymerized at atmospheric conditions. This suggested a more linear and homogeneous polymer arrangement for the scCO2 treated fibers. In a second step, sonication was used for the synthesis and impregnation of metal oxide nanoparticles (MnO2) onto the afore mentioned Ppy-silk fiber. The functionality of Ppy-MnO2-silk fiber was tested using methylene blue (spectrophotometrically) and hydrogen peroxide degradation (electrochemically). The result showed higher rate of MB degradation for scCO2 prepared Ppy-MnO2-silk fiber compared with control approached prepared Ppy-MnO2-silk fiber. The degradation of hydrogen peroxide using cyclic voltammetry showed that Ppy-MnO2 silk fiber could be used directly as a soft electrode for sensing H2O2. In conclusion, we demonstrated that the combination of scCO2 impregnation and sonochemistry could yield new or improved multifunctionality. We therefore argue, given the structural and chemical variations found in natural polymers, that similar results could be generic.

Resume : Ionosilicas recently emerged as a new family of functional organosilicas. These materials are defined as silica based materials containing covalently anchored ionic groups, and are synthesized via sol-gel reactions starting from ionic precursors. Ionosilicas combine high porosity, regular architecture on the mesoscopic scale with an unmatched chemical versatility, induced by the high number of incorporated ionic sites and the high variability of possible anion-cation combinations. In analogy to ionic liquids, which are considered as ‘designer solvents’, ionosilicas can be regarded as ‘designer materials’. We will illustrate the versatility of ionosilicas in the area of anion exchange. Ionosilicas efficiently adsorb high quantities of both organic and mineral pollutants. A first study concerning the adsorption of chromate ions revealed that ionosilicas display a very high adsorption capacity combined with rapid ion exchange kinetics. The polyvalence of ionosilicas was then shown in the area of the adsorption of anionic drugs, i.e. p-aminosalicylate (PAS). Isothermal titration calorimetry (ITC) experiments indicated different displacement enthalpies depending on the substitution of the cationic group. Specifically, PAS shows a particularly high affinity toward ionosilica material containing aromatic groups. We attribute this result to a pi-pi stacking contribution of the sorbent material with PAS. This work shows that tailor made ionosilica based adsorbents can be designed in view of the development of selective anion exchange materials.

Resume : In the last years the CO2 emissions are growing, leading to global climate change effects harmful for the entire ecosystem. In order to decrease the amount of CO2 emitted to the atmosphere, several CO2 capture methods have been studied in literature, such as gas phase adsorption on solid adsorbents. In this work, different organic-inorganic hybrid materials have been synthesized, characterized and tested as sorbents for CO2. On one side, hybrid organic-inorganic SBA-15 silicas functionalized with increasing amounts of amino groups were studied. Three different amino-silane species were used: 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane and 3-[2-(2-aminoethyl)aminoethyl] aminopropyltrimethoxysilane. A detailed study on the interactions of organosilane species with the silica surface was performed by using a combination of IR and SS-NMR spectroscopy, with particular emphasis to the determination of the silane chain length effect on the mobility of organic species on the silica surface. On the other side, we considered MCM-41 silica samples with different particle diameter, passing from micrometric to nanometric scale, in order to study the size effect of the support on the adsorption properties. The adsorption process was studied both qualitatively and quantitatively by using different techniques (i.e. FT-IR and SS-NMR spectroscopies, volumetric measurements, TGA and ZLC analysis) with a special focus on the reversibility of the reactions.

Resume : The synthesis of non-centrosymmetric hybrid materials possessing a magnetic order is the key condition in the search of multiferroicity. With this primary motivation, we have synthesized four new materials by hydrothermal synthesis from naphtyl and benzyl phosphonate derivatives and cobalt or manganese precursors. The structures of these compounds were resolved by X-ray diffraction on single crystal. This study permitted to show that the two series of compounds synthesised from benzyl or naphtyl were isotypics. All compounds have the same inorganic network, composed by a periodic stacking of pseudo-like perovskite layers formed by M2+O6 octahedrons (M2+= Co2+ or Mn2+) and PO3C tetrahedrons. These inorganic layers are separated by a double organic layer composed by the organic part of ligand and joined by hydrogene bonds. Furthermore, the four compounds crystallise in a non-centrosymetric space group. The magnetic studies of these compounds reveal two different behaviours depending on the nature of the cations. For the two cobalt compounds an antiferromagnetic transition was observed, whereas for the two manganese compounds a complex magnetic behavior, probably with a canted antiferromagnetic order, was observed. The synthesis, crystal structure and magnetic properties and first result of polarisation study will be presented.

Resume : Owing to their size and shape dependent properties, magnetic nanoparticles (NPs) are covering a wide range of applications. A step further would be to design new functional hybrid materials with highly hierarchical structures in order to control precisely their collective properties. As Fe3O4 is a non-toxic and cheap material, it could be interesting to increase its magnetic anisotropy for spintronic applications in order to solve data storage problems. Here, we report the original synthesis of a newly hybrid functional material in order to increase the magnetic stability of small Fe3O4 NPs. The exchange bias (EB) coupling property is used to increase the magnetic anisotropy through the coupling of antiferromagnetic and ferrimagnetic phases. Fe3O4@CoO@Fe3O4 core@shell@shell NPs showed a high magnetic stability and unexpected magnetic properties. To understand these properties, advanced characterization techniques such as EELS, EFTEM, XMCD or p-SANS were used. They give crucial information about the chemical composition of the interface. These newly designed NPs were also functionalized with an organic ligand to use them as organic-inorganic hybrid building block units. Hierarchical assemblies such as monolayers onto a substrate were prepared in order to study their collective properties as function of the interparticle distance.

Resume : Hybrid organometallic systems offer a wide range of functionalities, including magnetoelectric interactions. However, the ability to design on-demand ME coupling remains challenging despite a variety of host-guest configurations and ME phases coexistence possibilities. Here, we report the effect of metal-ion substitution on the magnetic and electric properties in the paramagnetic ferroelectric DMAAS crystals. Doing so we are able to induce and even tune a sign of the ME interactions in the paramagnetic ferroelectric state. Both studied samples with 6.5% and 20% of Cr become paramagnetic, contrary to the initial diamagnetic compound. Due to the isomorphous substitution with Cr the ferroelectric phase transition temperature increases nonlinearly, with the shift being larger for the sample with Cr content of 6.5%. A magnetic field applied along the polar c axis increases ferroelectricity for this sample and shifts Tc to higher values, while inverse effects are observed for sample containing 20% of Cr. The ME coupling coefficient of 1.7ns/m found for a crystal with 20% of Cr is among the highest reported up to now. The observed sign change of ME coupling coefficient with a small change in Cr content paves the way for ME coupling engineering.

Resume : ZnO is an oxide semiconductor which is used in a very extensive domains of industrial applications such as catalysis (e.g. tyres vulcanization), antibacterial coating, UV sun screen formulations… These applications require high specific surface area (nanometric materials) and the development of reproducible, efficient and easy-scalable industrial production processes. Our recent patented industry-capable (in terms of legislation concerns) and cost effective chemical solution approach (PCT WO 2016/038317 A1) led to mesospheric self-assembly hybrid ZnO-PAA nanomaterials (PAA = polyacrylic acid) that can be used as original scattering nanostructure and very high surface area ZnO support (>100m²/g). Herein, we will address the use of such self-assembly nanostructured ZnO materials as support of Cu(0) NPs for the catalytic hydrogenolysis of glycerol into 1.2 propanediol and as white LED nanoluminophor. We will demonstrate how and why optimizations of (i) the set-up of the synthesis (reaction and washing steps), (ii) the molecular weight of the commercial polymers PAAH (1800-250000) (iii) the temperature of the calcination of the self-assembly hybrid ZnO-PAA system, (iv) the conditions of deposit and reduction steps (in relation with the Cu content) and (v) the doping lead to Cu-ZnO with remarkable catalytic and white LED performances.

Resume : Due to the unique reactivity of their organoboron group, boronic acids and benzoxaboroles have become essential molecules for both molecular chemistry and materials science. Their range of applications spans from organic synthesis (Suzuki coupling, organocatalysis…), to the design of sensors for saccharides and the development of new drugs like Tavaborole. In recent years, we have focused on hybrid materials involving boronates and benzoxaborolates. In this talk, it will be shown how they can be used as ligands for the construction of coordination polymers, charge-balancing species in layered-double hydroxides, or functional groups grafted at the surface of inorganic materials like hydroxyapatite. For each family of materials, the importance of carrying out high resolution multinuclear solid state NMR experiments (11B, 13C, 1H, 19F, 17O, 27Al, 25Mg, 87Sr and/or 43Ca – depending on the material) and of combining experimental data to computational modelling will be demonstrated.

Resume : Metal-organic coordination networks are fascinating materials which attract numerous researches. Indeed since inorganic nodes and organic moieties constituting the networks can be modified at will, they can be used in numerous applications such as gas storage, catalysis, drug delivery…[1-2] They are classically obtained by solvothermal reactions. Post-synthetic modifications are an interesting alternative strategy allowing the formation of new networks which are not obtainable by de novo synthesis. They permit the introduction within the starting networks of new functional groups or functions which endow them new physical properties.[3] Using different imidazolium multicarboxylate salts and metal or lanthanide ions in solvothermal conditions, we have obtained series of low dimensional networks crystallizing for the most part in a centrosymmetric space group.[4-5] Following the objective to obtain multiferroic coordination networks, we will present in this communication our recent results concerning the adding of ferromagnetic and ferroelectric properties in these networks by means of post-synthetic modification. [1] G. Ferey, C. Serre, T. Devic, G. Maurin, H. Jobic, P. L. Llewellyn, G. De Weireld, A. Vimont, M. Daturi, J.-S. Chang, Chem. Soc. Rev. 2011, 40, 550. [2] G. Ferey, Chem. Soc. Rev. 2008, 37, 191. [3] S. M. Cohen, J. Am. Chem. Soc. 2017, 139, 2855. [4] P. Farger, C. Leuvrey, M. Gallart, P. Gilliot, G. Rogez, P. Rabu, E. Delahaye, Magnetochemistry 2017, 3, 1. [5] P. Farger, R. Guillot, F. Leroux, N. Parizel, M. Gallart, P. Gilliot, G. Rogez, E. Delahaye, P. Rabu, Eur. J. Inorg. Chem. 2015, 2015, 5342.

Resume : Integrating functional molecules into complementary metal-oxide-semiconductor circuit combines bottom-up with top-down processes to generate novel electrical devices.[1] Of particular interest is the integration of terpyridines, which are suited to complex a variety of transition metal ions and allow for form molecular wires formation by end-to-end coupling of terminal terpyridine groups. Such wires have already been applied in nanoelectrode configurations and exhibited conductance switching properties.[2] We report the stepwise growth of layers consisting of molecular wires, starting from surface bound terpyridine (4’-mercaptophenyl-2,2’:6’,2’’-terpyridine) forming a monolayer. The reactive metal ion precursor ((Ru(sol)3)(PF6)2) and a bisterpyridine ligand (1,4-Bis(2,2’:6’,2’’-terpyridin-4-yl)benzene) were added to the monolayer in turns. Infrared reflection absorption spectroscopy (IRRAS) and surface enhanced Raman scattering (SERS), combined with DFT calculations were utilized to document the elementary steps of Ruthenium terpyridine wire formation. The layer thickness of each growth step was monitored by variable angle spectroscopic ellipsometry (VASE). The combination of these analytical methods allows proving the successful formation of the desired complexes in situ and will support our efforts to integrate terpyridine-based molecular wires into nanoelectronic circuitry. [1] N. Babajani, J. Phys. Chem. C, 2014, 118, 27142 [2] S. Seo, Angew. Chem. Int. Ed., 2012, 51, 108

Resume : Surface Enhanced Raman Scattering (SERS), which offers high sensitivity to detect single molecule, is often used in biological analysis and medical diagnosis. In order to realize arbitral observation of local information in cells or tissues by Raman scattering, NIR excitable SERS substrates having high tissue transparency and positional control of enhanced sites are required. We prepared polymer core-shell particles, which were composed of polystyrene and amino-terminated polybutadiene, having magnetic nanoparticles in the core and gold nanoparticles (diameter = 20~80 nm) densely packed in the shell by using Self-ORganized Precipitation (SORP) method. Absorbance of composite particle was red-shifted as the diameter of introduced gold nanoparticles increased. These particles were magneto-responsive and showed SERS signal from adsorbed molecules by using NIR excitation (?=785 nm). In particular, high SERS signal intensity was shown when the size of introduced Au NPs is 50 nm, because absorption peak of composite particles and wavelength of excitation light was well matched.

Resume : The exfoliated 2D nanosheets of layered metal compounds (layered metal oxides, layered double hydroxides, transition metal dichalcogenides, and layered metal carbides) attract intense research interest because of their unique physicochemical properties and useful functionalities. The 2D inorganic nanosheets can be synthesized by soft-chemical exfoliation reaction and used as efficient 2D lego blocks for superlattice nanohybrids, porous nanocomposites, freestanding hybrid films, etc. The resulting 3D hybrid materials possess diverse promising applicabilities for energy and environmental technologies. In this talk, versatile use of exfoliated inorganic nanosheets as 2D lego blocks will be presented together with the application of inorganic nanosheet-based nanohybrids with tailorable physicochemical properties and functionalities such as electrode activity, photocatalytic activity, redox catalytic activity, electrocatalytic activity, gas adsorption capability, and nanobio application.

Resume : Recent research on surfaces with special wettability lead to the development of “liquid surfaces”, obtained through the immobilization of lubricant liquid on porous interfaces (SLIPS technology) inspired by the pitcher plant,[1] or through the grafting of highly flexible polymer brushes on surfaces inspired by biological lubrication systems.[2][3] In this work, we adapted the latter efficient and versatile method to fabricate the durable coatings on wood surfaces. The strategy is based on the modification of wood surface with a silicone oxide layer, followed by grafting of PDMS chains. Characterization of the modified surfaces with state of the art techniques revealed the homogeneous conformal coating on the structured wood surface. The obtained surfaces are slightly hydrophobic, due to the SiO2 base coating and the PDMS polymers. Interestingly, our modified surfaces were highly durable when compared to classical superhydrophobic coatings after prolonged immersion in water. We also report on a self-healing ability, likely provided through the rearrangement of the PDMS chain conformation after plasma treatment. Finally, we tested our modified wood for anti-smudge, antifouling, and antibacterial behaviors, which are significantly improved by the SiO2-PDMS coating system. With durable water repellency, quick self-healing ability and low adhesion to protein and dirt, we therefore expect this fabrication method can provide wood with longer service life and can help maintaining high aesthetic appearance in a variety of wood applications requiring protection. 1. Wong, T.-S., et al., Nature, 2011. 477: p. 443-447. 2. Wang, L. and T.J. McCarthy, Angewandte Chemie, 2016. 128: p. 252-256. 3. Lee, S. and N.D. Spencer, Science, 2008. 319: p. 575.

Resume : While MOFs have been primarily considered as promising candidates for separation and storage purposes, their use for the detection of chemical species by adsorption is also appealing as they might combine a high level of detection and a tunable selectivity. The goal of this work is to develop new stable luminescent MOFs able to detect molecules even in water. More specifically, we focused our attention on the use of ligands presenting an ESIPT-type fluorescence (Excited State Intramolecular Proton Transfer). ESIPT fluorescence is an ultra-fast process ( 80%) and their ability to detect traces of cations in water.

Resume : Polyoxometalates (POMs) are an unique class of redox and optically active metal-oxide anionic clusters that can be used as efficient cofactors to improve or tune the optical properties of photoactive molecules in the solid state. Firstly, photochromic powders [1] and polymers [2] have been designed by assembling POMs with switchable spiropyrans (SP) and spirooxazines (SN) via electrostatic interactions or covalent grafting. The nature of the POM governs the SP or SN photoisomerization, and some of these bistable hybrids are promising candidates in optical memory devices. Secondly, new supramolecular assemblies combining for the first time phosphorescent cationic cyclometalated iridium (III) complexes and POMs have been recently obtained. From this innovative coupling, the solid-state phosphorescence of an orange-emitter iridium complex was successfully modulated on a wide emission wavelength range, from green to red without any preliminary functionalization, but only by playing with the nature of the POMs and the crystal packing. [3]. These new chemosensors also show remarkable reversible vapoluminescent properties for detection of volatile organic compounds (VOCs) in the environment or workplace, even in presence of moisture. [1] K. Hakouk et al., J. Mater. Chem. C, 2014, 2, 1628. [2] I. Bazzan et al., J. Mater. Chem. C, 2017, 5, 6343. [3] P. Bolle et al., J. Mater. Chem. C, 2016, 4, 11392.

Resume : Hybrid materials and in particular transparent monolithic materials (xerogels, aerogels) have been intensively developed for optical applications (sensors, filters, imaging, photocatalysis…)..[1] The preparation of composite monoliths incorporating functional nanoparticles is an important challenge in the way to design such optical devices. Two approaches will be discussed; either the preparation of monolithic transparent silica based material prepared using the sol-gel process and incorporation of functional nanostructures (plasmonic, luminescent) or the preparation of monolithic composites using colloidal suspension destabilization process. The first strategy allowed the design of transparent hybrid plasmonic composites. The plasmonic nanostructures were functionalized in order to allow their homogeneous incorporation in transparent hybrid silica matrices using the sol-gel process.[2] Co-dispersion of the metallic structures with dyes was successfully achieved.[3,4] The role of the concentration, shape and size of the metal nanoparticles on the optical response was evaluated. The respective impact on the nonlinear optical response of the dyes will be discussed. The use of colloidal suspension of small building blocks nanoparticles to prepare microstructured materials by self-assembly represent another convenient route towards monolithic crystalline functional materials. Controlled destabilization of stable suspensions of nanoparticles leads to gelation of assembled nanoparticles and preparation of monolithic porous structures. This approach was used to prepare oxides (YAG), fluorides (Rare Earth) crystalline aerogels and mixed-composite aerogels with high controlled porosity, mechanical resistance and optical properties [5]. This offers a wide possibility of various compositions of highly porous materials for applications in catalysis, photocatalysis, optics, sensors. References [1] S. Parola, B. Julian-Lopez, L. D. Carlos, C. Sanchez, Adv. Funct. Mater. 2016, 26 (36), 6506-6544. [2] D. Chateau, A. Liotta, D. Gregori, F. Lerouge, F. Chaput, A. Desert, S. Parola, J. Sol-Gel Sci. Technol. 2017, 81, 147. [3] H. Lundén, A. Liotta, D. Chateau, F. Lerouge, F. Chaput, S. Parola, C. Brännlund, Z. Ghadyani, M. Kildemo, M. Lindgren, C. Lopes, J. Mater. Chem. C 2015, 3, 1026. [4] D. Chateau, A. Liotta, H. Lundén, F. Lerouge, F. Chaput, D. Krein, T. Cooper, C. Lopes, M. Lindgren, S. Parola, Adv. Funct. Mater. 2016, 26 (33), 6005-6014. [5] M. Odziomek, F. Chaput, M. Sitarz, F. Lerouge, S. Parola, J. Mater. Chem. C 2017. 5, 12561.

Resume : Polymers reinforced with conductive fillers have proved their potential as high-performance and multifunctional composites, presenting an increasing scientific and technological interest. The incorporation of fillers, mainly nanocarbonaceous, into polymers (epoxies, thermoplastics or elastomers) allow to combine their interesting characteristics with the mechanical and electrical properties of the fillers. The composites overall properties (mechanical, electrical and piezoresistive) are strongly influenced by the polymer, fillers and processing method. The percolation threshold (PT) is typically interpreted in terms of tunnelling or hopping, can be reduced to 0.1% vol. Solvent casting method present good fillers dispersion and low PT. Controlling the viscosity of the composites, the sensors can be applied by printing technologies, such as inject, screen or spray printing. Extruded composites do not need solvent and allow industrial scalability. This work reports on the modification of the mechanical (stiffness or stretchability) and piezoresistive sensibility of the composites to develop smart materials with wide range of applications. The main composites, processing methods and applications will be presented and discussed, as well as the main challenges and future trends. Work supported by Portuguese Foundation for Science and Technology- UID/FIS/04650/2013, PTDC/EEISII/5582/2014, SFRH/BPD/110914/2015- and from the Basque Government Industry Department by ELKARTEK program.

Resume : Hybrid materials, where a 2D filler is embedded in a polymeric matrix, attracted great interest in past years, because of the wide variety of matrix and filler properties and combinations, the possibility of synergic effect among them, and the easy accessibility to scalable production methodologies. Mostly, the bulk properties of these materials have been studied so far, especially looking at how the filler changes the matrix properties. Here we propose a change in perspective, by using the hybrid material as a platform to exploit the full potential of the filler regarding device applications. In particular, we show results where black phosphorus (bP) flakes are embedded in a poly (methyl methacrylate) matrix. Black phosphorus is a very interesting layered material, thanks to its properties such as in-plane anisotropy of optical and transport properties as well as direct band gap tuneable with layer number. The application of bP has so far been severely limited by its high sensitivity to oxygen, moisture, and light, which increases going from bulk material to thin flakes. We present a low cost scalable method, which involves exfoliation of bulk bP in the monomer and in situ polymerization, and which allows to obtain electronic-grade bP nanoflakes, embedded in a polymeric matrix that protects them from the environment and allows their processing into devices without degradation. This research was funded by EU trough the ERC project PHOSFUN (grant n°670173).

Resume : Additive Manufacturing (AM), commonly referred as Three Dimensional Printing (3DP), has emerged as a powerful technique to fabricate devices with a wide range of materials, both at industrial and laboratory scale. [1] Among all of the AM technologies, extrusion-based 3D printing known as Fused Deposition Modelling (FDM) is the most common technique to fabricate 3D objects.[2] The integration of composite science with AM technology opens new avenues in applications such as micro-electro-mechanical systems (MEMS), lab-on-a-chip, microfluidics, engineered materials and composites, microelectronics, tissue engineering and biosystems. The incorporation of carbon base nano-materials results in a better functionality in terms of electrical conductivity, electromechanical/chemical sensitivity and mechanical strength. [3] Despite of many advantages offered by 3DP of multifunctional nanocomposites, several challenges have to be addressed in order to employ their full potential. [4] In recent work we developed micro-diamond-polydimethylsiloxane (PDMS) microfluidic chips and thin films using indirect 3D printing and spin coating respectively. The composites provided a 200 % increase in thermal conductivity, significantly enhancing the dissipation of heat, achieving the optimum dissipation at 60 % (wt) micro-diamond.[5] In the present work we have fabricated, for the first time, a composite 3D printable filament of acrylonitrile butadiene styrene (ABS) containing high content of high pressure and high temperature (HPHT) synthetic micro-diamond. Physico-chemical properties of diamond containing filament were characterised. After modification of a commercial FDM printer, thermally conductive and electrically insulating heat sinks were printed within minutes. Heat transfer ability for pin, wing and fin shape heat sink designs was observed by using infrared camera and it was found that incorporation of micro-diamond has enhanced heat dissipation by 34 %, 36.2 %, and 27.5 % respectively. As electronics become smaller and more powerful, thermal management with effective heat dissipation increases longevity, reliability and performance of devices. This novel composite material open new era for 3DP to exploit unique properties of low-cost HPHT diamond for wide range of applications including future MEMS, electrofluidics, and embedded electronics. References 1. S. Waheed, J. M. Cabot, N. P. Macdonald, T. Lewis, R. M. Guijt, B. Paull, M. C. Breadmore, Lab. Chip. 2016, 16, 1993-2013. 2. S. C. Ligon, R. Liska, J. Stampfl, M. Gurr, R. Mülhaupt, Chem. Rev. 2017. 3. T. A. Campbell, O. S. Ivanova, Nano Today 2013, 8, 119-120. 4. C. Zhu, T. Liu, F. Qian, W. Chen, S. Chandrasekaran, B. Yao, Y. Song, E. B. Duoss, J. D. Kuntz, C. M. Spadaccini, M. A. Worsley, Y. Li, Nano Today 2017, 15, 107-120.

Resume : We propose a direct and fully colloidal route for the preparation of aqueous suspensions of highly stable and poorly aggregated layered double hydroxide (LDH) nanoparticles using hybrid polyion complex micelles (HPIC). HPIC micelles are obtained by complexation between metallic cations and the complexing block of asymmetric poly(acrylic acid)-b-poly(acrylamide) a or poly(vinylphosphonic acid)-b-poly(acrylamide) b (PAA-b-PAm or PVPA-b-PAm) double hydrophilic block copolymers (DHBC). We showed that the LDH colloids are obtained in two steps from mixed solutions of M2+ and Al3+ cations, and DHBC: i) first formation of HPIC micelles constituted almost entirely of Al3+ due to the preferential complexation of the trivalent cations, while the divalent cations remain free in solution; ii) transformation of the DHBC/Al3+ HPIC micelles into DHBC/aluminum hydroxide colloids upon hydroxylation with NaOH. Then the partial dissolution of DHBC/aluminum hydroxide and the progressive incorporation of M2+ ions leads to the precipitation of the LDH phase in the colloid. The formation mechanism depends on the M2+ speciation, e. g. the Cu2+/Al3+ couple is hydroxylated at lower pH than the Mg2+/Al3+ couple and the properties of HPIC micelles depend on the nature of the DHBC complexing block. Indeed Mg and Al yields in the HPIC micelles are higher upon complexation with PVPA than with PAA block of the DHBC. The complexation degree (R) (R = AA or VPA/(Mg + Al)) is a major parameter controlling the colloidal stability of the LDH suspension. It also controlled the hydrodynamic diameter of the DHBC/LDH colloids,, which decreased from 530 nm down to 60 nm, and the growth of the LDH phase with a mean size of the individual particles in the range 50-20 nm when R increased. XRD and TEM results show that the LDH particles are preferentially intercalated by the negatively charged PAA block of the DHBC rather than by chloride anions of the initial salts when R increases. Moreover, the stability of the colloids depends on the asymmetry degree between the anionic block and the acrylamide block and also on the architecture of the DHBC. This colloidal route appears promising for the developpement of biofunctional hybrid nanovectors and for basic catalysis applications. a. Géraldine Layrac, Mathias Destarac, Corine Gérardin and Didier Tichit, Highly Stable Layered Double Hydroxide Colloids: A Direct Aqueous Synthesis Route from Hybrid Polyion Complex Micelles., Langmuir 2014, 30, 9663. b. Géraldine Layrac, Corine Gérardin, Didier Tichit, Simon Harrisson and Mathias Destarac ,Hybrid polyion complex micelles from poly(vinylphosphonic acid)-based double hydrophilic block copolymers and divalent transition metal ions., Polymer, 2015, 72, 292-300

Resume : Hybrid materials with chalcogenate ligands (-ER = SR, SeR, TeR) and d10 coinage metals (M(I) = Cu, Ag and Au) are known for a long time mainly in the domains of biology and pharmaceutics.1 Indeed, copper-thiolates are present in most of the living organisms as metalloproteins, silver-thiolates are recognized for their anti-bacterial activity and some gold-thiolates, as the Myochrysine, have been used as antiarthritic drugs. Today, the d10 coinage Metal Organic Chalcogenates (MOCs) are gaining a growing relevance in materials science for their semiconductivity and photoluminescence properties. Indeed, the photoemission of these compounds is attributed to the presence of d10 coinage metals and their ability to display metallophilic interactions. Neutral MOCs, defined with the formula [M(ER)]n, can form cyclic oligomers and extended coordination polymers with 1D or 2D structures as a limited number. In this presentation we will show the variety of the chain-like and lamellar structures of these MOCs, associated to a rich palette of photophysical properties. Thus, some compounds exhibit high quantum yield (~70 %) in the solid state and some have an intrinsic triple emission associated with luminescence thermochromism allowing optical temperature sensing. This study will show the great potential of the MOCs as phosphorescent hybrid materials and their great potential in electronic devices, sensors or photocatalysis. 1. Veselska, O.; Demessence, A., Coord. Chem. Rev. 2018, 355, 240.

Resume : Copper- and cobalt-based layered simple hydroxides (LSH) are successfully functionalized by a series of fluorene mono- and diphosphonic acids, using anionic exchange reactions and a preintercalation strategy. The lateral functionalization of the fluorene moieties has only little impact on the overall structure of the obtained layered hybrid materials but it influences the organization of the molecules within the interlamellar spacing. For bulky fluorene (9,9-dioctyl derivative), luminescence is preserved when inserted into copper and cobalt hydroxydes, whereas it is completely quenched for the other fluorenes. Detailed characterization of the internal structure and chemical bonding properties for copper- and cobalt-based hybrids is performed via ancillary experimental techniques. For the copper-based LSH class, for which more elusive findings are found, first-principles molecular dynamics simulations unravel the fundamental stabilizing role of the H-bonding network promoted within the local environments of the fluorene mono- and diphosphonic acids. The cobalt series of compounds constitute a new class of hybrid magnets, with ordering temperatures ranging from 11.8 to 17.8 K and show a clear magnetoelectric effect. This effect appears above a threshold magnetic field, which is null below the magnetic ordering temperature, and it persists in the paramagnetic regime till about 110 K.

Resume : Color generation is commonly pigmentation-related and is spatially limited to tens of microns, two orders of magnitude above the diffraction limit. Colors can also be generated with interference devices such as photonic crystals and subwavelength plasmonic structures. The latter are suggested as the next generation for color display, because they have the potential to reach the diffraction limit resolution using advanced fabrication techniques. Furthermore, light can be efficiently manipulated by such plasmonic structures followed by polarization for instance. Hence, one can control the simultaneous tuning of the generated color. Plasmonic nanostructures such as hole arrays, grooves, disks, and slits have been shown to generate colors efficiently, and have the potential to function as dynamic color pixels. Yet, their size is still limited to several microns. Therefore, we exploit the plasmonic-hybridization of nano cavities milled in metallic films, which are excited by propagating surface plasmons, to induce coupling between them. [1-2] This is where Babinet’s principle does not hold, namely, holes cannot be considered complimentary to nanoparticles. Following hybridization, new states are formed: the ‘in-phase’ and ‘out of phase’ states, in analogy to molecular orbitals. The polarization state of the incoming optical field modifies the charge distribution around the cavities, thus, one can actively achieve the whole energy landscape of the optical range. Herein, we report on such active, sub-micron plasmonic devices. Despite their small size, we are able to generate multiple colors from these structures, depending on the polarization state of the incoming optical field. To examine the whole structure which acts as a unified entity, we utilize both optical far field microscopy, alongside cathodoluminescene (CL) spectroscopy. The properties of these plasmonic devices are unique and related to the interactions between the neighboring cavities. We present a thorough study of the modes which give rise to the enhanced mutual coupling between these cavities. This examination is possible due to spatial mapping of the photon emission for a given energy, which can easily be obtained by CL - providing a direct way to probe the local electric field. [1] E. Segal, A. Weissman, D. Gachet, and A. Salomon, Nanoscale, 2016, 8, 15296. [2] A. Weissman, M. Galanty, E. Segal, O. Shavit, and A. Salomon, Adv. Opt. Mat., 2017, 5, 1700297.

Resume : Metal Organic Frameworks (MOFs) constitute an important class of hybrid materials. Due to their high versatility, they can be used in an impressive number of applications, such as catalysis, gas storage and treatment, drug delivery… [1,2,3] In our group, we have recently focused on the solvothermal synthesis of coordination networks from symmetric imidazolium dicarboxylate or tetracarboxylate salts and transition metal or lanthanide ions. The compounds obtained with this strategy exhibit interesting physical properties such as magnetism and luminescence. [4,5,6] Based on these previous data, we currently work on the synthesis of lanthanide networks based on an asymmetric imidazolium tricarboxylate salt in order to compare the influence of the ligand’s asymmetry on the physical properties and the dimensionality of the networks. [1]. G. Férey, A. K. Cheetham, Science 1999, 283, 1125 [2]. J. L. C. Rowsell, O. M. Yaghi, Angew. Chem. Int. Ed. 2005, 44, 4670 [3]. P. Horcajada, C. Serre, M. Vallet-Regí, M. Sebban, F. Taulelle, G. Férey, Angew. Chem. Int. Ed., 2006, 45, 5974. [4]. P. Farger, R. Guillot, F. Leroux, N. Parizel, M. Gallart, P. Gilliot, G. Rogez, E. Delahaye, P. Rabu, Eur. J. Inorg. Chem. 2015, 2015, 5342. [5]. P. Farger, C. Leuvrey, M. Gallart, P. Gilliot, G. Rogez, P. Rabu, E. Delahaye, Magnetochemistry, 2017, 3, 1. [6]. P. Farger, C. Leuvrey, M. Gallart, P. Gilliot, G. Rogez, J. Rocha, D. Ananias, P. Rabu, E. Delahaye, Submitted.

Resume : By hybridization of high-capacity transition metal oxides (TMOs), low in conductivity and susceptible to huge volumetric variation upon lithiation/delithiation, with highly-conductive MXene, the MXene-based composite electrodes are particularly promising for high-capacity, high-rate lithium-ion batteries (LIBs), with outstanding electrochemical performance exceeding that of its individual components. Large, thin sheets of HCl-LiF-etched Ti3C2Tx are synthesized via the modified procedure with molar ratio of 7.5 LiF to 1 Ti3AlC2 in 9 M HCl etchant solution. Separately, with as-synthesized graphene oxide (GO) as template, various 10 at.% doped SnO2 nanosheets are prepared via wet-chemical synthesis and subsequent calcination to remove GO template. Co-doped SnO2 has been one of the most well-studied doped-SnO2 for LIBs anode application; whereas Fe, W as dopants have only been recently reported. In this work, we examine alternative methods, such as simply freeze-drying, or self-assembly with surface-modified TMO, to prepare the hybridization of few-layered HCl-LiF-etched Ti3C2Tx with graphene oxide (GO) template-synthesized doped-SnO2 nanosheets and evaluate the composites’ electrochemical performance. This work demonstrates the feasibility and progress beyond hitherto hybridization methods such as alternating vacuum filtration, spray coating and in-situ wet chemistry synthesis. Additionally, the synthesis and effect of Co, Fe, W-doped SnO2 nanosheets will also be elucidated.

Resume : Polymer dispersed liquid crystal (PDLC)-based smart windows are made in the simplest method among smart window types, and they are especially developed nowadays. Here, we report printing of Ag nanowire (NW) network/PEDOT:PSS films using a bar coater to replace conventional ITO film for cost-effective flexible polymer-dispersed liquid crystal (PDLC). To substitute vacuum-based high cost and brittle ITO electrodes, we adopted a Ag NW network/PEDOT:PSS electrode on PU substrate using bar coater. Outer/inner bending, dynamic fatigue tests as well as stretching tests demonstrated that the mechanical flexibility and stretchability of the bar coated Ag NW network/PEDOT:PSS films was superior to that of conventional ITO films. To show the feasibility of bar coated Ag NW network/PEDOT:PSS electrode on PU substrate, we fabricated 2.5 by 2 PDLC-based smart window on an optimized Ag NW/PEDOT:PSS network electrodes (40 Ohm/square, 82% optical transmittance). Superior flexibility of bar coated Ag NW/PEDOT:PSS electrode than sputtered ITO electrode indicated the possibility of the bar coated Ag NW network/PEDOT:PSS electrode for highly flexible smart windows. Also successful operation of flexible and stretchable PDLC-based smart window with Ag NW/PEDOT:PSS electrodes indicates that bar coated Ag NW/PEDOT :PSS films on PU substrate are promising low cost, high performance, and flexible transparent electrodes for cost-effective large-area smart window and can be substituted for ITO films, which have high sheet resistance and are brittle.

Resume : Light driven water oxidation performances of several Prussian blue analogues involving cobalt ions have recently been investigated in the presence of a [Ru(bpy)3]2+/persulfate system.1-3 Although cobalt hexacyanometalates stands forward due to their high catalytic activities ( a quantum yield of ≤88%), one of the main drawbacks of the system is its low stability during catalysis. Inspired by molecular dyads, herein, a step-by-step rational design of cyanide-based hybrid compounds, which incorporate water oxidation catalytic sites covalently coordinated to molecular photosensitizers, will be presented. The photocatalytic performance of these hybrid systems for light-driven water oxidation process will also be explained.

Resume : Recent observation [1,2] of magnetization plateau in TmB4 has revived interest in rare earth tetraborides. The rare earth tetra-borides are good metals where itinerant electrons are exchange-coupled to local moments. The long range RKKY interaction between local moments gives rise to a magnetic ground state. Interestingly, it is believed that the microscopic Hamiltonian for tetra-borides is describable on a (topologically equivalent) Shastry-Sutherland (SS) lattice. However, the physics of itinerant electrons in tetraborides is largely overlooked, which is found to be quite intriguing [3]. Based on GGA band structure calculations on metallic antiferromagnet TmB4, followed by a Wannier fitting, we find that the electronic structure can be described predominantly by 4 bands (hybridized f, d and p orbitals). Strong correlation effects and inter-orbital charge transfer are extremely important in this system and lead to an effective model whose connection to SS model is discussed. Using single-site, multi-orbital dynamical mean-field theory (MO-DMFT), we consider such effects, propose an effective model and address the possibility of an orbital-selective Mott transition in this system. [1] K. Siemensmeyer, et al., Phys. Rev. Lett. 101, 177201 (2008). [2] S. Sunku, et al., Phys. Rev. B. 93, 174408 (2016). [3] S. Pradhan et al., Materials Today: Proceedings 4 (2017) pp. 5532-5536 .

Resume : Water splitting is considered the most attractive pursuit in the field of solar energy conversion. In this study, we report the synthesis and application of a supramolecular hybrid of carbon nanodot (CD) and cobalt polyoxometalate (Co-POM) to solar water oxidation. The self-assembly of the alginate-based CD and Co-POM led to the formation of a spherical hybrid of CD/Co-POM. Owing to the facile transfer of photogenerated holes from CD under visible light irradiation, the hybrid donor-acceptor type of CD/Co-POM enabled the rapid scavenging of holes and accumulation of a long-lived oxidation state of Co-POM for efficient solar water oxidation, outperforming conventional [Ru(bpy)3]2 -based systems. We believe that this study offers new insights into the development of CD-based nanocomposites with various photocatalytic and optoelectronic applications.

Resume : The adhesion between TiO2/PI interface in previous study was not fulfill the results expected. The hardness and toughness can’t be enhanced by hard/soft interlaced structure due to poor adhesive strength and the composite shouldn't be put together distinctly with two different materials without gradient media in between. In this study we have introduced a meso-layer mixed TiO2/PI with proper ratio inserted into the interface of these two different materials. We have also changed the architectural design for lower TiO2/PI thickness to increase the repetition of total numbers of lamellar multilayers to accumulate stored energy and dissipate the propagation of the crack perpendicular to film; and H/E value was much higher than the original materials individually. One kind of bio-inspired thin film can be achieved like natural growth of creatures.

Resume : The reduction of radar backscatter with the use of radar-absorbing material has important implications in the stealth technology and electromagnetic compatibility. Nanocomposites consisting of carbon nanotubes (CNTs) and magnetic materials have potential applications in various fields like magnetoresistive random access memory, spin-polarized transportation, Electromagnetic interference shielding (EMI) and radar absorption. Metal-incorporated CNTs are found to be good microwave absorbers due to the modification of their electronic structure which helps in dielectric and magnetic loss of the incoming electromagnetic wave. In this work, we have synthesized the metal filled MWCNT with efficient and simple one pot chemical vapor deposition techniques using pyrolysis of metal precursor. CNTs filled with the 3d transition metals like Fe, Co. Ni, Mn renders them good electromagnetic-interference shielding and microwave absorbers behavior. The microwave absorption properties of these hybrids metal filled CNTs in the PVDF polymer matrix are studied in X band (8-12 GHz frequency range). The synergistic microwave absorption due to the enhanced interfacial electric polarization and ferromagnetic resonance of magnetic nanoparticles leads to enhanced microwave absorption and EMI shielding. The role of magnetism and its effect on the EMI shielding and radar absorption will be discussed. These hybrid composite systems have great potential for commercial and military applications.

Resume : In water splitting, oxygen evolution reaction (OER) is important process because high overpotential is required to achieve the current density for the reaction. Transition-metal nitrides (TMN) used as electrocatalyst materials for OER are being recently studied because of high yield, easy operation, and excellent catalytic activity by high electrical conductivity. In particular, iron-nickel nitride has very high catalytic activity due to owing to high electro-catalytic and high stability. Reduced graphene oxide (rGO) known as 2 Dimensional (2 D) carbon materials is extensively used as supporting material owing to high conductivity, large theoretical specific surface area, and excellent stability. In this study, we successfully synthesized Fe2Ni2N/rGO hybrid composite for OER electrocatalyst material through two-step process with hydrothermal method and annealing. The morphology of precursor and Fe2Ni2N/rGO hybrid composite was analyzed by FE-SEM. The crystallinity of sample was confirmed by XRD. GO was confirmed by Raman spectroscopy. And the components of as-prepared precursor were measured by FT-IR spectra. Furthermore, we analyzed electrochemical properties of synthesized sample.

Resume : Growth mechanisms of graphitic nanostructures on metal oxide by chemical vapor deposition (CVD) are observed at 750°C, using titania nanowire aerogel (NWAG) as a three-dimensional substrate and without metal catalysts. We temporally observe catalytic transformation of amorphous carbon patches into few-layer graphenes on the surface of the 5-10 nm diameter titania nanowires. The graphitization spontaneously terminates when the titania nanowires are encapsulated by a shell of approximately three graphene layers. Extended CVD time beyond the termination point (>1125 seconds) yields only additional amorphous carbon deposits on top of the few-layer graphene. Furthermore, it was discovered that amorphous carbon patches do not graphitize unless they grow beyond a threshold size 5-7 nm along the nanowire length, even after an extended thermal treatment. The electrical conductivity of the NWAG increased by four orders of magnitude, indicating that the graphene shell mediated by titania nanowires yielded an elaborate network of graphene patches throughout the complicated three-dimensional nanostructure of aerogel. Our results help us understand the growth mechanisms of fewlayer graphene on nanostructured metal oxide, and inspire a facile and controllable processing of metal oxide-nanocarbon fiber-shell composites.

Resume : A great deal of research effort has been devoted for the exploration of electrocatalysts for oxygen reduction reaction (ORR), since this reaction is a key process in fuel cells, metal-O2 batteries, photoelectrochemical cells, and so on. In this work, efficient manganese oxide-based ORR electrocatalysts are synthesized by a simple one-pot hydrothermal treatment with the anchoring of selenate anion (SeO42-). The anionic selenate clusters are anchored on the surface of a-MnO2 nanowire, leading to the weakening of (Mn-O) bond with the lowering of Mn oxidation state. Since the resulting elongation of (Mn-O) bond distance allows to enhance the interaction of a-MnO2 with oxygen species, the anchoring of selenate anion is advantageous in improving the ORR electrocatalyst activity of a-MnO2. Also, the immobilization of selenate cluster results in the improvement of charge transfer kinetics and the slight expansion of surface area. The present study clearly demonstrates that the anchoring of selenate anion is quite effective in exploring efficient ORR electrocatalysts.

Resume : The common 2D morphology and hydrophilic surface natures of exfoliated transition metal dichalcogenide (TMD) and transition metal oxide (TMO) nanosheets make possible the formation of homogenous colloidal mixture of these nanosheet materials. The obtained mixed colloids can be used as efficient precursor for intimately-coupled TMDTMO nanohybrids with improved functionality. In one instance, highly efficient noble metal-free electrocatalysts for hydrogen evolution reaction (HER) are synthesized by the restacking of MoS2 and MnO2 NSs with protons. The hybridization with MnO2 nanosheet is quite effective in enhancing the HER electrocatalyst activity of MoS2 with significant improvement of stability, which is attributable to the provision of more reactive MoS2 edge sites and enhanced charge transfer upon the addition of MnO2 nanosheet. The present result clearly demonstrates that the colloidal mixture of TMD and TMO nanosheets can be used as effective precursor for exploring high performance TMD-based hybrid materials.

Resume : The organic-inorganic hybrid perovskites hold the potential to revolutionize the field of energy and environment, owing to their remarkable light absorption and charge transfer properties. Methyl ammonium lead iodide (MAP), the most extensively studied candidate from the entire family of hybrid perovskites, has been in the limelight due to the ease of synthesis (crystals and films), band gap in the visible region of solar spectrum, high electron and hole mobilities in the system, all of which are the sought-after features for a potential photovoltaic material. A major disquiet for the field of hybrid perovskites, despite all the aforementioned advantages, is its susceptibility to degradation under ambient conditions- moisture, oxygen, and light, an aspect that poses a threat to its reputation. Several studies have focused on evaluating the degradation pathways of methyl ammonium lead triiodide and led to the conclusion that moisture, oxygen and light are the major culprits. Presented here will be our work where we have shown that other than the inherent chemical propensity of this material to undergo degradation due to the above mentioned parameters, another factor which is under-examined, is the substrate chosen for MAP deposition, i.e. the type and chemical nature of the photo-anode. Studies involving MAP deposition on FTO and different ‘types’ of TiO2 will be detailed. In addition to this we have also demonstrated a novel way to regenerate the desired MAP phase once the material degrades to an intermediate hydrated phase by using a simple and inexpensive chemical treatment of the degraded films using iodine, which we propose acts as a dehydrating agent to remove water from the hydrated degraded phase of MAP (on FTO and NW-FTO). Finally, due to the serious instability issues of perovskite, while the literature has shifted course from MAP to the perovskite compounds with altered anions, altered cations, mixed anions and mixed cations in an attempt to improve the stability, we have synthesized a hybrid material having the same stoichiometry, ABX3 as a perovskite material with the aim of introducing a bulkier organic cation A in place of smaller methyl ammonium for a structure with better symmetry and hence the stability. Our quantitative X-ray diffraction experiments done on imidazolium lead iodide (ImP) suggest its remarkable temporal stability over MAP under ambient conditions. ABX3 adopts a hexagonal unit cell structure as opposed to the cubic or tetragonal perovskite. We have fully characterized this new material in terms of its single crystal structure, thermal stability, ambient atmosphere stability, optical properties and established a systematic comparison with MAP.

Resume : An effective way to explore high performance electrode for supercapacitor is developed by employing exfoliated 2D layered MnO2 nanosheet as a hybridization matrix for Prussian blue (PB) material. The hybrid material of PB-layered MnO2 is synthesized by crystal growth of PB nanocrystal on the exfoliated MnO2 nanosheet at room temperature. Electron microscopic and spectroscopic analyses clearly demonstrate the homogeneous hybridization between PB and MnO2. The obtained PB-layered MnO2 nanohybrid shows expanded surface area than does the pristine PB material, reflecting the usefulness of hybridization with MnO2 nanosheet in increasing the porosity of PB material. Of prime importance is that the PB-MnO2 nanohybrid exhibits larger capacitances with better cyclability than does the MnO2 free-PB material. The present study clearly demonstrates that the hybridization with exfoliated metal oxide nanosheet is quite effective in improving the electrode performance of PB materials.

Resume : The great merits on alkaline electrolyzer regarding maturity, large capacity, and cost-effective features have drawn much attention as one of the applications for energy storage systems connected to the renewable energy sources such as the wind and solar. Compared to other water electrolysis technologies, alkaline water electrolysis is simple and mature technology but currently less efficient. Here, we will discuss improvements in alkaline water electrolyzers (AWE) by the significant interaction between engineering and material science disciplines. The challenges in material developments including electrodes and a separator to improve the cell performance and durability of alkaline electrolysis as advanced designs will be introduced.

Resume : The electrical conductivity and electromechanical stability of silicone rubber/silver nanocomposites have been improved by adding fillers such as silica particles and multi-walled carbon nanotubes (MWCNTs). With 18 vol% of silver nanoparticles, it was found that the electrical percolation network barely formed. When the silica particles increased up to 15 vol%, the electrical resistivity reached 3.0×10-3 Ω•cm, which is similar to the electrical resistivity at the percolation threshold without silica particles. However, the electromechanical stability results show that the silica particle is not an effective candidate for stretchability. With 15 vol% of silica particles, the resistance ratio (R/R0) of composites increased up to 10 at 30% strain. To improve the electromechanical stability, the MWCNTs were added up to 5 wt% in the silicone rubber/silver nanocomposites with 18 vol% of silver nanoparticles and the electrical resistivity showed 5.2×10-2 Ω•cm. Additionally, the nanocomposites with MWCNTs show an improved electromechanical stability. By adding MWCNTs, the resistance ratio increased to 1.8 as the mechanical strain increased to 30%. Also the resistance ratio of the composites with 10%, 20%, and 30% of strain was smaller than 1.5 after 1000 strain cycles. Experimental data show that MWCNTs prompted the electrical conductive network of silver nanoparticles in the composites. The electrical adhesives with 1-dimensional CNT could be utilized in various stretchable electronics.

Resume : Textile-based sensors are critical components of wearable devices due to its capability to perceive and respond to environmental stimuli in daily life. In this work, self-powered triboelectric wearable sensors have been fabricated based on polyvinylidene fluoride(PVDF) fibers stitched on the fabric by a sewing machine for the first time. With the high mechanical properties of as-spun PVDF fiber, a sewing machine can be utilized for the stitching of PVDF fibers on various fabric substrates. PVDF fiber stitches can provide remarkable triboelectric signals on the opposing surfaces of commercial fabrics such as cotton, nylon, and silk since PVDF has the high electron affinity compared to other spinnable polymers. Moreover, PVDF stitch-based triboelectric sensors are flexible, lightweight, and wearable as well as comfortable due to the all-stitched structures. For demonstrations in wearable devices, a smart glove and joint pads have been fabricated based on sewing machine stitching of PVDF fibers. These wearable stitching sensors enable the detection and discrimination of diverse hand gestures and body motions though the generation of intrinsic signal patterns depending on the specific hand gesture and body motions. The results of this work demonstrate the feasible fabrication approach of PVDF-based stitching sensor by sewing machine for detection of human biomechanical movements in cloth and garments.

Resume : Owing to increasing usages of electromagnetic devices, there has been a rapid growth in electronic and telecommunication industries which may cause serious electromagnetic pollution. Electromagnetic pollution not only disturbs the functioning of electromagnetic devices, but also alarms human’s health and may lead to serious disease such as leukemia and brain tumor. Here, we report lightweight activated carbon-NiZn nano ferrite composites with thickness of 1 mm performing excellent electromagnetic interference (EMI) shielding in the X-band (8.2-12.4 GHz). NiZn nano ferrite (NZF) powder was prepared by a simple sol-gel method followed by mixing with activated carbon in different weight ratios for desired electrical, magnetic and EMI shielding effectiveness. The thermogravimetric analysis revealed that the thermal stability of the composite materials increases with the weight percentage of the NZF powder. The vibrating sample magnetometer measurement confirmed that the saturation magnetization value (Ms) of composite materials enhances with the weight percentage of NZF powder which leads to enhanced magnetic loss of the EM wave. The EMI shielding of the composite material also increases with the weight percentage of the NZF powder, which is attributed to the enhanced magnetic properties, interfacial polarization and dielectric properties. The maximum EMI shielding effectiveness of the composite was measured to be -53 dB, which is dominated by the absorption of the EM wave. Hence, the composite can shield up to 99.999% power of the incident EM wave and can be suitable for the applications in defense and telecommunication.

Resume : Opal photonic crystals have been widely employed in materials science for various applications. Opal photonic thin films represent reflective colors by arrangement of the particles as FCC structures. In this study, we used anionically charged ZnS/SiO2 microspheres to fabricate opal films. For demonstration, we fabricated the opal film of the ZnS/SiO2 microspheres on the glass tiles. Such thin films showed specific reflective colors by constructive interference of light. In addition, we coated an inorganic binder upon the opal film to improve mechanical strength. Even with the inorganic binder at the interstitial spaces, strong diffraction of light was obtained because of the high refractive index of ZnS/SiO2 microsphere. Those tiles are expected to promise market-share in tile industry.

Resume : Nanospring shaped single wall CNTs (NS-CNTs) with the diameter of 20 ~ 30 nm was incorporated in PDMS dielectric elastomer generators (DEG) as nanofillers to increase of dielectric constant. Thin elastomeric films of PDMS with contents of NS-CNTs up to 11 wt% was fabricated by free standing casting method. DEG films coated with two compliant flexible electrodes. When properly charged these devices are able to convert mechanical into electrical energy. A disadvantage of the DEG devices which hinders some applications is the need of an external voltage source to charge them. For fabrication of an electret-based DEG that operates without an external voltage source, using the electret, a thin Teflon film will be used. The electret are dielectric materials that are in a quasi-permanent electric polarization state. This will be charged by using corona discharged equipment. To increase energy harvesting, the capacitance of DEG and strain rate of DEG are important factors. The output voltage of DEG with electret was greatly enhanced from 0.05 V to the value of 0.25 V, corresponding to a 500 % increase compared to neat PDMS. In addition, the strain rate is increased to 60 %, the output voltage increased about 200%.

Resume : Natural rubber is a key component of rubbery products, which are frequently subjected to high dyanmic loading conditions due to their excellent viscoelastic behaviour. Rubber generally are filled with varied filler types to improve its performance, which is called reinforcement. The main aspects influencing the rubber reinforcement are filler properties, filler-filler interactions, filler-polymer interactions as well as quality of filler dispersion. The most common applied filler is carbon black (CB), whereas advanced fillers based on carbon nanotubes (CNT) are very offten used becasue of their imporved behaviour e.g. high durability, high strength and low weight. Futurly the carbon based fillers are apllied due to their outstanding electric conductivity. The mechanical loading applied on the filled rubber, affects respective destroys the filler-filler and filler-polymer network, therefore the mechanical as well as electrical behaviour are influenced. This work is foccused on the preparation of NR based composites containing all common additives as well curatives, however varied content of hybrid fillers CNTx+CB30-x, where x = 0, 0.5, 1.0, 3.0 and 5 phr. Finally the effect of fatigue dynamic loading at tensile mode and different strains on electrical conductivity of rubber in dependence on varied content of hybrid filler CNT+CB has been studied and presented.

Resume : Core-shell nanostructure engineering has been proposed as a powerful and useful technology to fabricate functional materials for varying applications. In particular, plasmonic core-shell nanostructures with unique localized surface plasmon resonance, allowing surface-enhanced Raman scattering (SERS) occurred for an ultra-sensitive molecular-level detection. [1] Recently, graphene quantum dot (GQDs), a unique type of graphene derivatives, has stimulated a lot of attentions due to their exceptional properties including low toxicity, photostability, biocompatibility and excellent solubility. By coating a GQDs shell can significantly modify the optical properties and electronic structure. Moreover, bio-compatible Au nanostructures can generate great electromagnetic fields, leading a effective concentration of the incident light at the spatially narrow region around the nanostructures, providing a strong resonant behavior for SERS detection. Hence, the development of GQD/AuNP core-shell nanostructures can create a rational design of active materials for high sensitive SERS detection. However, the conventional approaches to prepare such nanohybrids are usually complicated, time consuming, inefficiency, and high temperature required. Here we demonstrate a rapid synthesis method of GQD/AuNP by using atmospheric-pressure microplasmas. Detailed microscopic and spectroscopic characterizations indicate that the morphology and size distribution of as-produced GQDs/AuNPs core-shell nanostructures can be controlled by changing the reaction conditions including initianl concentrations of GQD and Au presursor. Significantly, we found that the optical properities, especially the plasmonic properties, of the as-produced samples can be engineered by adjusting the dimentional ratio of core to shell of GQD/AuNP nanostructures. The systematic Raman study suggested that the GQDs/AuNPs heterostructures can performed as an effective material for SERS-based biomolecular sensing. References [1] J.-F. Li, Y.-J. Zhang, S.-Y. Ding, R. Panneerselvam and Z.-Q. Tian , Chem. Rev., 2017, 117, 5002−5069

Resume : With the increasing demand, synthesis of inorganic materials with controllable morphology has been predicted for material science research owing to their primal optical, electrical and catalytic properties. Continuous researches on morphology control have shown a dramatic change in materials behavior due to final structures and high surface area. This changeable behavior of material properties has opened the doorway in numerous fields. Nickel tungsten oxide (NiWO4) with 3-D structure attracted a great deal of technical and scientific attention for their wide use as reinforcing agents in photocatalytic, electro-catalytic and energy storage devices. Focusing on these concerns, three-dimensional (3D) flower-like controllable microstructures of NiWO4 were synthesized through surfactant free wet chemical method at low temperature (60 ºC). The wet chemical approach resulted in better yield as well as shortened reaction time and could challenge other renowned methods such as hydrothermal, solvothermal, sol-gel method etc. Interestingly, the uniform morphologies of NiWO4 could vary on the addition of hydrazine without surfactant in aqueous solution. By concluding, the probable mechanism behind the formation of flower-like microstructures was proposed with the aid of the scanning electron microscopy results. Through the thoughtful of the influence of the hydrazine, the morphology of NiWO4 is effectively designed, and this allows the advertising of the applicability of NiWO4 in different areas.

Resume : Photoelectrochemical water splitting has been considered as a promising route for hydrogen production using solar energy since the discovery of electrochemical photolysis of water by TiO2 in 1972. However, TiO2 has relatively wide energy band gap ca. 3.2 eV makes titania photoactive only under UV illumination. Thus, searching for efficient and stable photoelectrode materials is still the interest of research groups working on PEC water splitting. Among candidate of semiconductors, BiVO4 has been regarded as a robust and inexpensive photocatalyst for PEC water oxidation due to its moderate bandgap (2.4 eV). However, the very low charge-carrier mobility does not allow charge-carriers to be effectively separated. Various strategies have been investigated to improve the photocatalytical properties of BiVO4, e.g. doping, coupling BiVO4 with other semiconductors or noble metal decoration. The combination of MoO3 and BiVO4 leads to the formation of a composite photocatalyst characterized by higher photoactvity. It was recently demonstrated that the formation of heterojunctions obtained by coupling one semiconductor with another can the photogenerated electron–hole pairs separation and therefore inhibit their recombination. In this work, bismuth BiVO4 with thin films of MoO3 were photoelectrochemically characterized as photoanodes for water photooxidation. MS acknowledges the National Science Centre of Poland, NCN, for financial support under contract no 2016/23/N/ST5/02071.

Resume : Sn based anode materials (SnO2, SnS2 etc.) have been received much attentions as the anode materials of lithium ion batteries (LIBs) due to the large capacity, low cost, high abundance and relative low charge-discharge plateau compared to other candidates. However, Sn based anodes are severely limited by the irreversible reaction during the delithiation process induced large portion capacity loss, relative low effective capacity and initial coulombic efficiency (CE). In this work, we have selected several catalysts to promote the conversion reaction of Sn to SnO2 or SnS2 which is commonly deemed as an irreversible reaction during the delithiation process. For example, Co3O4, GeO2 nanoparticles are designed for SnO2 system, and MoS2 for SnS2 system. The designed hybrid nanocomposites, named as SnO2/Co3O4/reduced-graphene-oxide (rGO), SnO2/GeO2/rGO, SnS2/MoS2/3DG were synthesized by one or two steps of hydrothermal and/or solvothermal synthesis processes. Compared to the pristine SnO2/rGO and SnS2/3DG, our designed hybrid structures exhibit greatly enhanced electrochemical performance in terms of specific capacity, cycling stability, rate capability, as well as initial CE. Through detailed TEM or XPS analysis, the excellent electrochemical performance of the hybrid nanocomposites was attributed to the catalytic effect of catalyst (Co3O4, GeO2 or MoS2 nanocomposites) to promote the conversion of Sn to SnO2 or SnS2 and the Li2O or Li2S decomposition during the delithiation process. Based on the results, we propose a new route to increase the capacity of alloying-dealloying type anode material to beyond its theoretical value and enhance the electrochemical performance by using catalysts. The proposed mechanism may open up a new avenue for high performance anode material design for LIBs.

Resume : SiOx/C nanofibers with diameters of (300–400 nm) were fabricated using type I electrospun hybrid fibers of polyacrylonitrile (PAN) and SiOx as a precursor. The SiOx content in the hybrid fibermat could be well controlled via adjusting the ratio of tetraethoxysilane (TEOS) to PAN and adjusting the amount of acidic catalyst (HCl) in the precursor solution. The amount of SiOx in the hybrid fibermat was measured via thermogravimetry (TG) and the highest spinnable amount for this system was found to be ~ 27 wt.% which leads to formation of a flexible carbon nanofibermat of ~ 53 wt.% SiOx after having been pyrrolized under Ar atmosphere at 800°C. Free-standing carbon nanofibermats (with no binder or conductive additive) were tested electrochemically in a half-cell via cyclic voltammetry and constant-current charge-discharge. It was found that the 53 wt.% SiOx shows an initial specific discharge capacity of 816 mAh g-1 while being tested under a 100 mA g-1 current density and this specific capacity reduces to ~ 500 mAh g-1 in the next cycles.

Resume : Integration of many techniques into a compact platform has become a trend in nanotechnology and still has many interesting combinations to be explored, allowing a great technological advance and also the fabrication of new multifunctional materials. The main goal of this research is the characterization of area selective atomic layer deposition (ALD) with molecular control over size dimensions for novel nanostructured materials synthesized from graphene (Gr) and reduced graphene oxide (rGO). For this, a combination of cutting edge methods in nanofabrication for advanced applications is used. The use of Gr/rGO as a platform for nanodevices, sources for energy storage, gas, strain and magnetic sensors are just an example of this integration. In a standard procedure, we fixed the Gr/rGO inside a mini-reactor equipped with gas input/output channels providing precise flow control and low gas consumption. Subsequently, the assembly was moved into a dedicated scanning electron microscopy for electron beam induced deposition (FEBID) used as the patterning method for nanodecoration of graphene with a thin Cu and Pd layers. These deposits are seed layers and, when properly treated with purification methods, are catalytic layers for ALD nucleation. This integration of different technological processes in one place transformed“standard” equipment into a nanoscale direct-write platform for molecular control of nanofabrication.

Resume : Porous polymeric composites are widely used in many applications due to their characteristic properties such as lightweight, superior thermal insulation, high energy/sound absorbing abilities, low thermal conductivity, and large compressive strains. Specially, thermal insulating porous polymeric composites have been paid much attention on building materials, aerospace and aviation industry, and oil and gas industry. The heat transfer process in polymeric composites with porous structure is very complicated, and includes gas conduction, solid conduction and radiation. Convection can be neglected when the pores in polymeric composites are smaller than 4 mm in diameter. At low application temperature which is general condition for polymeric composites, the radiation can also be considered to be negligible. Researcher used hollow microspheres for various high performance structural foam materials. In this study we study the thermal insulation and thermomechanical properties of polymeric composites prepared using polymeric expanded and hollow glass microspheres, respectively. A one-step bulk polymerization was used to prepare porous hybrid multi-block polyurethane composites. This study carries out comparative research on porous polymeric composites filled with expanded organic and hollow glass microspheres. Tensile and compression tests have also been carried out for both composites. Details of the synthesis, thermal insulation and thermomechanical characterization are presented in this study.

Resume : Molybdenum disulfide (MoS2) is a layered transition-metal dichalcogenide (TMD) which has attracted huge interests for energy conversion and storage applications due to its interesting physical-chemical properties coupled with the possibility of obtaining 2D nanostructures. MoS2 exists in three different polytypes (stable 2H, meta-stable 1T and 3R). Recently, the synthesis of hybrid materials containing both the metallic 1T and the semiconducting 2H phases was investigated for hydrogen evolution reaction (HER) electrocatalyst and supercapacitor applications. In this work, we report a one-pot hydrothermal synthesis, with low environmental impact, of mixed 1T-2H few-layer MoS2 nanoflakes starting from phosphomolybdic acid and L-cysteine as Mo and S precursors, respectively. The complete morphological and structural characterization of the synthesized MoS2 has been performed by means of Raman Spectroscopy, X-Ray Diffraction, Field-Emission Scanning Electron Microscopy, and Transmission Electron Microscopy in comparison with commercially available 2H-MoS2 powder. Then, the thermal conversion of the 1T MoS2 on 2H MoS2 will be highlighted by means of X-ray Photoelectron Spectroscopy due to the possibility to quantify the relative amount of 1T and 2H phase. This controlled conversion allows to obtain materials with tailored electrochemical properties: the 1T-2H nanoflakes provide larger capacitance values and better catalytic performance towards HER when compared with full semiconductor phase.

Resume : As a result of rapid advances in nanoscience, Au and Ti evoke much interest in many application areas, especially in medicine. This is due to chemical inertness, high electrical conductivity, stability as well as biocompatibility and non-cytotoxicity. Moreover, Au exhibits activity towards detection of such biologically important molecules as proteins, nucleic acids or carbohydrates. In here, we demonstrate that dimpled Ti foil covered with Au nanoparticles (NPs) shows enhanced response for glucose oxidation when exposed to solar light compared to the dark conditions. Structured Ti foil has been produced in the process of anodization followed by chemical etching. The AFM inspection confirms formation of inverted caps with average diameter and depth estimated to be ca. 100 and 15 nm, respectively. Subsequently, ultrathin Au layers (up to 10 nm) have been deposited onto prepared substrate and then thermally dewetted by a pulsed laser at 266 nm. Different heterostructure morphologies, i.e. one NP or many NPs per dimple were observed depending on the laser processing parameters. Electrochemical measurements performed in the presence of glucose, confirmed that such substrates can be used as the sugar detection platforms. Moreover, it has been found that the electrochemical response of prepared material exposed to solar radiation is markedly higher (up to 50%) than the one observed in dark conditions. This work is financed by NCBR Poland via grant no LIDER/2/0003/L-8/16/NCBR/2017.

Resume : Natural composite materials show superior mechanical properties compared to its pure constituents, which is attributed to the specific arrangement of the components. Using a biomimetic approach, artificial materials have been fabricated showing a significant improvement of mechanical strength. These structures often possess a layered structure consisting of alternating layers of polymeric or organic material and minerals or ceramics. In our study, we fabricate a layered hybrid structure with M13 wild type phages as organic and ZnO as inorganic component. Using the convective assembly technique for phage deposition followed by deposition of ZnO particles from a deposition solution, multilayer samples were formed. For reference a monolayer of ZnO and a monolayer of phages was deposited on a Si substrate. In order to relate microstructure, mechanical properties and deformation mechanisms in the multilayer system, SEM and TEM imaging, and nanoindentation testing have been performed. SEM and TEM investigations revealed an alternating structure with uniform layer thicknesses and limited amount of interpenetration. The phage layers were ~20 nm thick; the thicknesses of ZnO layers varied between ~30 nm up to 800 nm. The grain size of the particles reached from 15 to 40 nm. In nanoindentation testing, a decrease in modulus, hardness as well as fracture toughness with increasing number of phage layers was found. These findings will be explained and discussed in detail.

Resume : The kinetic trends and the limiting step in the hydrolysis and condensation reactions for synthesizing hybrid materials by the sol-gel process remains controversial, which limits the understanding of the overall mechanism and further optimization of the properties of hybrid xerogels. Here we present a mathematical model for the kinetics for the hydrolysis and first condensation steps of alkyltriethoxysilanes (RTEOS, R = methyl, ethyl or propyl) that (a) describes the evolution of the structural intermediates formed during hydrolysis and first condensation steps as measured by 29Si NMR, (b) fits the quantitative kinetic data to model the reactions, and (c) provides the rate constants the and activation energy for the hydrolysis and initial condensation reactions for each alkyltriethoxysilane. For each hybrid precursor, the system can be described according to eleven parameters, five of the corresponding to the kinetic constants at 298.2 K, five to the activation energies, and one to the equilibrium constant for the third hydrolysis, which has been shown to be constant in the range of experimental temperature. Under excess water, the limiting step is the beginning of the condensation from fully hydrolyzed species, RSi(OH)3, whose concentration is controlled by the reversible hydrolysis of RSi(OC2H5)(OH)2 and the first condensation of RSi(OH)3 to form a dimer.

Resume : In this study, we investigate the kinetic efficiency of Ni-Fe and Ni-Al electrodes prepared by Physical Vapor Deposition(PVD) for Oxygen Evolution Reaction(OER) and Hydrogen Evolution Reaction(HER) in alkaline water electrolysis(AWE), respectively. First, Ni-Fe(or Al) intermetallic phase formed on Ni substrates by PVD, and then the heat treatment at 883 K followed by selective leaching of Al in 30% KOH from Ni-Al intermetallic phases was performed to produce higher active sites. XRD and SEM analysis results confirmed the Ni-Fe(or Al) intermetallic phases and porous structures of the Ni-Al electrodes. Electrochemical analyses such as cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy were also evaluated to understand the OER/ HER activity of the Ni-Fe and Ni-Al electrodes. As the presence of Fe increases the electrical conductivity and also redox properties of Ni, 100-fold OER activity enhancement over Ni electrode that can be achieved by Ni-Fe co-deposited electrodes in 1 M KOH. Also, electro-activity of the porous Ni-Al electrodes toward HER has exhibited high-performance, as 10-fold HER activity improvement over Ni. Furthermore, the AWE single cell with the Ni-Fe anodes and the Ni-Al cathodes will be discussed to correlate ex-situ OER/HER results and in-situ performance of AWE.

Resume : ZnO is an oxide semiconductor which is used in a very extensive domains of industrial applications such as catalysis (e.g. tyres vulcanization), antibacterial coating, UV sun screen formulations… These applications require high specific surface area (nanometric materials) and the development of reproducible, efficient and easy-scalable industrial production processes. Our recent patented industry-capable (in terms of legislation concerns) and cost effective chemical solution approach (PCT WO 2016/038317 A1) led to mesospheric self-assembly hybrid ZnO-PAA nanomaterials (PAA = polyacrylic acid) that can be used as original nanostructured and very high surface area ZnO support (>100m²/g). Herein, we will address the use of such self-assembly nanostructured ZnO materials as support of Cu(0) NPs for the catalytic hydrogenolysis of glycerol into 1.2 propanediol. We will demonstrate how and why optimizations of (i) the set-up of the synthesis (reaction and washing steps), (ii) the molecular weight of the commercial polymers PAAH and PAANa (1800-250000) and the ratio of their mixture, (iii) the temperature of the calcination of the self-assembly hybrid ZnO-PAA system, (iv) the conditions of deposit and reduction steps (in relation with the Cu content) lead to Cu-ZnO with remarkable high surface area and better catalytic performance than commercial ones. We will also extend the chemistry of such catalytic system to others metals NPs such as Pt, Pd …

Resume : We report on an innovative filter made from a natural material for the treatment of water. Membrane science is being implemented more and more and on a bigger scale. Thus, there is a real need for alternative technologies regarding their production. For this purpose, a bio-sourced material, beech wood, is used in this project. Indeed, this lightweight material has got good mechanical properties and its vascular network is designed for the transport of water from roots to leaves. Raw wood contains hydroxyl groups, which can trap dissolved metallic ions, but in order to improve this intrinsic property of the material, beech wood is chemically modified. We can attach active compounds using the –OH groups as an anchor. The chemical modification allows us bringing in new functionalities. In our study, we focus on the development of a product which can be used in a close contact with living beings. The wood membrane can act both as a filter and as an adsorbent. Its capacity to be implemented in a water treatment process is investigated with particulate matters and dissolved copper ions. We have shown that modification of wood is a necessary step for the uptake of metal ions and we are able to remove up to 14mgCu/g of dissolved copper in a batch process. We have observed that natural wood is capable of efficiently removing particles of size 20μm in a continuous process. Thus, the membrane could be implemented as a pre-filter in a water stream. The study aims to give rise to a competitive product made from wood. This research will give new insights on innovative applications of lignocellulosic materials.

Resume : Metal-organic frameworks (MOFs) are a chemically and topologically diverse family of porous materials composed of inorganic nodes (SBU) and organic linkers bound together by coordination bonds. MOF applications include gas separation and storage, sensing, catalysis, and bio-applications. For the construction of MOFs di-, tri-, and tetra-valent carboxylic acids are most often used as the linkers. A crucial limiting factor for most available MOFs is their low stability in aqueous media. Hydrothermally stable carboxylic acid based MOFs contain trivalent or tetravalent cations (Al(III), Cr(III), or Zr(IV)), however, even from those “stable” MOFs only few can withstand boiling water without the loss of porosity. We have successfully synthesized new series of isoreticular MOFs based on trivalent metal cations, namely Fe3+ and Al3+ and aromatic bisphosphinic acids as linker molecules. We demonstrate that some structures can stand even 24 h of boiling water without significant loss of porosity. The structures of obtained materials were solved ab-initio employing electron diffraction tomography which allowed even localization of hydrogen atoms in some cases. Our results confirm that multidentate phosphinic acids are promising linker molecules for construction of stable MOFs.

Resume : Hybrid perovskites like methylammonium (MA) lead iodide (MAPbI3) and bromide (MAPbBr3) have triggered intense activity in photovoltaics, with solar cells reaching efficiencies over 20%. Such a performance was attained partly by optimizing relative concentrations of halides and adding another cation to the equation, formamidinium (FA) [1]. Recently, the interplay between the vibrational spectrum and the dynamic disorder caused by the organic cations has been studied by Raman in MAPbI3 and MAPbBr3 as function of temperature [2]. In both cases, a drastic reduction of the inhomogeneous broadening of the inorganic cage phonons was observed at the tetragonal-orthorhombic phase transition occurring at about 160 K. Here we present a combined photoluminescence (PL) and Raman study of temperature-induced phase transitions of single crystals with formula MAxFA1-xPbI3 for compositions x=0.1 to 1 and temperatures between 10 K and 365 K. The strong free-exciton PL of the perovskites usually exhibits discontinuous changes in the energy of its maximum at different structural transitions, indicating concomitant changes in the electronic structure of the material. At low temperatures, the strong decrease in linewidth allows for the observation of impurity-related bound excitons and donor-acceptor pair recombination processes. The reduction of the Raman line broadening, in spite of being less marked for high FA content, is used to assess the occurrence of the transition to an orthorhombic phase.

Resume : Secondary battery is an essential part of modern society including electric vehicles, portable electronic devices and energy storage system for green energy. Lithium-ion battery(LIB) has dominated the rechargeable battery market due to its excellent energy and power density. However, some problems of LIB have been raised such as a limited resource, increasing cost and safety. Recently, aluminum-ion battery(AIB) is a promising candidate for next energy storage device owing to the natural abundance, low cost, non-flammability, and superior theoretical capacity (2235 mAh/g) based on three-electron redox property of aluminum. However, development of AIB system has been hindered by lack of suitable electrolytes and cathodes, and low energy. Lin et al. reported a remarkable cell performance using pyrolytic graphite foil as a cathode in ionic liquid at room temperature. However, research of these promising candidate is still challenging. Especially, a current collector plays an important part in rechargeable batteries which has to satisfy several requirements; mechanical strength, chemical and electrochemical stability in electrolyte and acceptability to active material. However, a few reports have been investigated concerning the electrochemical characteristics of the current collector for aluminum-ion battery. In this work, we investigated the electrochemical and chemical behaviors of metallic current collectors in aluminum-ion battery with acidic ionic liquid formed by mixing [EMIM]Cl and AlCl3 and graphite powder as a cathode. Through cyclic voltammetry (CV) and charge/discharge cycling test, we compared and analyzed the corrosive property of nickel, molybdenum and tungsten. Furthermore, the chemical stability of metallic current collectors was investigated by dipping in electrolyte. The physicochemical characteristics of metallic current collectors were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS).

Resume : Resistive switching effect has been explored in the hybrid nanocomposite of organic-inorganic materials by fabricating memristive device on a flexible PET substrate. Graphene and MoS2 assembly was incorporated as inorganic filler in the PMMA organic matrix. Configuration of as fabricated device is Cu/gMoS2-PMMA/ITO, which showed bipolar, nonvolatile and rewritable memory behavior at low operating voltage. A high off/on ratio, endurance and retention time were recorded without any substantial change in either HRS or LRS. Electrical characterization, when tested against several bending cycles, showed excellent durability and mechanical strength. The results broaden and deepen the understanding of memory phenomena in hybrid nanocomposites of 2D materials and polymers.

Resume : Magnetic and electroactive organic molecules constitute an attractive platform for both molecular electronics and spintronics. When these molecules are integrated between electrodes, the modest stability and reproducibility of the electrode/molecule contact constitute important obstacles for the progress of this research field. Here, we report on the synthesis of two new stable free organic radicals consisting of a perchlorotriphenylmethyl (PTM) unit, which holds the unpaired electron bearing one and two terminal alkyne groups to form Au-C σ bonds. The formation and stability of self-assembled monolayers and the electron transport through single-molecule junctions at room temperature have been studied. Combined analysis of the obtained results from both molecule/electrode systems demonstrates the formation of a robust covalent bond with gold through the alkyne linker, as well as a better-defined contact in comparison to classical sulfur-based linkers.[1] Furthermore, density functional theory and quantum transport calculations support the experimental observation remarking a low variability of conductance values for the C-Au based junction. The findings in our work suppose an important advance regarding the robustness and reproducibility in the preparation of devices based on electroactive molecules. [1] Bejarano, F., Crivillers, N. et. al. J. Am. Chem. Soc. 2018 DOI: 10.1021/jacs.7b10019

Resume : Despite the recent promise of transition metal carbides as non-precious catalysts for hydrogen evolution reaction (HER), their extension to oxygen evolution reaction (OER) in order to achieve the goal of overall water splitting remains a significant challenge. Herein, a new Ni/MoxC (MoC, Mo2C) nanoparticles supported N-doped graphene/CNT hybrid (NC) catalyst is developed via a facile, one-step integrated strategy which can catalyze both the HER and OER in an efficient and robust manner. The catalyst affords low overpotentials of 162 and 328 mV to achieve a current density of 10 mA/cm2 for HER and OER, respectively, in an alkaline medium which either compares favourably or exceeds most of the Mo-based catalysts documented in the literature. The electronic synergistic effect between MoxC, Ni and NC are responsible for the higher electrocatalytic activity wherein, a tandem electron transfer process yields both excellent HER and OER activity. This work opens a new avenue towards the development of a multi-component, highly efficient but inexpensive catalyst for overall water splitting.

Resume : We controlled the specific surface area and porosity of layered double hydroxides and its derivatives – calcined or reconstructed materials – utilizing protein template. In previous studies, we investigated the specific surface area of MgAl-CO3-LDH having crystallite size less than 10 nm increase upon calcination and reconstruction; whereas the porosity was not discretely defined in that LDH, calcined one and reconstructed one. In this study, in order to incorporate ordered porosity and to increase specific surface area, we introduced albumin which has size dimension ~ 5 nm during coprecipitation of LDH. Then the LDH was calcined to remove albumin template to introduce nanopores then reconstructed under the presence of albumin. Coprecipitation-calcination-reconstruction cycle was repeated and the specific surface area and porosity was fairly controlled. The starting LDH with albumin template showed specific surface area of 58 m2/g; however, the calcined ones had enhanced values of 119 and 208 m2/g for first and second cycle, respectively. The mean pore size showed decreasing tendency from 24 to 14 nm upon repeated calcination cycle, while the pore volume was fairly preserved regardless of cycle number. In order to explain the structural and chemical parameters affecting porosity of specific surface area, we measured powder X-ray diffraction, scanning electron microscopy and 27Al magic angle spinning nuclear magnetic resonance spectra.

Resume : In order to maintain and to have efficacy in sustained manner, we immobilized anionic antibiotic, levofloxacin (LFC), into layered double hydroxide (LDH). To find an optimum synthesis condition for LFC-LDH nanohybrid, two well-known hybridization methods, ion-exchange reaction and reconstruction, were carried out. According to X-ray diffraction patterns, ion-exchange reaction utilizing MgAl-NO3-LDH did not show effective immobilization of LFC molecule in their interlayer space. Although the nanohybrid obtained with reconstruction method did not exhibit layer expansion of LDH in X-ray diffraction, they formed sand-rose structure in which inter-particle cavity served as drug immobilization site. According to the elemental analysis, the maximum drug loading capacity for LFC-LDH was 41.7 wt/wt%. In order to comprehend the drug loading mechanism, we examined adsorption isotherm depending on drug concentration while the amount of LDH was fixed. Then, the LFC-LDH nanohybrid with maximum drug loading was subjected to time-dependent LFC release test in various media such as deionized water and saline media with or without fetal bovine serum supplement. Then the antibacterial efficacies of LFC-LDH and equimolar LFC were compared at various drug concentration in both gram positive, Bacillus subtilis and gram negative, Escherichia coli bacteria.

Resume : In semimagnetic or diluted magnetic semiconductors, the strong spin-spin interactions between band electrons and localized magnetic ions lead to a host of entirely new magnetooptical physical phenomena, such as giant Faraday, giant Kerr, photoinduced magnetization effects, whicht was first demonstrated in Hg1−xMnxTe by Krenn [1].We measured temperature dependencies of magnetization and temperature and angle dependencies of ESR spectra Hg1−xMnxTe from 5 to 300K. We investigated the crystal MHT by ESR method on spectrometer Varian E12, Bruker EMX CW and magnetization using PPMS-9. In the paramagneticstate, electron-spin resonance reveals a single exchange-narrowed resonance line with a g value near 2.0 due to all Mn2+ ions. A strongly exchange-coupled magnetic system such as MnHgTe can be described by the Hamiltonian, where the first term describes the superexchange interaction between two next-neighbor Mn spins with coupling constant J. The second term describes the Zeeman splitting. The third term Hint includes all interactions, which do not conserve the total spin and, therefore, contribute to the broadening of the ESR line. These are the crystal field, anisotropic exchange, and hyperfine interactions. We estimated these parameters from angular dependencies of ESR linewidth in three crystallographic planes. We investigated the dependencies of magnetic properties Hg1−xMnxTe from manganese concentration. [1] H. Krenn, W. Zawadzki, and G. Bauer, Phys. Rev. Lett. 55, 1510 (1985)

Resume : The detection of NO2 has been a critical issue and significant challenge for environmental protection. The advantages of traditional NO2 sensors based on metal oxide semiconductor (MOS), such as SnO2, In2O3, ZnO, etc, are high sensitivity and selectivity. Unfortunately, a huge drawback dramatically limits the application of MOS sensors: the high operation temperatures (typically 200-600℃). To lower energy consumption, NO2 sensor working at room temperature has been needed imperatively. A two-step hydrothermal synthesis approach was used to prepare N-doped reduced graphene oxide (N-rGO) anchored with ZnO nanoparticles for NO2 sensing at room temperature. N-rGO was achieved by using NH4OH as the N source, and controlled nucleation of ZnO on graphene oxide sheets was obtained by reducing the hydrolysis rate of Zn(OAc)2 based on adjusting the ethanol/H2O ratio and temperature. The size of ZnO nanoparticles is controlled to about 10nm. Attribute to the synergistic effect between ZnO and N-rGO, room temperature NO2 sensing performance of these hybrid materials is significantly improved in response and selectivity perspectives compared with the solo ZnO nanoparticles and the reduced graphene oxide.

Resume : Gallium selenide (GaSe) from a class of two-dimensional layered semiconductors is a promising material for usage in THz electronics, as the basis of various optoelectronic devices, a matrix for hydrogen storage, substrates in planar nanotechnologies, etc. Recently we have made a forecast concerning perspectiveness to use GaSe in oncology. Unlike photodynamic therapy for cancer when photosensitizers (porphyrins, chlorines or dyes) in conjunction with tissue O2 under high intensity light illumination produce strong oxidant - highly cytotoxic synglet oxygen to destroy a cancerous growth, GaSe in conjunction with tissue water (usually tumor tissues contain an excess of water in comparison to normal ones) under day light illumination interacts with H2O with formation of other strong oxidants - selenous and selenic acids. Here we discuss a mechanism of light-induced interaction of GaSe with water using a model based on peculiarities of gallium selenide crystallographic structure and different types of internal defects. Because the interaction of GaSe and H2O is initiated on the atomically smooth and inertness van der Waals surface (0001) of this material (but not on the lateral surfaces of GaSe nanoblocs with high concentration of surface states) the necessity to obtain nano-particles with mechanically undamaged (0001) surface for specific application is emphasized.

Resume : A versatile preparation route of functional ordered mesoporous materials will be described. It relies on the use of assemblies of hydrophilic diblock copolymers, in place of classical amphiphilic templates, as new structuring and functionalizing agents for the direct synthesis, at room temperature and in water, of polymer-functionalized mesoporous silica. The new structuring agents are dynamic PolyIon electrostatic Complex (PIC) micelles formed between double-hydrophilic-block-copolymers (DHBC) (constituted of a neutral block and an ionizable one) and an oppositely charged homopolyelectrolyte that serves as an auxiliary of micellization of DHBC polymers. The different advantages of using PIC micelles are the following: due to their sensitivity to physicochemical parameters, PIC micelles allowed the formation of various hybrid mesophases (cubic, 2D-hexagonal, lamellar...) by simply adjusting the synthesis conditions using a unique DHBC/homopolyelectrolyte system. This is due to the adjustable characteristics (composition, water content) of the polyion complex phase. The micellization process can be controlled by the pH or ionic strength, it is reversible in water and allows the recovery of the porogen polymers. Thus, the use of PIC micelles permitted the direct preparation of polymer-functionalized mesopores. This was possible due to the dissociation of the polyion complex within the pores, selectively releasing the auxiliary of micellization while the DHBC remained for functionalizing the pores. This new method ensures an homogeneous functionalization of the mesopores, a control of the functional polymer chain lengths and a high mesoporous volume. Moreover, the properties of the functional chains could be varied (acid, basic, metal-complexing...). Studies are under way to estimate the catalytic performances of the new functional materials. [1] C. Gérardin, J. Reboul, M. Bonne and B. Lebeau, Chem. Soc. Rev., 42, 4217 (2013). [2] E. Molina, J. Warnant, M. Mathonnat, M. Bathfield, M. In, D. Laurencin, C. Jérôme, P. Lacroix-Desmazes, N. Marcotte, and C. Gérardin Langmuir 31 (47), 12839 (2015). [3]. M. Bathfield, J. Reboul, T. Cacciaguerra, P. Lacroix-Desmazes, and C. Gérardin Chem. Mater. 28 (10), pp 3374 (2016). [4]. D. Houssein, J. Warnant, E. Molina, T. Cacciaguerra, C. Gérardin, N. Marcotte Microporous and Mesoporous Materials 239, 244 (2017).

Resume : Metallic networks or meshes are often claimed as promising alternative electrodes for various opto-electronic devices, such as solar cells. In this work, we explore possible advantages of integrating Ag fibre-composed meshes in flexible CIGS solar cells. A woven mesh of Ag fibres was fabricated on PET substrates by a draw-spun procedure followed with UV illumination and millisecond xenon lamp treatment. A sheet resistance of 17 Ohm/squ and optical transmittance of ca. 90% were measured for the developed Ag meshes. This conductive Ag mesh was integrated into four series of flexible CIGS cells with a thickness variation of Al-doped zinc oxide (AZO) layer ranging from 0 nm, 50 nm, 200 nm to 900 nm. The results indicate that, the layer of Ag mesh is not able to function as an efficient current collector alone as compared with the reference cell with 200 nm AZO layer. In the case of CIGS cell with a thin AZO layer (50 nm), the presence of Ag mesh can improve the fill factor, from 58% to 67%, while maintaining the similar open voltage and current density values. The reduced thickness of AZO layer helps to reduce parasitic absorption; however, the gain is partially weakened by the shadowing effect of Ag meshes. The difference of cell stability under a range of strain ratios up to 3%, with and without the integration of Ag mesh, will also be presented.

Resume : Using a two-step approach based on pulsed laser ablation in liquids, we prepared a colloid of Ag nanoparticles (AgNPs) with the purpose of application as an eye drops model. The beam of appropriate fluence at the fundamental wavelength ( = 064 nm) of a Nd:YAG laser system (repetition rate 10 Hz, pulse duration 15 ns) was directed to a Ag target immersed in double-distilled water to produce the original colloid. Histograms of the micrographs obtained by transmission electron microscopy showed that the mean size of the nanoparticles so created was close to but above 10 nm. No particle size over this value is necessary to be present in the colloid to make it suitable for the purpose chosen. The original colloid was additionally irradiated by an unfocused laser beam of appropriate energy and duration to reduce the nanoparticle size and modulate its distribution. The optical extinction spectrum of the original colloid in the UV and visible ranges demonstrated the presence of a plasmonic band typical for the AgNPs colloids. We also found that the third harmonic (THG = 355 nm) of the laser system used lying within this band is the wavelength for the most effective post-ablation treatment achieving the AgNPs size desired. The AgNPs colloid’s toxic effect on Candida, gram-positive and gram-negative bacteria was also studied and established.

Resume : Using atomic force microscopy (AFM) one can discern the different components of a membrane-electrode-assembly (MEA). Especially in the electrodes, which consist of catalyst, support materials and ionomer binder, the distribution of these components affects MEA performance and degradation rates. Electrodes prepared from three different solvents were investigated with material-sensitive and conductive AFM. With AFM the ionomer phase, which can be distinguished from the catalyst by its higher deformability and adhesion, was analyzed. Furthermore, conductivity mappings were correlated with the nanomechanical properties measured by AFM. The conductive area fractions follow the same slope as the current revealed by the polarization measurements. As confirmation, SEM measurements and EDX mappings of the F-content were performed. Segmented printed circuit board-operated electrolyser MEAs were analyzed by SEM and AFM. Higher concentration of Nickel detected in the electrodes and the membrane correlates with the lower current density of the segments and indicates a higher degradation of the MEA. At these segments, membrane degradation was also detected with AFM with surface potential and stiffness mappings.

Resume : The existence of amine functionalities in ordered hybrid materials is quite attractive in a wide variety of areas, such as base catalysis coupling, immobilization of functional molecules and biomolecules, drug delivery, and chemosensing, among others. In this work, amine-functionalized bridged silsesquioxanes (BSs) were synthesized from bis[(3-trimethoxysilyl)propyl] amine via a solvent-mediated route. Four samples (BS-1, BS-2, BS-3 and BS-4) were prepared using optimized amounts of binary or ternary mixtures of three solvents (water, ethanol and THF) in the absence of a catalyst, or in the presence of a base or an acid. The different conditions tested resulted in different morphologies: transparent films or white powders. Face-to-face stacking of flat or folded lamellae yielded quasi-hydrophobic platelets or superhydrophilic onion-like nanoparticles. While BS-1 and BS-2 exhibited emission quantum yields of 0.05±0.01, exciting emission quantum yields of 0.38±0.03 and 0.33±0.04 were found for BS-3 and BS-4, respectively. The latter two values are the largest ever reported for amine-functionalized siloxane-based hybrids lacking aromatic groups. Fast Grotthus proton hopping between =NH2+/=NH groups (BS-3) and =N-/=NH groups (BS-4), promoted by H+ and OH- ions, respectively, and aided by short amine-amine contacts provided by the onion-like morphology, account for this unique optical behavior.

Resume : Hydrogen is an alternative and ideal energy source to overcome the future energy demands without contribution to the greenhouse effect. Recently, it is widely extracted from the fossil fuel resources with harmful byproducts.[1] So, for the clean H2 production we need alternative and cost effective methods. Among all, the H2 generation via water splitting received great attention, because the water electrolysis technology produces the pure H2 from the earth-abundant resource of H2O without any harmful byproducts.[2] To date, it is highly challenging to separate the hydrogen efficiently from H2O. Herein, we developed the low-cost metal chalcogenide electrodes of NiCo2S4 and Ni3Se2 on 3D-porous nickel foam (NF) support to enhance the utilization of active areas and fast gas bubbles ejections by using in-situ hydrothermal method.[3] Also, the NF acts as good and stable current collector to enhance the electron movements during the water electrolysis. The properties of as-prepared electrodes have been studied using various physicochemical analyses, including the SEM, TEM and XPS. In electrochemical water splitting, the NiCo2S4 /NF electrode exhibits the OER overpotential of 260 mV at 10 mA cm-2, comparatively the Ni3Se2/NF electrode shows lower water oxidation overpotential of 310 mV even at 10 mA cm-2.. In water reduction, the NiCo2S4/NF electrode requires the overpotential of 210 mV to attain the cathode current density of 10 mA cm-2. Furthermore, Ni3Se2/NF electrode shows the ultra-durability of 350 h without any major voltage loss at an OER current density of 100 mA cm-2. Accordingly, to check their real water electrolysis ability we assemble the porotype two electrode alkaline water electrolyzer using two different metal chalcogenide electrodes. Interestingly, the constructed electrolyzer produces the overall water splitting current density of 10 mA cm-2 at the cell voltage of 1.65 V than the commercial water electrolyzer (~2.0 V), and the hydrogen gas has been continuously produced over 21 days without major cell voltage loss. This result indicates that the metal-chalcogenides electrodes are most suitable bi-functional electrocatalysts to replace the precious electrodes in efficient alkaline water electrolysis. References: [1] J. Li and G. Zheng, Adv. Sci., 4, 2017, 1600380. [2] L. C. Seitz, C. F. Dickens, K. Nishio, Y. Hikita, J. Montoya, A. Doyle, C. Kirk, A. Vojvodic, H. Y. Hwang, J. K. Norskov and T. F. Jaramillo, Science, 353, 2016, 1011. [3] A. Sivanantham and S. Shanmugam, Adv. Funct. Mater., 26, 2016, 4661.

Resume : Si-SiOx core-shell nanoparticles were granulated and subsequently coated with C, and their microstructures and electrochemical properties were investigated. Porous microspheres with diameters from 5 ~ 20 um were obtained by spray drying process, and there was no microstructural variation after 30 min’s C-coating by conventional chemical vapor deposition process. The porosity was originated from necking between Si nanoparticles by SiOx shells. The porous microstructure plays an important role especially of buffering against volumetric changes during charge/discharge. While the nanoparticles exhibited higher than 100 % of volumetric expansion after 50 cycles, the porous microsphere showed only 30 % for the same conditions. All the electrochemical properties such as initial reversible capacity, initial columbic efficiency, and capacity retention were not changed before and after granulations. The enhancement of mechanical buffering without change of electrochemical properties could be explained by efficient expansion and formation of solid electrolyte interface in porous microstructures during the first lithiation. The reversible capacity and columbic efficiency were 1382 mAh/g and 75 %, respectively after the first lithiation.

Resume : Defect characterization of interfacial layers in perovskite based solar cells A. Puaud a, S.H. Yang b , T.P. Nguyen a a Institut des Matériaux Jean Rouxel, Université de Nantes- CNRS, Nantes, France. bInstitute of Lighting and Energy Photonics, National Chiao Tung University, Tainan Taiwan R.O.C Hybrid inorganic/organic perovskite solar cells have been intensively investigated as an emerging technology aiming at producing devices of low cost and high performance for sunlight energy conversion. The performance of such devices is found to depend strongly on the quality of the interface between perovskite and the transport layers, especially on the formation of defects, which affect the charge carrier recombination. In this work, we report the results on electrical characterization of solar cells using CH3NH3PbIxCl3-x perovskite as active energy conversion materials and different inorganic nanorod arrays (ZnO, WO3, TiO2) as an electron transport material (ETM) in order to investigate the role of the inorganic/organic interface in the solar cell operation. The electrical characterization of the devices in the configuration ITO/ETL /CH3NH3PbIxCl3-x /P3HT/ Au was performed by current-voltage (I-V) measurements and the defects were investigated by the charge based deep level transient spectroscopy (Q-DLTS). The analysis results show that the efficiency of devices strongly depends on the nature of the oxide nanorod arrays used as HTM. Highest efficiency is obtained for solar cells having ZnO nanorod array layer. Investigations of defects in devices by the Q-DLTS technique provide trap parameters of perovskite bulk and interfacial layers. Defects in perovskite are present in all cells and are essentially deep traps (of activation energy > 400 meV). Specific interfacial defects of activation energy in the range of 100-360 meV have been determined for each ETM/perovskite contact. The defect formation at the electron transport layer/perovskite interface and the cell performance are discussed from the obtained measurement results.

Resume : In this study, the multi-scale simulation methods including molecular dynamics (MD), coarse-grained molecular dynamics (CGMD) and dissipative particle dynamics (DPD) were used to study the properties of mixture of alkyl acrylate copolymer (ACM) rubber and nylon 6 plastic, and the dispersion pattern and mechanical properties of dynamic cross-linked phase changes. Through the simulation of the forming of the mixture of plastic and rubber, it was found that the structure tends to form a co-continuous phase under specific compatibility characteristics and action parameters. The structure of this co-continuous phase will strongly influence the forms of the ACM rubbery state after the dynamic cross-linking reaction. A simulation of adding cross-linking reaction in to the structure having the co-continuous phase is further conducted. It is predicted that the crosslinked portion that forms the crosslinked elastomer contributes much to the overall mechanical strength. This feature can improve the mechanical strength.

Resume : Conductive hybrid nanofillers have become the front facet of the recent research interest because of the scientific and techno-commercial significance of these materials. Herein, we report the fabrication of economically feasible and high-performance thermoplastic polyurethane (TPU) nanocomposites filled with hybrid nanofiller of functionalized carbon nanofiber (FCNF) and ketjen carbon black (K-CB) by using facile and effective solution blending approach. TPU-based nanocomposites are prepared with varying hybrid nanofiller content from 0 to 10 wt% to enhance the electromagnetic interference (EMI) shielding efficiency with tuned electrical conductivity and balanced physico-mechanical properties. Incorporation of hybrid nanofiller in TPU matrix led to a drastic enhancement in thermal durability and electrical properties. Excellent electrical conductivity of 0.089 S/cm is achieved owing to the strong synergistic interaction between FCNF and KCB along with the formation of continuous conductive bridge of hybrid nanofillers throughout the TPU matrix. The superior EMI shielding performance was about 36.4 dB in X-band frequency when the hybrid nanofiller content was fixed at 10 wt%. Further, we report the huge changes of EMI shielding performance of TPU nanocomposites when composite thickness was varied. We also addressed the serviceable performance in electrical conductivities and EMI shileding performances after exposed to thermal-air ageing treatment. The novelty of this present work lies in the unique synergism arising from the combination of two nanofillers, which serves as outstanding EMI shield material as a capable candidate against EM pollutions which have explicitly been rarely considered previously.

Resume : Hybrid inorganic-organic materials have a very high performance in optical materials due to their high transparency, their tailorable refractive index, and their chemical inertness and mechanical robustness. Therefore one can find many commercial applications of such materials in fields like protection coatings, antireflection, or dye markers. In this report we shine a light on the performance of hybrid materials in various optical applications. In systematic studies we were able to show how important a covalent linkage in organic dye modified silica materials is. Particular leaching and photobleaching is influenced by the matrix and the dye incorporation. Within these studies we developed routes for the preparation of inorganic nanoparticles that incorporate a variety of dyes. It can be shown that stability of the dyes is correlating with the location of the dye in the particle and the density of the matrix. In addition, we present a method to prepare continuously fluorescent dye incorporated nanoparticles by a microjet approach.

Resume : Carbothermic reduction in the chemistry of metal extraction (MO(s) + C(s) → M(s) + CO(g)) using carbon as a sacrificial agent has been used to smelt metals from diverse oxide ores since ancient times. Here, we paid attention to a new another aspect of the carbothermic reduction remained unnoticed till now to prepare activated carbon textile for high rate-performance supercapacitors. On the basis of thermodynamic reducibility of metal oxides reported by Ellingham, we employed not carbon, but metal oxide as a sacrificial agent in order to prepare activated carbon textile. We conformally coated ZnO on bare cotton textile using atomic layer deposition (ALD), followed by pyrolysis at high temperature (C(s) + ZnO(s) → C’(s) + Zn(g) + CO(g)). We figured out that it leads to concurrent carbonization and activation in a chemical as well as mechanical way. Particularly, the combined effects of mechanical buckling and fracture occurred between ZnO and cotton were turned out to play an important role in carbonizing and activating cotton textile, thereby significantly increasing surface area (nearly 10 times) compared with the cotton textile prepared without ZnO. The carbon textiles prepared by carbothermic reduction showed impressive combination properties of high power and energy densities (over 20 times increase) together with high cyclic stability.

Resume : Thermoelectric materials have been intensively investigated over the past decades due to their ability to convert waste heat to electricity. Recently, a theoretical study using density functional theory (DFT) combined with the Boltzmann transport theory predicted extremely high thermoelectric performance in hole-doped germanium selenide (GeSe) crystals along the b-crystallographic direction. The calculated value of figure of merit ranging from 0.8 at 300 K to 2.5 at 800 K is even higher than that of hole-doped tin selenide (SnSe), which holds the current experimental record among bulk systems. To the best of our knowledge, only 2 groups have lately reported experimental results on the thermoelectric properties of poly-crystalline GeSe samples. Both used stoichiometric quantities of high purity elements and melting technique to synthesize materials in experiments and reported, however, much lower thermoelectric performance compared to the prediction. In this work, we use the same method to grow samples and determine that they actually are bi-crystal of 2 Van der Waals layered materials, GeSe (intrinsic p-type) and GeSe2 (intrinsic n-type). Low experimental thermoelectric performance might stem from this coexistence.

Resume : The development of the electronic vehicle and electronic device is increasing the necessity about the next generation secondary battery having the higher energy density constantly. Most powerful one of candidates satisfying the necessity of the next generation battery is exactly the lithium-sulfur battery. The lithium-sulfur battery (2600 Wh/kg) have the advantage that it have the theory energy density which is higher than the existing other battery (Li-ion battery : 570 Wh/kg, Li/MnO2 battery : 1000 Wh/kg) and can realize the with low cost environment-friendly battery. However, in order to commercialize, it must resolve problem of low energy density, low cycle stability and poor charge/discharge efficiency. The cause of this problem is that is the insulating property of sulfur, the dissolution and shuttle phenomenon of the lithium-polysulfide. In this study, the S-GO/Carbon composite of the film-type were prepared through a chemical synthesis and filtration without binder. Graphene oxide is used as the isolation film preventing the dissolution of the lithium-polysulfide and the carbons (super P, GNP, MWCNT) were used as the conductive agent improving the conductivity. Free standing S-GO/Carbon composite prepared without binder was directly used as the cathode of lithium-sulfur battery and electrochemical characteristics were evaluated.

Resume : First row transitions metal oxides have made a niche as alternative electro catalyst to replace expensive platinum as catalyst for oxygen reduction reaction (ORR) of polymer electrolyte membrane fuel cell (PEMFC). Among various metal oxides manganese dioxide has very good potential as ORR catalyst due to the presence of multiple oxidation states during in situ electrochemical reaction. In this work, rod shaped manganese oxide (MnO2) was synthesized by one step, low cost and easy hydrothermal method. To enhance its activity, doping of iron in various ratios was done. The surface morphology was studied by field emission scanning electron microscope and elemental composition was determined by energy dispersive X-Ray spectroscopy. The surface composition was investigated using X-Ray photoelectron spectroscopy and crystal structure through X-Ray Diffraction. N2 physisorption was done to know the surface area. Their ORR kinetics and mechanism was investigated in dilute alkaline medium using Rotating Disc Electrode and Rotating Ring Disc Electrode setups. As a catalyst for ORR, iron doped MnO2 (FM) shows an onset potential of 0.89 V (vs RHE) and half wave potential at 0.65 V, which is very close to commercial Pt/C (onset potential = 0.96 V and half wave potential = 0.72 V). It follows direct pathway of reducing oxygen to generate water, without involving formation of any intermediate. It also presents superior stability with negligible degradation after operating continuously for 25000 seconds than Pt/C. The excellent electrochemical performance is mainly attributed to large surface area due to rod structure, higher number of active sites, short diffusion length and stability of rods, indicating that indeed iron doping enhances its electrochemical ability. The low cost nanorods have potential to replace Pt/C in energy conversion devices.

Resume : Metal Organic Frameworks (MOFs) are crystalline nanoporous hybrid materials, built from metal ions and organic linkers. These materials have attracted a lot of interest in the last decades for their potential application in many areas: from capture, storage, separation and conversion of gases to (photo-)catalysis and drug delivery, from optoelectronic to sensors, from magnetism and ferroelectricity to light harvesting and energy transfer. They offer vast potential for the design of materials with molecularly selective interfaces, novel physical properties, enormous surface areas and a diverse array of functionalities. A great number of different organic linkers has been used in the synthesis of MOFs and particular attention has been recently devoted to those revealing photo-responsive activity. Among these class of linkers, we focused our attention on azo dyes due to their easiness of synthesis, photostability and robustness under MOF assembly conditions. The present contribution deals with the synthesis of a new azo dye-based Cerium MOF with azobenzene-4,4'-dicarboxylic acid (organic linker) and Ce(III) nitrate (inorganic salt) using N,N-dimethylacetamide (DMA) as solvent. The synthesis conditions were optimized by means of high-throughput methodologies. The new optimized material was characterized by single crystal and powder XRD, TGA, optical spectroscopy, adsorption volumetry and quantum-mechanical calculations.

Resume : In order to overcome the issue of intensive use of fossil fuels, new energy sources are under investigation. In particular, a fuel economy based on hydrogen is a major challenge. While hydrogen is currently mainly produced from fossil fuel catalytic reforming, a sustainable approach based on its synthesis from green and renewable sources is required. In particular, hydrogen production from solar light-driven water splitting is a promising technology. However, the process requires the development of photo-anodes having efficient conversion of light energy into chemical one. Several semiconducting nanomaterials were already designed as photo-electrodes and integrated to photo-electrochemical cells leading to water oxidation at their surface and injecting electrons in the external circuit until their counter-electrode for proton reduction into hydrogen. Nevertheless, photocatalytic materials with high performance are often active only in the UV domain. In order to extend their activity in the visible domain, several kinds of photosensitizers can be used. In this communication, we will use as photosensitizers a new kind of carbon nanomaterials, namely carbon dots (CDs). CDs correspond to a new class of carbon nanocrystals which possess the same fascinating photophysical properties than quantum dots, but in contrast to them, they do not contain heavy metals, making them environmental friendly. In this work, we will investigate the use of CDs as photosensitizers for two classical photocatalysts, TiO2 and polyoxometalates, and the hybrid systems will be investigated for photoelectrocatalytic applications, in particular for hydrogen generation.

Resume : Collective behavior of optical molecules was shown to significantly alter their properties in terms of intensity and spectral response. Yet in mild conditions the extent of this phenomenon is usually limited to a few molecules, due to lattice imperfections and exciton-phonon scattering. In this work, optically tailored nano-cavity plasmons were used to enhance the collective emission in porphyrin based J-aggregates, by strong coupling. The aggregates were aligned with respect to the plasmonic structure by a method which combine of mechanical and chemical means, and polarization switching was used to study the effect of the plasmon on their collective behavior. The hybridized system was investigated by transmission and emission spectroscopy, and by non linear spectroscopy.

Resume : Graphene has been extensively studied as active material in the preparation of electrodes for supercapacitors. Various strategies have been adopted to improve the mechanical properties, specific surface and capacity storage. For this purpose, new materials based on nanocomposites, 1D materials including carbonaceous yarns and fibers, or decorated graphene with different nanoparticles were used. In this paper we studied the influence of carbon dots in graphene used as electrodes for aqueous EDLC capacitor. Thin films consisting of graphene/carbon dots architectures were prepared starting from precursors based on graphene oxide and carbon-silicon dots with core-shell structure. Under different concentrations carbon dots have been investigated as potential spacer to improve the specific surface of electrode and capacitance. Different techniques including FTIR, UV-Vis, X-ray, Raman, AFM and fluorescence spectroscopy have been used for characterization of carbon dots. The capacitive performance of graphene/carbon dots material was evaluated by cyclic voltammetry and charge-discharge cycles revealing in a split cell test setup a specific capacitance of up to 300 F g-1 and a retention capacity of 95% after 10000 cycles.

Resume : A hybrid particle is unique in a way to combine various functionalities in a single body. The way of the distribution of components gives rise to the development of new stimuli responsive, programmable, synergistic or advanced materials. Among other hybrid materials, anisotropic particles have particularly attracted increasing attention in recent years because of their directionality based on the anisotropic distribution of their components. Janus particles, for instance, exhibit the extreme case of anisotropy, where two components are placed at two opposite sides of the particle. Synthesis of Janus structures has been advanced significantly for polymeric materials in last two decades. However, even though the metallic and inorganic Janus structures offer wider spectrum of properties and application areas, their synthesis is still a challenge as it is complicated and difficult to achieve. The currently available techniques successfully demonstrate the successful synthesis and immense potential of metallic Janus structures; however, they either require very special conditions for synthesis or produce particles with significant defects; therefore, they are far from being scalable. In this presentation, we will introduce a novel technique for fabrication of anisotropic metallic structures that is scalable, environmentally friendly and robust. The abilities of the technique will be demonstrated on the fabrication of anisotropic Bismuth-Tin (Bi-Sn) and will exemplify its various structures including the Janus form. The Bi-Sn system will be considered as a model and the findings will be elaborated on the other systems as the technique allows easy adjustments over the other hybrid combinations. The fabricated particles have a potential to be used as building blocks for nano-capsules and membranes, enable the formation of more stable Pickering emulsions and allow the reaction at interfaces thus offer an easy means of product separation. Incorporation of stimuli-responsive moieties may induce a change in particle’s shape and that triggers the release of encapsulated materials. Janus particles can also be self-propellant benefiting from the anisotropic chemistry on its surface, thus can be used as nano- or micro- motors and offer an application that can be programmed by controlling the fuel reactions. The potential use of fabricated particles for such applications will be demonstrated.

Resume : Recent years, the self-healing materials science will seek further hot key research issues in material science. However, these materials are still mechanical, chemical, thermal and ultraviolet light, such as a complex due to external factors that damage tends to decrease physical properties, which decreases the life of the material by direct impact. In order to solve such a problem, many researchers such as commonly found in nature are capable of being self-healing studies focusing on the given material of that concept began. In this study, polyurethane with disulfide links was synthesized and evaluated the mechanical properties and self-healing efficiency. The self-healing polyurethane can be applied to a variety of applications such as coating and adhesives in both aerospace and building materials.

Resume : Printable electronics and flexible electronics offer the potential to add functionality to everyday objects at very low costs that would be difficult with conventional technologies. This was pushed by the large success of organic electronics over the past few decades due to their attractive features such as low process temperatures, good mechanical flexibility, light weigh and the possibility to use a wide range of substrates. Besides that we can prepare these devices using inexpensive solution processes over large areas. These benefits offered by printable and embedded electronics have being recognized in many sectors. On the other hand, metal oxide electronic materials are quite attractive since they provide a large variety of different and possible applications due to the diverse spectrum of properties ranging from thin films to nanostructures. Concerning applications they are becoming increasingly important in a wide range of applications like transparent electronics, optoelectronics, magnetoelectronics, photonics, spintronics, thermoelectrics, piezoelectrics, power harvesting, hydrogen storage and environmental waste management. In terms of production tecnhiques rf magnetron sputtering has been well established and has demonstrated high performance devices, however these require complex high vacuum equipment which is a major drawback, especially if we are targeting low cost applications. In contrast, the solution process has many advantages such as large-area depositio

Resume : Additive manufacturing (AM) has attracted a lot of attention in the past decade. Formerly, the focus was on obtaining good shape stability and easy processing methods. Nowadays, technologies for manufacturing in combination with innovative materials lead to ideas of including more sophisticated functionalities to the printed components. The goal of our investigations is to 3D-print a quantumdot-(QD) based light emitting sensor for biomedical applications. This demonstrator will feature a sophisticated 3D shape with array elements for different wavelengths. These elements will incorporate four different types of QD-based materials and will be excited by UV-light from the bottom. Hence, there are several functions combined in one material: Precise shape, refraction and/or diffraction and defined light emission. Therefore, the material needs to meet crucial requirements: UV-curability with low shrinkage and high shape stability, high transparency and refractive index with no yellowing effect, stability vs. oxygen and water, good matrix properties for the QDs, nontoxicity as well as bio-inert behavior. Our formulated nanocomposite is able to emit light at preadjustable specific wavelengths and fulfills the aforementioned requirements. So we successfully created new light emitting organic-inorganic nanocomposites for the AM of optical components through stereolithography, including dynamic light processing.

Resume : Antarctic, on average, is the coldest and windiest continent in the world, where the lowest recorded temperature is -89 degree and it suffered from many blizzards throughout the year. Although the severe environment, dozens of penguin species were found in here due to their high adaptation. They daily dive in water at sub-freezing temperature but it was confirmed that no one had never observed ice or frost on the feather of a healthy penguin. It was discovered that the feather structure contains innumerable tiny pores that working as the air trap to block the heat transfer. In addition, penguins apply the preen oil produced by a gland to the feather continuously using their beak. The combination of hierarchical structure and oil will make the feather very slippery and super water repelling. Inspired from the unique of penguin feather, we proposed an approach to minimize icing adhesion of the condensed water droplets on a surface by the combination of poor thermal conductive material and low surface tension oil. Hierarchical of oil-infused elastomer textures was also fabricated in order to minimize projected contact area with condensed droplet for decreasing the heat transfer. Different concentration of oil in elastomer solution was tested to show the contribution of slippery in removing iced droplets after icing process. The textured surfaces present ultra-low adhesion strength with ice droplets comparing with several materials and the valuses show the approximately an inverse proportion to the concentration of oil infusion in elastomer solution. The results can be used for understanding of anti-icing phenomena and introducing a facile approach for icephobic surfaces

Resume : Since the first study on gels performed by Thomas Graham in nineteenth centuryandthe first time synthesis of hydrogel reported by DuPont scientists in twentieth century, nowadays hydrogels find many applicationsin sensor, biocompatible optical devices, water purification technologies etc. Due to flexibility and smart material, hydrogels are being used in various applications such as drug delivery, biosensors and pollution control. Hydrogel is defined as soft mater consisting of crosslinked three-dimensional structure of hydrophilic polymer, which can absorb huge amount of water or biological fluid. In the currentwork, we present state of the art in the field as well as an overview of our recent research performed. We analyze how the presence of hydrophilic groups in polymer (hydroxyl, carboxylic) are responsible for high water absorption ability of hydrogel and discuss insolubility issues of hydrogel in water that is due to the crosslinking among the chains of polymer. The swelling ability of smart hydrogels exhibiting the change on exposure to environmental conditions is considered. As use of hydrogel in wider applications is often limited by its poor mechanical and thermal stability, we demonstrate that nanomaterials (titanium oxide, iron oxide, graphene oxide, carbon nanotube etc.) which can be inserted into the hydrogel matrixmay lead to formation of hybrid hydrogel with better mechanical and thermal properties.

Resume : Recently there has been great interest in designing thin film materials that possess highly anisotropic properties. For this purpose, metal nanoparticles are particularly interesting due to their localized surface plasmon resonance and high conductivity, and significant progress has been made in the area of metallic nanowire and nanorods synthesis and device application in the past several years. The hierarchical organization of these nanoscale building blocks into functional assemblies and ultimately a useful system is still a challenge, and discovering new bottom-up methods to assemble one-dimensional nanomaterials into two- or three-dimensional structures with well-controlled location, orientation, and spacing across multiple length scales has attracted lots of attention, owing to the potential applications in electronic and optical devices. In this talk, I will show how Grazing Incidence Spraying, a new assembly technique we have recently introduced, allows forming oriented thin films of anisotropic nano-objects over large areas with highly anisotropic optical and electrical properties [1-4]. The Layer-by-Layer assembly approach is used to build multilayer thin films of oriented gold nanorods and silver nanowires, paving the way for hybrid thin films with complex and tuneable architecture, e.g. for plasmonic chiral layers showing giant circular dichroism. [1] S. Sekar, V. Lemaire, H. Hu, G; Decher, M. Pauly, Faraday Discuss. 2016, 191, 373-389. [2] R. Blell, X. Lin, T. Lindstrom, M. Ankerfors, M. Pauly, O. Felix, G. Decher, ACS Nano 2017, 11, 84-94. [3] H. Hu, M. Pauly, O. Felix, G. Decher, Nanoscale 2017, 9, 1307-1314 [4] P.T. Probst, S. Sekar, T.A.F. Koenig, P. Formanek, G. Decher, A. Fery, M. Pauly, ACS Appl. Mater. Interfaces 2018, doi: 10.1021/acsami.7b15042.

Resume : Following the concept of integrating molecular electronic devices into traditional CMOS circuitry, molecularly functionalized metal nanoparticles (NP) are employed. Especially complexes of ruthenium with chelating terpyridine ligands exhibit interesting properties. They can act as a switch of constant length, based on a redox mechanism, addressed by electrical or optical pulses. The application of 1,4-bis(2,2':6',2''-terpyridin-4'-yl)benzol (BTP) ligands as a linear linking moiety allows the formation of Ru-BTP diads, triads or even longer molecular wires. Here, we use 15 nm Au-NP functionalized with 4'-mercaptophenol-2,2':6'2''-teryridin (MPTP) and the corresponding (MPTP)2 -ruthenium complex. We immobilized such Au-NP in between heterometallic nanoelectrode gaps consisting of AuPd and Pt. These gaps were tailored in a double layer resist electron beam lithography process to match the dimensions of the used NPs. The resulting devices are installed in a probe station and cyclic IV-measurements were performed in order to determine the device properties. The thus deduced conduction is compared to estimations of the conductance through the respective molecules by using Landauers formula. Finally the devices are characterized by SEM. Furthermore, the principles of growth of Ru-BTP based molecular wires are investigated by XPS measurements.

Resume : Oligomeric benzylsulfides are optimized to coat the surface of gold nanoparticles (Au-NPs).[1] Some of these multidentate macromolecular ligands passivate the Au-NP’s during their formation by reduction of chloroauric acid and control thereby their dimensions. Particular optimized dentritic,[2] linear,[3] or tripodal[4] macromolecules are able to coat an entire particle resulting in a 1/1 ligand/particle ratio. By attaching a masked ethinyl group to the ligand Au-NPs are obtained exposing a single functional group. These Au-NPs can be considered as heavy inorganic/organic hybrid molecules and can be processed by wet chemistry. In first attempts dumbbell architectures were assembled by oxidative acetylene coupling[5] and even larger hybrid architectures comprising up to four Au-NPs were obtained by click-chemistry[6]. Our current focus is set on controlling larger Au-NPs by coating ligands in order to make hybrid architectures interacting with visible light accessible. [1] J. Hermes et al., Chimia, 2011, 65, 219. [2] J. P. Hermes et al., Chem. Eur. J., 2011, 17, 13473. [3] M. Lehmann et al., Chem. Eur. J., 2016, 22, 2261. [4] E. H. Peters et al., Part. Part. Syst. Charact., 2018, 35, DOI: 10.1002/ppsc.201800015. [5] J. P. Hermes et al., J. Am. Chem. Soc. 2012, 134, 14674. [6] F. Sander et al., small 2014, 10, 349.