Advanced composite materials: new production technologies, unique properties, new applications

Resume : Rapid development secure emergency shelter (RDSES) provides a temporary to a semi-permanent building for leisure, construction and humanitarian assistance. The shelter must be water and weather proof. The shelters can be assembled in a short period of time.The stackable shelters can be transported efficiently and stored externally for prolonged periods without additional maintenance. FibralSpec, an EU funded project, investigates the design of the RDSES shelter. The initial design of the RDSES shelter was made out of glass fibre reinforced polymer (GFRP), whose weight was approximately 500 kg. Stronger and lighter fibres such as carbon fibres are expected to reduce the weight of the initial RDSES design without losing mechanical properties. This paper will present the selection of the composite materials for the RDSES shelter. Carbon fibres, glass fibres, flax (natural) fibres in forms of woven fabrics were used as the reinforced materials. Epoxy was used as matrices. Hybrids of synthetic (carbon or glass) fibres and flax fibres were also considered for the shelter materials. Sandwich composites with Polypropylene (PP) honeycomb core will be investigated to increase the shelter thickness and hence to maintain bending properties without adding excessive weight. The composites and sandwich composites were manufactured via hand lay-up and vacuum bagging techniques. The bending properties of composites were measured by conducting three-point bending tests. The physical properties such as density of and the water absorption properties of composites will be reported. The water absorption properties of the composites will be studied by applying Fick’s diffusion law. The life cycle assessment (LCA) of the composites produced for the RDSES shelter will also be conducted by using LCA software, GaBi 6. Finally, the effects of the waste treatment of composites containing fibres as reinforcing materials will be assessed via SimaPro 9 software, in order to reveal possible environmental burdens that can arise after the end-of-life of the RDSES shelter.

Resume : The interface properties of fibre and resin often influence significantly the performance of all types of composites, such as failure mode and fracture toughness. Normally, push-in and push-out tests were carried out under continuous loading until a debonding or failure is detected; however, the creep behaviour under a load lower than the critical load is also very important to determine the interfacial strength and the mechanical strength between the fibre and the resin. The nano-creep behaviour and time-dependent properties of a commercial carbon fibre reinforced composite were investigated using a novel environmental instrumented nano-indentation machine. The mechanical properties such as indentation hardness, reduced modulus, indentation displacement and indentation creep of the composite were evaluated by means of the Oliver-Pharr method. The tests were carried out at different testing conditions in terms of loading rate, peak load, hold time, atmosphere (different humidity) and temperature (room temperature, 50, 80 and 100°C). Two different diamond indenters (Berkovich and cone indenter) were used in the push-out tests. The cone indenter had some advantages over the Berkovich indenter in terms of extended range of displacement before interference with the surrounding resin. A single fibre needs a critical load/stress to be pushed out under the continuous loading mode, and the critical load is strongly linked to the thickness of the composites sample, the location of the fibre in the resin and other environmental factors such as temperature. It was found that the fibre becomes difficult to be pushed-out at elevated temperature; the displacement and creep rate are both reduced with the increase of temperature due to the resistance caused by the expansion of the fibre and the resin. Key words: Creep, carbon fibre, push-out, push-in, nano-indentation This work has received funding from the EU FP7 Project “Functionalized Innovative Carbon Fibres Developed from Novel Precursors with Cost Efficiency and Tailored Properties” (FIBRALSPEC) under Grant Agreement No. 604248.

Resume : Epoxy resin is one of the most important organic matrices in composite industry and finds application in demanding sectors due to excellent mechanical strength, thermal stability, and chemical resistance. Various fillers are used in epoxy composites in order to alter their chemical and mechanical properties. Glass transition temperature (Tg) is an important and critical property in composite product designing. Tg is not an isolated thermodynamic transition. The mobility of the polymer chains increases significantly over this temperature. Polymerisation chemistry, degree of curing and filler properties in composite varies the Tg value. Carbon fibre in epoxy composite can alter the chemical and mechanical properties at the expense of Tg. In addition, it is also interesting to know the impact of surface modified carbon fibres in epoxy for altering the Tg of composite. The thermal study was focused on epoxy composite filled with commercial and in-house produced carbon fibres prior and after plasma surface modification. Thermal properties of the composite are analyzed by Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA). The modified and unmodified carbon fibres in composite shows changes in thermal behaviours of composite. Tg of composite altered. Thermal degradation in TGA shows enhanced thermal stability of composite than plain epoxy. Reference: • B. Qi, S. R. Lu, X. E. Xiao, L. L. Pan, F. Z. Tan, J. H. Yu, Enhanced thermal and mechanical properties of epoxy composites by mixing thermotropic liquid crystalline epoxy grafted graphene oxide., eXPRESS Polymer Letters Vol.8, No.7 (2014) 467–479 • Chen J., Taylor A. C.: Epoxy modified with triblock copolymers: Morphology, mechanical properties and fracture mechanisms. Journal of Materials Science, Vol. 47, (2012) 4546–4560. This work has received funding from EU FP7 Project “Functionalized Innovative Carbon Fibres Developed from Novel Precursors with Cost Efficiency and Tailored Properties” (FIBRALSPEC) under Grant Agreement No. 604248.

Resume : Polymer based composites reinforced by weft-knitted fabrics produced from various kinds of fibers are very promising materials and an interesting object of study due to their new multifunctional properties. In the framework of FP7 FIBRALSPEC project (grant agreement 604248) carbon fibers from PAN precursors had been produced in National Technical University of Athens and weft knitted fabrics for reinforcement of polymer based composites had been manufactured in Institute for Problems of Materials Sciences of Ukraine. The main principles of processing of such kind of fibers had been applied. The glazing on the base of PVA had been proposed and fibers with glazing had been produced in a pilot line for production of carbon fibers with enhanced properties established in IPMS. The main principles of production of combined weft-knitted fabrics had been developed and analyzed. Combined weft-knitted fabrics containing caprone and glass yarns had been proposed. Their main physical and mechanical properties had been evaluated. Epoxy resin (Huntsman type) composites reinforced by weft knitted fabrics had been manufactured. In the case of unidirected arrangement of four layers in composite ratio of binder to reinforcement part was equal 29:71. Tensile and bending strength had been evaluated. Investigations of screening properties (protection from electromagnetic radiation) had been made.

Resume : Existing production needs increasingly stringent requirements for advanced materials properties to widen their applications within more harsh and extreme conditions with simultaneous search of cost efficient production processes. The investigation of the modification impact of initial carbon materials on operational characteristics of products were targeted. Yuzhnoye is the end-user of modified carbon fibers to be used in its own production. Application of different modified materials is the road to introduce advanced materials with additional (comparing to initial) functional properties without having losses in structural integrity. Advanced carbon fibers have wide application area thanks to its unique properties and allow solving complicated tasks in material science and technologies independently from their current possibilities limits. Main task is the adaptation of gained experience to the development of the innovative demonstrators. Namely, here the demonstrators mean model cases of “cocoon” type that are used for engines cases, fuel and cryogenic vessels. Application of such cases allows increasing mass to energy characteristics of aerospace vehicles. Therefore, based on standard techniques the model cases of “cocoon” type should be produced based on materials before and after modification. The simulation of operation loads should be applied in accordance to developed test procedures. The key point is their comparative estimation of strength and mass characteristics of structure with enhanced properties of modified carbon composite material. The studies are carried out in the frame of Horizon-2020 Grant Agreement №685844 (H2020 NMP-22-2015).

Resume : We exploit organic functionalization of carbon nanostructures (CNSs), such as fullerenes, single and multi-walled carbon nanotubes (SWCNTs, MWCNTs) and graphene-based materials (GBMs) to achieve improvements in their dispersion in organic media, i.e. solvents and polymer phases. This last aspect is particularly appealing for the production of polymeric nanocomposites with potential uses as stimuli-responsive smart materials in several applications, ranging from optoelectronics to sensing and biomedicine [1]. We recently mainly focused on the diazotization process, commonly referred to as Tour reaction, to produce functionalized CNS derivatives, which can be employed as nano-fillers for polymer phases, improving the homogeneity of the dispersion and the physical properties of the final nanocomposite. The 1,3 dipolar cycloaddition of azomethine ylides to double bonds in CNSs (also called Prato-reaction) is another functionalization process of which we often make use. Specifically, we targeted photovoltaic (PV) applications, by combining functionalized CNSs with semiconducting polymers and nanomedicine (particularly tissue engineering) by combining functionalized CNSs with bio-compatible polymers. In the field of non-conventional PV, we focused on Perovskite Solar Cells (PSCs), contributing to the development of new materials for both hole [2] and electron transporting layers [3]. Within the nanomedicine field, we proposed and tested new bio-compatible scaffolds for the growth and differentiation of neuronal cells in vitro [4,5]. We are currently exploring also possibilities of in vivo testing, with focus on peripheral nerve regeneration. We will therefore report here on our most relevant results in the aforementioned fields. References: [1] For a review on the topic see: T. Gatti et al. Eur. J. Org. Chem. 12, 6500 (2016). [2] T. Gatti et al. Adv. Funct. Mater. 26, 7443 (2016). [3] P. Topolovsek et al. submitted paper [4] N. Vicentini et al. Carbon 95, 725 (2015). [5] G. Scapin et al. Nanomedicine 11, 1929 (2016).

Resume : Thermally conductive polymer composites offer new possibilities for the thermal management in electronic devices. An approach of current interest to improve the thermal conductivity of polymer composites is the addition of hybrid nano and micro fillers with high thermal conductivity. The objective of this paper is to study the effective thermal conductivity of the composites with nano and micro fillers. The nano fillers used were carbon nanotubes and alumina nanowires, and the alumina and boron nitride particles with different shape and size were selected as the micro fillers. The random close-packed structures of micro fillers were obtained using packing simulations, and finite element analyses were performed to predict the composite thermal conductivity. In addition, experimental measurements of the thermal conductivity of the manufactured polymer composites were carried out by using a steady-state method. The microstructure of the composites was also examined using a scanning electron microscope. The results showed that the addition of nano fillers to the matrix significantly increased the thermal conductivity of the composites with close-packed structure of micro fillers.

Resume : Carbon Fiber Reinforced Polymers suffer from poor electrical properties, therefore there is a great interest in increasing their conductivity and simultaneously increasing the mechanical performance. One of the ideas is to introduce carbon nanotubes or graphene into CFRP by different routes. However, many of the approaches successfully tested in laboratory conditions do not fulfill the specifications in the industrial scale given by their end-users. Within Horizon 2020 EU program, the project with acronym PLATFORM is tasked with development of new types of nano-enabled products which could be easily applied in industrial environment (www.platform-project.eu). Untill now, pilot lines which produce three types of nano-enabled products such as buckypapers, CNT treated prepregs and CNT-doped veils have been successfully manufactured. Such products differ in manufacturing approach, properties and possible application area. All of them contain carbon nanotubes and therefore can be applied to increase CFRP electrical and mechanical properties. One example of nano-enabled products are CNT-doped veils developed by SME located in Poland (www.tmbk.pl). These nonwovens are produced by melt-blown process, which allows to obtain thin and lightweight materials with high flexibility. The usage of CNT-doped veils as interlayers in CFRP met the end-users expectations related to easy handling and fitting to specific process parameters such as melting range and compatibility with other used materials. It was revealed that CNT-doped veils can indeed increase the electrical conductivity of CFRP through the laminate thickness. However, the level of improvement is strongly affected by process conditions and the measurement technique. The research leading to these results has received funding from the European Union Horizon 2020 Program under Grant Agreement n° 646307 with title ?Open access pilot plants for sustainable industrial scale nanocomposites manufacturing based on buckypapers, doped veils and prepregs?.

Resume : The nanofilled polymer composites are more efficient and economically sound in comparison with conventional polymers or polymer blends, because they are characterized by significantly enhanced complex of physical-mechanical properties, even at very low content of nanofiller due to its specific chemical or physical interactions with polymer matrix at the nanoscale. High performanceCyanate Ester Resins (CERs) based thermosetting polymers (polycyanurate networks, PCNs) exhibit high glass transition temperature (Tg> 250oC), excellent preservation of physical-chemical properties at elevated temperature, low dielectric constant (ε ≈ 2.5 ÷ 3.2) and water adsorption, therefore theyare commonly used in structural aerospace composites, in electronic insulating applications, as adhesives [Fainleib A., Bardash L., Boiteux G., Grigoryeva O. in book “Advances in progressive thermoplastic and thermosetting polymers, perspectives and applications”, eds. Mamunya Ye., Iurzhenko M., ch.10, p.379-424, 2012]. In this work the thermostable polymer nanocomposites in situ synthesized from different CERs and multi-walled carbon nanotubes (MWCNTs) have been investigated, and asignificant effect of ultra-low content of the nanofiller on physical properties of the nanocomposites have been fixed.It has been found that addition of even 0.2-0.3 wt. % of MWCNTs provides increasing up to 90 % of tensile strength for the nanocomposites studied, improving stability to thermal-oxidative destruction. Varying MWCNTs content allows controllingtheirproperties from isolator to conductor.

Resume : Dispersibility of filler in polymer matrix and interfacial interaction are challenging for producing high performance polymer nanocomposites. In this study, thermoplastic polyurethane (TPU) nanocomposites incorporated with graphene nanoplatelet (GNP) and polydopamine functionalized GNP (PDA-GNP) were prepared by in situ polymerization. The influence of polydopamine (PDA) interfacial layer on the microstructures, morphology, thermal and tensile properties of TPU nanocomposites was investigated by small-angle neutron scattering (SANS), scanning electron microscope (SEM), dynamical mechanical analysis (DMA) and mechanical test. It was demonstrated that PDA-GNP exhibited homogeneous dispersion without aggregation in TPU matrix. Compared with pure TPU, the tensile strength, strain at break and toughness of TPU/PDA-GNP with as low as 0.5 wt % PDA-GNP increased by 313%, 16% and 279%, respectively. This individualized phenomenon was attributed that the interfacial covalent bonding between PDA-GNP and TPU resulted in well interfacial compatibility and specifically associated with the microstructure of TPU matrix.

Resume : Despite advanced mechanical characteristics, low electric conductivity of polymeric composites limits their application in aerospace and other areas. Two basic approaches, which are widely used to solve this problem, are disperse conductive particles incorporation into polymer matrix and conductive elements (metallic wires, meshes, foils) introduction into composite structure architecture. Both these approaches have their pros, cons and limitations. As an alternative, authors propose to increase electric conductivity of composites through generation of thin metallic conductive layer on the reinforcement (fibre, fabric, prepreg) surface by cold spray. This method is low-cost and can be realized as continuous production of conductive prepregs on an industrial scale. Efficiency of proposed method in terms of electric conductivity improvement and mechanical characteristics variation was experimentally validated for glass and carbon fibre reinforced samples with 1.5, 3.2 and 8.4 % content of copper particles. Specifically, CFRP samples conductivity was reduced from 78?10-6 ??m up to 1.65?10-6 ??m and is comparable with some metallic alloys conductivity. Three-point bending test results demonstrated negligible influence on composites bending strength, which varies within experimental data scatter. Additionally, samples microstructure analysis demonstrated that copper particles contact with carbon fibres, which guarantee transversal electric conductivity.

Resume : Inkjet printing technology for the last decade is growing tremendously and has been attracting several research related activities in the field of printed electronics. The technology offers numerous advantages e.g. deposition accuracy in micrometer range, additive process, high digital flexibility towards processing of patterns, low material consumption at R&D scale and industrial relevant up-scaling nature etc. In this work, we report on all inkjet-printed thin-film transistors (TFTs) and their performance regime. The inkjet-printed TFTs are manufactured using (a) Poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) PEDOT:PSS and silver (Ag) as conductor materials for developing the source, drain and gate electrodes; (b) a cross-linked poly(4-vinylphenol) cPVP as gate dielectric; (c) Dimethylchlorosilane-terminated Polystyrene was introduced as a polymeric inter-layer to improve the charge transport mechanism between the source and drain electrodes, and semiconductor interface; and (d) a polymer based amorphous semiconductor FS0096 from Flexinks inc. All the mentioned functional material inks were deposited using a piezo-electric assisted DoD inkjet printer Dimatix Material Printer 2831 and print-head cartridges offering 10 pL drop volume (under ambient condition). The main focus of this research work, is to represent the difference in the TFTs performance regime when the fundamental materials for developing a TFTs e.g. the source and drain electrodes are varied using Ag and PEDOT:PSS, in combination with and without the implementation of a polymeric inter-layer i.e. Dimethylchlorosilane-terminated Polystyrene for better charge transport. The fabricated TFTs containing the polymeric interlayer over the printed source and drain electrodes provide a superior interface for the deposition of the organic semiconductor layer by passivating it, which in return also improves the molecular structure / assembling of the semiconductor material once they are deposited. This can lead into an improved charge transport mechanism and hence high electrical performance (e.g. higher source-drain current, high charge mobility, low threshold voltage etc.) from the inkjet-printed TFTs. This present work demonstrates a drastic variation in the performance of the TFTs that can be implemented for developing organic circuitry for various applications.

Resume : Structural materials for aviation application are often exposed to extreme operational conditions, especially to high temperatures. The applicability of carbon plastics used in engines depends on the heat resistance of polymer matrix used as binder in composite material. Sometimes such materials have to withstand the temperature up to 300 ºC and even higher. The novel high temperature resistant densely crosslinked polymer matrix is formed by step-by-step curing in temperature range from 220 to 300 ºC of the mixture of polyfunctional epoxide and polyfunctional aromatic nitrile in the presence of specific initiators, catalysts and fillers. The final copolymer network contains highly thermally stable heterocycles in matrix chemical structure: triazine, isoindoline, phthalocyanine, oxazoline. Controlling the components ratio, type and amount of the additives and temperature/time schedule allows regulating physical-mechanical and thermal properties of the carbon plastics obtained. The glass transition temperature of the polymer networks obtained varied from 240 to 400 ºC (DSC data), the temperature of 10% mass loss varied from 400 to 500 ºC (TGA data). The average value of flexural strength at standard conditions was 837 MPa, and 285 MPa at 300 ºC (the retention of strength ? 34 %). The average value of tensile strength at standard conditions was 890 MPa, and 806 MPa at 180 ºC (the retention of strength ? 91 %), and 690 MPa at 250 ºC (the retention of strength ? 78 %). Tensile modulus was 95330 MPa at standard conditions and 96660 MPa at 180 ºC. The average value of compression strength at standard conditions was 504 MPa, and 316 MPa at 180 ºC (the retention of strength ? 63 %), and 142 MPa at 300 ºC (the retention of strength ?28 %).

Resume : Technical decision for useful recycling of the wastes from mechanical treatment (milling, drilling, turning) of structural carbon plastics had been proposed. Such kind of wastes are powdered small dispersive particles consisting from carbon fiber fragments and wastes of epoxy resin. The collection and storage of this waste requires the costs of environmental measures, so their utilization and the following using are of great interest today. Structure and composition of such wastes had been described. It was proposed to sort these wastes in correspondence with their sizes (sieving through a sieve) and use these products for production of so called secondary composites. Taking into account peculiarities and forms of the carbon fiber fragments (high modulus, high strength) the most simple way of their using - introduction to polymer binder in correspondence with technology of the production of polymer composites reinforced by dispersive particles. Technology of the production for secondary polymer based composites with the content of fillers of 6 wt.%,12 wt.% and 18 wt.% had been proposed. Tribological properties of secondary composites had been tested at special stand M-22. The results of measurements showed that addition of the wastes of carbon plastics essentially increases wear resistance of secondary composites not only in air but also in water environment. The optimal value of concentration of additives had been determined. It is equal 18 wt.%. This amount of additives ensures the decreasing of the wear and temperature in the working zone of friction unit. It allows to recommend secondary polymer composites for their using as advance materials for loaded sliding bearings and dispersive wastes of mechanical treatment of carbon plastics as an effective additive for wear resistant friction materials. The work had been performed under the financial support of FP7 FIBRALSPEC project (grant agreement 604248)

Resume : Magnetite nanoparticles and its derivatives such as maghemite, hematite, and doped ferrites with Co, Mn, or Ni can be efficiently prepared by various chemical methods. These compounds in nanoparticles form can be used as a base for heterogeneous nanocomposites. Presence of magnetic nanostructures plays important role in manipulation and properties. Besides that different compounds can be attached to their surface, for improving their functionality. In our case, obtained particles have a mean diameter varing from 11 to 16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. Surface of proposed nanoparticles was functionalized with ?COOH, ?NH2, -OP, -SH, etc. groups to obtain active linkers. Presence of active groups is crucial for further reactions leading to nanocomposites fabrication. In the following step functionalized nanoparticles can be connected with third particles (catalyst, biological particles (lipids, enzymes, DNA, etc.) or other nanostructures (nanowires, nanotubes, fullerenes)) or reactive surfaces. Characterization of the pristine nanoparticles and effective composites was done by TEM, XRD, and Mössbauer spectroscopy. The effect of the obtained nanocomposites can be monitored by FTIR, Raman spectroscopy. Authors acknowledge COST MultiComp Action CA15107. The work was partially financed by EU founds via project with contract number POPW.01.03.00-20-034/09-00, POPW.01.03.00-20-004/11-00 and by NCN founds (2014/13/N/ST5/00568).

Resume : The adhesion properties of adhesive between polymer and metal are becoming more important due to the increasing demand on carbon fiber-reinforced plastic/steel hybrid composites for the automobile parts. The adhesion properties such as failure strength, fracture toughness and failure mode are known to be dependent with temperature and strain rate. To analyze those adhesion properties at various strain rates and temperature, time-temperature superposition principle is used through the shift factors, which are obtained from dynamic mechanical analysis. The failure strength and fracture toughness are measured at various temperature and strain rate using a butt joint test, lap shear test, double cantilever test and end notched flexure test. By using time temperature superposition, it is shown that the failure strength and fracture toughness increase as the strain rate increases. In addition, the failure strength and fracture toughness at very high deformation rate and low deformation rate can be predicted where experimental data is unobtainable. A viscoelastic model that can account for the influence of strain rate and temperature on the adhesion properties is developed in this work.

Resume : For the polymer bearings concept different approaches have been applied. At the beginning the computer simulations were done. In order to understand how the heat is dissipated by the bearing system a thermal simulation was performed. A structural simulations using ABAQUS was done to investigate contact area and for better define computational model for thermal analysis. The heat is generated on the contact area between the polymer bearing and the shaft.In order to reduce the amount of generated heat, friction-reducing coatings were applied on the shaft. Taking into account all the requirements and the conclusions drawn from thermal simulations three materials for bearings were selected. Two polymeric materials with very low coefficient of friction and good wear and heat resistance. Most of polymers are very good thermal insulators therefore bimetallic bearings were tested too. During each tribological test, temperature inside bearings, friction force, ambient humidity and temperature were measured. The tests were performed at a load in the range of 1,4 to 1,7 kN and rotation speed from 50 to 300 RPM. Comparing the obtained results, the best combination is bearing made of fluoropolymer with shaft covered by ‘diamond like carbon’ coating.

Resume : The electrical properties of two component composite of epoxy-glue and Bi-Mn-O ceramics, containing 66 wt.% Bi-Mn-O, were studied. Reference samples were Bi-Mn-O ceramics with sillenite structure and epoxy-glue. Secondary electron images and backscattered electron images were collected for the epoxy and the epoxy-Bi-Mn-O samples. Scanning electron microscopy showed homogenously distributed Bi-Mn-O powder in the epoxy matrix. It has been detected that the Bi-Mn ratio was different from the nominal value. Moreover, structure of the samples was determined with use of the XRD measurement in 300–450 K range.The electric impedance was measured for frequencies f = 40 Hz – 1 MHz in the 180 – 440 K range. It was analysed with use of electric permittivity e*(T,f) and modulus M''(T,f) representations. The tested epoxy-Bi-Mn-O sample exhibited low dielectric losses. The samples of epoxy-Bi-Mn-O composite show several electric conductivity relaxations. The dominating one is related to activation energy Ea= 0.6 – 1.0 eV, varying with temperature range. Therefore the Vogel Fulcher-Tammann relationship was applied for relaxation times obtained from modulus M''(T,f) representation. The other processes were not resolved clearly. The relaxation times were discussed in framework of the polymer-ceramic particle interfacial layer model

Resume : The presents work expands our previous studies related to cellulose processing with room temperature ionic liquids and simultaneous integration of functional nanoparticles towards photocatalytically active and easily recyclable nanocomposite porous films based on a renewable matrix material. Porosity can be tuned by the selection of phase separation conditions for films of casting solutions of cellulose in ionic liquids or their mixture with an organic co-solvent. TiO2 nanoparticles confer to the nanocomposite photocatalytic activity while the Fe3O4 make it magnetically active. The co-doping of TiO2-cellulose composite with Fe3O4 nanoparticles did not diminish the photocatalytic activity of the final composite which can be easily separated from solution with a magnet. By Fe3O4 doping, the composite temperature can be homogenously increased by exposure to a high frequency alternating magnetic field. For an optimal thermal response in magnetic field the magnetite nanoparticles have to be homogenously dispersed within the polymer matrix. The preparation method for the casting solution has been found to play an essential role for the fabrication of nanocomposite materials in which the functional nanoparticles are homogenously dispersed in a non-agglomerated form. Besides the presented flat porous sheet nanocomposites, by non-solvent induced phase separation processes similar photocatalytic and magnetic porous cellulose nanocomposites can be shaped also in spherical form.

Resume : The development and characterization of a new family of water based gel-like systems containing hydroxypropyl guar gum (HPG) with borax as crosslinker are presented in this contribution. In the formulation glycerol is introduced as plasticizer, and its role is broadly investigated. The effect of the components on the structure, on the viscoelastic behavior of the system and on the activation energy related to the relaxation process has been investigated by means of rheology, Nuclear Magnetic Resonance (NMR) and Small Angle X-ray Scattering (SAXS) [1-2]. Results indicated that the mechanical properties of the systems can be tuned by varying the amount of each component; 11B-NMR and 1H-NMR measurements highlighted the role of glycerol in the crosslinking mechanism, with the formation of a glycerol-borate complex. The characterization approach is used to identify the best formulation, in the view of a future application in the field of cultural heritage conservation, in particular for the cleaning of surfaces of historical and artistic interest [3]. The main goal is to obtain a system adaptable to the roughness typical of surfaces of many artifacts. The best formulation was used for preliminary cleaning tests on a stucco artifact deriving from the decorations of La Fenice theatre, in Venice. The tests suggest a promising efficacy in selective cleaning of the surface and make these materials particularly interesting in the field of restoration. [1] T. Coviello, P. Matricardi, F. Alhaique,R. Farra, G. Tesei, S. Fiorentino, F. Asaro, e-XPRESS Polym. Lett. 2013, 7, 733. [2] Y. Cheng, K.M. Brown, R.K. Prud?homme, Biomacromolecules, 2002, 3, 456. [3] I. Natali, E. Carretti, L. Angelova, P. Baglioni, R.G. Weiss, L. Dei, Langmuir, 2011, 27, 13226.

Resume : In this work for the production of strong brazed ceramic joints the wetting and contact interaction on interface of tin dioxide - binary metal melts (Ag-Cu, Ag-Sn, Cu-Sn, Cu-Ni) were studied. The wettability of ceramic surface was carried out by sessile drop method in vacuum at T = 1270 - 1370 K. It was shown that the most of investigated alloys (Ag-Cu, Ag-Sn, Cu-Sn) are not wetting of ceramic substrate (the contact angles are about 70 - 110 deg.). It's not enough for brazing such material. For using this binary metal melts we need to add adhesion active component, for example, Ti. However, Cu-Ni system can be used for brazing and metallization of tin dioxide ceramics: the contact angle for Cu-5Ni is 40 deg., for Cu-15Ni - 22 deg. The microstructure of ceramics-metal interface was studied. The optimal conditions for brazing and metallization of tin dioxide ceramics by Cu-Ni fillers were defined.

Resume : The structure and morphology of metallic nanofilms deposited onto solid surfaces of inorganic and organic materials has been extensively studied. At the same time significant scientific interest is the investigation of metallic nanofilms deposited onto liquid surfaces of various organic and inorganic materials. In this paper we investigated the morphology of aluminum and tungsten nanofilms (ie, one of the lightest and one of the heaviest materials) with thickness of 5  150 nm deposited by electron-beam sputtering onto castor and diffusion oils surfaces, and also onto indium and tin metal melts surfaces. It is established that the metallic nanofilms of aluminum and tungsten deposited onto indium and tin melts were continuous and during last solidification the surfaces relief of these materials and all defects in their crystallization were replicated. When very thin tungsten and aluminum nanofilms (5  10 nm) were deposited onto liquid organic materials (castor and diffusion oils), the films were not yet continuous and were individual conglomerates that were at a considerable distance from each other. With an increase in the thickness of the tungsten film up to 100 nm on the same surfaces, it was already continuous though it was considerably corrugated. The aluminum film onto liquid organic surfaces was continuous though it was slightly corrugated already at film thickness of 50 nm and with increasing its thickness up to 100 nm the film became strongly corrugated, while maintaining its continuity. Thus, the possibility of thin films depositing even heavy metals onto liquid surfaces was shown and their morphology was investigated.

Resume : Tetragonal Zirconia-based ceramics are characterized by high strength, fracture toughness, corrosion resistance and bioinertness. The CoO additive provides bright blue colour of ceramics and makes them promising cutting tools. It was investigated the influence of synthesis method on the variation of physicochemical properties (phase and chemical composition, morphology, specific surface area, primary particles size) of nanocrystalline powders in the ZrO2-Y2O3-CeO2-Al2O3 system after heat treatment up to 1300 C. Starting powders were synthesized by hydrothermal synthesis in an alkaline medium and combined method of hydrothermal synthesis/mechanical mixing. It was determined that CoO reduced the temperature of low-temperature phase transformation F-Zr2-T-Zr2 and neutralized the Al2O3 influence on this transformation regardless of the synthesis method and manner of CoO introducing.

Resume : A thermodynamic analysis of the contact interaction of Tantalum with aluminum nitride, alumina and silica was carried out. Expected compositions of interaction products in investigated systems were determined. The wetting of Tantalum with Cu-Ni melts was studied. It was show that the Nickel addition to the Copper melt contributes to the intensive wetting of Tantalum (the contact angle at 1423 K decreases from 75 deg until full spreading). Strong brazed Tantalum compounds with aluminum nitride and alumina-ceramics VK 94-1 were received. The bending strength is more than 60% from the strength of the brazed ceramic. The microstructure of brazed joints has been studied too. The positive role of Nickel in the formation of the brazed seam was fixed. It was show that the use of Ta foil as a ductile interlayer between brazed nonmetallic and metallic materials with significantly different thermal expansions has been perspective.

Resume : Realization of effect of Removal of an electric current allows to regulate process of removal of thermal and electric energy from a place of defeat of Cu-net by a lightning. This effect depends on a construction and properties of soldered knots of net. Wetting of wire surface by solder at creation of a wire net construction has great value. The studying wetting of compact materials on the base of pure Cu and bronzes (tin, beryllium, aluminum) by the low temperature alloys on the basis of Sn at 250–450 °C have been carried out. The sessile drop method with “capillary purification” method was applied. At wetting of bronzes by Sn–Ag–Cu solder showed the big activity in comparison with alloys Sn, Sn–Pb, Sn–Bi. Results on wetting of Cu and bronzes substrates by O-2 (Sn– ~99,95%), Sn–Pb (Sn–61 mass%), SAC (Sn–3,2% Ag–0,7% Cu), CASTIN (Sn–2,5% Ag–0,7% Cu–0,5% Sb) and Sn–Bi alloys showed, that Cu and beryllium bronze by alloys are wetted better. Sn–Ag–Cu solders were used for metallization and soldering of Cu-net construction. The Cu wire by thickness of 0.1 mm has been metallized, and the net with cells soldered in knitted-soldered construction was produced. Electrical resistance of О-2, SAC, Sn–Bi and Sn–Pb alloys as well as specific surface resistance of knitted-soldered copper net has been determined. It was established that metallization of Cu wire and soldering the knots of net influence on value of specific surface resistance of knitted-solder copper net essentially.

Resume : The alloys on the basis Ti, Zr, Nb, V are used, as the welding alloys for soldering different ceramic materials, as structural materials, and recently, as amorphous metal materials. However isothermal melting and homogenisation of such alloys were impossible. For following reasons Ti, Zr, V, Nb- containing alloys have high activity in a contact to the majority of standard refractories. Earlier we studied wetting of CaF2, BaF2, MgF2, SrF2 by metal alloys. The anomalous phenomenon – non-wetting at high temperatures and abnormal inertness effect of fluorides to contact with aggressive alloys with large contents of Ti, Zr, V, Nb have been established. It allows, to use refractory fluorides as refractory for manufacturing products from them (crucibles, cups), which can be used for melting and homogenization of chemically aggressive alloys. At melting of such alloys in fluoride crucibles it has been established, that due to the big differences in factors of temperature expansion (factor for fluorides on much more than factor for metals) a mechanical compression of an alloy, which is cooled, in crucible occurs. It results to destruction of the crucible. To resist to such phenomenon and taking in attention the wetting of fluorides by such alloys (the big contact angles) we have suggested to use for melting and homogenization of such alloys the crucibles, which are disassembled. The crucible will consist of several parts. Such crucibles it is possible to use a plenty of times.

Resume : Composite films on the base of thermoplastics filled by carbon nanoparticles are interesting for production of electro conducting polymer materials. The results of investigations of carbon nanoparticles (nanoplates) produced from pine chips by means of carbonization and following milling as a filler of electroconductive composites are presented. Their sizes in plane are from 0,1 µm till several tens of microns and their thickness is not exceed 100 nm. The values of electrical conductivity of nanoplates which had been measured according to original method are about 10-2 ? 10-3 Ohm cm. Introduction of nanoparticles to polyethylene matrix had been performed by means of joint mixing of polyethylene granules and preliminary produced carbon nanoparticles in planetary mill. The values of the content of carbon nanoparticles were equal 0,1; 0,5 and 1mass.%. Optimal values of milling duration and concentration of carbon nanoparticles in composite had been determined on the base of the results of the measurements of electrical conductivity and strength of the produced films. Presented results allow to consider planar carbon nanostructured particles produced from plant raw materials as a perspective filler for electro conducting polymer based composite films.

Resume : A novel power generation with no temperature difference has been performed by using polycrystalline Ba8AuXSi46-X clathrate with p-n junction. The sample was sintered with a powder consisted of n-type Ba8Au4.5Si41.5 clathrate and p-type Ba8Au5.5Si40.5 clathrate powder layers by using a Spark Plasma Sintering method. The sintered sample was cut to contain the interface of two layers for power generation without temperature difference at 27-500 °C. Electric voltage can be observed around 2.0 mV at 500 °C. Samples of Ba8AuXSi46-X (X = 4.0, 6.0) and Ba8AuXSi46-X (X = 4.8, 5.2) were also prepared in the same way. The generated voltage under uniform temperature increases with difference of the Au chemical composition. This power generation mechanism needs a material with a wide band gap n-type, a narrow band gap intrinsic semiconductor, a wide band gap p-type semiconductor junction. The electrical properties of the Ba8AuXSi46-X clathrate dramatically change depending on the Au composition. The generated voltage can be observed by heating and the voltage increases with difference of Au composition between n- and p-type semiconductors. The novel electric power generation is anticipated to improve the energy conversion efficiency compared to Seebeck effect because electric power can be obtained only by raising the temperature with no temperature difference.

Resume : During casting a suspension in a thin layer, the tape surface can be fractured because of suspension collection into drops due to poor wetting of the lyophobic surface of the carrier. There are several ways to solve this problem: change the chemical composition of suspension to improve the wetting or use of substrate without lyophobic coating. Of particular interest is the method of eliminating defects when both methods are unacceptable. For suspension creation as solid phase was used BaTiO3 nanopowder produced by «Nanotechcenter» (ua) with a particle size of 20 - 25 nm. As the organic binder was used a polymer solution of polyvinyl butyral (PVB) with molecular weights from 40 000 to 75 000 g/mol in organic solvents ethanol and butanol. Dibutyl phthalate was used as the plasticizer. In this work was used the suspension of the following composition: the concentration of the polymer solution from 5 to 10 wt. %, The ratio of polymer plasticizer: 2:1, ratio of powder polymer solution: 1:2. TTC-1200 tape casting machine where used to obtain tapes. Improvement of suspension wetting angle was acquired by its pre-cooling. Cooled to 5ºC suspension shows a reduction of wetting angle to the substrate by 7º. Roughness criteria of the tape obtained from pre-cooled suspension with a temperature of 5 °C were: Rz = 85 nm, Ra = 24 nm. The average thickness was 350 nm and tapes show good continuously. Roughness criteria of the film obtained from the suspension with a temperature of 25 ºC were: Rz = 110 nm, Ra = 43 nm. The average thickness was 900 nm and a tape was strongly fragmented. The obtained data shows that pre-cooling of suspension is not only improved continuously of the tape on the lyophobic carrier, but also reduce the thickness and roughness of the film.

Resume : Metakaolin based geopolymer matrix composites reinforced with different volume fractions of high-modulus short polyvinyl alcohol(PVA) fibres (PVAf/geopolymer composites) were prepared and the mechanical properties, fracture behaviour and microstructure of as-prepared composites were studied and correlated with fibre content. The results show that short PVA fibres have a great strengthening and toughening effect at low volume percentages of fibres (1.5and 2 vol.%). With the increase of fibre content, the strengthening and toughening effect of short PVA fibres reduce, possibly due to fibre damage, formation of high shear stresses at intersect between fibres and strong interface cohesion of fibre/matrix under higher forming pressure. The property improvements are primarily based on the network structure of short PVA fibre preform and the predominant strengthening and toughening mechanisms are attributed to the apparent fibre bridging and pulling-out effect. This composite was expected to be used as a coating to protect reinforced concrete against corrosion.

Resume : Multilayer reaction films are used in the technology of permanent connection of various materials. For transformation of solder from a solid to a liquid state used a heat effect of exothermic reaction of formation of intermetallic compounds. As initial materials were used powders of aluminum and nickel. The mixing of the pure powders was carried out in the gravity type mixer for 4 h. Mechanical activation was provided in a planetary for 5 min at 600 Rev/min in argon-gas area. The obtained micrograph of the initial powder compound showed that the particles of aluminum powder are spherical in shape with an average particle size from 5 to 10 μm, the nickel particles were smaller and have had a spongy structure. As a result of mechanical activation produced large composite particles, with a diameter about 800 μm. The product of the reaction of combustion of the tape obtained by rolling of the initial compound is the totality of phases AlNi, Al2Ni3. As a result of combustion of the tape obtained by rolling of mechanically activated mixtures formed a single phase structure corresponding to the equilibrium phase AlNi. Thus, the mechanically activated powders by rolling the obtained multilayer reactive foil, with the effect of SAF, with the onset temperature of exothermic effect, at least 50 ºC lower than in strips of similar composition made by multiple rolling. Indirect estimates in the received samples, the interlayer distance is in the range from 40 to 120 nm, which is comparable to multi-layer foils made of magnetron sputtering. The proposed method is cheaper than average and significantly exceeds their performance.

Resume : The use of scalable methods to build-up graphene-based nanostructures endowing advanced functional properties are highly desirable for practical applications. Achieving a large area coverage of pristine graphene is still a major limitation for the applicability of this material. As an alternative, in this work, we present a graphene based polymer composite soluble in water promising to be exploited in energy storage, electrodes fabrication, selective membranes and biosensing. Graphene oxide (GO) was produced by the traditional Hummers´ method being further reduced in the presence of poly(styrene sulfonate) sodium salt (PSS), thus creating stable reduced graphene oxide (rGO) nanoplateles wrapped by PSS (GPSS). Molecular dynamics simulations were performed to better understand the interactions between PSS molecules and rGO nanoplatelets, with calculations supported by FTIR analysis. The simulations elucidate the GPSS self-organized structure governed by intermolecular forces without chemical adsorption. The formation of the soluble GPSS permits the fabrication of high quality layer-by-layer (LbL) films with polyalillamine hydrochloride (PAH) without hindrance electronic properties of rGO. Raman and electrical characterizations corroborated the successful modifications in the electronic structures from GO to GPSS after the chemical treatment, resulting in (PAH/GPSS) LbL films four orders of magnitude more conductive than (PAH/GO).

Resume : Solid oxide fuel cell (SOFC) is a device for production of electrical energy from chemical reaction between oxygen and hydrogen, which react via solid / ceramic electrolyte. These fuel cells provide many advantages over traditional energy conversion systems including high efficiency, reliability, modularity, fuel variety, and very low levels of emissions. Quiet, vibration-free operation of SOFCs also eliminates noise usually associated with conventional power generation systems. SOFC hold the greatest potential of any fuel cell technology with low cost ceramic materials. SOFCs operate at relatively high temperature (600-900 °C). This high temperature gives them extremely high electrical efficiencies, and fuel flexibility, both of which contribute to better economics, but it also creates engineering challenges. The goal of the study was to compare electrical properties of different SOFC made along different technological approaches and tested at the same conditions. To date, two types of SOFC have been compared, namely, fuel cells used fabricated with tape casting technique at Frantsevich Institute for Problems of Materials Science (IPMS), and the second one those are available commercially. The electrochemical performance of the cells was tested at temperatures between 600 and 800 °C using humidified pure hydrogen (~5%) in a mixture with argon (~95%) as a fuel and air as an oxidant. The obtained data demonstrate much better performance of the SOFC newly developed; they will be used for structural optimization of SOFCs and their manufacturing route.

Resume : During cathode codeposition of metals with molybdenum (tungsten) from oxide tungstate-molybdate melts, the following factors are the key: the difference between the standard electrode potentials of the alloy components; the similarity of their crystal lattices; the rate of mutual diffusion of the alloy components atoms. With closeness of the standard electrode potentials values (Eo < 0.2 B) of the coprecipitated metals and with similarity of their crystal lattices (Mo-W case), the cathodic process proceeds under conditions close to equilibrium. In this case, it is possible to obtain continuous deposits of components alloy throughout the entire composition range. With Eo > 0.2 B and different types of crystal lattices (Mo(W)-Ag(Cu) cases), the cathodic process occurs under conditions far from equilibrium. In this case, the formation of deposits of three types: spongeous, deposits of one component sprouted by dendrites of other component, and acicular. With Eo < 0.2 B and different crystal lattices (Mo(W)-Ni(Co) cases), the cathodic process occurs, as in the first case, under conditions close to equilibrium. In this case, it is possible to obtain continuous deposits of intermetallic compounds. With Eo > 0.2 B and crystal lattices of the same type (Mo(W)-Re case), the cathodic process occurs under conditions far from equilibrium. In this case, inadherent powdered deposits are usually formed.

Resume : In many cases, the functionality of the product is determined by the properties of their surface. Having strengthened the surface layer, it is possible to increase the service life of shafts, bearings, cutting tools and other products, which are affected by intensive wear, by an order of magnitude. Wear resistant coatings are used in the aerospace industry, nuclear power, automotive industry, in the manufacture of tool materials. The usage of coatings can increase the life of products by several times, saving costly and scarce metals. Any structural obstacles arising on the path of the moving dislocations, increase the strength limit of the material, but also reduce the fracture toughness, and vice versa. Overcoming this contradiction, it can be made a composite material that combines sturdy, solid inclusion with plastic, viscous, crack-resistance matrix. The created powder materials can be successfully used for process of wear-resistance coating. The affinity of the chemical compositions of the base and the coating creates good conditions for ensuring between them a strong adhesion - one of the most important conditions for high working capacity of the product. In this regard, the development of iron-containing wear-resistant coatings for aerospace components made of iron alloys seems to be relevant and promising. Comparative studies of the resistance to abrasion of detonation coatings based on iron aluminides have shown that the coating with an intermetallic matrix structure with inclusions of solid phases in the form of oxides has the highest indices. The lowest resistance to abrasion wear has a coating whose microstructure base represents a two-phase mixture of relatively soft intermetallic phases. Thus, the issue of ensuring the working capacity of iron alloys in various engineering constructions can be successfully solved by using coatings from mechanically synthesized powders based on the Fe-Al system. The proposed method of detonation spraying of these coatings with the optimal choice of the technologic parameters provides good adhesion of the obtained coatings, that can be easily verified by visually analyzing the coatings partially worn down to the main material by the flow of abrasive particles. The transition from the base to the coating has the smooth nature, there is no step, which indicates a high adhesion strength, capable of retaining the coating until it is completely worn with abrasive particles.

Resume : Co-precipitation of molybdenum (tungsten) and nickel from oxide tungstate-molybdate melts is a typical case of electrodeposition of alloys, the components of which have different types of crystal lattices and close values of electrode potentials. Addition of a molybdenum (VI) oxide to a nickel-containing tungstate melt reveals a wave of reduction of the dimolybdate ion. The difference of the deposition potentials of nickel and molybdenum is 0.090-0.115 V at 1173 K. Electrodeposition was carried out at cathode current densities 0.05-0.1 A/cm2 within the temperature range 1123-1173 K. Concentrations of MoO3 and NiO were varied within 0.025-1.0 and 0.05-1.5 mol. %, respectively. At various ratios of MoO3 and NiO concentrations, it is possible to deposit continuous layers of MoNi, MoNi3, and MoNi4 intermetallides. The regularities described above are also characteristic for the deposition of tungsten-nickel alloys.

Resume : Experimental electrochemical measurements and thermodynamic calculations have made it possible to construct the relative and absolute acidity (basicity) scales for tungstate-molybdate melts of different cationic and anionic compositions. The most basic ones were melts containing NaBO2, Na3PO4, Na2CO3, Na2MoO4, and Li2CO3, the most acidic ones containing Na2S2O7, MoO3, Na4P2O7, Al2(MoO4)3, WO3, Al2(WO4)3, Na2B4O7. These scales are used to determine the relative acidity (basicity) of oxyanions or other particles exhibiting acid-base properties and to predict the structure of melts based on tungstates and molybdates, the composition of cathode products, and the nature of electrode processes and equilibria in these melts. To check quantitatively the reversibility of platinum-oxygen electrodes, the EMF of electrochemical chains in halide oxide and oxide melts were measured.The pre-logarithmic coefficients of the experimental dependences of the platinum-oxygen electrode potential on the concentration of oxygen ions correspond to the Nernst equation. Additional evidence was the absence of hysteresis in micro-polarization measurements. The stability and reproducibility of the potentials were also proven experimentally.

Resume : Hydrogen storage alloys are well known as a group of new functional intermetallics, which can reversibly absorb/desorb significant amount of hydrogen at ambient conditions. Over last decades, AB5-type rare eath-based hydrogen storage alloys have been widely used commercially as negative electrode materials in NiMH batteries. However, AB5-type intermetallic compounds suffer from relatively low discharge capacities (~320 mAh/g) that does not meet growing requirements for high energy and high power NiMH batteries. In recent years, a new family of AB3-type Mg-containing alloys with higher electrochemical capacity and good rate dischargeability was developed. These alloys are considered as the promising electrode materials for high performance NiMH batteries though the cycle stability and the overall electrode properties of AB3-type alloys still have to be improved. The electrode performances correlate closely to the composition homogeneity and phase homogeneity of the alloys, thus the development of suitable preparation techniques for homogenous alloys is essential. In the course of this research, experimental setup for the obtaining of alloys using the method of powder sintering in Ar gas was created. It includes the unit for gas drying and purification, which is crucial for the elimination of the possible oxidation during sintering. Thermal treatment of powder mixtures cold pressed in tablets was carried out in quartz reactor pre-filled with purified argon. The heating in La-Mg-Ni system was conducted stepwise, primarily to 630 – 650 °C aiming at introduction of Mg into the alloy followed by heat treatment in the temperature range of 850 – 1050 °C. Preliminary results suggest formation of non-stoichiometric compounds in the studied system that inspires further research.

Resume : In this study, we have attempted to develop a plasma-assisted pulsed laser ablation (PLA) technique to obtain functional particles in liquid. Oxygen atmospheric-plasma (AP) particles as oxidation agents were generated using barrier dialectic-discharge system. AP particles were ejected to liquid as a reaction solution for PLA. A laser target dipping in the liquid was ablated by focused laser beam (Nd: YAG laser, wavelength: 355 nm or 1064 nm) irradiation. Functional particles were produced by a chemical reaction of ablation plumes with the liquid including AP particles. Just after the ablation, a drop of water containing fine particles was casted onto a metal grid plate for transmission electron microscope observation. We have observed the existence of many nano-particles (diameter: below ~ 50 nm). Crystallizations of them were measured by X-ray diffraction method.

Resume : Composite materials based on hydroxyapatite are widely used for bone tissue engineering. There is evidence of a positive effect of the presence of strontium in osteoplastic materials in the case of a Ca/Sr certain ratio. To examine the effect of the addition of Sr2+, a study was made by introducing it into the material composition based on biogenic hydroxyapatite and sodium silicate glass phase (85/15 % wt.). The strontium was introduced into the composition in an amount of 1% wt. Composite materials were obtained at sintering temperatures of 500 and 780 °C and a sintering time of 1 hour. The effect of additions of glass phase and strontium affect changes in the crystal lattice of biogenic hydroxyapatite was investigated with the help of X-ray phase analysis. Changes in the parameters of the crystal lattice (periods a and c) occur even at a temperature of obtaining composites of 500 °C. When strontium oxide is added, the crystal lattice changes in the periods (004), (211), (202) and the relative intensity I(202)/I(211) increases, which indirectly confirms the partial replacement of calcium ions by strontium ions in the structure of biogenic hydroxyapatite. Also the behavior of composites in vitro in physiological solution was studied.

Resume : The work is devoted to investigation of composite powders formation methods influence on the structure and functional characteristics of the NiAl-CrB2 plasma-sprayed coatings The serial powders of NiAl intermetallic compound and chromium diboride have been used as basic materials for the experiment. The NiAl-15 (30) wt. % CrB2 composite powders for coatings deposition were obtained by three different technologies: by conglomeration of mechanical mixture of initial powders on the organic binder; hot pressing technique and sintering in vacuum of a mixture of the initial components with following briquettes grinding to powder with a particle size -100 70 microns. The results of friction surfaces structure investigation after wear testing have shown that the method of powder particles obtaining, using a hot-pressing technology or sintering, is the most appropriate. Coatings made of powder mixtures, which were obtained due to this technology, showed less areas with damages of materials. It was investigated that enrichment of the diborides additives content in the intermetallic coating to 30wt. % leads to wear rate of coating increasing, because coating becomes more brittle. Refractory particles (diborides) pulling out from the coating and amount of abrasive in friction zone increases, thereby increasing the wear rate of coating. It was established that the additives of borides into intermetallics leads to the formation of oxide tribo-films which further behaves as solid lubricant that prevents the adhesive seizure of contact surfaces and improves wear resistance of tribo-couple.

Resume : The aim of our work was to compare the ionic conductivity of conventional 8YSZ and promising 10Sc1CeSZ electrolytes for solid oxide fuel cells (SOFC) obtained from the widely used commercial powders as well as to establish the factors which make the main contribution to the resistance and activation energy of ceramics obtained under identical technological conditions. 10Sc1CeSZ electrolytes were obtained from three different types of 10 mol.% Sc2O3 – 1 mol.% CeO2 – 89 mol.% ZrO2 powder (1 – VMMC, Ukraine; 2 – DKKK, Japan; 3 – Praxair, USA). The admixtures percentage was about 0.01 wt.% – for the type 1 (mainly silica and alumina) and type 3 (mainly silica and titania); and 0.001 wt.% – for the type 2 of the powders. 8YSZ electrolytes were obtained from the 8 mol.% Y2O3 – 92 mol.% ZrO2 made by Tosoh, Japan. After 24 h milling and 30 MPa pre-pressing the samples were sintered at 1400 °С in the air. The grain size of all three types of the 10Sc1CeSZ ceramics was about 0.5-1 μm. All the 10Sc1CeSZ and 8YSZ samples had ionic conductivity not lower (0.019-0.059 S/cm at 600°C) and activation energy not higher (0.88-1.07 eV) than its known from the literature. It was shown that grain boundary conductivity prevails in YSZ electrolytes due to the higher association enthalpy of the grain at temperatures below 560°C which depends on the dopant size. In 10Sc1CeSZ electrolytes the charge transfer passes mainly through grains: the main contribution to the grain boundary resistivity in technically pure materials (type 1 and 3) is given by the SiO2 segregations at the grain boundaries; and grain-to-grain contacts – in highly pure materials (type 2). Grain boundary resistivity of the type 1 samples was two times higher than the type 3 samples due to the presence of Al2O3 admixtures and its scavenging effect for the SiO2 segregations known for its conductivity diminishing.

Resume : The development of modern technology requires the creation of new materials that will resistance in the damaging water environments conditions. That is why there is a need to create new composite materials that guarantee the reliability and the appropriate level of functional properties including in corrosive environments. Particularly acute is now the problem of hydropower equipment parts protection (water-turbine engines blades) from hydro-abrasive wear and cavitation. In this work as a matrix for new composites creation selected intermetallic NiAl and NiTi, as well as reinforcing additives - chromium borides. These borides are resistant to corrosion and cavitation wear. The complex researches of developed composite materials on cavitation and hydro-abrasive resistance were conducted. Cavitation studies of starting materials and developed composites from them were performed using an ultrasonic disperser for 30 hours. As working environment a tap water was used. Steel was used as reference material. It is shown that the surfaces structure of intermetallics and the developed composites after tests in all cases without special mechanical damages. The original NiTi material is characterized by the presence of local single damage sites. In addition, as a result of the tests carried out, it can be concluded that for this material the effect of cavitation is expressed in the etching of the material surface under study. At the same time, grain boundaries begin to appear. The remaining materials at this stage of the study are characterized by the absence of any visible structural changes. In contrast to the above materials for the steel sample, after 2 hours of testing, there are areas of surface damage in the form of ulcers or shells. After 6 hours of cavitation, the whole surface under investigation contains separate foci of failure, which is associated with the production of the ferrite phase of this material. The structure and hydro-abrasive resistance of NiAl and NiTi intermetallides , as well as developed composites materials NiAl (NiTi) -15% CrB2 and NiAl (NiTi) -30% CrB2 after the tests for 20, 40 and 80 hours were studied. Tap water was also used as the working medium; silicon carbide was used as an abrasive material. It is shown that the surfaces structure of the initial intermetallides and the developed composite materials is characterized by the absence of the sites of material destruction. The effect of the impact is the polishing of the materials surfaces. The surface of such materials after the tests practically does not wear out compared to steel.

Resume : Mineral trioxide aggregate (MTA), mainly consisting of Portland cement and bismuth oxide, is a commonly use dental filling material. Within MTA, bismuth oxide serves as the radiopacifier and canal filling effect after clinical treatment can be revealed. In the present study, hafnia was used to replace certain amount of bismuth oxide by using either sol-gel process followed by post heat treatment or spray pyrolysis method. The structural and morphological properties of the so-prepared bismuth/hafnium oxide composite powder was examined by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The optimum composite composition was added with Portland cement and then mixed with deionized water to investigate its solidification characteristics. Experimental results showed that, by using bismuth/hafnium oxide composite powder, a significant improvement in radiopacity can be noticed. The best radiopacity performance can be observed with 10 mol.% hafnia addition. The heat-treated sol-gel composite powder exhibited a radiopacity of 6.26 mmAl. Whereas spray pyrolyzed composite powder exhibited a radiopacity of 6.41 mmAl, that is the highest in the present study.

Resume : In this study, we developed a novel ?green? nanocomposite based on graphene oxide (GO) and titanium dioxide nanoparticles (TiO2 NPs) with targeted application in a memory devices. GO was synthesized by using the conventional solution method (Hummers? method) followed by surface modification by ?green? reductants. While TiO2 NPs were synthesized using green chili plants as the bio-mass precursor for the NPs. Nanomaterials were studied by complimentary techniques: NPs demonstrated the average size of 10 - 20 nm and their optical absorption spectra revealed a sharp absorption around 385 nm corresponding to an optical bandgap of TiO2 ~3.22 eV. The X-ray diffraction pattern confirmed a dominating anatase phase, primarily textured along (101). Raman spectra of GO has demonstrated both D and G bands, as well as 2D line, peculiar for 2D carbon materials. The presence of carbonyl (40%), carboxyl (17%), epoxy (3%) and oxygen substitution functional groups was identified and quantified on GO surface using XPS spectroscopy. It is observed, that upon reaction of GO with diverse ?green? reductants (Glucose, Vitamin C and Caffeic Acid) the surface chemistry and functional groups availability on graphene surface is modified differently, affecting its properties. . The memory effect of ?green? nanocomposite is investigated as a function of GO to TiO2 NPs ratio. In order to fabricate a simple resistive switching memory device, Pt (90 nm)/Ti (10 nm) metals were deposited by using e-beam evaporation technique. The devices (Pt/Ti/GO-TiO2/Pt/Ti) with 2:1, 1:1, and 1:2 ratios of the component materials were screen-printed and characterized by using current-voltage (I-V) sweeping. The switching properties were varied significantly with the changing components ratio, which proves the potential of the novel green nanocomposites for nonvolatile resistive memory devices for future printed electronics, smart labels, RFID tags etc.

Resume : Pressure sensors can generate signals under certain pressures and operate in a manner, namely, signal transduction. This prominent feature enables the successful application of pressure sensors in personal electronic devices, artificial intelligence and industrial production applications. The rapidly advancing electrical sensing techniques and organic electronics have contributed to significant progress in the development of flexible pressure sensors, which possess unique advantageous properties such as outstanding flexibility, low cost, and compatibility with large-area processing techniques. In particular, many flexible pressure sensors based on organic materials have been fabricated, and their sensing capacities even surpass human skin, the largest sensory organ with thousands of specialized pressure-sensing receptors. Through large-area integration of flexible devices, active sensing matrices have been fabricated which tend to be ideal candidates for electronic skin (e-skin) applications. Here, we introduce a simple pressure sensor structure of Al/parylene which is easily fabricated on a large area and applicable for flexible or wearable sensor networks. The sensing properties such as sensitivity, limit of detection, linearity, and response time are discussed.

Resume : In lightning protection panels consisting from layered carbon plastic protection of the material from the action of electrical charges of lightning and Joule heating is realized due to number of dissipative processes. Usually it is considered removal of electrical charges from the place of injury through the meshes or grooved foils at the surface of carbon plastic into earthing (winding energy systems) or into oncoming stream (aviation). Additional mechanism of energy dissipation which can be technically realized by introduction of carbon nanoparticles into epoxy binder (situated between carbon fibers) and creation of conducting dielectric had been considered. The level of electrical conductivity can be regulated by changing of the concentration of carbon filler and using of prepreg technology of carbon plastic production. By arranging into the panel the laminate layers filled by carbon nanoparticles it is possible to absorb the part of lightning energy by heating of carbon plastic. In that case it is necessary to avoid the essential heating which can cause composite local burning and electrical arc in the air space of the blade. The proposed method is based on the using of mutual influence of the parameters of the surface resistance of carbon laminate and the electrical conductivity of the volume of the composite matrix. The example of the calculation of electrical conductivity of layered carbon plastic reinforced by carbon nanoparticles with enhanced resistance to the local burning due to lightning had been presented

Resume : Composite construction for protective ceramic elements from reaction sintered silicon carbide and polymer supports based on glass fabric TG-660. Epoxyurethane oligomers with polyoxypropylene (ПЭУ-1) and oxytetramethylene (ПЭУ-7) fragments with hardener of anhydride type had been synthesized. For various ratio oligomer:hardener angle tangent of mechanical losses, dynamic elastic modulus and losses modulus had been measured. It was shown that polyepoxyurethanes may be used as damping compositions and optimal composition for polyepoxyurethane is the composition with 5 wt. parts of hardener. Ceramic-polymer composites with supports based on polyepoxyurethane matrixes are characterized by the high values of impact resistance under small outbarrier deformation (not more than 10 mm). In ceramic-polymer composites with discrete structure (on the base ofceramic elements of cylinder forms) polyepoxyurethane matrixes showed the high level of physical and mechanical properties and adhesion to ceramic, increased values of life cycle and decreasing of the weight of protective constructions

Resume : The influence of preliminary mechanical activation (MA) of 80 vol.% ZrB2–15 vol.% α-SiC–5 vol.% B4C raw mixture in a high-energy activator for 15, 30, 60 and 120 minutes on its structural-phase state has been studied. X-ray diffraction analysis of the initial powders and milled (activated) products showed a broadening of the diffraction lines profile with an increase in the mixtures grinding time, that indicates the nanocrystalline structure of the polycrystals (Scp-10 m2/g). The microstructural analysis (by SEM "JEOL") showed the formation of nanostructured particle agglomerates with an increase in MA time. Chemical analysis of MA products showed the iron presence in mixtures, the amount of which increases with grinding time and was 3.55, 4.66; 5.31 and 5.09 wt.%,respectively. Hot pressing of MA mixtures was carried out in graphite molds without a protective atmosphere. In order to study the formation of the ceramics structure at hot pressing, mixtures of 80%vol. ZrB2– 15% vol. α-SiC– 5% vol. B4C system after MA were hot pressed under isometric conditions in two regimes: 1– at 2100 °C for 5 min. and 2 –at 2150 °C for 15 minutes. The calculated density values (ρ, g/cm3) increased with the increasing of MA time, sintering temperature and duration according to theregimes, for regime1: 4.61, 4.90, 4.90 and 4.52 g/cm3; and for regime 2:4.84, 5.11, 5.15 and 5.43 g/cm3. A similar regularity was found for σbend, which average value for the regime1 is 350 MPa, and for the regime 2 it is 468 MPa.The structure of hot-pressed samples from mechanically activated mixtures of 80 vol.% ZrB2–15 vol.% α-SiC–5 vol.% B4C system shows more uniform phases distribution and fine-grained structure in comparison with the same samples without MA.

Resume : It is very difficult to obtain nonporous and fine-grained ZrB2 pure ceramics by hot pressing. The study of the processes of ultra-high temperature ceramics (UHTC) formation, which combines the stages of carbothermal reduction of ZrSiO4, the synthesis of ZrB2 and SiC at hot pressing in the ZrB2-B4C-ZrSiO4-C system has been carried out. Thermodynamic calculations of ZrSiO4 interaction reactions depending on the carbon content in the mixtures (1 to 8 mol) were carried out in the temperature range of 1000-2000ºС. Calculations showed that the most complete decomposition of zircon ZrSiO4 to ZrO2 and SiO2 with the formation of ZrC and SiC should proceed by the ZrSiO4 + C reaction at carbon content of 4-8 moles at about 1750ºC. The optimal conditions for reactive hot pressing sintering of the ZrB2-B4C-ZrSiO4-4C composition in temperature range of 1970-2150ºC at duration of 5-30 minutes has been developed. Herewith, the obtained material has uniformly distributed fine-dispersed ZrB2 and SiC phases, according to the microstructural and X-ray phase analysis, with high density and strength characteristics (ρ = 5.29 g/cm3 and bend = 594.12 MPa.). Apparently, when the ZrSiO4 decomposes into ZrO2 and SiO2, the reaction of 2ZrO2 + B4C+3C = 2ZrB2 + 4CO(g) occurs with the formation a secondary ZrB2. Herewith, SiO2 is reduced to SiC. Combining the carbothermal synthesis of nano-SiC at hot pressing promotes the formation of composites with uniform components distribution and allows to avoid the additional stages such as obtaining a highly disperse SiC powder, mixing and co-grinding of the powders.

Resume : The creation of reusable aerospace vehicles that come back to the Earth after the flight task accomplishment will significantly decrease the cost for insertion of cargos to the orbit. Today there are dozens of projects dedicated to reusable transportation aerospace systems at different development stages with diverse structural schemes. The most promising are two stages systems (German project “Zinger”, French project “Hermes”) that possess acceptable exploitation characteristics when using first stages with wings in order to come back to the starting place as a plane. One of the main issues during the creation of reusable flight vehicles is creation of heat-resistant and heat-protective materials and structures. The analysis of thermal operational modes shows that the most problematic are surfaces, which operational temperatures lay in a range of 850 ˚С to 1200 ˚С. The siliconized carbon-carbon composite materials, high-temperature ceramic and heat-resistant metallic alloys can be used in the above-mentioned temperature range in air environment. The most perspective materials are heat-resistant alloys with low-density and high specific performances, while metals are the most reliable structural materials. The advantages of metals are conditioned by their ability to plastic flow and self-reinforcement. Based on analytical review of scientific research results it was defined that one of the most perspective materials are multicomponent alloys based on niobium with high mixing entropy and aging nickel alloys that represents the alloy Ni-Cr-Тi-Аl. The target of this work is creation of aging nickel alloys and alloys based on niobium with high mixing entropy. As a result of performed study, two casting alloys were created - 56Nb-10Cr-10Al-16Ti-5Mo-2Zr-1Si and Ni-20Cr-3Al-2Ti and their properties were investigated within the temperature range of 20 ˚С -1200 ˚С. The work performed based on Grant Agreement № 607182 within the Seventh Framework Programme (FP7/2011-2014), “Light TPS”.

Resume : In the present study, DC-sputter deposition (of Ti-6Al-4V) followed by nitriding (by plasma nitriding and plasma ion implantation) have been adopted for developing ultra-fine nano-nitride dispersed surface on AISI 316L stainless steel substrate. Followed by sputtering and nitriding, a detailed characterization of the surface (in terms of microstructure, phases and bond strength), and its mechanical properties (nano-hardness, Young?s modulus and coefficient of friction) have been carried out. The microstructure of the sputtered Ti-6Al-4V consists of very fine particulates of alpha in the form of clusters. Plasma nitriding and nitrogen ion implantation of the sputter deposited titanium lead to formation of ultra fine white precipitates of titanium nitrides dispersed in the ? matrix. The adhesion property of the coating has been evaluated through nano-scratch testing. An enhancement in bond strength has been observed after nitriding which is attributed to nitride formation and with a maximum adhesion strength observed due to ion implantation because of a higher depth of penetration of nitrogen and finer nitride formation. The maximum improvement in Nano-hardness and Young?s modulus after nitrogen implantation is due to the presence of nitrogen in solid solution and formation of nitrides.

Resume : Aluminium matrix composite reinforced with different weight percentage of functionalized graphene nano platelets (GNPs; 0, 0.25, 0.5, 1.0 wt%) were fabricated via semi-powder metallurgy method and spark plasma sintering. Microstructural characterization was conducted via field emission scanning electron microscopy equipped with electron dispersive spectroscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy. Tensile properties of the nanocomposites were also evaluated. Atomic force performed on the (GNPs) showed that GNPs were having less than 10 layers of graphene. Al-0.5 wt% functionalized GNP composites showed homogeneous dispersion in Al matrix and no chemical reactions were seen at the interfaces between Al and GNPs. The tensile test revealed 33% increment in yield strength of Al-0.5 wt% GNPs. Further, increase in GNPs concentration (1.0 wt%) resulted in decrease in tensile properties attributed to agglomeration of GNPs present in Al matrix. The roles of strengthening in composites were discussed with different possible strengthening mechanisms. Detailed fractography cariied out on the nanocomposites indicate a change of fracture mode from ductile to brittle with increase in the amount of GNPs. Keywords: Graphene nano platelets; Al matrix composite; Tensile properties; Spark plasma sintering; Strengthening mechanism

Resume : The present investigation, a detailed study of wear behavior of titanium based foam developed by powder metallurgy route has been carried out. Titanium based foam has been developed by powder metallurgy route using cenosphere, NaCl and NH4CO3 as space holders under optimum processing conditions. Followed by processing, a detailed characterization of the microstructure and phase of the composite has been carried out. The wear behaviour of the samples has been evaluated by fretting wear testing unit against WC ball at varied applied load of 10 N and 20 N and an oscillating frequency of 10 Hz. The detailed objectives include understanding the role of space holders on the characteristics (microstructure, phase, composition, porosity) and wear behavior of the foamed coupons. Finally, the mechanism of wear has been investigated through a detailed observation of the post wear microstructures.

Resume : The fiber laser welding of Ti64 alloy to SS 304 by some pure intermediate layers were developed. The scope of this research is to improve the joint strength of materials pair by usage of composite interlayer sheets. The microstructure and fracture characteristic of the joints were analyzed by OM, SEM, EDS and X-ray diffraction. The intermetallic compounds were observed in the Ti/weld interface, and the joints all fractured at the Ti/Filler interfaces. In order to estimate the area which intermetallic phases formed in the weldment, the microhardness experiments were done on the cross section of each sample. First, laser welding done by pure Cu which laser positioned at the interface of titanium and stainless steel achieved joint strength of 227 MPa. In order to strengthen the joint strength of the weld, the pure nickel and vanadium sheets added to the copper which then showed the strength raised about 31 % and 51 %, respectively. The best value for cross-weld tensile strength of the joints was up to 343 MPa, recovering 51 % of titanium alloy strength. All experiments performed at the same laser power.

Resume : Development of modern highly-porous biomaterials for bone tissue engineering has been based on the enhanced knowledge of materials science and the way these materials interact at cellular and tissue levels. Highly porous glass-ceramics based on biogenic hydroxyapatite and SiO2-Na2O glass with addition of Aerosil® and sodium hydroxide solution have been prepared by foam replica method at sintering temperature 900 °?. The samples were examined by optical microscopy (binocular stereo microscope MEIJI Techno, Japan), XRD analysis (DRON-3M computerized diffractometer, Russia) and IR spectroscopy (FCM Fourier spectrometer, Russia). The compressive strength was determined by a uniaxial compression using a universal machine (Ceram test system, Ukraine). Experiments in vitro were carried out to estimate bioresorption of materials, in particular their solubility in the physiological isotonic solution (0.9 % NaCl water solution) at 36.5±0.5 °?. According to the XRD results it was established that during sintering, the hydroxyapatite phase (??5(??4)3(??), JCPDS No. 9-432) of biogenic hydroxyapatite in the glass-ceramics was not changed, which was confirmed by IR spectroscopy results. Prepared samples are characterized by a permeable macrostructure with total and open porosity of 85 and 80 %, respectively, and a compressive strength of 0.4 MPa. Based on in vitro experiments it was established that the bioresorption rate of glass-ceramics is equals 0.11 wt.%/day. Prepared highly-porous materials are promising for replacement of defective cancellous bone tissue in surgery. The publication contains the results of studies conducted by President?s of Ukraine grant for competitive projects No. F70/17295 of the State Fund for Fundamental Research

Resume : Human skin is an advanced functional material, playing a variety of vital functions in everyday life. Skin properties, structure and performance are all influenced by many internal and external factors, of which the level of hydration seems to dominate. Water on human skin arises from sweating and sweat accumulation or from external factors, such as rainfall or increased air humidity. Due to the presence of keratin, the stratum corneum (SC, horny layer of skin), is able to take up water leading to significant adjustments of its properties. Water uptake causes swelling of the cells within the SC, increasing its thickness and decreasing the surface roughness of skin. Moreover, water acts as a strong plasticizer on human skin and leads to a vast decrease in the SC stiffness (Young’s modulus drops from the GPa to the MPa range). Smoother and easier deformable hydrated skin exhibits higher real contact area with other materials and, as a result, higher friction-coefficient values. Here we propose a new bio-mimicking composite skin model, consisting of an elastomeric, pressure-triggered sweating system and a water-responsive layer, composed of gelatine and textile. The skin model undergoes the same skin-specific changes caused by prolonged water exposure; it swells, smoothens, softens and follows the same changes in the frictional behaviour. A water-responsive, pressure-triggered sweating skin model can be applied instead or next to the conventional in vivo investigations focused on the influence of various atmospheric conditions and sports activities on skin properties and frictional behaviour. Moreover, it can act as a suitable system to better understand the influence of water on human skin properties and performance.

Resume : Nowadays, intense research is focused on the development of “smart implants” based on biodegradable metallic materials. We report a new type of thin films obtained from two independent materials collected on a single biodegradable metallic substrates by Combinatorial Matrix Assisted Pulsed Laser Evaporation (C-MAPLE) technique. The coatings were obtained using a KrF* excimer laser source (λ = 248 nm, τFWHM ≤ 25 ns). The aim of this study is to enhance the cellular adhesion of surrounding tissue to the biodegradable substrate by finding the optimal ratio between tow biocompatible metamaterials: Ligning to Chitosan. The obtained coatings preserved their initial composition, as demonstrated by physical-chemical analyses: Optical Florescence Microscopy, Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), inductively coupled plasma mass spectrometry (ICP-MS). Electrochemical measurements, impedance spectroscopy and in vitro immersion tests were conducted to evaluate the corrosion resistance of the uncovered and covered biodegradable metallic substrates into physiological fluids. In vitro assay revealed that the obtained thin films are non-cytotoxic. The antimicrobial effect of the covering layers was tested against S. aureus and E. coli strains, involved implant associated infections. The deposited films where monitored over a timeframe of 8 and 24 hours, to monitor the antimicrobial evolution of the two bacteria, and the according ration between lignin and chitosan. The results proved that C-MAPLE method allow for the fabrication of efficient shield barriers against corrosion, biofilm formation and contamination with bacteria.

Resume : The problem of creating suitable materials for prostheses used in the damage of bone tissue is acute permanently. There are various types of materials which are proposed for these purposes: a) inactive materials (some metals, for example Ti, Ta); b) bioinert materials (oxides, particularly, ZrO2, Al2O3), and c) bioactive materials (apatites, for example, Calcium hydroxylapatite (CaHap) or fluoroapatite (CaFap); phosphate or mixed phosphate-silicate glasses; other phosphates). The use of composites in which the bioactive material (CaHap or CaFap, for example) is combined with inactive or bioinert one to obtain a bioactive implant with high mechanical strength and durability reveals most promising. The studies of synthesis of nano-composite including CaFap, from one hand, and alumina, Al2O3 – from another – are carried out. Earlier we developed an essentially new way of synthesis of CaFap in saline melt (NaCl-KCl) at moderate temperature (700°C). At the synthesis of CaFap as initial Ca – containing components CaCO3, CaO, CaF2, and P – containing component NaPO3 were used. To avoid possible hydrolysis, the process is better carried out in an inert atmosphere (argon). The XRDA data suggested formation of well crystallized product. The washed out in water powders consist of nano-scale particles associated into the stick-like aggregates of various sizes. To obtain the nano-composite of CaFap and alumina in a weight ratio of 2 : 1 as initial components Ca10(PO4)6F2 and Al(OH)3 (the last is an industrial product) were taken. The synthesis of the composite CaFap – alumina was performed by solid – state route. Initial butch (mixture of powders) was pressed into pellet and sintered in three stages for 2 hours at each of them: stage 1 – 650°C, stage 2 – 1000°C, and stage 3 – up to 1350°C. After each stage the tablets were ground and pressed again. Thus we obtained rather strong tablets of white (with light gray tint) color.

Resume : High scalability and conductive fibers have important application prospects in the field of wearable devices. Using multi-scale structure coordination gain principle, we first proposed a imitation shell nano scale and micrometer screw structure combined with building materials, the micro is nano scale clay brick layer structure, the secondary structure is helical structure of the micron scale. The combination of these two kinds of structure gives the fiber with high elongation and high mechanical strength, so it has high toughness. In helical fibers into luminescence cadmium selenide (CdSe) quantum wires and found that the helical fibers in non polarized light under the excitation of a polarization of polarized light, polarized light (left-hand or right-hand) type is determined by the spiral direction of the fiber, the polarized light intensity can be regulated by mechanical deformation of helical fibers. References: (1)J Zhang, W Feng, H Zhang, Z L Wang, H A Calcaterra, B Yeom, P A Hu*, N A Kotov, Multiscale deformations lead to high toughness and circularly polarized emission in helical nacre-like fibers, Nature Comm, 2016, 7,10701 (2)X N Wang, Y F Qiu, W Cao, PA Hu, * Highly Stretchable and Conductive Core–Sheath CVD Graphene Fibers and Their Applications in Safe Strain Sensors, Chem. Mater, 2015, 27 (20), pp 6969–6975 (3)Z Ma, Y Qiu, H Yang, Y Huang, J Liu, Y Lu, C Zhang, PA Hu* Effective synergistic effect of dipeptide-polyoxometalate-graphene oxide ternary hybrid materials on peroxidase-like mimics with enhanced Performance, ACS Appl Mater Inter, 2015, 7(39), 22036-45

Resume : We demonstrate facile strategy to develop polymer composites with unusually enhanced electronic and thermal conduction behaviors via 3-dimensional (3D) Cu hollow networks. The composites with efficient Cu conduction pathway were easily prepared through the electroless plating of Cu on expanded bead (EBCu), followed by conventional thermal compression with polymer matrix. The EBCu/polycaprolactone (PCL) composites revealed excellent electromagnetic interference effectiveness (EMI SE) of 88 dB at 8 GHz as well as thermal conductivity of 5.1 W m-1 K-1 despite the extremely low Cu content of 6.8 vol%, resulting in decreased density of composites. Especially, the EMI SE and thermal conductivity values were rapidly increased with the decrease of density, because the increased EBCu content contributed to not only decreased density of composite but also formation of efficient Cu conduction pathway with low percolation threshold of 0.034.

Resume : Electromagnetic pollution and electromagnetic interference (EMI) caused by electrical and electronic equipment have increased substantially with the rapid development of information technology. Electronics and their components with higher power, smaller size and faster operative speed emit the unwanted electromagnetic waves, which not only lead to malfunctioning and degradation of electronics but also threaten human health and the surrounding environment. EMI shielding has become the effective method and key technology to protect human and environment from the negative effects, which is of great importance in both fields of the civil and military. In addition to high-efficiency EMI SE, being light weight and flexible are another two key factors for EMI shielding materials, especially in areas of aerospace, modern aircraft, communication, flexible electronics and wearable devices. In our previous work, super elastic and ultralight graphene/cellulose fiber hybrid aerogel with excellent EMI shielding effectiveness (SE) was developed [1], and the effect of graphene aerogel pore size on EMI SE of epoxy composites was investigated [2]. In present study, large-sized graphene sheets (LG) and doping strategy were employed to fabricate lightweight and flexible graphene paper with exceptional EMI shielding performance. Compared with the smaller sized ones, LG with fewer defects and more conjugated carbon domain size as well as better alignment result in higher electrical conductivity and strength of graphene paper. The iodine doping further improves the carrier density of LG by formation of triiodide ("I" _"3" ^"-" ) and pentaiodide ("I" _"5" ^"-" ) through charge transfer process without deteriorating the mechanical property, thus leading to superior EMI shielding effectiveness (SE). The EMI SE of iodine doped LG film with thickness of 12.5 μm is up to ~ 52.2 dB at 8.2 GHz, which is much higher than that of undoped LG with the same thickness (~ 47.0 dB). More important, the improvements in EMI SE is contributed to the SE absorption, while the SE reflection is almost unchanged. The mechanisms of improved EMI shielding performance as well as mechanical property were investigated and discussed. The present study provides a facile way to fully develop graphene in lightweight and flexible EMI shielding materials and devices. References: [1] Wan Y-J, Zhu P-L, Yu S-H, Sun R, Wong C-P, Liao W-H. Ultralight, super-elastic and volume-preserving cellulose fiber/graphene aerogel for high-performance electromagnetic interference shielding. Carbon. 2017;115:629-39. [2] Wan Y-J, Yu S-H, Yang W-H, Zhu P-L, Sun R, Wong C-P, Liao W-H. Tuneable cellular-structured 3D graphene aerogel and its effect on electromagnetic interference shielding performance and mechanical properties of epoxy composites. RSC Advances. 2016;6(61):56589-98.

Resume : Stretchable conductors which can retain high conductivity under substantial stretching and bending deformation can enable a wide variety of new applications in electronic skins, sensors, and deformable capacitors. Three different types of stretchable conductors with excellent properties were fabricated. The binary conductive network structure was constructed based on cotton or PU sponge which had an interconnected and junction-free macro-porous structure as the skeleton to support the two dimensional AgNWs network, leading to excellent electrical and mechanical properties. During the fabrication of stretchable conductors, polydopamine was used to enhance the adhesion between the conductive nanomaterials and polymer to construct the high conductive network. The dip-coating or pre-strain methods were explored to tuning the microstructure of nanocomposites, which controlled the resistance of nanomaterials. The as prepared composites showed high electrical and mechanical properties. Moreover, the excellent conductance is maintained up to 1000 stretching or bending cycles. The significant electromechanical properties was also demonstrated by a simple stretchable circuit composed of a light-emitting diode (LED) and stretchable conductor during bending, twisting or stretching.

Resume : Amorphous chalcogenides are widely used in infrared optical elements, acousto-optic and all-optical switching devices, holography recording media, etc. Chalcogenide alloys that exhibit remarkable contrast in their electrical and optical properties between the amorphous and crystalline states are promising for data storages. We focused on the several amorphous Ge-Sb-Te and Ge-As-Se alloys with systematic increase of the Ge-content. Raman spectroscopy has been employed to investigate the compositional dependencies in the vibrational properties of selected materials. Raman spectra of Ge-As-Se samples showed that the backbones of the studied samples consist of AsSe3/2 pyramidal units, edge- and corner-shared GeSe4 tetrahedral units. Systematic compositional changes of characteristic constituent Raman bands’ intensities showed that Ge-As-Se samples contain different nanophases whose concentration is changing along chosen compositional cross-section. Systematic compositional changes in Ge-Sb-Te alloys result in the evolution of the observed Raman bands. The shift of the strongest band in the Raman spectra of studied alloys can be interpreted in the term of the interplay of its component bands’ intensities. Obtained compositional trends in the intensities of Raman bands may enable one to predict vibrational properties of other amorphous Ge-Sb-Te alloys along the studied compositional line.

Resume : Organic-inorganic hybrids are one type of the variety of composite materials. We propose the self-organization (SO) and self-assembly (SA) approach for formation of such hybrids. SO and SA layers are potential objects for photovoltaics, optoelectronics, biosensing, as well as gene and drug delivery applications due to: (i) unique properties of both the isolated molecule and self-organized molecular assemblies or aggregations; (ii) the combination of a high absorption coefficient of organics and good Si transport properties; (iii) hybrid compatibility with well explored Si planar technology. Our approach is based on the next innovations: (i) low-cost ecological bio- or synthetic organic compounds; (ii) room-temperature process of molecular self-organization and assembly for 2D structures; (iii) simple technology of chemical bath deposition from aqueous solution. At the first time we used heterocyclic amines for self-organization of organic layers on nanostructures silicon substrate. We used heterocyclic amines: thiamine diphosphide, b) clonidin, c) metamizole sodium, d) procainamide, e) sulfacil sodium. The morphology of self-organized films had a wide variety of morphology: net-like, ring-like, fibers, stars etc. New knowledge about the mechanisms of self-organization of organic molecules on the surface of inorganic materials during the formation of hybrid organic-inorganic structures allow the better understanding of many processes, such as the passivation of surface, changing of the charge trap states, influence of chemicals on the energy level alignment, altering the work function of surfaces, direction for the charge carriers injection and extraction, control of the organic layers morphology.

Resume : The development of complex nanopatterned three-dimensional (3D) structures with high resolution, high aspect ratio, high areal density and tunable features from a soft template is one of the most important challenges in high performance nano-devices such as opto-electronics, display devices and nanobiotechnology. To date, several approaches, which include nanoimprint-, block copolymer-, interference lithography and electrodeposition have been suggested to fabricate 3D 10nm scale patterned materials. However, they have serious problems such as high process cost and difficulty of resolution / large area. In this study, we introduced a new patterning technique, named “secondary sputtering lithography (SSL)”, that enables the fabrication of 10 nm-scale 3D patterned nanostructures with high aspect ratios over large areas by utilizing secondary sputtering phenomena during conventional ion-etching process. This innovative method we have developed utilizes the angular distribution of target particles by ion-beam bombardment, which leads to deposition of target materials on side-walls of patterned polymers. We have fabricated a variety of complex 3D patterns with ultrahigh-resolution, including lines, hole-cylinders and cup shaped structures. In addition, this approach can create the nanopatterned ITO surface without greatly decreasing the electrical and optical properties of the surface, since our SSL technique is a one-step process that simultaneously etches and deposits materials without any further surface treatments and deposition processes. Also, based on the secondary sputtering phenomenon, we have successfully fabricated the nanopatterned ITO layers with sub 20nm high resolution and high aspect ratio for liquid crystal devices without a conventional polymer alignment layer fabrication process. Accordingly, the new, secondary sputtering lithography approach will serve as a new technique for fabricating complex nanoscale patterns with 10nm scale ultrahigh resolution, 3D structures and high aspect ratio.

Resume : Carbon nanomaterials (CNMs) has recently found applications in terms of superhydrophobic coatings. Here we propose the novel use of large-scale produced multiwall carbon nanotubes, graphene nanoplatelets, and carbon black as hydrophobic agent in wood technology applications. We present simple methods of CNMs deposition via drop casting and dip coating, using CNMs dispersed in organic solvent and aqueous solution. The quality of coating was investigated by fluorescence microscopy and scanning electron microscopy, which showed that even a small amount of multiwall carbon nanotubes or graphene nanoplatelets creates a homogeneous coating onto wood surface. The contact angle measurement gave the results of 145° for the best samples, which confirmed that their surface is superhydrophobic. Moreover, we proofed that the developed method increases hydrophobicity independently on porosity or chemical composition of various woods. Finally, we developed a model describing superhydrophobic properties of wood coated with carbon nanomaterials. Acknowledgements D.?. and A.D. would like to thank National Science Centre, Poland for funding (project no. 2015/19/N/ST8/02184).

Resume : Chemical grouting technology is an effective means to deal with the foundation defects and leakage. However, most gels of the chemical grouting materials have poor toughness, and are easily broken under external force. Nanocomposite hydrogel has excellent mechanical properties and toughness, but the viscosity of its slurry is high and the permeability is poor. In this paper, the surface of clay-nanosheets was modified with different ions and organic molecules to improve its dispersion in aqueous solution. The rheological property and gelation process of clay-nanosheets crosslinked organic-inorganic composite chemical slurry were researched. Furthermore the internal structure, mechanical properties and strength of solid sand body of gels were characterized and analyzed. The permeability characteristics of organic-inorganic composite chemical grouting materials was studied by the penetration test in several sand media. The paper presents a theoretical and technical basis for the application of clay nanosheets based nanocomposites hydrogels in foundation treatment by chemical grouting.

Resume : ZrB2-15 MoSi2 and ZrB2-3SiC-5 WC corrosion-resistant plasma coatings have been deposited by shrouded plasma method on a specially designed equipment on carbon-carbon composite material (СССM) of 50 × 24 × 5 mm. The coated samples were subjected to a supersonic flow of combustion products of air-fuel and oxygen-fuel mixtures impact. The coatings thickness was 0.4-0.7 mm. At the maximum mode (maximum surface temperature of the coatings), the flow stagnation temperature was 2100 ° C, the flow stagnation pressure was 0.45 MPa. The determining surface temperature in the tests was 1470 ± 10 ºС, the maximum temperature - 1692 ºС. The test conditions differed in these two series by the concentration of oxygen in the gaseous medium, i.e. with the intensity of oxidation processes and thermal stresses outside the heat spot, caused by different diameters of the jet - the source of heating. The surface temperature in the tests was kept at 1600°C for 200 sec at one heating cycle. The test results in both cases correlate well with each other. It is established that the mechanism of these compositions coatings destruction is different. The preferential destruction of the ZrB2-15 MoSi2 coating takes place outside the heating spot and is related to thermal stresses caused by high temperature gradients under local heating conditions at the accepted test scheme. The material demonstrates high thermal-erosion resistance and preservation of the integrity of the coating during the whole test period without breaking down for 600 sec. The destruction of ZrB2-3SiC-5 WC coating in the tests has the character of the material layer by layer taking away (thickness ~ 50 μm) in the heating spot. In this case, the destruction occurs before the complete removal of the coating for 500 sec. For comparison, two tests of C/C-SiC substrate were carried out under the same heating conditions. Herewith, the determining surface temperature was increased to 1660 ° C (due to the СССM higher value of radiation coefficient - its measured value was  = 0.85) at a total duration at two heating cycles of 234 sec. As a result of the tests, the linear removal of the СССM was not less than 0.5 mm, and its surface on the whole area of the heating spot was damaged to a depth of at least 0.5 mm. The damage has the character of the carbon matrix "washing away" while maintaining the reinforcing framework. Under the conditions of thermal erosive action of combustion products of air-fuel mixture of supersonic flow with a temperature of 2100 ° С, the tested UHTC coatings are appeared to be rather promising increasing the lifetime of the CCCM up to the beginning of the surface destruction for no less than 20 minutes for ZrB2-15 MoSi2composition and for 12 minutes for ZrB2 - 3 SiC - 5 WC composition.

Resume : Polymer based, particularly micro/nanosized polymer composites, now are under intensive studies as their perspectives spread from paper electronics to forensic examination and eco-friendly sorbents. This work was devoted to fabrication and study of the set of ?cellulose-oxide? micro/nanocomposite materials. So called cool-pressing procedure was used to produces the composite materials of the ?ceramics-like? morphology. Several sets of the composite samples both (un-doped) and embedded with inorganic oxide dielectric micro/nanoparticles (complex oxide vanadates, phopspates or zirconia) were prepared and studied. Morphology of the pure and doped micro/nanocellulose, structural and physical properties of the samples were studied and various experimental techniques were used to do it. Morphology of the samples was studied using optical and electronic microscopy tools. The morphology showed both grains of the cellulose and the luminescent particles of complex oxides. Temperature dependences of the specific capacity and dielectric losses tangent were measured in -100 ? 1000C temperature range when frequency of electric field varied from 1 to 100 kHz. As result, components of the complex dielectric permittivity, ?*, ?0 conductivity and other relaxation parameters were evaluated. Luminescent characteristics of starting and doped samples were taken, analyzed and compared with the data concerning free oxide particles. Measured characteristics and properties are of great importance for possible applications of mentioned composites in various fields.

Resume : Nowadays, one of the most important materials are elastomeric materials and their products. These materials are playing a serious role in almost types of machines. Once, there is no common material could be used for manufacturing details for any working conditions. Science researches are doing their best to promote technical properties. It is known that elastomeric materials products which ensure the capacity of many aggregates of rocket and space equipment that can be operated in extreme conditions. Definitely it involves high heat resistance materials for solid propellant rocket motors that must withstand high temperatures. Nowadays, a special rubber produced by various rubber fillers which have different activities is using as internal thermal insulation material. At the same time, their heat-shielding properties need to be improved. One of methods for improving protective properties of rubber composite materials is using carbon nanotubes (CNTs) as filler. CNTs structure makes ability for creating more effective heat resistance coating of rubber composite. According to our estimation vulcanizates with CNTs as an active filler will improve heat-shielding properties such strength and elastomer properties, abrasion and tear resistance. Moreover, the thermal insulation coating volume in solid rockets is substantial and density of CNTs does not exceed 1400 kg/m3 . These properties of CNTs make them auspicious to be used as filler. As well it can be used for reducing the structure net weight of solid propellant rocket.

Resume : Exchange-coupled nanocomposite magnets (NCMs) composed of hard and soft magnetic phases can be applied in various fields such as electronic vehicle motors. Although maximum energy product ((BH)max) of NCMs are expected to become higher than that of neodymium magnets, it is difficult to create high-performance NCMs because a coercivity (Hc) of NCMs easily decreases with the increase of the volume fraction of the soft phase. In fact, we succeeded in synthesizing highest-performance L10-FePd/Fe NCMs by the reduction-diffusion of Pd/?-Fe2O3 heterostructures, however the Hc could reach only 9.01% of a theoretical value. Therefore, we need to unravel how the Hc of NCMs can be improved. Here we demonstrated that an optimum phase-segregation fashion enable L10-FePd/Fe NCMs to obtain higher Hc and (BH)max. Statistical analysis of first-order reversal curves (FORCs) clearly showed that the Hc of NCMs decreased with the change from a core-shell to a dimer structure. It was also suggested by FORC analysis and micromagnetic model that the change of Hc with tuning the grain size of L10-FePd phase and the volume ratio of NCMs depended only on the different phase-segregation fashion. Thus, we revealed the necessary conditions for synthesizing NCMs with high Hc and succeeded in fabricating higher-performance L10-FePd/Fe NCMs with 26.5% Hc of a theoretical value. This research was supported by "Development of magnetic material technology for high-efficiency motors" commissioned by NEDO.

Resume : The electronic properties of interfaces in semiconductor devices are crucially dependent on the detailled atomic structure of the contact plane. Most studies on solar cell interfaces are carried out on technologically prepared interfaces. In this study we start from idealized single crystalline interfaces prepared by MBE, MOMBE, ALD etc. under very well defined UHV conditions and investigated in situ by UPS, XPS, LEED, STM and XPEEM. In particular we report on our attempts to model the junction in chalcopyrite thin films by well defined interfaces to clarify the influence of grain boundaries, lateral inhomogenities and chemical variations across and aside the contact plane. Chalcopyrites of the Type CuYX2 (Y=Ga, In;X=S,Se) were grown by MBE as single crystalline samples in various orientations and were studied by surface analytical tools like XPS, UPS, LEED, STM and XPEEM in situ. Especially the application of synchrotron radiation in photo emission experiments is an extremely powerful tool to gain insight into the morphology and structure of hetero contacts. In a single deposition experiment it is possible to determine the band alignment, band bending, chemical reacted interfaces and their crystalline structure with high accuracy. By following the development of the contact phase to ZnO, ZnSe, ZnS step by step in an UHV environment, all properties of the interface are determined on an atomic scale with high resolution. Beside the formation of an ordered vacancy compound of the absorber the existence of various interfacial layers are detected and their influence on the parameters of a cell is discussed.For CuInSe2 the formation of Cu poor interface layers is observed by SRXPS by the formation of the interface to ZnSe buffer layers. The development of Cu-poor surface phases was discussed by Zunger et al. and is here detected unambiguously. To determine the band alignment valence band spectra have to be recorded to obtain the valence band onset. Here we will show that the right value can only be obtained by using synchrotron radiation as the correct position of the valence band in k-space has to be determined at the Γ-point.Further details on interface properties will be given by presenting XPEEM results on energy converting interfaces.

Resume : Solid Oxide Fuel Cell (SOFC) is a promising device for obtaining alternative energy. SOFC based on anode substrate is the most common configuration. Because of that anode should provide mechanical stability of whole cell. Since the main electrochemical reaction of fuel oxidation is occurred on the anode side, it should have enough porosity (>25%) to facilitate the supply of fuel and remove by-products from reaction site. These requirements impose difficulties on material choice. Typically, anodes are making from NiO and 8YSZ powders mixture. However, in this case it is difficult to provide uniform phase distribution in anode structure, which can cause decrease in anode performances. This problem can be solved via manufacturing of highly porous zirconia skeleton and its further impregnation with nickel salt. The present work is devoted to elaboration of highly porous zirconia skeleton made from 3,5YSZ. Using of 3,5YSZ instead of 8YSZ should allow to provide required mechanical strength with increasing porosity. The porosity of 3,5YSZ skeletons was ensured with different amount of a pore-former (starch) 10-, 16-, 22-, 29-, 42-, 51-, 58-, 64-, 69-vol. %. Influence of porosity on mechanical strength of 3,5YSZ skeletons was studied. It was found that replacement 8YSZ with much stronger 3,5YSZ is acceptable for anode-support ceramic skeleton fabrication. Addition of 51-vol.% of starch provides in 3,5YSZ skeletons open porosity 38% and mechanical strength of 92 MPa.

Resume : In introduction questions of use of micas and influence of heat treatment on their physicomechanical characteristics are considered. In the main part influence of extent of hydration of crystals of natural micas on the provision of clusters of the inverse lattice 00l is investigated. Carried out by methods of computer model operation studying of crystals of natural micas of two types consisting of layers with sizes of d1?10 blocks ? and d2?14 ?. These blocks correspond to phlogopite (d1) of vermiculite (d2). D1 and d2 blocks form the mixed layer crystals. If concentration of one of phases exceeds value 0,7, then on a x-ray monocrystal diffractogram there are reflexes only of this phase. If concentration are in an interval 0,3÷0,7, then on a diffractogramreflexes of both phases are found. In all cases, except monolayer structures, diffractions of 00l-clusters of the inverse lattice around their ideal provisions are observed. Questions of influence of a charging condition of mica on electret characteristics of fluorinated coverings are considered. For the fluorinated coverings formed on a surface mica substrates depending on substrate type electronic or dipole polarization is shown. The coverings of the fluorine containing oligomer formed on the juvenile surfaces of mica are nanoelectret since the size of charging areas on the surface of mica is commensurable with nanosizes, and this charging mosaic leads to essential changes in physical characteristics of coverings in comparison with coverings of the fluorinated oligomers formed on inert substrates. Existence of an electret state in coverings of fluorinated oligomers, has to have significant effect on the tribochemical reactions happening on a demarcation of couples of sliding friction modified by fluorine containing oligomer.

Resume : Systems with lanthana, yttria and rare-earth oxides are perspective for the development of transparent ceramics, laser and other optoelectronic components, ceramics for the intermediate temperature solid oxide fuel cells with high ionic conductivity. Alternatively to cubic garnets, the transparent ceramic matrices based on rare earth oxides and their compounds are considered perspective for advanced laser systems. Solid solutions based on La2O3-Y2O3 system (such as LaxY2-xO3, where x=0.05÷0.20) doped with lasing additives (Nd, Eu, Sm, Tb, Er, Yb) have been subject of research. Many excellent characteristics were achieved for these laser media, but all of them did not result in breakthrough as compared to garnets. High symmetry cubic crystals, the non-cubic anisotropic crystals attract interest to be more effective laser matrices than their isotropic competitors because they enable to harvest excitation energy randomly from all surrounding, but emit monochromatically mostly in one selected direction. The fabrication of laser-grade anisotropic ceramics through the conventional particulate processes is not realistic because of resulting randomly oriented grains and grain boundaries and additional optical scattering. Fabrication of transparent polycrystalline ceramics from non-cubic materials requires precise crystal orientation control so that optical scattering losses at the grain boundaries are prevented. In present work, first the phase relations and solid solutions based on ordered perovskite phase like LaYO3 and C-type cubic solid solutions in the systems La2O3-Y2O3-Ln2O3 (Ln = Nd, Eu, Yb) at 1500, 1600 °C in air in the whole concentration range were studied. The phase compositions were studied by XRD, microstructural phase and electron microprobe X-ray analyses. The study of solid state reaction of Nd2O3 and Y2O3 at 1500, 1600 °? showed that three types of solid solutions based on hexagonal A-Nd2O3, monoclinic B-Nd2O3 and cubic ?-Y2O3 in the Nd2O3-Y2O3 system are formed. These solid solution fields were separated by the two-phase fields (A + B) and (B + C). The boundaries of the homogeneity fields for the solid solutions based on A-Nd2O3, B-Nd2O3 and ?-Y2O3, as well as lattice parameters for solid solutions were determined. The refined solubility of Y2O3 in A- modification of Nd2O3 is about 4 mol % at 1500, 1600 ?C. The solubility of Nd2O3 in cubic ?- modification of yttrium oxide attain ~28 mol % at 1500 °? and ~30 mol % at 1600 °?. The lattice parameters of the C phase varies from ? = 1.0604 nm in pure Y2O3 to ? = 1.0715 nm (1500 °C) and 1.0718 nm (1600 °?) in two-phase sample (B + C), containing 30 mol % Y2O3. The solubility of Y2O3 in monoclinic neodymia attains 20-45 mol % at 1500 °? and 21-50 mol % at 1600 °?. The lattice parameters of the B phase varies from ? = 0.6368, b = 0.4085, ? = 0.6710 nm, ? = 81.64 in two-phase sample (A + B), containing 15 mol % Y2O3 to ? = 0.6897, b = 0.4139, ? = 0.6678 nm, ? = 95.63 in two-phase sample (? + ?), containing 50 mol % Y2O3 (1500 °?) and from ? = 0.6615, b = 0.3615, ? = 0.6708 nm, ? = 75.94 in two-phase sample (? + ?), containing 20 mol % Y2O3 to ? = 0.6936, b = 0.3638, ? = 0.6659 nm, ? = 80.45 in two-phase sample (? + ?), containing 50 mol % Y2O3 (1600 °?). In the ternary system La2O3-Y2O3-Nd2O3, the continues solid solutions based on A-Nd2O3, B-Nd2O and ?-Y2O3 (1600 °C), as well as LaYO3 (1500 ??) were revealed. Acknowledgements: This work was supported by SFFR Ukrainian-Belarus joint R&D project, No. F73/111-2016 (2016-2017) and Ukrainian-Indian joint R&D project, No. ?/128-2015-2017.

Resume : Film-forming materials (FFМ) are used as initial substances for obtaining thin-film coatings by so-called PVD (Physical Vapor Deposition) method most often. In a CVD (Chemical Vapor Deposition) method the coating is formed in a course of gaseous reactions between volatile components on the substrates. Earlier we developed CVD composite on the basis of system Ge-ZnS. The calculated value of conditional temperature (Tc=TP≈1.33Pa) for the composite (590°С) is much lower, than for both ZnS (820°C) and for Ge (1410°C). Thus, according to XRDA, the nano-composite type coating is obtained though the initial materials being microcrystalline. It makes possible to improve essentially optical and operational (especially, mechanical durability) parameters of coatings and to expand domain of transparency of Ge up to the border of a visible range of a spectrum. The materials evaporating and condensing in a similar way are named CVD-composites. Ge-Sb2S3 composite makes it possible obtaining coatings with much higher mechanical durability in comparison with a coating produced from pure Sb2S3. Other CVD-composites as FFМ on the basis of binary compounds are investigated also, namely: Ge-ZnSe, Ge-Sb2Se3, Ge-In2Se3, Ge-EuS, Ge-EuSe, Ge-ZnO, Ge-GeO2, and Ge-SnO2. Their considerable part has shown also a high level of optical and operational parameters of coatings. It is proposed to expand series of FFМs of CVD-composite type, using complex chalcogenides as one of components, for example systems: Ge-ZnIn2S4, Ge-MnIn2S4, Ge-EuIn2S4, Ge-EuIn2Se4, Ge-YbIn2S4, Ge-YbIn2Se4 etc

Resume : The combination of titanium diboride with silicides of groups iV-VI metals makes it possible to produce materials with high heat resistance, wear resistance, hardness, tribological properties and good fracture toughness. In the present work, the method of mechanochemical synthesis, which, in contrast to the method of mechanical mixing of corresponding borides and silicides, makes it possible to obtain a uniform distribution of different phases in the nanosized state, is used. The composite nanosized powders of boride-silicide systems were prepared by the mechanochemical synthesis method. The features of the phase composition and structure of the obtained powders with a particle size of 40–70 nm were studied. The initiating effect of TiB2 on the formation of silicide phases in the process of simultaneous mechanosynthesis was shown. The obtained electrolytic coatings of the composition Ni–TiB2–MoSi2 showed high wear resistance under sliding friction conditions and can be recommended for the hardening and restoration of the surfaces of machine components and mechanisms.