The stability of the hydrophobic properties of coatings with textured surfaces made of polytetrafluoroethylene and ultra-high molecular weight polyethylene during storage, as well as during prolonged contact with water and aqueous solutions of sodium chloride has been studied. Polymeric coatings were applied to the surface of a polyethylene terephthalate track-etched membrane by electron-beam deposition to produce composite membranes for water desalination. It is found that polytetrafluoroethylene coatings tend to age under the influence of real environmental condi-tions and gradually lose their hydrophobic properties. The water contact angle of these coatings decreases during storage samples of composite membranes. In contrast, the water contact angle of ultra-high molecular weight polyethylene coatings practically does not change during storage of membrane samples. A study of the stability of polymeric coatings during prolonged contact of composite membranes with water and aqueous solutions of sodium chloride showed that coatings made of ultra-high molecular weight polyethylene are stable both in water and in aqueous solutions of sodium chloride. Polytetrafluoroethylene coatings are more stable to the action of aqueous salt solutions than water.

The interaction of the ectodomain of the human coronavirus spike protein with the phospholipid monolayers formed on the aqueous subphase surface has been investigated. The changes in the molecular organization of monolayers of two neutral phospholipids—dipalmitoylphosphatidylcholine and dipalmitoylphosphatidylethanolamine—after the injection of a protein solution underneath the monolayer have been analyzed. Experiments were performed with a recombinant ectodomain of the S-protein, expressed in a CHO-K1 cell strain. Electron microscopy data showed that the protein is trimerized. Grazing incidence diffraction measurements were performed to study the influence of the trimer ectodomain of the S-protein on the structure of the dipalmitoylphosphatidylcholine monolayer. It is found that protein injection under the monolayer does not induce disturbance of the monolayer crystal structure. The experimental results obtained in X-ray studies and compression isotherm measurements indicate that the interaction with the S-protein does not result in destabilization of the monolayer for both phospholipids.

Carbon fiber epoxy resin plastic (CFRP) has been widely used as skin structure, solar panels and antenna of the satellite due to its high strength and low density. However, CFRP will be caused a rise in temperature under the solar irradiation from the space environment by its high solar absorption, which will affect its long-term application performance. It is necessary to prepare thermal control coatings (TCCs) on the CFRP surface. In this paper, we reported a new coating preparation method on CFRP by gravity deposition to fabricate SiO 2 stacking structure for lightweight and low solar absorption. By analyzing morphologies of the SiO 2 coatings, the best preparation ratio and particle size were confirmed, and the coating with particle staking structure was successfully obtained. The solar absorption of the coating is as low as 0.13 with a surface density of 106 g/m 2 , and the surface temperature can be reduced by 23.4 degrees C, providing new prospect in thermal control coating applications on CFRP surface.

Based on the analysis of the literature on the possibility of using neural networks to create new materials with high functional properties, the article considers a solution to the problem of determining the operational stability of polymeric composite materials by creating physical and chemically sound mathematical prediction models. Epoxy resins of the UP-637 and EA brands with an isophorone diamine hardener were chosen as the matrix of the model composite material, and oligobutadiene rubber of the SKN-10 KTR brand was chosen as the modifier. It justifies directions of work necessary for development of new materials creation methodology with optimal characteristics, building a model for changing the properties of materials at variation of composition and implementation of full-scale mathematical modeling of physical and chemical processes of polymer composite materials aging at changing level and time of climatic factors influence. Verification of the obtained dependence of service characteristics on the composition of the material and the level of influencing climatic factors was carried out on the basis of data from full-scale tests in a temperate climate. The proposed methodology for modelling the properties of polymer composite materials will reduce the development time of new materials and allow creation of polymer composites based on epoxy resin containing fillers of various natures (carbon, mineral and polymer) with high performance parameters.

Carbon fiber epoxy resin (CFRP), as space satellite antenna materials with great application prospects to transmit and receive signals. It is necessary to ensure its normal operation through surface thermal control, which can be achieved by covering with a flexible film. Polyimide (PI) films modified by ceramics particle have been widely studied in the field of flexible devices. However, there is no research on multifunctional PI films with thermal control and wave transmission multifunctional performance. In this study, ZrO2 modified flexible PI films (PI/ZrO2 films) which can be covered on the surface of satellite antenna was prepared, and its solar absorption and wave transmission properties were studied. Prepared films exhibited excellent heat resistance and mechanical properties, and the addition of ZrO2 increased their thermal stability. The solar absorption of films with 50% ZrO2 is the lowest for 0.30, and the highest reflectance can reach to 88.4%. In addition, the maximum dielectric constant of the films was less than 2.5, and the dielectric loss was less than 0.03, showing an excellent wave transmission performance. The films can be covered on the satellite antenna, and also can be used for other space environment or wave transmission requirements.

Ce-induced effects on the self-assembly of arachidic acid Langmuir monolayers was studied in this work. The monolayers were formed on the liquid subphase in the presence of Ce(III) ions. A new type of structural configuration is found for such monolayers, in which the monolayer maintains its structural ordering despite being compressed beyond the collapse point. Instead of forming 3D aggregates as in the typical collapsed state, the monolayer appears to be corrugated. Grazing incidence X-ray diffraction and X-ray standing waves confirm these findings. The diffraction pattern for the monolayer in a new state is represented by the unclosed diffraction rings with maxima near the sample horizon. This diffraction pattern is quantitatively reproduced in the numerical simulations by assuming the corrugated monolayer. The details of the conditions under which these corrugated Langmuir monolayers were observed and the analysis of the diffraction data are described.

The multilayer (Ti/DLC) x 3 films were deposited using a DC arc evaporator with a titanium cathode and a pulsed cathode-spark evaporator with a graphite cathode. Following the deposition of the films, a heat treatment process was performed in air and Ar atmosphere at temperatures of 200 degrees C and 400 degrees C. The investigation of the films involved the examination of their structure, surface morphology, and chemical composition using AFM, SEM, XPS and Raman. Additionally, the mechanical properties of the films were assessed by nanoindentation, sclerometry and wear test. Changes in the structure, RMS roughness, & Scy;-sp2/& Scy;-sp3 ratio of carbon atoms in the film and the formation of Ti-C carbide were determined in relation to the heat treatment conditions. Studies have demonstrated that subjecting materials to heat treatment at temperatures of 400 degrees C results in a decrease in friction coefficient and an increase in hardness. The deposition of films on the working surfaces of microdrills with subsequent heat treatment leads to a reduction in wear, an extension of their service life, and an improvement in drilling accuracy as compared to microdrills without films. Furthermore, microdrills with (Ti/ DLC) x 3 films annealed in air at 400 degrees C exhibit negligible size reduction and better drilling accuracy.

Because of the fatigue resistance and light weight, carbon fiber reinforced resin composite (CFRP) has widely used in expanded solar panels, key components of space stations and antenna panels. However, the space environment of solar irradiation will cause the CFRP temperature rise due to its high solar absorption, which affects the long-term application. It is necessary to prepare thermal control coating (TCC) on the surface of CFRP. In this paper, a new preparation method of CFRP surface coating by gravity deposition is reported to obtain ZrO2 and polytetrafluoroethylene particle stacking structure with low solar absorption. The high scattering intensity of particle stacking structure coating was verified by simulation. Through the analysis of the morphologies and XPS of the coating, the optimal ZrO2 content was determined, and the particle stacking structure was proved. The coating exhibits good thermal shock property. The solar absorption of the coating is as low as 0.08, with a surface density of 196 g/m(2), and the surface temperature can be reduced by 38.8 degrees C under irradiation, which provides a new prospect for the application of thermal control coating on the CFRP.

Coating systems using epoxy resin, organic silicon compounds (octadecyltrichlorosilane (OTS) and hydrolyzed heptadecafluoro tetrahydro decyltrimethoxysilane (HDFS)), and fluoropolymers (polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF)), were applied to carbon steel. Epoxy (EP) coating and EP/OTS, EP/HDFS systems were produced via spin coating, while PTFE and PVDF layers were deposited using electron beam dispersion. Wettability, surface structure, and tribological properties were assessed through contact angle measurement, Fourier transform infrared reflection (FTIR), and tribotechnical test. Anticorrosion resistance was evaluated using electrochemical techniques, salt spray, and adhesion tests. Surface modifications with silicon compounds and fluoropolymers increased hydrophobicity, anticorrosion behavior and wear resistance. The water contact angles of EP, EP/OTS, EP/HDFS, EP/PVDF, and EP/PTFE were 84°, 108º, 116º, 96º, and 128º, respectively. Coating treatments reduced the friction coefficient. No corrosion was observed on treated surfaces after 336 hours in a salt spray chamber, while untreated EP showed rust after 96 hours. The hydrophobic systems based on epoxy resin, silicon compounds, and fluoropolymers are effective for protecting metal structures, with fluoropolymers providing higher protection to silicon compounds.

The results of a study of the structure and physical and mechanical properties of diamond-like coatings (DLC) on sublayers of different hardness are presented. The coatings have high hardness, but at the same time they are prone to delamination and destruction due to high residual internal stresses. The fracture toughness was determined by the nanoindentation method and the energy calculation method using approach-retraction curves. Atomic force microscopy was used to study the surface structure and deformation region after nanoindentation. A change in the surface structure and roughness of DLC was established depending on the sublayer. Low roughness is characteristic of DLC on a copper sublayer. Applying а titanium sublayer leads to an increase in the elastic modulus of the DLC. The microhardness of both coatings is practically the same. AFM studies have shown two different types of DLC deformation after nanoindentation with a Berkovich pyramid. A crack on coatings with a copper sublayer propagates around the indentation print, and on an DLC with a titanium sublayer, it propagates along the edges of the indentation. It was found that the fracture toughness of DLC on a Ti sublayer is 33 % lower compared to DLC on a Cu sublayer due to a decrease in stress relaxation inside the coating. The considered coatings can be used in microelectronics for protection against mechanical damage on contacting and rubbing surfaces.

Gadolinium‒aluminum‒gallium garnet crystals are grown with charge compositions Gd3AlxGa5 – xO12 (x = 1–3) and Gd3Al2Ga3O12:Ce3+. The effect high-temperature annealing in air has on the optical properties of these crystals is established. It is shown that annealing does not affect the state of cerium oxidation. X-ray fluorescence reveals a deficiency of gallium in all the investigated crystals.

The photophysical properties and efficiency of photosensitized singlet oxygen formation by meso-tetrakis(4- N-methylpyridyl)porphyrin in a complex with hydroxyapatite nanoparticles were studied. At least three types of complexes characterized by different access of oxygen to porphyrin molecules were shown to form on the surface of the hydroxyapatite nanoparticles. Rotation of the pyridyl substituents of porphyrin in the complex with hydroxyapatite nanoparticles was found to be significantly hindered, while porphyrin molecules on the surface of the nanoparticles were in a less polar environment than in water. The quantum yield of photosensitized singlet oxygen formation was observed to decrease by at least nine times for porphyrin in the complex with hydroxyapatite nanoparticles. Porphyrin was released from hydroxyapatite nanoparticles and the efficiency of singlet oxygen formation increased although it did not reach the values characteristic for free porphyrin if the pH decreased to less than 5.0 (pH < 5.0).

Tungsten oxide (WO3) is highly regarded as one of the most promising working electrodes for electrochromic devices due to its large optical modulation, however, it suffers from degradation at the WO3/electrolyte interface. Herein, we developed an ALD-Al2O3/Li-based electrolyte hybrid layer as organic/inorganic solid electrolyte interphase (SEI) to improve the cyclic stability of the WO3 thin films. In situ formation of SEI has been confirmed by an analysis of components (such as Li2CO3, Li2O, and PC) of the electrochromic WO3 thin films with the ALD-Al2O3 interface layer after electrochemically cyclic treatment. As for comparative analysis of microstructural and electrochemical properties of the electrochromic WO3 thin films with and without the ALD-Al2O3 interface layer, we emphasize that the SEI, introduced by the ALD-Al2O3 interface layer and produced by electrochemical cycling, embodies its optimality properties. With the introduction of SEI, the cyclic stability of the WO3 thin film can be significantly enhanced, allowing for a stable transmittance modulation (1500 cycles with 94 % retention). This work offers a new strategy to improve the cyclic stability of WO3 thin films and enlightens the design on stable interface for electrochromic electrodes.

Structure and morphology of epitaxial [Fe/Cr](30 )multilayers with ultrathin Fe layers (nominally 0.12 nm and 0.08 nm) have been investigated by X-ray reflectivity, synchrotron Mo center dot ssbauer spectroscopy at low temperature and grazing-incidence small angle X-ray scattering (GISAXS). The films demonstrate Kondo-like behavior of electrical resistivity. The GISAXS patterns reveal their cluster-layered structure. The observed side maxima give the information about the sizes and distances between lateral inhomogeneities. Mossbauer reflectivity spectra measured below the critical angle of the total reflection support the existence of the cluster-layered structure of the samples. Magnetic hyperfine field distributions show that largest number of 57Fe atoms is situated in interfaces of iron clusters and their number increases in the thinnest films.

Artificial joint replacement represents the most effective approach for addressing joint pathologies. However, friction and wear, the production of debris and the release of metal ions reduce the durability of artificial joints and negatively impact human health. This study focuses on a CoCrMo alloy joint femoral head and an ultra-high molecular-weight polyethylene cup, which are commonly used as standard artificial joint friction couples. Two different types of films have been deposited on the surface of the joint femoral head. Multilayer TiN/(Ti/DLC) x 3 films were deposited on the surface of the alloy ball via pulsed cathode-arc discharge, and a friction experiment was carried out by a hip friction simulation tester. As an alternative film for use in medicine, TiN films were deposited by direct current arc evaporation of the titanium cathode in a nitrogen atmosphere at a partial pressure of 1.2 x 10-1 Pa. Prior to conducting the wear test, the film structure was studied through Raman and XPS spectroscopy. The surface morphology and adhesion of the films to the joint femoral head were studied.A change in the mass of the prosthesis has been seen when comparing the presence and absence of deposited films. Inductively coupled plasma mass spectroscopy has shown the effectiveness of protecting the surface of the prosthesis with the deposited TiN/(Ti/DLC) x 3 film. This method successfully reduces the concentration of Co and Cr released during friction. The findings indicate that the TiN/(Ti/DLC) x 3 film deposited on the joint femoral head reduces the wear of the UHMWPE cup and did not degrade over five million cycles, thus signifi-cantly exceeding the operating life of the TiN film. The results show that TiN/(Ti/DLC) x 3 film demonstrates a 55 % reduction in the generation of abrasive debris in the UHMUPE cup. Furthermore, it effectively prevents the release of metal ions from the alloy femoral head.

C/SiC composite has been widely used as a high-temperature material for engineering components due to its excellent thermal properties. Facing the rapid development and threat of high-energy laser, study on the ablation resistance under laser irradiation is strongly required. In this work, a continuous high-energy laser was applied to explore the laser ablation behavior and mechanism of C/SiC composite. From the results, C/SiC composite shows different morphologies when irradiated at various laser power densities for 500 and 700 W/cm(2). We divided the ablation area into three regions; the central, transition, and edge regions, where the formation of SiO2, SiO, and the breakage of carbon fiber were observed. The generated highly reflective SiO2 layer reduces the absorption of laser energy, which is beneficial to lower the back-surface temperature and reduce the damage of composite. In addition, we put forward the ablation physical models and ablation mechanisms irradiated at different power densities. The work provides a basis for the laser ablation resistance of C/SiC composites under different conditions.

Polytetrafluoroethylene (PTFE), octenidine dihydrochloride (OCT), and zinc oxide (ZnO) were used to modify the polypropylene nonwoven material by the methods of "wet chemistry" and low-energy electron beam deposition (EBD). The influence of nonwoven material modification on the morphology, chemical composition, filtration, and antibacterial properties was established. The modified material has antibacterial activity against the gram-positive strain Staphylococcus aureus and against gram-negative strains of Escherichia coli and Klebsiella pneumoniae (suppression of bacterial growth for materials with OCT was 100%, with ZnO-70%). PTFE application to Aquaspun leads to a significant increase in the contact angle (from 141.3 & DEG; to 152.7 & DEG;) and air filtration efficiency (from 78.3% to 83.4%), which provides the barrier properties of the material. It was established that the material obtained using low-energy EBD demonstrated a more pronounced antimicrobial potential against the tested strains of St. aureus.

Amorphous carbon (a-C) coatings are characterized by high internal stresses, relatively low thermal stability, low impact strength, poor adhesion to metal substrates, which limit their applicable scope. To eliminate these disadvantages doping with metals and heat-resistant compounds is used. Relaxation annealing and the introduction of sublayers are also used to modify the structure, predicted changes in the mechanical properties and the strength of the adhesive joint. Composite a-C coatings were deposited from the carbon plasma of the pulsed cathode-arc discharge and the flow of evaporated titanium atoms by a direct current arc in the nitrogen atmosphere at its partial pressure of 5 x 10-2 Pa. The AFM examination showed a change in the surface morphology after annealing and a decrease in surface roughness. Raman spectroscopy revealed an increase in the degree of misorientation of the carbon matrix after annealing at 350 degrees C, while a decrease in the size of the Csp2 clusters was observed for the Ti/a-C:Ti coatings. The XPS method established the effect of the annealing temperature on phase transformations, i.e. the formation of carbonitride compounds, which resulted in a higher rigidity of the carbon matrix, reducing the coating plasticity due to a decrease in the metal component and an increase in the concentration of oxide and carbonitride compounds. The indentation method proved a decrease in the hardness of the coatings containing TiN layers, while an increase in hardness for Ti/a-C:Ti was observed, which was associated with the structure change and an increase in the concentration of the TiC bonds. The sclerometry showed that the presence of titanium layers in the coating leads to an increase in the adhesion strength of the coatingsubstrate system. The TiN layers do not provide high adhesion to the a-C layers, which is associated with the limited ability of titanium atoms to interact with carbon atoms.