Structure and catalytic activity of the novel heterostructured FePt/h-BN nanomaterials in carbon monoxide oxidation reaction were studied. Transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction methods were used for structure and surface chemical composition investigation. Developed materials were demonstrated to have enhanced catalytic activity with 100% CO conversion at 250 °C. Structure ordering in FePt nanoparticles was observed during thermal activation of the material.

The structure of new heterogeneous FePt/ h -BN nanomaterials and their catalytic activity in the model reaction of carbon monoxide oxidation have been studied. The structure and surface composition were analyzed by methods of transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. It is established that the new materials exhibit pronounced catalytic activity and can provide complete CO conversion at a temperature of 250°C. The process of thermal activation involves ordering of the structure of FePt nanoparticles.

The continuous hexagonal boron nitride (h-BN) coating with the ~100-350 nm thickness was produced from the aqueous solutions of the lithium and sodium borates. The saturated solution was applied on the silicon support by the spin coating, dried under the normal conditions and treated in the ammonia atmosphere under 1300 °C. Such method is a promising way for the fabrication of protection coating. For example, for the protection of the carbon products from an oxidation under high temperature atmosphere.

In this work, the photocatalytic activity and sorption capacity of heterogeneous structures AgCl/h-BN obtained by the polyol method were studied in comparison with the initial micron-sized h-BN powder. The chemical and phase composition, as well as the surface microstructure, were analyzed by scanning electron microscopy, energy dispersive spectroscopy, X-ray phase analysis, and X-ray photoelectron spectroscopy. High photocatalytic activity and sorption ability of heterogeneous structures AgCl/BN in the reaction of the organic dye methylene blue decomposition under ultraviolet irradiation were demonstrated.

Continuous nanocrystalline coatings of hexagonal boron nitride ( h -BN) with a thickness of ~1000‒350 nm are prepared from highly concentrated aqueous solutions of lithium and sodium borates, which display good film-forming properties. The borate solutions were applied on silicon substrates by spin coating followed by drying in air and treatment in ammonia at a temperature of 1300°C. This method is deemed promising for creating protective coatings (e.g., for protecting carbon products from oxidation at elevated temperatures).

In this work, the interaction of a mixture of Al and BN nanopowder with hydrogen microwave plasma was studied. Using X-ray diffraction analysis, scanning and transmission electron microscopy, the formation of AlN and AlB2 nanocrystals as a result of short-term (~ 30 ms) interaction of Al vapor with h-BN was established. Obtained results also indicate the formation of hydrogenated hexagonal boron nitride h-BN-H. The critical shear stresses were calculated for the interfaces between BN and Al, AlB2, and AlN. Approaches for increasing the strength of the composite materials based on hexagonal boron nitride and aluminum are discussed.

Experimental and theoretical investigation of new Al/SiC heteroparticles has been carried out. It is predicted that due to the appearance of a strong interface between Al and SiC, a composite material based on A; and SiC must have a significantly higher tensile strength than pure Al. Theoretical predictions are confirmed in the experiment. In particular, it is shown that the introduction of nano-SiC in a concentration of 10 wt.% in the aluminum matrix leads to an increase in the strength limit of the composite at room temperature to 317 MPa.

New Al/SiC heteroparticles are investigated experimentally and theoretically. A composite material based on Al and SiC is predicted to exhibit a markedly higher tensile strength than pure Al due to the robust interface between Al and SiC. The theoretical predictions receive experimental confirmation. Specifically, incorporation of nano-SiC into the aluminum matrix to a level of 10 wt % is shown to increase the ultimate tensile strength of the resulting composite at room temperature to 317 MPa.

AbstractIt is established that 1 at % Eu_2O_3 addition to the composition of TiCNiCr electrode influences the energy parameters of electrospark deposition process and increases the rate of coating formation.

С целью придания биоактивным покрытиям TiCaPCON нового качества - антибактериальной активности – материалы были легированы Ag в количестве 0.4–4.0 ат. %. Серебро в состав покрытий вводили двумя методами. Покрытия с содержанием Ag 0.4, 1.2 и 4.0% были получены путем одновременного распыления композиционной мишени TiC0.5 Са3(РО4)2, полученной методом самораспространяющегося высокотемпературного синтеза, и металлической мишени Ag. Также было получено покрытие TiCaPCON–Ag (4.0 ат. %) путем ионной имплантации Ag в ранее осажденное покрытие TiCaPCON. Состав и распределение элементов по толщине покрытия исследовали методом оптической эмиссионной спектроскопии тлеющего разряда (ОЭСТР). Структура и морфология покрытий были изучены методом сканирующей электронной микроскопии. Полученные результаты свидетельствуют о формировании наночастиц Ag как в объеме, так и на поверхности покрытий, однако их размер и распределение по толщине покрытия зависели как от концентрации Ag, так и от метода осаждения покрытий. Установлено влияние температуры осаждения покрытия на распределение частиц Ag в покрытии. Исследование кинетики растворения Ag методами масс-спектрометрии с индуктивно связанной плазмой и электрохимическими методами показало, что скорость растворения Ag определяется соотношением размера наночастиц Ag и толщины оксидного слоя на поверхности.

Different approaches to formation of hard multicomponent coatings with improved tribological characteristics in a wide temperature range are considered. It is shown that deposition of a thin surface layer or introduction of additional structural components into nanocomposite coatings, which play the role of a solid lubricant, lowers substantially the friction factor and increases the wear resistance

Методом магнетронного распыления получены покрытия в системе Mo–Si–B–(N). Контроль содержания азота и кремния в покрытиях осуществлялся за счет использования различных газовых смесей Ar + N2 и варьирования количества сегментов Si в зоне распыления мишени MoSiB. Структура покрытий исследована с применением методов растровой и просвечивающей электронной микроскопии, рентгенофазового анализа, инфракрасной и оптической эмиссионной спектроскопии, спектроскопии комбинационного рассеяния. Механические и трибологические свойства покрытий определены с помощью методов наноиндентирования, скратч-тестирования и трибологических испытаний, в том числе при температурах 20, 500 и 700°C. Исследована жаростойкость покрытий. Установлено, что покрытия с максимальным содержанием Si и N обладают наилучшими свойствами: твердость 32 ГПа, упругое восстановление 66%, низкий коэффициент трения при повышенных температурах, а также жаростойкостью до 1200°C.

The effect of silicon on oxidation resistance of Mo–Si–B–N coatings produced by magnetron sputtering has been investigated. The silicon content was controlled with the composite target composition as well as with various area of silicon segments put in the target erosion zone. Using TEM, SEM-EDS, and GDOES, the composition and structure of the coatings have been studied after deposition and after exposition in the air at tempera- tures of 500–1300 °C. Caused by formation of dense top-layer based on silicon oxide, oxidation resistance is found to increase when silicon concen- tration raises in the coatings, thus preventing oxygen penetration deep into the coatings at heating. The maximum oxidation resistance at a level of 1300 °C can be reached in Mo–Si–B–N coatings containing 40 at.% Si.

To increase the biointegration of titanium implants, hard bioactive nanostructured coatings based on titanium carbonitride alloyed with phosphorus, calcium, tantalum, and silicon have been suggested and successfully passed approbation. Their influence on the electrochemical properties of coatings in a model biological solution is considered in this study. All coatings are shown to be in a stable passive state, while alloying does not substantially worsen their electrochemical properties. An example of optimizing parameters of vacuum deposition of the coating with the purpose of improving its electrochemical characteristics is considered for one of the compositions.

Рассмотрены клеточные и молекулярные механизмы регуляции процесса дифференцировки остеобластов, вклад сигнальных путей и транскрипционных факторов. Ключевым регулятором остеогенеза считается транскрипционный фактор Runx2, который индуцирует синтез белков, специфичных для остеобластов – щелочной фосфатазы, матриксной металлопротеиназы-13, костного сиалопротеина, коллагена типа I, остеокальцина. Адгезивные взаимодействия клеток с подлежащим субстратом важны для процессов пролиферации преостеобластов, остеогенной дифференцировки, минерализации внеклеточного матрикса. Эффективное прикрепление и распластывание клеток на подложке определяется фокальными контактами и актиновым цитоскелетом. Фокальные контакты являются механосенсорными структурами. Посредством трансмембранных рецепторов – интегринов, участвующих в образовании фокальных контактов, клетки остеогенного ряда реагируют на ригидность клеточных субстратов, их химический состав и топографию поверхности. Киназа фокальных контактов FAK является ключевым игроком сигнализации, связанной с фокальными контактами. Микро- и нанотопография поверхности существенным образом влияет на остеогенную дифференцировку.

The structure and properties of TiN, Ti-Si-N, Ti-Al-Si-N, Ti-Cr-Si-N, Ti-Zr-Si-N, Ti-B-N, Ti-Cr-B-N, and Ti-Si-B-N coatings obtained by reactive electric-arc evaporation and magnetronic sputtering of Ti, TiSi, TiAl, TiCr, TiZr, TiBN, TiCrB, and TiSiB targets are compared. Tests of cutting tools with these coatings in the drilling, turning and milling of steel indicate that the coating increases the tool’s life by a factor of 5–20.