The potential for barium sulphate nanoparticles to be used in a variety of important fields has sparked a lot of attention. Methods for obtaining this material by milling (top-down approach) are not very popular due to the difficulty of controlling the size and shape of particles, as well as changes in their physicochemical properties during milling. More promising is the bottom-up approach, which is the interaction of Ba2+ and SO42− ions in a liquid environment. Direct precipitation is the simplest method; however, it does not allow control of the particle size. Microemulsions, microreactors membrane dispersion, as well as spinning disc reactors are used to overcome drawbacks of direct precipitation and allow control of particle size and shape. This is ensured mainly by intensive controlled micromixing of the precursors with concentrations close to saturated ones. The present review focuses on recent advances in the production of barium sulfate nanoparticles using various approaches, as well as their advantages and limitations. The issues of scaling up the techniques are also considered, and promising methods for obtaining BaSO4 nanoparticles are also discussed.

This review is devoted to the possibilities of using mechanochemical processing and to achievements in this field for obtaining materials for a wide range of purposes. The mechanochemical processing of various materials and compositions in energy-intensive grinding devices allows the production of innovative systems, ensuring the necessary complex structure and properties. A detailed analysis of the processes of mechanochemical processing in the production of designs for various purposes is given, and the latest practical results in this area are highlighted. A detailed analysis of the processes of mechanochemical processing in the production of structures for various purposes is given, as well as recent practical results in this area, such as the use of mechanochemical processing to increase the performance of aluminum and other metals used as a combustible substance in energy-intensive systems. This review also presents the prospects for the use of mechanochemical processing to obtain physiologically active drugs from plant materials, which is an effective method for creating new materials in the field of pharmaceuticals, animal husbandry, veterinary medicine, crop production, etc.

This work is a study of the conditions for obtaining boron carbide, magnesia, and aluminum oxide composites by self-propagating high temperatures synthesis (SHS). The substances used to synthesize the composites were boron oxide, magnesia, and aluminum oxide. The SHS with the reduction stage was conducted as the following aggregate reaction: 2B2O3+6Mg+xC--->ByCx+6MgO, 2B2O3+4Al+xC=2Al2O3+ByCx. The metallothermic SHS using boron oxide seems more attractive than the current carbide production methods characterized by long-time and multistage physico-chemical processes requiring increased material, energy, and financial costs. The thermodynamic calculations of the phase composition of the products and the adiabatic combustion temperature for systems B2O3–Mg– C, B2O3–Al–C were made in the FastStage program. The calculations and tests allowed identifying the optimal conditions of SHS. The products of SHS were examined by X-ray phase analysis and the SEM method. The compositions of the B2O3–Mg–C system obtained by SHS were represented mainly by boron carbide, magnesia, magnesium borate, and Mg3B2O6. The products of the B2O3–Al–C system obtained by SHS contained boron carbide, alumina, and aluminum boride.

The goal of the present work is the synthesis of the refractory zirconium diboride powder in the combustion mode. One of the most effective methods of synthesis of the refractory zirconium diboride powder is the self-propagating high-temperature synthesis method (SHS) with a preliminary mechanical activation of the initial components. Initial components of the SH-synthesis are borate ore, zircon, aluminum powder and magnesium. After the SH-synthesis obtained products were processed by 37.5% HCl and were washed with distilled water. Final composition and microstructure of SHS products were investigated with X-ray phase analysis and SEM. Boron-containing SHS-powders can be used as bio-protection in nuclear engineering, production of abrasive powders, ceramic, composite materials and coatings.

В данной работе исследована вероятность получения композиционных материалов на основе карбида бора методом самораспространяющегося высокотемпературного синтеза (СВС) в системе В2О3–Al–С. Термодинамические расчеты процессов СВС проводятся с целью определения температуры горения в адиабатических условиях, когда отсутствуют теплопотери и равновесного состава продуктов горения. С помощью программы FactSage проведены термодинамические расчеты равновесного фазового состава конечных продуктов СВС и адиабатической температуры горения системы В2О3–Al–С в зависимости от начальной температуры СВС, исходного состава компонентов исследуемых систем. В результате проведенных расчетов были определены оптимальные условия СВС-процесса для получения наибольшего количества карбида бора в композиционном материале. По результатам термодинамического анализа показана возможность получения методом СВС композиционных материалов на основе карбида бора и корунда в В2О3–Al–С при начальной температуре СВС, равной 700 оC.