A new variant of the method for preparation of the ion exchange substrate for plants is described in the paper. The cationic component has been obtained by equilibrating of the cation exchange resin with a concentrated solution of salts of the main biogenic cations K+, Ca2+, Mg2+; the anionic component is obtained by neutralization of the OH- form of anion exchanger with a concentrated mixed solution of the acids containing the nutrient elements that is HNO3, H3PO4 and H2SO4. Both components are mixed and the microelements are added to obtain the full ion exchange substrate.

Nickel nanoparticles and its composites have been synthesized in a water–DMSO (1:1) mixture by reduction of Ni(NO3)2×6Н2О with sodium tetrahydridoborate. It has been found that, to obtain Ni nanoparticles in 5.0 mM Ni(NO3)2×6Н2О solution, it is best to use 5-fold excess of NaBH4. Nickel nanocomposites have been formed on the basis of polyvinylpyrrolidone (PVP), hydroxyapatite and aluminium powder. The relationship between Ni(NO3)2×6Н2О concentration and (PVP)Ni composite morphology has been established, which allows to form nickel particles of various shapes with a PVP polymeric carrier. These nickel NPs and its composites have proved to be efficient catalysts in the reaction of reductive (Na[BH(OAc)3]) amination of 4-carbomethoxybenzaldehyde with N-(2-methyl)-4-(pyridin-3-yl)pyrimidin-2,5-diamine to give methyl 4-{(4-methyl-3-(4-
(5-methylpyridin-3-yl)pyrimidin-2-ylamino)phenylamino)methyl) benzoate.

Superparamagnetic ferrite nanoparticles in the system of MgxZn1–xFe2O4 (х = 0.25; 0.5; 0.7) have been prepared by coprecipitation, spray pyrolysis and the nitrate-citrate approach. The dependence of the phase composition, morphology and magnetic
properties of the nanoparticles on their chemical composition and synthesis conditions have been studied. The crystallinity degree and particle size tend to increase with the increase of the synthesis temperature and duration. The saturation magnetization of the nanoparticles increase as well due to cation redistribution between spinel structure sublattices, which is accompanied by reduction of the inversion degree. In the case of spray pyrolysis method, the correlation between saturation magnetization and ferrite composition is weak, while for coprecipitation and the nitrate-citrate approach it goes through a maximum. The highest saturation magnetization of 30 а∙m2∙kg–1 relates to  kg0,5Zn0,5Fe2O4 sample obtained by the nitrate-citrate approach.

Tribological properties of composite Langmuir–Blodgett monolayers of 2,4-heneicosanedione (HD) with particles of hexagonal (α-BN) boron nitride formed on silicon and steel surfaces by the horizontal precipitation method have been studied.
It was found that incorporation of α-BN (the average particles size ~ 600 nm) into the structure of the HD Langmuir layer resulted in an increase of minimal area per molecule from 0.27 to 0.34 nm2 and wear stability of HD monolayer. Composite LB films of HD with α-BN particles can be used as protective coatings in precision friction units.

Two different methods have been employed for fabrication of Nd0.4Sr1.6NiO4–d ceramics with focus on the microstructure and density of ceramic samples. Conventional sintering at 1100–1300 °C has been found to yield porous materials. Rapid grain growth at ≥1 300 °C induces the development of microcracks associated with a strongly anisotropic expansion of
Nd0.4Sr1.6NiO4–d tetragonal lattice. On the contrary, spark plasma sintering (SPS) at 1100 °C enables fabrication of dense gastight ceramics, but is accompanied by the structural transformation from tetragonal (I4/mmm) to orthorhombic (Immm) symmetry due to oxygen losses from the lattice under low-p(O2) conditions of SPS process. The post-treatment conditions were optimized to oxidize sintered samples and to restore tetragonal structure while preserving gas-tightness of ceramics.

The template method for the synthesis of microporous silica gels has been developed. It has been shown that rapid deposition of silica gel from Na2SiO3 solution containing the necessary amount of aluminium or iron salt (5% wt.) formed microporous silica. On the contrary, silica gel samples obtained by mechanical mixing of silica gel and the metal hydroxide possess micromesoporous structure.
The effect of salt template nature on structural parameters of silica gel has been studied. It has been shown that the effect of the salt templates depends on the hydration heat of the ions. concentration of the template in gel composition and drying temperature.

The effect of aluminium coagulants’ composition on colloidal characteristics of kaolin dispersions (diameter, particle size distribution, density and sedimentation rate of aggregates) has been investigated by the laser diffraction method. Shape and structure of aggregates have been characterized by comparing the experimentally determined fractal dimension values and computer simulation data. When aluminium sulphate was used as a coagulant, the size of aggregates has been found to increase, while their density decreased, for dispersions of mixed aluminium hydroxide aggregates with kaolin, as compared to pure aluminum hydroxide dispersions. In the case of  pentahydroxydialuminium chloride, the reverse relationships have  been observed.

The distribution of neonicotinoid insecticides (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) in different extraction systems has been studied at 20 ± 1°C. Distribution constants (P) and distribution ratios (D) of pesticides between hexane and the polar phase, rapeseed oil and the polar phase have been calculated. Based on the experimental data, the sample preparation technique has been developed for the determination of neonicotinoid residues in rapeseed, sunflower, linseed and olive oils by high performance liquid chromatography with diode array detection. The extraction method of sample preparation is simple, low reagent and time consuming, and provides chromathograms without analyte peak interference. The recoveries of pesticides from plant matrices are more than 80%. The method allows to determine neonicotinoid insecticides at concentrations below maximum residue levels established in the Republic of Belarus for vegetable oils.

A series of polyfluorinated benzaldehyde oxime and pyrazinecarboxylic acid esters has been synthesized. Antimycobacterial properties of the synthesized compounds have been studied. It has been shown that several of the compounds are superior to currently used anti-TB drugs in their ability to slow the growth and development of mycobacteria

Synthesis and solvatochromic properties of new dyes, derivatives of dibenzothiophene-5,5-dione with intramolecular charge transfer, substituted in positions 1,3,4,7, has been described. Their absorption and emission spectra depending on solvents polarity have been investigated. Compounds synthesized showed a pronounced positive solvatochromic effect. High spectral sensitivity of 1-hydroxy-5,5-dioxo-5H-dibenzo[b,d]thiophene-3,7-dicarboxylic acid dibutyl ester to changes in solvent polarity can be used, for example, to determine the water content in the aprotic solvents with low (<40 kcal / mol) ET(30)
values.

A new method for the catalytic preparation (using copper salts) of the anion exchanger with ternary amino groups has been developed. The best conditions for synthesis of this ion exchanger, such as catalyst and aminating agent (dimethylamino propylamine) concentrations and process time, have been found. The acid-base properties of functional groups have been determined by potentiometric titration. By the analysis of isopiestic curves, water-holding capacity of the anion exchanger has been estimated and these results used for determination of the anion exchanger applicability for air purification. The experimental sorption results show the practical applicability of the ion exchanger for air purification from acidic impurities (on the example of sulfur dioxide sorption) in a wide range of relative humidity.

The material composition and physical properties of rocks from Lower Cambrian (Stradech and Ryta series) and Wend (Kotlin series) stratigraphic units from Bug structure wells, located within the eponymous underground gas storage facility, have been studied. The regularities of depth dependence for geochemical, geophysical, etc. parameters of reservoir rocks and cover rocks have been established. They are important when selecting a regulatory system for formation gas energy and storage operation safety assessment.

There is a trend in the world for production growth of hardly recoverable heavy oils and bitumen with high content of resin-asphaltene substances that precipitate when aggregated, causing stability loss of oil dispersies. The goal of this work is to establish regularities for the effect of oil soluble surfactant additives containing the polar functional groups of different chemical nature on the processes of flocculation and sedimentation of model oil dispersions. Methods emplоyed are infrared spectroscopy, turbidimetric titration and dispersion analysis. It has been found that the domestically produced surfactant additive containing both amino and phosphate groups in the chain causes synergistic effect, due to simultaneous action of these functional groups, that slows down flocculation processes (efficiency is 108%) and sedimentation of model oil dispersions, which is confirmed by 13 times reduction of rates and sedimentation constants and 1.6–3.2 times decrease of associate size for resin-asphaltene substances. This results in the increase of aggregative and kinetic stability of the colloidal system. It has been shown that the additive is an effective flocculation inhibitor and dispersing agent for oil dispersion systems, that can be recommended for practical application as a substitute for expensive imported analogues.

The review is devoted to terpenoid-maleic adducts and their derivatives. Terpenoid-maleic adducts find wide application in various industries. In this review, the ways of adducts’ preparation, their properties, afterproducts on their basis and application in various compositions are discussed. Levopimaric and abietic rosin acids, turpentine components, terpene hydrocarbons, solid turpentine polymers and rosin oils formed in production of rosin and its glycerol ester, have been used as raw materials for production of adducts.