Carbonated hydroxyapatite of predominant B-type of substitution has been synthesized at various temperatures, carbonate concentrations and time of immersion in mother solution. Carbonated hydroxyapatite synthesized at 80 °C contains the largest amount (up to 9 wt.%) of calcite impurity and has a low specific surface area (40 m²/g). Lowering the synthesis temperature to 20 °C leads to a slight decrease in the content of calcite impurity (up to 5–7 wt.%) and an increase in the specific surface up to 125 m²/g. The introduction of the maturation stage for carbonated hydroxyapatite precipitated at 20 °C for 4 days suppresses the calcite impurity formation and leads to the increase in the specific surface up to 155 m²/g.

Influence of highly disperse nanostructured modifiers of alumina – magnesia, partially stabilized zirconia – on the consolidation processes of composite ceramics of industrial corundum powders annealed at 1600–1700 °C, changes of its microstructure and physico-mechanical properties is investigated. It is established, that due to processes of self-diffusion of active modifiers there is a distribution of their nanograins on the borders of miсroparticles of corundum powder. In addition, nanostructured modifiers fill a pore space that causes sliding of particles under mechanical and thermal loads of material and transfers the mechanism of fragile destruction to pseudo-plastic. The entered nanostructured modifiers promote the process of lamellar zones formation throughout the material that also strengthens its mechanical properties. The correlation of composite ceramics structure and their physico-mechanical characteristics are developed.

The study of the chemical composition of water formed during pyrolysis of waste tyres was made. The obtained pyrolytic water was characterized by FT-IR techniques, gas chromatography-mass spectrometry, dissociation extraction and a distribution chromatography method. It was found out that pyrolytic water consists of about 93 compounds, from which 27 compounds were identified by GC-MS method. Quantitative analysis established that total content of compounds is up 0,90 g/dm3, from which caprolactam – 46 %, cyclohexanone – 5, aniline – 17, benzonitrile – 6, о-cresol – 2,6, p-cresol – 2,8, benzothyazole – 4,9, 2,4-dimethylquinoline – 4,6, phthalimide – 2,5 %. By dissociative extraction of organic acids and bases it was shown that peaks of some components of chromatogram contain minor components. Distribution coefficients in hexane-water system of cyclohexanone, aniline, benzonitrile, о-cresol, p-cresol, 2,5-dimethylphenol, benzoic acid, benzothyazole, caprolactam, 1-methyl-isoquinoline, 2,4-dimethylquinoline and phthalimide were defined.

Based on the distribution constants of biphenazate, obtained experimentally and also calculated from literature data on the solubility of biphenazate in water and organic solvents, as well as experimental data on the extraction of biphenazate from plant matrices by various extractants, we selected the optimal conditions for extracting biphenazate from apples and cucumbers. The conditions for the purification of the extracts were also selected. Acetonitrile in the presence of ammonium sulfate and hexane was used for extraction of the pesticide. Purification of extracts of plant materials was carried out by partitioning between hexane and water-acetonitrile mixture. The samples obtained after this treatment were pure enough to determine the residual amounts of biphenazate in them at the maximum residue level determined in Belarus and the countries of the European Union, or lower using widespread liquid chromatography with diode-array (ultraviolet) detection.

Tert-butyloxycarbonylprolylleucylglycinamide is obtained both by the interaction of tert-butyloxycarbonylprol ylleucylglycine ethyl ester with a methanolic ammonia solution and by the reaction of glycine amide with a mixed anhydride which was synthesized from tert-butyloxycarbonylprolylleucine and isobutylchloroformate. The removal of the tert-butyloxycarbonyl group by the action of formic acid or a dioxane solution of hydrogen chloride and treatment of the resulting salts with the corresponding base yielded a prolylleucylglycinamide, by the interaction of which with acetic, benzoic or 5-phenylisoxazole-3-carboxylic acids chlorides acyl derivatives of prolylleucylglycinamide are obtained.

2-Amino-4-acetylthiazolo[5,4-b]indole and its bromosubstituted analogue contain a free amino group and are initial compounds for chemical modification in order to obtain on their basis functional derivatives having high therapeutic activity. By the interaction of these 2-aminо-4-acetylthiazolo[5,4-b]indoles with succinic and maleic anhydrides, the corresponding imides and amides were obtained, which are of interest for use in order to create on their basis antihypoxic and actoprotective agents.

Synthesis of new asymmetric poly-π-conjugated 1-substituted derivaties of 5,5-dioxodibenzothiophene containing 1,2,3-oxadiazole fragment in the main chain of conjugation and cyclic fragments as the central chromophore are synthesized. The preparative yield of the target compounds was achieved using phosphorus (V) oxychloride as a cyclizing agent. The compounds obtained have high melting points and are blue phosphorescent luminophores.

Over the past decades, molecular docking has become an increasingly popular tool for the development of new drugs. To search and design new compounds, a detailed study of the interaction of existing complexes of ligands with the target protein is necessary. According to the purpose to identify amino acid residues of the B domain of protein A of Staphylococcus aureus involved in interaction with immunoglobulins G, we studied the interaction mechanisms during the formation of a complex of protein A of the Staphylococcus aureus cell wall and immunoglobulins G by molecular docking. By the means of molecular docking we selected four amino acid residues of Phe132, Gln129, Tyr133 and Phe124, which we can use to construct a peptide analog of the active binding site of protein A with the Fc fragment of immunoglobulins G. The obtained results can serve as starting point for an effective strategy for finding new medicines, in particular, they can be used to further develop biospecific sorbent for the selective removal of immunoglobulins G from human blood.

Rheological properties and concentration cross-overs of anionic acrylamide copolymers in saline solutions (potassium chloride) were investigated by using capillary viscometer method. Area of non-overlapping coils between the crossover concentration and the concentration of fluctuation mesh formation was determined; it was shown that with increase of salt concentration this area practically disappears, i.e. mass transfer mechanism changes near the crossover concentration. It was shown that at low concentrations of potassium chloride increasing the content of ionic groups of macromolecules leads to reduction in the crossover concentration and increase in the effective volume. It is found that the kaolin adsorption capacity decreases when polymers are adsorbed from saline solution, and the adsorption constant is significantly higher in the presence of salt than in water.

The work describes the production of complex fertilizers of prolonged effect on the basis of acid-free processing of phosphate rock of the Vyatka-Kama Deposit. The authors investigated the influence of chemical composition of salts and mass ratio between salt and phosphate components on the degree of activation of the phosphorite flour of the Vyatka-Kama Deposit (VKPF) during its treatment with solutions and suspensions of nitrogen-containing mineral salts and potassium chloride. It has been determined that the content of available form of P₂O₅ in phosphorite increases by 1.5-2 times, and the greatest activating effect is provided by ammonium salts. The use of preliminary mechanical activation of VKPF, in the method investigated, provides the increase in the content of available form of P₂O₅ by 11–13 %. The mechanism of interaction of the main minerals of phosphorite with salt additives (ammonium sulfate, ammonium nitrate, ammonium chloride, carbamide, potassium chloride) is proposed. The dynamics of changes in the content of ammonium nitrogen in fertilizer compositions at each stage of the process has been determined. The method for producing complex fertilizers based on phosphorite flour of the Vyatka-Kama Deposit has been developed and patented.

Single-stage process of obtaining active carbon by thermal processing of plant raw materials (mixture of different types of wood sawdust) impregnated with the mixture of phosphoric acid, urea and nitric acid salts has been developed. Active influence of impregnates on the process of carbonization and formation of carbon residue has been demonstrated. It is established that carbon residue obtained in the interval of heating 20–700 °С possesses high sorption activity to the vapors of organic compounds and has ion-exchange capacity. It has been shown that the value of carbon residue depending on the impregnate used in the wood increases by 3,1 times at 600 °С and by 4,2 times – at 700 °С as compared to the yield of non-treated initial raw materials.

This work shows the possibility of obtaining potassium sulfate by converting phosphogypsum and potassium carbotane by the reaction CaSO₄ + K₂CO₃ → ↓ CaCO₃ + K₂SO₄. The optimal conditions for this process are determined. It is shown that in an aqueous medium at a temperature of 20 °C, a stoichiometric ratio of the initial components, the rotation speed of the stirrer 200 rpm for 15-30 min, the degree of use of Ca²⁺ ions is 94-95 %. Potassium sulfate contained in the liquid phase is transferred into the solid phase by evaporation and subsequent crystallization.

By the method of mathematical planning of the experiment, the influence of the liquid-solid ratio and the content of waste of salt deposits in magnesia hardening backfill mixtures on their technological properties have been studied. The plan of the experiment has been chosen, the regression equations describing the influence of anhydrite wastes and halite wastes content on the density, spreadability and early setting time of backfillingsolutions, volumetric mass, and 28-day uniaxial compression strength of hardened materials have been obtained. As a result of the statistical analysis of mathematical models, the significance of their coefficients, adequacy, efficiency and the ability to calculate technological characteristics of backfilling mixtures by type and content of man-made raw materials have been estimated.

The article is devoted to the 110 anniversary of the birth of the Belarusian scientist, the founder of the section of chemical science – Chemistry of solids, the organizer and the first director of Institute of the General and Inorganic Chemistry of the National Academy of Sciences of Belarus, academician of the Academy of Sciences of Belarus – Mikhail Mikhaylovich Pavlyuchenko. In the article, the career devoted to search of the implication and chemical mechanism of the processes proceeding with participation of solids is described. Identification of the defining stages (limiting stages) and regularities of thermal dissociation reactions and synthesis of different classes and various structure of substances, as well as the definition of ways to operate these processes are described in this paper. His pedagogical and practical activities were purposeful, he looked for and found the young people interested in scientific research, excited them with his ideas, prepared 40 candidates and 3 Doctors of Chemistry. Together with the academician N. F. Ermolenko and the engineering structure of the institute, he prepared, proved the ways and possibilities of use and enrichment of sylvinites of the Starobinsky field, and repeatedly reported for the government and wide audience on importance of chemical industry development in Belarus. His course of life is a service to science and the Homeland.