Quantum-chemical modeling of the polyaniline (PANI) molecule was performed. Methods for synthesizing PANI via oxidative polymerization were developed, and the morphology and physicochemical properties were comprehensively studied and optimized. Polymer-composite materials consisting of PANI and carbon-based materials within a PLA matrix were formed. According to cyclic voltammetry and impedance spectroscopy, these composites exhibit conductivities ranging from 0.10 to 25 S/cm, making them promising for use in various sensor devices in microand nanoelectronics, biomedicine, as well as in the development of anti-corrosion and antistatic coatings.

Hybrid composites based on calcium carbonate-phosphates and fibrin were obtained by wet precipitation in presence of citrated plasma (6–50 vol.%). Inorganic component of the composites represents amorphous calcium carbonatephosphates and  amorphized  carbonated  hydroxyapatite  (A-type)  with  a  Ca/P  ratio  of  1.71.  After  15  days  of  aging in the SBF model solution, the hybrid composites are enriched with biomimetic apatite (up to 8.8 wt.%) without changing  of Ca/P ratio of 1.71. Fibrin macromolecules provide partial removal of CO₃^2–ions from the structure of hybrid composites and apatite-forming capacity in the model SBF solution. Hybrid composites absorb up to 92 % of ciprofloxacin from aqueous solutions; the sorption capacity reaches 0.126 mmol/g. During 10 days of soaking in physiological solution, the composites release up to 89 % of the antibiotic; rate constant of ciprofloxacin release for composites measures 0,021 mmol/(g ∙ h^0.25) versus 0,051 mmol/(g ∙ h^0.10) for calcium carbonate-phosphates

Benzocyclopentaquinolines and benzacridines were obtained via cascade three-component condensation of substituted aldehydes, 1,3-cycloalkyldiketones and 2-naphthylamine or 1,5-diaminonaphthalene with a yield of 60–88 %. The synthesized polynitrogen heterocyclic compounds are of interest for biotesting for various types of activity and also as bulk ligands for obtaining metal complexes – promising catalysts for cross-combination reactions. Using the quantum chemical modeling method by conducting nonempirical calculations with a theory level of HF/6-31G, a complete optimization of geometric parameters was carried out and the electronic structure of 18 esters of 4,5-dichlorothiazole carboxylic acid with substituted benzocyclopentaquinolines and benzoacridines was determined.

An efficient synthetic scheme for 5-amino-4-methoxybenzo[d]isoxazoles has been developed starting from 3-(5-isopropyl-2,4-dimethoxyphenyl)-6,7-dihydrobenzo[d]isoxazole-4(5H)-one – a scaffold for the preparation of new Hsp90 inhibitors. The key stages in the synthesis included dibromination at position 5, aromatization, and subsequent copper-catalyzed cross-coupling of 5-bromo-4-methoxybenzo[d]isoxazole with sodium azide, with simultaneous reduction to 5-amino-4-methoxybenzo[d]isoxazole. Using the developed scheme, a potential Hsp90 inhibitor was obtained, which showed high antiproliferative activity against breast cancer cells of BT-474 line (IC₅₀ = 5 µM) and moderate activity against MCF-7 cells.

A comparative analysis of the efficiency of milk protein hydrolysis by trypsin and neutral protease using different methods of their addition was conducted. It was found that proteolysis by trypsin (enzyme-substrate ratio 1 : 40) at a temperature 37 °C and pH 8.0 leads to the formation of 81.2 ± 5.5 % of peptides with molecular mass less than 3.0 kDa, while protein hydrolysis by neutral protease (enzyme-substrate ratio 1 : 20) under the same conditions produces 86.6 ± 4.7 % of low molecular weight peptide fractions. It was shown that sequential application of trypsin and neutral protease allows obtaining, on average, 94.9 % of short peptides in comparison with the joint addition (91.3 ± 1.1 % of low molecular weight peptides). The application of the single enzyme provides the production of partial hydrolysates that can be used in the formulation of functional foods with reduced allergenicity, while the sequential and joint addition of trypsin and neutral protease generates extensive hydrolysates, which are considered optimal ingredients in the creation of hypoallergenic food products.

New scientific data on the solubility sodium hexafluorosilicate in the Na₂SiF₆–H₃PO₄–H₂O system in the range of changes in the content of orthophosphoric acid 40–65 wt.% under isothermal and polythermal conditions are presented. A decrease in the solubility of sodium hexafluorosilicate in solutions of orthophosphoric acid was established, with an increase in its concentration from dilute to content solutions over the entire range of temperature changes from 20 to 80 °C. This phenomenon, according to the authors, is due to a decrease in the amount of solvent (H₂O) as the concentration of the acid increases on the one hand, as well as an increase in the number of water molecules for ion hydration, in particular H₅P₂O₈– formed during the dissociation of orthophosphoric acid molecules, the dipoles of which do not participate in the process of salt dissolution. A change in the content of an acid has a much greater effect on the change in solubility compared to temperature, which led to the conclusion that defluorination of concentrated solutions of orthophosphoric acid is more preferable, since it allows to achieve a higher degree of defluorination when using alkali metal salts as a precipitating reagent. The analysis of the presented data on the effect of temperature and content of orthophosphoric acid is the basis for the subsequent selection of optimal conditions for the technological process of defluorination of extractive phosphoric acid by the method of precipitation using alkali metal salts and the prediction of the achieved residual content of fluoride ions.

The results of studies on the behavior of the copper trace element in the production of complex nitrogen-phosphorus fertilizers – ammophos and nitroammophos are presented. It is shown that, when copper oxide and sulfate are introduced into solutions of phosphoric and mixtures of nitric and phosphoric acids, copper appears in the form of dihydrophosphate. Copper hydrophosphate precipitates in the ph range of 1.6–2, and at a ph above 6 copper ammonium phosphate is formed. During ammonization of a mixture of nitric and phosphoric acids containing copper, copper hydrophosphate is formed in the ph range of 1.2–4.1, and at a ph above 5.2, copper ammonium phosphate precipitates. Under the conditions for obtaining copper-containing ammophos, copper is in the form of a mixture of hydrophosphate and copper ammonium phosphate. Under the conditions for obtaining nitroammophos, copper is mainly in the form of hydrophosphate with a lethal content of copper ammonium phosphate. Both in ammophos and in nitroammophos, copper is in a form assimilated by plants, which indicates the possibility of introducing the microelement copper at various stages of obtaining complex phosphorus-containing fertilizers.

The influence of applied fertilizers (manure, which is a fresh mixture of excrement and liquid or composted) on the properties of soils, ground and surface waters, as well as the general state of ecosystems of the water–soil–groundwater type were studied using the developed nitrate-selective sensors. Singleand double-layer microsensors based on conducting polymers (polypyrrole and bis-polyethylenedioxythiophene) made on the basis of a graphite rod have been developed and their suitability for monitoring the nitrate-ion content in natural ecosystems of the water–soil–underground water type has been evaluated.