The corrosion resistance of coatings (thickness 70 µm) based on epoxy powder paints modified with aliphatic amine or a mixture of anticorrosive pigments to the action of sodium chloride solution and salt spray has been studied. It is showed that with the increase of molecuar weight of initial epoxy oligomer and also at the incorporation of chemisorbing alifatic amine, containing polar groups, to the decrease in the permeability of the sodium chloride solution into the coating material is observed. It has been established that the observed changes in the properties of the coatings are due to the formation of a spatial structure of the polymer with different cross-link frequencies. It is shown that the introduction of a mixture of anti-corrosion pigments into the composition of paints provides a significant increase in the protective properties of coatings and a high preservation of the physical and mechanical properties of coatings in comparison with the base compositions. For 9000 hours of testing in a sodium chloride solution, the strength characteristics of the coatings decrease by about 10–12 % from the original ones. Based on the results of tests of coatings to the action of salt spray, the possibility of using the developed epoxy powder paints for operation in environments of a high atmospheric-corrosive category – C 5–1, including the application of coatings directly on a metal surface (Direct to metal) without multi-stage preparation of the metal surface for painting, is shown.

Copolymers of methacrylic acid and natural terpene monomers (α-pinene; β-pinene; ∆3-karene) with the molecular weight of (0.3–0.5)∙104 and a content of carboxyl groups of 14.5–16.3 % were synthesized. For the synthesized copolymers, hydrodynamic radius and the Kuhn segment, which characterizes flexibility of a polymer chain, were determined, as well as the Huggins constant in aqueous and saline solutions, and concentration regions for formation of supramolecular structures. In the presence of a cationic surfactant (benzetonium chloride, Hyamine), depending on the concentration of copolymers in the system, polymer-surfactant complexes were formed in soluble and insoluble forms. It has been shown that the effectiveness of the stabilizing action of soluble complexes with respect to an aqueous dispersion of calcium carbonate increases with an increase in the content of nonpolar groups in the polymer chain. A cationic surfactant (Hyamine) has been proposed as a precipitant in the method for the quantitative determination of carboxyl-containing polymers in aqueous and saline media.

The process of flocculation of a calcium-magnesium solid phase formed in an aqueous-salt solution with the introduction of calcium-containing precipitants using polyacrylamide, cationic and anionic acrylamide copolymers was studied. With the introduction of polymers, an increase in the dispersion settling rate was observed in the concentration range of 0.5–3.0 mg/g, to a greater extent for the anionic copolymer. In the presence of an amine-containing surfactant, the sedimentation rate increased with the introduction of polymers by a factor of 1.1–1.3 compared to dispersions without surfactants. Using an anionic copolymer as an example, it was shown that the adsorption of amine and the sedimentation rate of dispersion increase with the increase of the polymer molecular weight. It was found that the concentration of the anionic copolymer and the pH of the medium also influence the adsorption of amine. Based on the obtained data, an effective method of water-salt solutions purification from amine-containing surfactants and magnesium salts (purification degree 99.5–99.8 %) that can be used at mining and processing enterprises was developed.

The effect of sodium polyacrylate, polyethylene glycol of various molecular weights, and their mixtures on the dispersion stability of calcium and magnesium carbonates was studied. It was shown that in the presence of a binary system, the light transmission of the dispersion decreases 1.2–1.5 times, the content of fine fraction particles increases by 1.1–1.3 times compared to the individual components. The stability of the dispersion of carbonates depends on the components ratio in the binary system and their molecular weight. The formation of adsorption solvated layers of polyacrylate and polyethylene glycol molecules at the interphase boundary contributes to an increase in the stability of the carbonate dispersion.

A cationic flocculant with an amide-type polymer matrix was synthesized by modifying polyacrylamide according to the Mannich reaction. The use of a modified polymer leads to an increase in the adsorption of the polymer on solid phase particles in an aqueous dispersion of kaolin, an increase in the rate of kaolin sedimentation by a factor of 1.2–1.4, and makes it possible to expand the concentration range of dispersion destabilization compared to polyacrylamide.

The influence of polycarboxylate and naphthalene-sulfone superplasticizers, paraffin hydrophobizator and complex hydrophobic-plasticizing additives on the structural characteristics, physical-mechanical, hydrophysical properties, corrosion resistance and frost resistance of fine-grained Portland cement concretes was studied. Structural parameters of concretes (average and true density; density coefficient; total, open, closed porosity) were compared with compressive strength, water absorption, softening coefficients and salt resistance of materials. It is shown that the introduction of superplasticizers increases the density, softening coefficients and salt resistance, reduces the water absorption of Portland cement structures, and the use of paraffin hydrophobization and complex hydrophobic-plasticizing additives increases the closed porosity as a result of the formation of mosaic hydrophobic films on the surface of solid phases, which have a positive effect on the hydrophysical and physical-mechanical properties of concretes.

The effect of sodium dodecyl sulfate and sodium oleate on the structural-rheological properties of a dispersed hydrogel based on polyacrylic acid was studied. It was shown that the viscosity of hydrogel compositions with surfactants is higher than the viscosity of the individual components and increases with increasing temperature from 20 to 40 °C. Compositions with sodium oleate are non-Newton liquids and exhibit thixotropic properties.

The conditions and the patterns of copper and nickel nanoparticles formation by direct reduction from aqueous solutions of their salts in nitrogen atmosphere were studied, and nanocomposite materials based on magnesium oxide and metal nanoparticles coated with protective oxide shell were obtained. The obtained materials are of interest as sorbents for the purification of aqueous media from toxic impurities, as well as catalysts in organic synthesis, in particular for the production of methanol from carbon dioxide. Phase composition, thermal stability, microstructure of nanocomposites, as well as their sorption properties, were studied. The powders of magnesium oxide and nanocomposites based on it were found to have high sorption capacities with respect to lead and chromium ions – up to 2989.0 and 499.9 mg/g, respectively.

The process of modifying aqueous powder suspension materials (APS) based on solid epoxy film-forming agents with highly dispersed powders of magnesium oxide was studied: production by ChemPur (n-MgO – primary size of particles is 36 nm), and magnesium oxide synthesized by a template method from the concentrated bischofite solution (MgOlab – primary size of particles is 102.8 nm). It was shown that presence of active functional surface OHgroups in both samples of magnesium oxide leads to the formation of secondary structures: aggregates and agglomerates. The nature of the influence of the size of aggregates of MgO particles and the conditions of dispersion on the properties of protective coatings is established. The nature of the influence of particle size and dispersion conditions on the properties of protective coatings is established. Optimal properties of coatings based on APS, sedimentation and aggregative stability of suspensions are implemented only under the condition of effective mechanical dispersion in a bead mill, when the most intensive destruction of large aggregates of n-MgO up to 50–60 nm occurs. The distribution of nanoparticle agglomerates in APS at the micro level (700–800 nm) using the MgO-lab does not lead to a significant change in the properties of APS and coatings based on them.It is shown that the introduction of n-MgO into APS allows reduces the curing temperature of the coatings from 110 to 90–100 °С. It is caused by the increase in the density of cross-linking of the spatial structure of polymer. The strength of modified coatings upon impact and tension increases by 2 times in comparison with the base composition, which does not contain nanomodifier, during curing of coatings at100 °C. In comparison with the known water-borne epoxy paints and varnishes, APS compositions are one-pack, they are more technological in use, have a long lifetime (up to 12 months in comparison with the viability of known two-pack epoxies, 1-8 hours). Materials can be used in industry for the protection of metal products, both as primers and as independent coatings.

It is shown that the stability of the water and salt dispersion of kaolin decreases with the introduction of a cationic polyelectrolyte and its mixtures with a surfactant. The flocculating ability of the cationic polyelectrolyte decreases with increasing content of ionic groups. An increase in flocculation in a salt medium was established with the introduction of the mixture of polyelectrolyte with an anionic surfactant, as well as with the sequential addition of components to the kaolin dispersion.

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.

As a result of the study, the effect of curing accelerators (heterocyclic amine and zinc-containing accelerator) on the structure, physico-mechanical and protective properties of coatings based on powder epoxy-polyester compositions was established. The introduction of accelerators into the compositions affects the depth and speed of the curing process of film formers and provides the possibility to reduce the curing temperature. It has been established that the use of heterocyclic amine accelerator is more effective than a zinc-containing catalyst. For compositions containing heterocyclic amine, a decrease in gel time and an increase in the complex of physico-mechanical and protective characteristics of the coatings are observed, which were evaluated for the resistance of the coatings to the static action of a 3 % solution of sodium chloride. It is shown that changes in the protective properties of coatings, depending on the composition, correlate with the structural parameters of the polymer film and are due to the formation of the spatial structure of the polymer with different cross-link density. The use of mixtures of the investigated curing accelerators leads to an increase in the density of the polymer spatial network. This provides high protective properties of coatings to the action of aggressive electrolytes by reducing the permeability of corrosive media into the coating material. For 5000 hours of testing there are no pockets of corrosion under a film and no significant disruption of the continuity of the coatings (bubbles, peeling, wrinkling and cracking) in comparison with the basic compositions that do not contain accelerators.

Physicochemical aspects of the regulation of interfacial processes occurring at the oil-water-rock interface in the presence of ionic surfactants and their compositions are considered with the goal of developing efficient, scientifically grounded innovative technologies ensuring enhanced oil recovery and refining. A complex of studies of surface phenomena in the presence of ionic surfactants made it possible to identify criteria for evaluating the effectiveness of their action at the oil-water-rock interface, which makes it possible to predict the behavior of surfactants in real conditions of oil production and to use them purposefully in various enhanced oil recovery technologies.

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 adsorption capacity on the interphase surfaces of solution / air and solution / mineral material of binary mixtures of anionic (alkylbenzenesulfonic acid and its sodium salt (ABSCNa)) and nonionic surfactants (Tween-80) was studied. It has been established that the adsorption interaction of binary mixtures of surfactants with the surface of quartz and dolomite is affected by the presence of potential-determining ions that activate the surface of mineral materials, the charge and hydration of the anionic antagonists, the nature of the intermolecular interactions between the surfactant-components of the mixture. It was shown that the ABSCNa / Tween-80 mixture, characterized by low adsorption capacity to the mineral materials under study and absence of interaction between the surfactant components of the mixture, has a maximum oil displacement capacity from the surface of dolomite and quartz.

Influence of cooling and mixing rate on the process of schoenite crystallization from saturated salt solutions was investigated in laboratory conditions. It was established that as the system’s cooling rate and mixing speed increase, a significant decrease of the induction period of schoenite crystallization is observed. Fivefold increase of the cooling rate increases sizes of schoenite crystals by an average of 2.5–3.0. Mixing rate increase leads to the formation of a fine crystalline precipitate (crystal size 10−20 μ m).

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.

Interfacial interactions of cationic surfactants of various chemical structures at the solution / finely dispersed mineral material (quartz and dolomite) interface were studied. It is established that the modification of the surfaces of quartz and dolomite with cationic surfactants leads to a change in the structure and radius of the capillaries due to the formation of adsorption-solvate shells. The hydrophobic ability of cationic surfactants is determined by the structure of the hydrophilic part of their molecules – the balance of amino groups in the alkyl chains and the absence of steric hindrances during adsorption interaction with the surface of mineral materials. The mixture of surfactants containing six amino groups and a polyhydric alcohol glycerin has an effective hydrophobic ability from both aqueous and highly mineralized solutions.

The factors of negative influence on properties of mineral fertilizers based on potassium chloride have been discussed and ways of their elimination have been investigated. The regularities of the influence of inorganic and organic modifiers on physico-chemical and mechanical properties of fine-dispersed and granular potassium chloride have been established. Technologies of producing potassium fertilizers with improved properties have been developed on the basis of the obtained data.