The historical review of the Institute of General and Inorganic Chemistry of the National Academy of Sciences of Belarus considers all periods of the Institute’s evolution, starting with its organization in 1959, forming the main structural divisions and areas of research and development (1959–1968), structuring these areas and accelerating their development (1969–1990), optimization and headway with a primary focus on the scientific support of important tasks of industry and the agricultural complex of the Republic of Belarus (1991–2019). The information on the formation and development of scientific schools at the Institute, their outstanding achievements and examples of successful implementation of developments in enterprises and organizations of the national economic complex is presented. In chronological order, the results of the activities of the Institute scientists structured by the main scientific areas are reviewed, and references to their published books and monographs are given.
The studies on the development of flotation enrichment technology for potash ores (sylvinite, kainit-halite, carnallite-kainit-halite) were conducted. Optimal flotation conditions: salt composition, density and pH of the dispersion medium, collector of the useful component, auxiliary reagents-frothers, hydrophobisators, depressors for obtaining highly enriched potassium-containing concentrate have been developed for each ore. On the example of sylvinite ore enriched by direct flotation in ore-saturated solutions with a density of 1235 kg/m3, it was shown that the use of a combination of frothers (pine oil, polyethylene glycol) and apolar reagents (liquid paraffins, industrial oil) as part of a complex collector based on higher aliphatic amines (C16 –C18) provides an increase in the extraction of potassium chloride to the concentrate with high quality of the latter. For kainite-halite ore enriched by direct flotation in the saturated aqueous solution of magnesium chloride with a density of 1284 kg/m3 and pH 6–7, lower aliphatic amines (C10 –C12) in combination with amyl alcohol or caprylic acid are effective as a collector of kainite. Carnallite-kainite-halite ore is enriched by reverse flotation in aqueous solutions of magnesium chloride with a density of 1285–1295 kg/m 3 and pH 3–4 using the halite collector of the hydrochloric acid salt of alkylmorpholine.
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.
Hybrid biomaterials based on amorphous hydroxyapatite and blood components (fibrin, citrate plasma) were developed by chemical precipitation of hydroxyapatite in a biopolymer matrix (pH 11; Ca/P ratio 1.67) and by mixing 6–14 wt.% of hydroxyapatite gel (pH 7.0–7.2) with bipolymers. Chemically precipitated hydroxyapatite in biopolymer matrices is single phase or contains ticalcium phosphate impurity up to 30 %, mainly α-modification in fibrin matrix and β-modification in citrate plasma. The interaction of hydroxyapatite gel into the fibrin leads to significant amorphization of hydroxyapatite and an increase in its bioresorbability. Holding the composites with hydroxyapatite obtained by chemical precipitation in the Simulated Body Fluid model solution for 75 days leads to their partial resorption and simultaneous increase of biomimetic apatite, with its greater weight gain on composites with a fibrin. Hybrid biomaterials based on a fibrin obtained from the patient’s blood and hydroxyapatite gel showed positive result during implantation, allowing to form an adequate configuration of the defect, expanding the possibilities of ENT surgery.
The paper studies the wetting of aluminum and glass surfaces with disordered roughness created by technologically simple methods: chemical deposition with simultaneous self-organization of nanoparticles on microprotrusions and valleys, as well as the application of thin coatings using polymer-dispersed systems with polymodal particle size distribution. Super-hydrophobic coatings with an edge wetting angle of 160–170° and a wetting hysteresis of no more than 10° on electrochemically nanostructured aluminum, processed by the dispersion with the polymodal distribution of aerosil microparticles, silicon oxide nanoparticles SiDB and carbon nanocomposite SHDB (Nanosintal, Belarus) in fluorinated varnish. The regularities of changes in the wetting angle of silicate glass with the coating of the same varnish with small additives were established, showing its significant growth with an increase in the content of aerosil microparticles and a decrease in the lacquer concentration. The increase in the content of SiDB and SHDB does not significantly affect the contact angle, but it significantly reduces the hysteresis of its wetting, which gives the glass the effect of “lotus”.
The phenomenon of strong stabilization of concentrated aqueous dispersions (emulsions) of polymers by colloidal particles of organic nature (microparticles of synthetic latexes), not accompanied by a significant increase in effective viscosity, opened, firstly, the possibility of carrying out the processes of pigmenting them at low energy costs with a maximum yield (dynamic state, meets the conditions of intensification of heterogeneous chemical-technological processes) and, secondly, determined the directions of further research in this area. So, in contrast to the classical method of emulsion stabilization by mineral microparticles adsorbed directly on the surface of their droplets, microparticles of organic origin interact with them through an interlayer of the dispersion medium, localizing in the immediate vicinity of the dispersed phase and thus maintaining a high mobility of the interphase boundaries. In this regard, the proposed method for predicting the type of emulsions of polymers, taking into account the contact wetting angle and the wetting area of the surface of solid particles of a stabilizer with water and a polymer, requires further verification on various systems. The obtained data of fundamental importance also allowed us to propose new applications of stabilized concentrated artificial latexes for solving applied problems.
An import-substituting film former is developed – an aqueous epoxy emulsion and composite materials based on it (glue, anti-corrosion primer, waterproofing impregnation, paint for decorating glass products).
Low-temperature synthesis of the mesoporous silicates containing d-metals is carried out. The measured isotherms of low-temperature nitrogen adsorption-desorption by chrome, vanadium and zirconium silicate adsorbents belong to Type IV (b) of sorption isotherms on IUPAC classification. Such isothermal curves are inherent in mesoporous systems with the M41S type of ordering of the making elements. Increasing рН of sedimentation and metal content lead to amorphization of samples and distortion of a supramolecular lattice with uniform regular geometry and a long-range ordering.
Catalytic properties of MgFe2O4 nanoparticles during oxidative destruction of non-steroidal anti-inflammatory drug ibuprofen were studied. The influence of the conditions of the catalytic process on the efficiency of ibuprofen decomposition was established. It was shown that at the catalyst content of 0.5 g/L, H2O2 concentration of 20.0 mmol/L and pH of 6.0 for 40 min, a decrease in the ibuprofen concentration from 10.0 mg/L to less than detected limit is achieved. It was found that in the process of catalytic destruction the degree of ibuprofen mineralization reached 100 %. The conducted research shows the prospects of practical application of the developed Fenton-like heterogeneous catalyst for wastewater treatment from pharmaceutically active compounds.
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.
The influence of the preparation method, gypsum content and liquid-solid ratio on the process of hardening and properties of mixed gypsum-magnesia binders intended for laying in the developed space of salt areas has been studied. With the introduction of fillers – waste from the development of salt deposits and plasticizers – in them, filling mixtures, which are non-linear viscoplastic thixotropic systems with a certain period of stress and strain relaxation, have been obtained. The phase composition of hardening products, electrokinetic, rheological and physico-mechanical properties of the obtained plasticized filling mixtures depending on the method of injection, the type and content of plasticizers have been investigated. At optimum liquid-solid ratio and the plasticizer content of the mixture with low static and dynamic yield stress and effective viscosity and extended setting time have been obtained.
The features of clay-saline (potassium and sodium chlorides) dispersions flocculation using polyacrylamide and its cationic and anionic copolymers are described, including the effect of flocculant concentration, solid concentration in dispersion, method of polymer dissolution in water or saline solution on the sedimentation rate and flocculation density. It is shown that polyacrylamide has the highest flocculating ability towards clay-saline dispersion, and cationic copolymers – the lowest effect. It is shown that in concentrated clay dispersions flocculation starts at lower flocculant dose rate and occurs in a narrow range of polymer concentrations. The sedimentation rate of clay in salt dispersion increases by 15–20% with the introduction of flocculant in two stages, and by 50% times – with consequent dosing of cationic and anionic flocculant. It is also stated that polymer solutions prepared using concentrated salt solutions of potassium and sodium chlorides provide a higher efficiency of clay flocculation in comparison with solutions of polymers prepared in water.
It is known that when water are used for technological purposes, in circulating water supply systems of enterprises as a coolant during continuous heating and cooling, the formation of insoluble precipitates, most often calcium carbonates, occurs on the walls of heat exchangers, which leads to a large number of problems, even production can be stopped for cleaning equipment. To prevent the formation of salts, it is necessary to use precipitation inhibitors. Sodium polyacrylate was investigated as a precipitation inhibitor. The composition, morphology and IR spectra of calcium carbonate precipitate obtained in the absence and in the presence of sodium polyacrylate were studied. It was established that the effect of sodium polyacrylate on the mechanism of crystallization of carbonate sediment depends on the pH of the initial solution. The results of IR spectroscopy, X-ray diffraction analysis and images obtained by electron microscopy indicate the participation of polymer molecules in the formation of the crystalline structure of the carbonate precipitate.
ISSN 2524-2342 (Online)