AbstractAcid methods for processing of bauxites and aluminosilicates with high silicon content become attractive in connection with the exhaustion of natural alumina-containing resources suitable for processing by standard procedures based on using alkalis. The main problems in using acid procedures are associated with organization of closed-loop processes with low consumption of chemicals and power

AbstractThe process of detonation synthesis of nanodiamonds from ternary systems was developed with conversion tetryl as their main component. The dependence of the yield of detonation nanodiamonds and their content in the diamond blend on the tetryl content in the ternary composition was shown as well as that of the yield of detonation nanodiamonds on the oxygen balance of the blend. The conditions

AbstractThe results of studying the effect of temperature and pressure on conversion of methane and the catalyst lifetime during the catalytic decomposition of methane with the formation of hydrogen and nanofibrous carbon on a Ni–Cu catalyst are presented. The pressure varied in the range of 1–10 atm at the temperatures of 600 and 675°C. It was found that when increasing pressure, the total yield of

AbstractThe thermal oxidative degradation of a polymer composite material based on polytetrafluoroethylene and oxyfluoride glass of composition 18BaF2–31SiO2–19B2O3–24BaO–8TiO2 under dynamic conditions has been studied. It is noted that the decomposition process takes place in several stages. The gaseous products of thermal oxidative destruction of the composite material were studied by mass spectrometry

AbstractQuaternary ammonium salts containing gem-dichlorocyclopropane and 1,3-dioxolane groups were synthesized in high yield. The reactions of dichlorocarbonation of styrene and O-alkylation of 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane in the presence of quaternary ammonium salts were studied. It was established that in the O-alkylation reaction, compounds containing cycloacetal and allyl moieties

AbstractThe possibility of using composite films based on polyvinyl alcohol (PVA) and Na-carboxymethylcellulose (Na-CMC) as a separating material is considered for nickel-zinc and silver-zinc batteries. The sorption properties and porous structure of PVA/Na-CMC composite films treated with potassium hydroxide, as well as the electrochemical characteristics of nickel-zinc battery cells (open circuit

AbstractThermal degradation in air of Nafion proton-conducting polymer in composites containing nanostructured carbon materials [carbon black of Vulcan XC-72 grade and a graphene-like material (thermally expanded graphite)] and platinum nanoparticles was studied by nonisothermal kinetic analysis. The effect of the contact of Nafion with one or another material of the composite on the degradation kinetics

AbstractThe kinetics of oxygen absorption during the oxidation of methyl linoleate in Triton X-100 micelles has been studied. The order of the reaction with respect to the initiator diminishes from 1 to 0.6 with an increase in the total content of Triton X-100 per the unit volume of solution, since by the time of reaching the maximum oxygen absorption rate, the system consists of mixed micelles, which

AbstractElectrolytic recovery of platinum metals onto electrodes of fibrous carbon materials from solutions formed by processing of copper–nickel ores, gold- and silver-containing concentrates (gold and silver refining), platinum–rhenium catalysts, and simulated solutions from spent nuclear fuel reprocessing was studied. Combined flowsheets including electrolysis with fibrous carbon electrodes, anodic

AbstractThe review deals with the development of catalysts for the production of aromatic hydrocarbons from syngas. The thermodynamic aspects of the syngas conversion to aromatic hydrocarbons and the influence of the properties of the catalytic system on the yield and composition of the reaction products are considered. The mechanisms of the reaction on different catalysts are presented, and the influence

AbstractExtraction of rare earth elements with solutions of di(2-ethylhexyl) hydrogen phosphate or tributyl phosphate in heptane, toluene, or tetrachloromethane is accompanied by the origination and development of spontaneous surface convection. The spontaneous surface convection is manifested in the form of interfacial oscillation but can also lead to its break. The spectral composition of spontaneous

AbstractA thermodynamic calculation of the possibility of mass transfer of metal compounds in conditions of filtration combustion of metal-containing mixtures was carried out. According to the results the metals were divided into two groups: the first group includes metals that form both condensed and gaseous phases, and the second group includes metals that are only in the condensed phase. Under conditions

AbstractAl-Doped ZnO (AZO) nanocrystals with a novel cactus morphology have been successfully synthesized by a facile and efficient hydrothermal method. The crystal structure, surface morphology and chemical composition of the samples were determined by X-ray diffraction and scanning electron microscopy with an energy-dispersive X-ray analyzer, indicating that the presence of a small quantity of Al

AbstractAnionic copolymerization of acrylonitrile with methyl acrylate under the action of the 1,4-diazabicyclo[2.2.2]octane–ethylene oxide initiating system was studied. Similarly to the anionic homopolymerization of acrylonitrile, the copolymerization is accompanied by the intra- and intermolecular chain transfer to the polymer. The influence of the copolymerization conditions on the intensity of

AbstractThree zeolites (Beta, Mordenite and ZSM-5), which present different pore channels but the same Si/Al ratio (25), were used as catalysts to investigate the effects of acidity and channel structure on the catalytic activity for toluene butylation at 180°C in an automated high-pressure stainless steel reactor. The same Si/Al ratio of the three zeolites did not result in a similar catalytic activity

AbstractMorphological features of iron-containing composites based on silicon, titanium, vanadium, and boron nitrides and prepared by self-propagating synthesis were examined by scanning electron microscopy, and the content of elements (B, Si, N, Ti, V, O, Fe, C, Al, Mg, Ca) on their surface was quantitatively estimated using an attachment for EDX microanalysis. The optical properties of the composites

AbstractComparative experimental data on the four-step countercurrent extraction treatment of a mixture of naphthene vacuum gas oil and residual extract with dimethyl sulfoxide and with a 90 : 10 (wt %) mixture of N-methylpyrrolidone with ethylene glycol are presented. The mixed extractant based on N-methylpyrrolidone, compared to dimethyl sulfoxide, ensures more exhaustive removal of eight carcinogenic

AbstractRheological properties of composite hydrogels of agar with carboxymethyl cellulose sodium salt (NaCMC), intended for water conservation, were studied. The viscosity and yield stress of the hydrogels can both increase and decrease depending on the ratio of the polymer components in the hydrogel. Heating of the starting mixture for hydrogel preparation in the magnetic field influences the rheological

AbstractClay modified by potassium fluoride (KF-modified clay) was used as an ecological alternative and heterogeneous catalyst for the preparation of chalcones via Claisen-Schmidt condensation. In this paper, we have synthesized classical chalcones by condensation of benzaldehyde substituents with acetophenone. Moreover, the other chalcones were also synthesized during the condensation of benzaldehyde

AbstractAt elevated temperatures (130 and 180°C) in hydrothermal autoclave conditions, the possibility of deep extraction of noble metals from poor intermediate products of refining (or affinage) production was investigated. The conditions (temperature, processing conditions) of leaching of impurity elements into the solution are determined, under which the uncontrolled distribution of precious metals

AbstractThe field of temperatures and conversions in the catalytic process of bulk polymerization of isoprene in apparatuses with a fixed bed of the reaction mixture (polymerization forms) has been studied theoretically and experimentally. It is shown that in an apparatus with a thin layer (3 mm high) the process temperature regime is close to isothermal. In an apparatuses with a higher layer (6 mm

AbstractIn this study, Ni/TiO2/NaX zeolite nanoparticles were synthesized by hydrothermal and wet inoculation methods and characterized by XRD, FTIR, SEM, EDXA, TEM, and BET/BJH techniques. Desulfurization of gasoline under visible light was investigated in a batch reactor under mild conditions. Response surface methodology with central composite design was used to investigate mass of Ni/TiO2/NaX zeolite

AbstractA dielectric barrier discharge (DBD) plasma setup was developed to decompose phenol present in industrial wastewater by the varying discharge voltage and to study its effect on the degradation. Filamentary type of micro-discharge was found to be formed which was observed as numerous streamer clusters in the current waveform. The ozone gas generated from the reactor, was utilized directly and

AbstractThe chemical mechanical planarization (CMP) performance of the Si-face and C-face 6H-SiC substrates were compared using potassium permanganate (KMnO4) as an oxidizer and the alumina (Al2O3) nanoparticles as the abrasive particles over a pH range from 2 to 10. The results indicate that there was a significant difference in the CMP performance between Si-face and C-face 6H-SiC substrates, indicating

AbstractZinc oxide nanodispersions of a wedge- and rod-shaped particles were synthesized, their main colloid-chemical characteristics and antimicrobial properties were determined. It has been established that rod-shaped nanoparticles have a higher antimicrobial activity against a number of test microorganisms. The results of the study can be used to create detergents with antibacterial action.

AbstractIn this study, nano-emulsions were prepared by phase inversion temperature within the system liquid paraffin /Span80-Tween80/–water and also the effect of NaCl concentrations on phase inversion temperature (PIT) system and droplet sizes of liquid paraffin were studied. The changes in electrical conductivity with temperature for emulsions with 10 wt % liquid paraffin, 12 wt % surfactant mixture

AbstractThe methods for producing bismuth pentahydrate from metallic bismuth by the interaction of oxide or basic bismuth nitrate with solutions of nitric acid were compared using X-ray phase, chemical, atomic absorption, mass spectrometric analyses, and electron microscopy. The possibility of preparing it from bismuth metal as a result of oxidation of the latter and processing of the produced oxide

AbstractIsomerization of liquid hydrocarbons to obtain high-octane components of gasoline fuels in superacid catalytic media based on the trimethylamine hydrochloride–aluminum chloride ionic liquid with the addition of various salts was studied. The density, viscosity, and thermal stability of the catalytic systems obtained were studied. Regular trends in the influence of the physicochemical properties

AbstractPromising energetic materials 1,1-diamino-2,2-dinitroethylene (DADNE) and its derivatives in which one or both hydrogen atoms of the amino group are substituted by the NH2 or OH group were studied by quantum-chemical methods using PBE0 hybrid functional with the cc-pVDZ basis set and the coupled cluster method on the CCSD/aug-cc-pVDZ level. The thermal stability of such substances depends on

AbstractOxidation of tetradecahydroundecaborate ion with manganese dioxide is considered. The influence exerted by the structure of the crystal lattice of manganese dioxide polymorphic modifications (α, β, γ, δ) on the MnO2 activity in tetradecahydroundecaborate ion oxidation is analyzed. The decaborane yield reaches a maximum if MnO2 prepared by the reaction of aqueous solutions of MnSO4 and KMnO4

AbstractThermodynamic and kinetic aspects of the carbon dioxide reforming of methane are considered. Data on the types of catalytic systems used and on specific features of the commercial implementation of the process are systematized. The optimum temperature and pressure ranges for the carbon dioxide reforming of methane are 700–900°C and 2–4 MPa, respectively. Detailed analysis of the published data

AbstractThe rheological characteristics of polymer mixtures used for making multilayer polyelectrolyte covers on carbonate cores in drug delivery systems were studied. The cover structure is primarily determined by the first polymer layer, its excess charge, concentration, and ionic surrounding. The correctness of the interpretation of the viscometric data is confirmed by scanning electron microscopic

AbstractThe results of studies of the influence of dust from electrostatic precipitators of cement kilns on the synthesis of a binder containing mainly dicalcium silicate are demonstrated. The presence of alkali potassium and sodium oxides, as well as sulfate ions in the dust of electrostatic precipitators during annealing of a carbonate-siliceous mixture, promotes the formation of a solid solution

AbstractComparative studies (gel permeation chromatography and evaluation of turbulent drag reduction effectiveness on a turbulence rheometer) of ultra-high molecular weight polymers from a series of higher alpha-olefins (hexene, octene, decene, dodecene) used as hydrodynamic drag agents have been carried out. It was found that the activity of hexene in the polymerization on a titanium magnesium catalyst

AbstractBisazomethines derived from D,L-camphor, 2-adamantanone, and aliphatic diamines were prepared. The possibility of using bisazomethines as vulcanization accelerators was examined. The physicomechanical parameters of vulcanizates based on SKI-3 and their resistance to thermal oxidative aging were determined. The influence of the bisazomethine structure on the vul canization rate was found. Among

AbstractThe neutralization of toxic hydrazine fuel accidents and spills is an urgent task of protecting the biosphere. The effectiveness of using shungite for sorption and catalytic destruction of unsymmetric dimethylhydrazine and its transformation products in the environment has been established. The interaction of shungite with unsymmetric dimethylhydrazine that has fallen into water and soil is

AbstractIn this study, microstructure and corrosion property of CoCrMo coatings reinforced with different content of multi-walled carbon nanotubes (MWCNTs) nanoparticles fabricated by laser cladding (LC) on titanium alloy (TC4) substrates are investigated. Microhardness, metallographic, X-ray diffraction (XRD), and the electrochemical analysis are carried out to clarify the role of CNTs on the improvement

AbstractThe structure and properties of urethane varnish coatings based on isocyanate-containing prepolymers are studied using the methods of atomic force microscopy, thermomechanical analysis, differential scanning calorimetry, and dynamic mechanical analysis. By the modification of isocyanate-containing prepolymers with dicyandiamide, the possibility of producing urethane varnish coatings having

AbstractThe sewage sludge and the chemical composition of its ash were characterized experimentally. Mineral compounds of the ash were studied by X-ray microanalysis, X-ray diffraction, and IR spectroscopy. The fusion temperatures of the sewage sludge ash were determined by the cone method. The main parameters of the slag formation (base to acid ratio, slag viscosity index, and fouling index) were

AbstractThe results of studies on the recovery of carbon fibers by the method of low-temperature solvolysis from prepreg and reinforced plastics based on it are reported. The surface of carbon fibers extracted from prepreg and carbon fiber reinforced plastics (CFRPs) was characterized using scanning electron microscopy, thermal analysis, Fourier transform infrared spectroscopy, and Raman spectroscopy

AbstractCatalytic recombination of hydrogen and oxygen as radiolysis gases was studied using ceramic blocks of cellular structure as a catalyst support. The characteristics of the catalyst samples obtained were compared to those of the presently used granulated catalyst RK-102-12 (OPK-2). The possibility of preventing the transition of the catalytic recombination of hydrogen and oxygen to the flame

AbstractThe development of efficient methods for preconcentration and purification of petroleum metal porphyrins is the necessary condition for further progress of basic and especially applied research concerning the properties of these compounds and their role in oil genesis and maturation. This study deals with chromatographic preparation of high-purity vanadyl porphyrins using a sulfuric acid cation

AbstractThe effect of 1,1,9-trihydroperfluorononanol-1 immobilized on montmorillonite nanoclay on the nature of structural transformations and the properties of polycaproamide composites was studied. Using the methods of electron, atomic force microscopy and differential scanning calorimetry, we established the features of changing the diameter and height of spherulites in non-oriented films of this

AbstractUsing X-ray diffraction analysis, transmission electron microscopy, and complex thermal analysis, it was shown that brushite crystals are formed from aqueous solutions of ammonium hydrogen phosphate and calcium nitrate. The hydrothermal treatment of brushite results in the formation of quasi-one-dimensional hydroxyapatite nanoparticles, the longitudinal size of which is about 400 nm, and the

AbstractThe effect of the α-olefin addition in the pyrolysis feedstock on the yield of ethylene, propylene, and divinyl (butadiene-1,3) was studied using the n-hexane–hexene-1 model system under conditions of a laboratory flow-type thermal pyrolysis setup. It was found that the total yield of unsaturated hydrocarbons C2=–C4= depends on the ratio of n-hexane : hexene-1 in the initial mixture and is

AbstractThe work studied the hydrogenation of benzene and its derivatives on the mesoporous silica gel synthesized by the template method, doped with dysprosium and modified with nickel nanoparticles. The surface morphology and texture characteristics of the obtained sample were studied by scanning and transmission electron microscopy, X-ray phase analysis, and inductively coupled plasma mass spectrometry

AbstractThe possibility of synthesis of nanodispersed composites Fe3O4@M(II)-Fe layered double hydroxides (M = Mg, Ni) is shown by mechanical processing a mixture of solid salts M(II) (M = Mg, Ni), Fe(II) and Fe(III) with solid sodium hydroxide, followed by washing the reaction products with water. The formation of magnetite in the composite occurs due to the interaction of salts of ferrous and trivalent

AbstractThe patterns of epoxidation of linoleic acid methyl ester in a mixture of methyl esters of sunflower oil fatty acids with atmospheric oxygen in a bubble column reactor are analyzed at various feed rates of the gas phase. It was found that the oxidation process takes place in the transition region, under diffusion control conditions. The contributions of the diffusion and kinetic components

AbstractA study using a set of physicochemical methods has shown that treatment of single-wall carbon nanotubes synthesized by the electric arc method with an aqueous solution of hydrogen peroxide (followed by treatment with hydrochloric acid) and with a mixture of concentrated nitric and sulfuric acids leads to a decrease in the content of inorganic impurities in the bulk of the finished materials

AbstractA procedure was developed for preparing lithium tantalate (LiTaO3) charge homogeneously doped with lithium from high-purity tantalum-containing solutions, based on heat treatment of lithium-, tantalum-, and zinc-containing citrate precursors. The thermolysis products were studied by thermal analysis, X-ray diffraction, and IR absorption spectroscopy. The optimum synthesis conditions and zinc

AbstractMonochloroacetic acid esters and amides containing carbo- and heterocycles and heterocyclic esters and amides derived from commercial aryloxyacetyl chlorides were synthesized. The structures of the compounds were confirmed by 1Н and 13С spectroscopy. The herbicidal activity of the substances was studied with respect to mono- and dicotyledonous plants. The relative antioxidant activity of the

AbstractActivated carbons of grades AG-5, SKT-6A, and LiderKarbon-E, impregnated with copper sulfate with an additive content of 10–20 wt % and modified with fullerenes in the amount of 0.003–0.006 wt % were prepared and studied. The introduction of additives reduces the volume of micropores up to 36% with a slight decrease in the volume of mesopores. Modification of activated carbon by fullerenes

AbstractThe use of mechanochemical activation of the powder at the stage of mixing the components and consolidation by spark plasma sintering made it possible to synthesize material based on silicon carbide, which has a weight loss of less than 0.04% when tested for heat resistance at 1500°C for 100 h. A ceramic material was produced at a consolidation temperature of 1800°C, its hardness was 32 GPa

AbstractPublished data on noncatalytic pyrolysis of natural gas in molten metals are analyzed. The most illustrative results obtained in the past two decades are described. The use of molten metals as reaction medium allows solving the problem of coking of pyrolysis reactors owing to the flotation of the carbon formed to the molten metal surface. The use of liquid metal bubbling reactors allowing the

AbstractThe synergistic effect of divinylbenzene and triallyl cyanurate on the properties and structure of the thermoplastic vulcanizate prepared from a blend of polypropylene and hydrogenated styrene–butadiene–styrene triblock copolymer by vulcanization under dynamic conditions with 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane was revealed. The synergism consists in the enhancement of the strength

AbstractIsopropanol is one of the main organic impurities present in bioethanol. Effect of the isopropanol impurity in the feed on catalytic dehydration of 92% ethanol to ethylene over an aluminum oxide catalyst was studied in a gradientless reactor under the conditions of kinetic control at 350–400°С. The maximum permissible concentration of isopropanol in ethanol was found to be 0.7 g L–1, which

AbstractThe results of a study on the production of graphite–diamond nanocompositions by partial oxidation of a detonation synthesis blend in aqueous solutions of nitric acid under pressure in the temperature range 120–230°C are presented. A part of the graphite shell was subjected to selective oxidation. According to the results of kinetic studies in a 400 mL autoclave, an oxidation process scheme

AbstractLiquid-phase oxidation of styrene with hydrogen peroxide in the presence of a catalytic system based on (NH4)10W12O41 + Ce(NO3)3 + H3PO4, supported on a microstructured carbon material and treated with an aqueous Н2О2 solution, was studied. The major reaction products are phenyloxirane and benzaldehyde, with phenylacetaldehyde, 1-phenylethane-1,2-diol, and benzoic acid also present. The kinetic

AbstractThe dielectric properties of flaxseed, sunflower, mustard, rapeseed, and olive oils were studied in the temperature range 25–70˚C and in the frequency range of the electric field 25 Hz–1 MHz. A mechanism for the hardening of vegetable oils is proposed according to temperature-dielectric spectroscopy. The hardening of oils is interpreted as a combination of crystallization processes of triglycerides

AbstractThe possibility of using aspen bark modified with zinc and iron chlorides for preparing highly porous materials with specific properties was examined. The effect of the treatment temperature and modifiers on the structural and electrochemical parameters of the carbon-containing product was revealed. Carbonization of aspen bark modified with ZnCl2 yielded a material with the specific surface