Abstract Using 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

Abstract The 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

Abstract The 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

Abstract The 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

Abstract The 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

Abstract A 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

Abstract A 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

Abstract Monochloroacetic 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

Abstract Activated 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

Abstract The 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

Abstract Published 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

Abstract The 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

Abstract Isopropanol 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

Abstract The 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

Abstract Liquid-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

Abstract The 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

Abstract The 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

Abstract Plant biomass (such as wood, agricultural and logging waste) is considered a raw material with better environmental characteristics than fossil fuels. The main prospects for bioenergy are associated with combustion and gasification in small power systems, including as part of hybrid power plants. To increase the efficiency of gasification processes, an oxygen-enriched gasifying agent is often

Abstract The catalysts were synthesized based on the spent industrial aluminum-chromium catalyst used in the hydrocarbon dehydrogenation by SABIC Co., and the catalysts were modified with copper and potassium carbonate. The catalysts were tested in the oxidative dehydrogenation of ethylbenzene to styrene. It was found that the prepared and modified 1 wt % Cu catalyst, upon the conversion of ethylbenzene

Abstract The influence of parameters of the dry-jet wet spinning process was studied on properties of porous polysulfone hollow fiber membranes. The air gap distance, the dope extrusion pressure, bore fluid pressure and temperature were chosen as the studied parameters. Their effect on the geometric and morphological properties of membranes was investigated. The optimal parameters were revealed for

Abstract A procedure was suggested for highly efficient extraction of fullerenes from electric arc carbon black, with the degree of recovery reaching 86% of the carbon black weight. Analysis by HPLC and by IR and Raman spectroscopy shows that the extracts obtained consist of a mixture of fullerenes. The possibility of preparing highly water-soluble fullerene derivatives from the extracts by hydroxylation

Abstract Graphite-like carbon nitride (g-C3N4) nanopowders were synthesized by heat treatment of urea in air at a temperature of 450–550°С for 30 min and studied by X-ray diffraction and infrared spectroscopy. The main processes resulting in the formation of g-C3N4 from urea under the above conditions was established using the method of simultaneous thermal analysis. It was found that with an increase

Abstract Processes and products of ion exchange of günterblassite (K,Ca,Ba,Na)3–xFe1–y[(Si,Al)13O25(OH,O)4]·7H2O (microporous silicate, structurally intermediate between smectites and zeolites) and three samples of zeolite gmelinite (Na,K,Ca,Mg)x[(Si,Al)12O24)·nH2O of different composition with cations of various metals were studied. It was shown that günterblassite exhibits high activity and sorption

Abstract The use of both cellulose and polyurethane rubbers of the PU-8TB and PU-8A grades is discussed in the work to create film materials for draining oils. By the method of IR spectroscopy, the chemical interaction between the hydroxyl groups of cellulose and the carboxyl groups of polyurethane rubber is confirmed. Peculiarities of the thermal properties of the films are studied, which make it

Abstract The inluence of the heat treatment conditions and of the time of hydrothermal treatment at 210°С on the phase composition and size of crystallites and nanoparticles of lanthanum orthophosphate (LaPO4) was considered. The heating conditions in the course of hydrothermal synthesis of LaPO4 influence the structural transition of lanthanum orthophosphate of rhabdophane structure into the phase

Abstract The preparation of bifunctional catalysts with high catalytic selectivity for the n-alkanes hydroisomerization still remains challenging for the production of bio-diesel. Herein, two series of Pd/SAPO-41 bifunctional catalysts are prepared by the ultrasonic-assisted impregnation (xPd/S41-U) with different treating time and conventional incipient wetness impregnation methods (0.30Pd/S41-I)

Abstract The results of a study of melting the commercial waxes in the composition of asphaltene-resin-paraffin deposits and for comparison of petroleum waxes in multicomponent solvents of various nature are presented. It was found that with an increase in the amount of the aliphatic component in the solvent, the content of the crystalline phase in paraffin wax rises. Patterns in the variation of paraffin

Abstract Rheological properties of cellulose and chitin solutions with additions of montmorillonite nanoparticles in NaOH/urea/thiourea aqueous-alkaline solutions were studied. X-ray diffraction analysis shows that montmorillonite nanoparticles in hydrated cellulose and chitin films are in the intercalated state. Analysis of the Fourier IR spectra of the composite films reveals the shift of the Si–O

Abstract The effect of the residual catalyst for the synthesis of multi-walled carbon nanotubes (MWCNTs) on the electrophysical properties of MWCNT–polyethylene composites produced by melt mechanical mixing was studied. The residual catalyst content was varied by changing the MWCNTs synthesis time. The nanotubes used in the work were characterized using transmission and scanning electron microscopy

Abstract Sorption of a series of alkaline earth and nonferrous metals (Ca, Mg, Cu, Ni, and Zn) from lithium hydrocarbonate and chloride solutions onto ion-exchange resins of various classes was studied. The highest values of the static exchange capacity were observed in sorption from a LiHCO3 solution onto imino carboxylic ion exchangers Amberlite IRC 748 (Rohm and Haas, the United States), Purolite

Abstract The calcium pectinate hydrogel particles with an average diameter of 100.0 ± 50.0 nm were synthesized by ionotropic gelation method. The possibility of incorporating of trans-cinnamic acid plant growth regulator into them up to 56.3 wt % was shown. The obtained calcium pectinate particles, including those containing a plant growth regulator, were characterized by transmission electron, atomic

Abstract A novel curing agent containing phosphorus and carboxyl group compound diphenyl(2,3-dicarboxylpropyl)phosphine oxide (DPDCPPO) was synthesized and used as a curing and flame retarding agent for epoxy resins (EP). Its chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy, 1H, 13C and 31P NMR. The DPDCPPO was mixed with phthalic anhydride (PA) by different

Abstract Three-layer metal–viscoelastic polymer–metal composites with thermoplastic plasticized films based on polyvinyl acetate as a viscoelastic polymer layer were studied by dynamic mechanical analysis. The temperature dependences of the mechanical loss coefficients and components of the complex elastic modulus were obtained experimentally for composites with different ratios of the thickness of

Abstract The results of the development and studies of heterogeneous catalysts for decomposition of highly concentrated hydrogen peroxide used as monopropellant and oxidant in rocket engines are summarized. Being nontoxic, hydrogen peroxide is an excellent alternative to highly toxic hydrazine and dinitrogen tetroxide used today in rocket engines and is only slightly inferior to them in the energy

Abstract The use of the separated anode and cathode spaces during electrodeposition of the Fe–W alloy from a citrate bath (separation was carried out using a membrane with an average pore diameter of 0.74 μm) made it possible to significantly (up to 2 times) increase the current efficiency and deposition rate when using a graphite anode and to increase the performance electrolyte (constancy of surface

Abstract The use of reverse polarization during the electrodeposition of the Zn–Ni–Co alloy made it possible to increase the amount of alloying components, Ni and Co, in the composition of the deposit. It is established that the inclusion of cobalt in the composition of the Zn–Ni coating and the use of the reverse electrolysis mode contribute to the production of finer crystalline coatings with corrosion

Abstract The possibility of obtaining potassium sulfate by converting calcium sulfate (phosphogypsum) and potassium chloride in an ammonia solution was investigated. The optimal conditions for the process at various concentrations of ammonia solution were determined. When using a 25% solution of NH3, the stirring time is 30–60 min, the consumption rate of KCl is 160% from stoichiometry. When using