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Extractive Crystallization of Salt and Phase Equilibria in the Ternary System Sodium Nitrate – Water – Dipropylamine

Authors: Mezhueva M. A., Danilina V. V., Kurskii V. F., Cherkasov D. G.

Phase equilibria in the ternary system sodium nitrate – water – dipropylamine where the constituent binary liquid system is characterized by a trend to form a lower critical solution temperature (LCST) were studied using the visual-polythermal method in the range −10.0–90.0° C. It was found that the introduction of sodium nitrate into the water – dipropylamine system led to a significant decrease in the mutual solubility of the components.

Researching the Oxidation Process of Sulfur-Alkalaine Sewage Components Using Ni2+ Catalyst – Containing Galvanic Wastewater

Authors: Savelyeva A. V., Savelyev S. N., Levin A. S., Fridland S. V.

The effect of different concentrations of nickel (II) ions on the oxidation rate of mixed wastewater pollutants with ozone-air mixture for 30 minutes with an ozone concentration of 3 mg/l was studied. It was shown that adding nickel (II) ions at a concentration of 300 mg/l reaches the maximum degree purification of wastewater as a result of oxidative processes on the COD value, equal to 40.4%, which is 10.1% more compared to the catalytic oxidation of the investigated wastewater pollutants with the air oxygen participation.

The Synthesis of New Organoselenium Heterocyclic Compounds: 2,4-Diaryl-5,6,7,8-Tetrahydroselenochromilium’s Salts

Authors: Direnko D. Y., Drevko Y. B., Drevko B. I.

The synthesis of novel organoselenium heterocyclic compounds is of great theoretical and practical interest because of high biological activity. The known methods of synthesis of hexatomic selenium containing heterocyclic compounds allow us to obtain only monoaryl-substituted tetrahydroselenochromilium salts. In this study, the reactions of 2-(3-oxo-1-aryl-3-phenylpropyl) cyclohexanones were carried out with hydrogen selenide in situ under conditions of acid catalysis in diethyl ether.

The Research of the Behavior of Cefixime in Aquatic and Biological Media by Spectrophotometric Method

Authors: Kulapina E. G., Kulapina O. I., Anikina V. D.

The research of behavior of cefixime in biological media was conducted by spectrophotometric method. It was shown that the maximum of light absorption of cefixime against the background of oral fluid is observed at λ = 292 nm and for blood serum at λ = 289 nm. The interval of linear dependence optical density – concentration of cefixime is 3–50 mkg/ml. The optimal conditions of precipitation of proteins in the studied biological media were revealed.

Visual Colorimetric and Colorimetric Determination of Cefuroxime

Authors: Marakaeva A. V., Kosyreva I. V.

Cefuroxime is a cephalosporin antibiotic with a wide spectrum of antibacterial activity for gram-positive and gram-negative microorganisms. It is in the list of vital and essential drugs for medical use. Currently, spectroscopic, chromatographic, electrochemical methods are used to determine cefuroxime. In current study we developed test agents in the form of indicator papers and powders with an immobilized Fehling reagent for the rapid determination of cefuroxime. Cellulose paper and silica gel were used as a solid matrix to create testing means.

Alkaline Hydrolysis Kinetics and Physico-Chemical Properties of Acrylic Copolymers Based on Acrylic Acid, Its Esters and Vinyl Acetate

Authors: Bayburdov T. А., Obshitser А. S., Romanova Y. O.

Kinetic regularities of the alkaline hydrolysis of copolymers of methyl acrylate, butyl acrylate, vinyl acetate and acrylic acid of several chemical compositions under various conditions were studied by IR spectrometry. The initial rate of alkaline hydrolysis and the limiting conversion degree were shown to increase with increasing concentrations of the components of the reaction mass and temperature.

Total Charge of Chitosan and Chitosan Succinyl Macromolecules Effect on the Stability of Particles of Silver Iodide Sols in Polymer-Colloidal Based Dispersions

Authors: Bazunova M. V., Bazunova A. A., Khlobystova E. S., Kulish E. I.

Obtaining stable polymer-colloidal dispersions based on watersoluble polymers and inorganic colloidal particles, such as silver iodide sol, followed by removal of the dispersion medium is one of the ways to create hybrid biomedical materials (e.g. films, threedimensional matrices). The current work is devoted to studying the possibility of increasing the stability of polymer-colloidal systems based on silver iodide sols, succinyl chitosan and chitosan polysaccharides by reducing the total charge of macromolecules.

Synthesis and Physicochemical Properties of Grafted Copolymers of Chitosan and Acrylic Monomers

Authors: Bayburdov T. А., Shmakov S. L.

The search and analysis of English-language 2004–2019 scientific literature devoted to the graft polymerization of acrylic monomers (acrylic acid and acrylamide being examples) onto chitosan to obtain novel materials with valuable properties was made. It was revealed that radical copolymerization, with potassium or ammonium persulfate, cerium-ammonium nitrate being initiators was used for grafting. Microwave, UV radiation and gamma rays were also used. To obtain gel, a cross-linking agent (N,N’- methylenebisacrylamide) was introduced. Glutaraldehyde was also used for cross-linking.

Quasi-binary Section Ag2SnS3-Sb2S3

Authors: Mamedov S. H.

Silver thiostannates and chalcostannates are widely used as promising functional materials which have semiconductor, thermoelectric, and photoelectric properties. The goal of this research is to study the Ag2SnS3-Sb2S3 phase diagram and determine the boundaries of solid solutions based on both components. Alloys were investigated using methods of physicochemical analysis. Based on the results of the study, a condition diagram of the Ag2SnS3-Sb2S3 system was constructed.

Синтез и конформационные особенности пергидропирролодиазациклоалканонов

Authors: Grinev V. S., Linkova E. I., Yegorova A. Y.

The reactions of 4-phenyl and 4-(p-tolyl)-4-oxobutanoic acids with 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane by heating in an aprotic non-polar solvent initially proceed through a nucleophilic attack of the amino group on the carbon atom of the oxoacid carbonyl group to form the corresponding amide.

Improved Synthesis of 2,3,4,6-tetra-О-acetyl-α-D-glucopyranosylhalogenes and 2,3,4,6-tetra-О-acetyl-α,β-D-glucopyranose – Glycosylating Agents of Biologically Active Compounds

Authors: Spiridonova A. V., Krasnikova N. V., Krasnikov S. V.

O,N-Glycosylation reactions are used for the synthesis of prodrugs based on various pharmaceutical substances. This, in turn, can significantly improve their pharmacokinetic and pharmacodynamic parameters, as well as reduce toxic effects. In current study, the objective was to propose new variants of the synthesis of active glycosylating agents, superior to the previously known ones in terms of the use of highly toxic substances, the anomeric composition of the products and the reaction time.

Assessment of Growth-Regulating Activity and Ecotoxicity of Diarylidene-Substituted Cyclohexanones

Authors: Rogachaeva S. M., Zhutov A. S., Shilova N. A., Klochkova I. N., Borisova S. V.

The search of new biologically active substances to be used as herbicides and plant growth regulators is carried out. The two compounds were used – 2-benzylidene-6-(m-nitrobenzylidene) cyclohexanone (1) and 2-benzylidene-6-(p-fluorobenzylidene) cyclohexanone (2). They are similar in structure, but containing different functional groups in one of the benzene rings: -NO2, and -F. Their dose-dependent effect on the germination and growth of Triticum aestivum and Barbarea vulgaris was investigated.

Phase Equilibria and Salting Out of Butyric Acid in the Sodium Chloride – Water – Butyric Acid Ternary System

Authors: Cherkasov D. G., Hrykina A. V., Umetchikov V. A., Smotrov M. P.

Phase equilibria in the water–butyric acid binary system in the range of −10÷0° C and in the sodium chloride–water–butyric acid ternary system in the range of 10.0÷60.0° C were studied using the visual polythermal method. The phase diagram of the water–butyric acid binary system at −9.5° C is characterized by eutectic equilibrium, the solid phases of which being ice and butyric acid crystals. The metastable delamination range was found on the ice crystallization field, bounded by a binodal curve with an upper critical solution temperature of −3.7° C.

Complexation of Polymyxin B1 Derivatives with Heparin

Authors: Shalygina V. V., Vlasova E. N., Anan'eva E. P., Gurina S. V.

The method of coprecipitation from aqueous solutions at a neutral pH value was used to study the interaction of polymyxin B1 derivatives with sodium heparinate. They were compared with the initial unmodified antibiotic and with the initial antibiotic in a solution of the corresponding polymer, covalently unbound with it.

Study of Rheological Properties of Sodium Salt Solutions of Carboxymethyl Cellulose

Authors: Chernova V. V., Kotyashov M. S., Lazdin R. Y., Kulish E. I.

Rheological characteristics of polymer solutions not only affect their processing, but can also influence on the structure and properties of products obtained from the solutions. This work is devoted to the study of rheological properties of sodium salt aqueous solutions of carboxymethyl cellulose in water. It is shown that the studied solutions are characterized by the presence of concentration area of unstructured semi-separated solutions without network formation.

Viscosity Properties of Chitosan Solutions in Glycolic Acid

Authors: Babicheva T. S., Shipovskaya A. B.

Viscosity properties of chitosan solutions with molecular weights of 700 and 200 kDa in 1.5% glycolic acid were studied in a wide range of polymer concentration and ionic strength of the medium by means of capillary and rotational viscometry. The concentration dependences of the specific viscosity were plotted. The influence of the molecular mass of chitosan and the NaCl-controlled ionic strength of the medium on the hydrodynamic volume of macrochains and their polyelectrolyte properties was established. The size of a polyion with an almost completely compensated charge was estimated.

Regulation of the Physicochemical Properties of Acrylic Copolymers by Graft Polymerization onto Cellulose and Starch

Authors: Bayburdov T. А., Shmakov S. L.

Scientific literature in English from 2010 to 2019, devoted to the problem of the development of sorbents based on polymeric materials, intended for collecting spilled oil and oil products from the surface of reservoirs, was scanned and analyzed. Three most numerous classes of polymeric sorbent materials (cellulosic materials, acrylate copolymers and synthetic rubbers) were identified, and the oil sorbents proposed are characterized. Prospects of using sorbents of these classes for cleaning up the surface of reservoirs from oil spills were discussed.

Synthesis of Magnetic Sorbents Based on Magnetite Nanoparticles and Humic Acids and Their Application for Sorption of Phenolic Ecotoxicants

Authors: Gubin A. S., Suhanov P. T., Kushnir A. A.

Fe3O4 nanoparticles coated with humic acids isolated from chernozem, sapropel, peat and brown coal were obtained using hydrothermal synthesis. The properties of the obtained sorbents were carried out using IR spectroscopy, SEM and TEM, whereas saturation magnetization was established using a vibration magnetometer. The maximum content of nitrogen-containing groups was found in humic acids obtained from sapropel, while the minimum amount was found in brown coal. The sorption properties of these polymers were checked among 12 different phenols.

The Study of the Complexation of Volatile Organic Compounds with β-cyclodextrin and Its Derivatives in Aqueous Solutions by Headspace Gas Chromatographic Analysis

Authors: Kapralova T. S., Onuchak L. A., Kuraeva Y. G., Pariichuk N. V.

Two methods of determining the complexation constants of “volatile organic compound (VOC) – 2-hydroxypropyl-β-cyclodextrin (HP-β-CD)” were tested by headspace gas chromatographic analysis. It was shown that the complexation constants of VOC with HP-β-CD calculated using 2 approaches were comparable with each other. The increase in complexation constants was observed for homologues with the increase in the molar mass and dipole moment of molecules.

Modified Potentiometric Sensors of Various Types for Ceftriaxone Determination

Authors: Kulapina E. G., Chanina V. V.

The planar unmodified and modified by polyaniline, nanoparticles and their binary mixtures potentiometric sensors of various types were manufactured on the basis of tetradecylammonium associates (TDA) with complex connections silver (I) – ceftriaxone (Ag (I) – Ceftr). In sensors of I type electroactive components (EAC) and modifiers were brought in carboniferous ink. The polyvinylchloride plasticized unmodified and modified membranes on the basis [Ag2 (Ceftr)2] 2- · 2TDA were used in the sensors of II type; C (EAC) = 1,2,3%.

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