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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%.

Improvement of Potentiometric Determination of Ammonium Ions in Surface Waters for the Samples with a High Concentration

Authors: Shatunov V. M., Fokina A. I., Ashikhmina T. Y.

The problem of choosing a technique for determining ammonium ions, in concentrations above 1 gm/cdm, in surface waters, as in complex matrix, is one of the important problems of monitoring the condition of water bodies contaminated with ammonium salts. The solution to this problem will allow us to reliably assess the ecological condition of water bodies and the degree of reduction of environmental load during pollution elimination measures.

The Investigation of Benzimidazoles’ Sorption on Modified Silicagels and Hypercrosslinked Polystyrene by HPLC

Authors: Yadrova A. A., Shafigulin R. V., Bulanova A. V.

The production of good-quality, effective and harmless pharmaceutical products and import substitution of drugs are of top priority for the pharmaceutical industry. Benzimidazole and its derivatives are active substances of many drugs due to the wide range of their pharmacological activity. In the article under consideration the sorption of the newly synthesized benzimidazole’s derivatives from liquids media was studied. Reverse phase high performance liquid chromatography (RP HPLC) is the most appropriate method used for the analysis of biologically active substances, particularly drugs.

Pre-Concentration and Extraction of Samarium Isotopes by Precipitation of Slightly Soluble Hydroxides and Fluorides of Metals

Authors: Salmenbayev S. E., Nurgaysinova N. K., Umarov M. A.

The comparison and assessment of the efficiency of using the precipitation of sparingly soluble metal hydroxides and fluorides for the extraction and pre-concentration of samarium isotopes from the solution simulating acidic leachate of the soil were made. It was shown that the precipitation of samarium isotopes was achieved quantitatively at the pH of about 7 and the co-precipitation of alkaline and alkaline earth elements did not exceed 20%.

Density Calculation for Mixture Melts of LiF + NaF

Authors: Garkushin I. K., Lavrenteva O. V., Nikitina A. S., Andreeva Y. A.

Salt mixtures are used as molten electrolytes of chemical current sources, solvent melts of inorganic substances, heat storing compositions, fluxes for welding and soldering. Modern coolants include alkali metals and their halogenides. Lithium-containing thermofors have a special place. Density is one of the important properties of the melts used. The paper presents the analytical description of the density for the mixture melts of LiF + NaF of various compositions in the temperature range of 1130 ... 1320° K.

Physico-Chemical Principles of Structure Formation of Gypsum Binding Materials

Authors: Kuzmina R. I., Yerzhanova N. S., Kunasheva Z. K.

The article shows the results of the study of composite materials obtained by the modification of mineral resources with active mineral components, which is the main direction in the production of new materials of high quality. In this work, binding materials were obtained on the basis of construction gypsum and carbonate drilling sludge, which is a retarder of the setting time as well. The physical and chemical properties, the structure of the system, and the phase influence of the modifier on the structure and hardening of the obtained new materials were investigated.

Application of Mathematical Model of Adsorber for the Development and Optimization of Adsorption Modes

Authors: Nikiforov I. A., Krivonosov A. A., Nikiforov A. I., Chesnokov E. A.

A mathematical model of the adsorber was developed using the Toth equation. Microporous mordenite was synthesized to confirm model validation. The structure and characteristics of the obtained sorbent were confirmed by SEM, N2 adsorbtion, XRD and XRF methods. Adsorption of the hydrogen-methane mixture on H-form of synthesized mordenite was carried out at the pressure of 2 MPa and the temperature range of 20–35 °С. Based on the mathematical model of the adsorber, the possibility of developing a process for separating a mixture of hydrogen and methane at high pressure was shown.

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