02.00.00 Chemical sciences
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INVESTIGATION OF ASCORBIC ACID ADSORPTION ON KSMG SILICA GEL
Description
The article studies adsorption of ascorbic acid on KSMG silicagel. The experimental results, the basic thermodynamic characteristics of ascorbic acid adsorption on oxide silicon have been used for treatment of adsorption mechanism of ascorbic acid on silica KSMG. Results of the study ascorbic acid adsorption on silica gel KSMG may be used for further identification of it in the various objects
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SYNTHESIS OF SUBSTITUTED ISOXAZOLO[5,4-b]PYRIDINE AND THEIR ANTIDOTE ACTIVITY
Description
To develop the novel herbicide antidotes for the sunflower vegetative plants, the group of chemical compounds, belonging to the derivatives of isoxalopyrazolopyridines was synthesized and their antidote activity both in the laboratory and field experiments was studied. The compounds with a high antidote effect were found
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Description
The present work describes the chemical synthesis of poly-N,N-diallyl pyrrolidinium bromide and polyN,N-diallyl morpholinium bromide - high-molecular compounds containing quaternary nitrogen atoms, which included in two five- and/or six-membered heterocyclic rings. These polymers are perspective modifiers for industrially produced anion-exchange membranes, the use of which should significantly improve the resistance to degradation of the membranes at over-limiting current regimes. The structure of obtained polymers was characterized by FTIR, 1H and 13C NMR spectroscopy. The optimal reaction conditions, which increase the yield of desired products, were defined. It is shown that is preferable to use 1-butanol as a solvent and benzoyl peroxide as an initiator
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ELECTRICAL CONDUCTIVITY OF IONEXCHANGE MEMBRANES IN SOLUTIONS CONTAINING CARBOXYLIC ACIDS
Description
The article presents the experimental results of the study of the concentration dependence of the electrical conductivity of heterogeneous ion-exchange membranes that are in contact with solutions of weak electrolytes - carboxylic acids. It is shown that in this case the membrane conductivity is higher than the conductivity of the solution, wherein the conductivity of cation exchange membranes substantially greater (by an order of magnitude) than the conductivity of anion exchange membranes. This fact must be considered when designing the actual electrodialysis processes of processing solutions containing organic ions. The work identified the need to develop modern ideas about transport and the structural organization of ion-exchange materials, to describe the structure of the ion-exchange membranes that are in contact with weak electrolytes solutions
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DEVELOPMENT OF A METHOD FOR FIXING PERFTORSULFOPOLIMER MF-4SK ON A HETEROGENEOUS MEMBRANE-SUBSTRATE
Description
The article illustrates the results of the research dedicated to finding a method of combining two polymeric materials - ion-exchange membranes having different chemical nature. It shows a method of applying a homogenous film MF 4SK on the surface of the heterogeneous membrane substrate to produce a chemically and mechanically stable asymmetric bipolar membrane. We have selected membrane substrate ensuring the best electrochemical performance
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Description
Theoretically and experimentally, we investigated the process of adjusting the pH of natural water of hydrocarbonate class electrodialyzer with bipolar membranes with channel length of 40 cm. We experimentally measured concentration of components, pH of the solutions in alkaline and acid channels of electrodeposition depending on the current density. The article describes a mathematical model for long channels; to scale the mass transfer characteristics of the process there was applied and verified a method of compartmentalization, which gave the possibility to calculate the dependence of the component along the channel length at different velocities of flow of the solution. Numerical calculations were compared with experimental data on electrodialyser of 10 cm and 40 cm length
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RESEARCH IN MICRODEFICIENCY OF POLYMERS (ELASTOMER COMPOSITIONS) UNDER UNIAXIAL DEFORMATION
Description
Macrodeficiency of polymeric materials, including the pervasive one, is a consequence of the development of initial microdefects which appear in polymers both due to external factors and during their processing. This article solves the task of identification the interrelation and interdependence of structural microdefects of various polymeric materials, consisting in the estimation of the structural parameters under uniaxial deformation. It is experimentally shown that the process of changing microdefects in the material bulk begins to flow more intensely during deformation of the material, having anisotropic structures in the bulk. Change of the parameters of microdefects is not observed compared to the starting material at small quantities of the deformation. In the area of deformation corresponding to the transition of the material from isotropic to anisotropic state parameters of microdefects do not depend on the degree of deformation of the sample, and abrupt changes of the parameters of microdefects are observed after completing the formation of anisotropic patterns. It is shown experimentally the identity of the parameters of microdefects in the bulk material (rubber-based natural caoutchouc) during deformation with the quantities of local deformations at the edge of the artificially created macrodefects. Under uniaxial deformation more than 280-300% and the growth of the quantities of local deformations come out at the edge of the artificially created macrodefects and normalized linear dimension k and decrease the total number n of microdefects
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Description
The аrticle is devoted to study of adsorption of enzymes, antioxidants contained in horseradish root on starch to create enterosorbent with anti-oxidant properties. For this goal we have studied adsorption isotherm calculated constants, thermodynamic parameters (change of enthalpy, entropy, and isobaric-isothermal potential); sorption kinetics of enzyme-antioxidants on starch and calculate the main characteristics. The method of producing of enterosorbent - antioxidant on based starches has been developed based on the experimental data. The ready sorbent is a white powder having no taste and smell. In biological fluids and water, it is insoluble. The enterosorbent on starch does not dissolve in water and biological fluids. It is the solid component. This enterosorbent can be used to protect the gastrointestinal tract of humans and animals against a wide variety of oxidants and peroxide. The results of this work will form the basis for the study of the antioxidant properties of the resulting enterosorbent. The results showed that during the tests, the enterosorbent on the starch showed good antioxidant properties. It has high antioxidant activity with respect to hydrogen peroxide
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Description
Surface energy of polymers determines such important properties of polymers like wetability, adhesion, ability adsorption of low molecular weight substances. Inner organization, the structure of the polymer and the dynamics of interaction between macromolecular chains are shown at last. At the same time, the micro-defects (inhomogeneity) of polymers, which is an integral part of the structure are changed during deformation and must contribute to changing of the surface energy and its components. This article solves the task of detecting changes in the parameters of surface energy of polymers under uniaxial deformation. Data for the quantitative indicators of the surface properties total surface energy and its dispersive and polar components are presented. The calculations showed that the disperse and polar components of all the samples of polymer materials are about 98% of the total and, therefore, is crucial. For the first time experimental data, illustrating the change of surface energy of polymeric materials had been obtained, including elastomeric compositions, when uniaxial deformation. The relative changes of the surface energy vary from 54.5 per cent to 125 %. A decrease of total surface energy and its dispersion component is observed during deformation of polymer samples of different structure and chemical nature
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DEVELOPMENT OF A NEW MODEL OF CALCULATIONS OF VALUES OF ATOMIC RADIUMS
Description
The article presents the results of studies of changes in the atomic radii of the elements of the periodic table, depending on their atomic masses. It is shown that the appearance of p- and d-orbitals introduces a significant contribution to the value of the atomic radius, and the appearance of f-orbitals makes a significantly smaller contribution to the given value. A radial-mass model of calculations of atomic radii for the elements of the Periodic Table was developed. Optimal conditions for making calculations were chosen. For the first time the values of atomic radii for elements with the order number 103-120 are calculated. It is shown that the values of atomic radii for elements with the order number 103-120 are in the range from 140 to 335 picometers and regularly change in the period
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