Chemistry

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

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.

Physico-Chemical Principles of Structure Formation of Gypsum Binding Materials

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.

Density Calculation for Mixture Melts of LiF + NaF

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.

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

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%.

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

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.

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

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.

Modified Potentiometric Sensors of Various Types for Ceftriaxone Determination

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%.

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

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.

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

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.

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

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.

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