Izvestiya of Saratov University.
ISSN 1816-9775 (Print)
ISSN 2541-8971 (Online)


Химия

Phase Equilibria in the Ternary System “Potassium Iodide – Water – Tert-Butyl Alcohol” within 5–30°C

Studying of the influence of the salt nature and temperature on the liquid-liquid equilibrium in the ternary systems “salt – binary solvent” is topical for the development of the salting-in–salting- out theory. In addition, the ternary potassium iodide-water-alcohol systems are constituents of the quaternary iodine – potassium iodide – water – alcohol ones, studying of which is of practical interest in terms of determining the mixed solvent compositions with the highest iodine-dissolving power.

Phase Equilibrium for the System KH2PO4 – K2SO4 – H2O at 25°С

Potassium dihydrogen phosphate is widely used in industrial and agri- culture. The solvent extraction method for producing KH2PO4 from the more cheap extraction phosphoric acid and potassium chloride has gained growing attention recently. To evaluation influence SO42– on the crystallization KH2PO4 it is nessesary comprehensive knowledge of the phase equilibria in the system K+// H2PO42–, SO42– – H2O. The ternary system KH2PO4 – K2SO4– H2O was determined at 25 °C by the improved isothermal method of section.

Transformation of a Stable Catalyst of Catalytic Riforming Facility with Using the Catalyst R-98

One of the most important tasks of modern refineries is the modernization of existing plants to increase production and improve the quality of the commodity. In this connection, the catalytic activity of the industrial catalyst of the reforming pro- cess R-98 (containing in its composition platinum and rhenium, in the amount of 0.25% by weight of each) in the conversion of a stable catalyst was studied. Stable catalyst is released from the stabilizer column of the catalytic reforming unit.

Synthesis and Ways of Formation of Hydroxyphenyl Substituted Benz[4,5]imidazole-1,2,3,4,5,6- hexahydro[1,2-a]quinazolines

To synthesize new potentially biologically active benzimidazoloquinazolines, a three-component condensation of 2-aminobenzimidazole, cyclohexanone and hydroxylatedbenzaldehydes was studied. The reaction proceeds regioselectively when the equimolar ratios of the reagents are boiled for 3 hours in N,N-dimethylformamide and is accompanied by the formation of ortho-phenyl substituted hexahydrobenz[4,5]imidazolo [1,2-a]quinazolines having an angular articulation of the rings and a different number and position of hydroxyl groups in the phenyl substituent.

Qualitative and Quantitative Estimation of Intramolocular Hydrogenic Communication in a Row of Orto-R-phenyl-substituted Tetrazolohexahydroquinazolines

The onе-pot interaction of C-aminotetrazole, cyclohexanone and o-R-benzaldehydes (in contrast to unsubstituted benzaldehyde benzaldehyde) leads to the formation of additionally linear tetrazohexahydroquinazolines, their isomers with an angular articulation of the rings. The appearance of isomers with angular articulation of the rings can be explained by the total influence of the spatial and electronic effects, and the influence of the low-energy interaction by the type of hydrogen binding NH ··R (VVS) can not be ruled out.

Electroanalytical Properties of Non-modified and Polyaniline Modified Solid Contact Cefazolin Selective Sensors

Cefazolin is a cephalosporin antibiotic of the third generation. It is widely used in medical practice for the therapy of various infectious-somatic pathologies. The work was aimed at the creation of solid-contact potentiometric cefazolin-selective sensors. For the first time, polyaniline was used to stabilize the potentials of solid-contact sensors. As the membranes active components, the compound of tetradecylammonium (TDA) with the silver (I) – cefazolin complex were applied.

Sorbents Based on Natural Bentonites, Modified by Polyhydroxocationes Zirconium(IV), Aluminum and Iron(III) by the «Coprecipitation» Method

Presently, the bentonite clays are the popular materials which used in the adsorption refining. The bentonite is characterized by the extensive surface, the high mechanical strength, also it is the cheap and affordable material. In comparison with another cheap natural sorbents, the bentonites are differenced by the high sorption capacity towards to the anions of the various salts. However, the natural bentonite undergoes modification for more effective purification.

Properties, Soil Degradation and Fitotoxicity of Starch Composites with Polyvinyl Alcohol

Composite films were obtained from a mixture of starch, polyvinyl alcohol, and a plasticizing additive based on aspartic acid. The surface morphology, structural features of the composites, and their behavior in a polythermic mode were studied by scanning electron microscopy, X-ray diffractometry, IR spectroscopy, differential thermal and thermogravimetric analysis. Only carbon dioxide was detected in the gaseous products of thermal decomposition of the samples. The sorption and physico-mechanical properties of our composite films were analyzed.

Polymeric Sorbents for the Collection of Oil and Oil Products from the Surface of Reservoirs: a 2000–2017 Review of the English-language Literature (Part 1)

The scientific literature in English for 2000–2017, 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, has been scanned and analyzed. Three most numerous classes of polymeric sorbent materials (cellulosic materials, acrylate copolymers and synthetic rubbers) have been 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 are discussed.

Synthesis and Functionalization of Magnetite Мagnetic Nanoparticles with Сhitosan

Superparamagnetic magnetite nanoparticles (MNP) have gained much attraction from the beginning of 21century because of its potential applications in biology, medicine, theranostics, physics, chemistry and chemical analysis due to unique multifunctional properties, including small size, superparamagnetic behavior, low toxicity, high adsorption properties used for magnetic solid-phase extraction (MSPE) in water purification and chemical analysis.

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