Chemistry

Phase Equilibria and Component Solubility in the Binary System Water + Dipropylamine

Dipropylamine is one of the promising antisolvents for extractive salt crystallization, but its solubility in water and phase equilibria in its aqueous solutions over a wide temperature range has not been studied in detail until now. The review of the literature shows that the water-dipropylamine system is classified as a self-separating system with a lower critical solution temperature (LCST). We used the visual-polythermal method in a –25–90°C range to study phase equilibria in the binary system water-dipropylamine and to plot the phase diagram of the system.

Computer Model of Phase Complex of Ternary System LiCl–Li2MoO4–Li2WO4

The solution of theoretical and practical problems based on phase equilibria in multicomponent systems is the basis of materials science: the synthesis of metals, alloys, semiconductors and many other substances and mixtures. The first stage in the study of phase diagrams is their calculation by various methods. However, the current state of the theory does not allow us to calculate the phase diagrams accurately and correctly even for binary systems.

The Studying of Components Ratio Influence in Mixed Monolayers of Quantum Dots and Arac hidic Acid on the Films Morphology Based on Them

The formation process of quantum dots stabilized by the trioctylphosphine oxide and arachidic acid molecules mixed monolayers was studied. An equation that determines a dependence of numbers of organic matrix molecules that separates quantum dots on e from each other in the close-packing Langmuir monolayer from quantum dots size was proposed. An existence of minimal numbers of organic matrix molecules for changing and tuning a distance between quantu m dots in the Langmuir monolayer was shown.

Polymeric Sorbents for the Collection of Oil and Oil Products from the Surface of Reservoirs: a 2000–2017 Review of the Russian-language Literature (Part 3)

The Russian 2000–2017 scientific, technical and patent literature devoted to the problems of the development and practical applications of polymeric sorbents for the collection of spilled oil and oil products from the surface of reservoirs and for the purification of hydrocarbon-containing aquatic environments was searched and analyzed.

Topological Transformation of Phase Diagram for Сut 2 of the Composition Tetrahedron of the Quaternary Potassium Nitrate – Water – Pyridine – Butyric Аcid System within 5–60°С

Phase equilibria and critical phenomena in component mixtures of the cut 2 of the composition tetrahedrone of the quaternary system potassium nitrate + water + pyridine + butyric acid whose constituent ternary liquid system had a closed binodal curve were studied by means of the visual-polythermal method within 5– 60°C. We first proposed a method to find the coordinates of the end point of the critical tie line of monotectic state in quaternary systems salt + three solvents.

Formation of Continuous Series of Solid Solutions in Salt Systems

Formation of continuous series of solid solutions in ternary and more component systems (reciprocal systems) without extremum in liduidus of binary systems, consist of metals, oxides, salts has been devoted to a considerable number of works. Solid solutions are solid two- or multicomponent homogeneous systems of variable composition (for example, type А xB1-x), in which atoms or ions of components, mixing in different ratios (0 <x <1), form a common crystal lattice, characteristic of one of components.

Sensor System for Determining α-Amino Acids

The principles of creating ion-selective electrodes for a-amino acids in a historical retrospective are considered. It is shown that until recently, when the creation of potentiometric membrane sensors, the main emphasis was made on the formation of more selective sensors able to selectively determine the concentration of some analyte in multi-component systems. The material for such sensors were ionselective membranes, which were created specific to a particular analite, but were not specific to the entire class of such analyzers.

Spectrophotometric Study of the Stability the Quercetin and Rutin Solutions at Different Acidity of the Medium

Flavonoids are a group of polyphenolic compounds present in many plants, fruits, vegetables, nuts, flowers etc. They exhibit a wide range of bioactivity and have gained much attraction last two decades because of its potential applications in biology, medicine, and chemical analysis due to their antioxidant, medicinal (antiviral, antibacterial, antiallergic effects) and complexion properties. One of the main properties of flavonoids especially quercetin is their oxidation by oxygen dissolved in water or organic solvents mainly in basic media.

The Transformation of n-nonane in Conditions of Catalytic Cracking on ZSM-5 and V2O5/ZSM-5 Catalysts

The daily increasing demand for high-quality motor fuels requires constant improvement and modernization of existing technologies for oil refining. One of the main secondary processes of recycling hydrocarbon raw materials in industry, which allows to obtain high-octane components of automobile gasoline, valuable liquefied gases and raw materials for petrochemical industries is catalytic cracking of various types of distillate and residual raw materials. Nowadays, most catalysts of an industrial catalytic cracking contain expensive rare earth elements and platinum in its composition.

Some Transformation 2-Pentene-, Pentane-1,5-Diones and Their Halogen-Substituted Analogues with Thioacetamide

Given the ability of 1,5-dicarbonyl compounds to emerge in the presence of ammonia, urea and its derivatives of N-containing heterocyclic compounds, possibility of сyclization 2-pentene- and pentane-1,5-diones and their dihalogensubstituted analogues with thioacetamide.

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