Chemistry

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.

Сенсорные системы для определения α-аминокислот (обзор)

Рассмотрены принципы создания ионоселективных электродов на α-аминокислоты в исторической ретроспективе. Показано, что до последнего времени при создании потенциометрических мембранных сенсоров основной акцент был сделан на формирование более селективных датчиков, способных избирательно определять концентрацию отдельного аналита в многокомпонентных системах. Материалом для таких сенсоров являлись ионоселективные мембраны, которые создавались специфичными для конкретного аналита, но не были специфичными для всего класса таких аналитов.

. Спектрофотометрическое изучение устойчивости растворов кверцетина и рутина при различной кислотности среды

Спектрофотометрическим методом изучено влияние рН и времени на изменение спектров поглощения молекулярной и диссоциированной по первой гидроксигруппе форм двух флавоноидов – кверцетина и рутина. Показано, что молекулярная форма кверцетина (рН 3–6) устойчива в водном растворе в течение 10 мин, а оптическая плотность диссоциированной формы (рН 8–10) в зависимости от рН быстро уменьшается уже в первые минуты. Интенсивность поглощения света молекулярной и диссоциированной форм рутина практически не изменяется на протяжении 10–20 минут.

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.

Chromatographic Separation of Some Triazines by HPLC

Sorption properties of simazine, atrazine, propazine and prometrin on commercial chromatographic columns of LiChrospher 60 RP select B, Hypersil BDS-C18, and Zorbax SB-C18 were studied by reversed-phase high-performance liquid chromatography with photodiode matrix detection. The influence of the composition of the mobile phase on the chromatographic characteristics of the separation is considered. It was found that with the content of acetonitrile in a mixture of PF from 10 to 30 vol/vol. the chromatographic peak of atrazine is practically not manifested.

Physico-mechanical Properties of Silicon-chitosan-containing Glycerohydrogels Plates Based on Chitosan L- and D-ascorbates

Silicon-containing glycerohydrogel thin-film plates based on chitosan L- and D-ascorbates were obtained by means of biomimetic sol-gel synthesis using silicon tetraglycerolate as a biocompatible precursor. Their stress–strain characteristics were studied. For all the samples of our glycerohydrogel plates, stress–strain curves were recorded, characteristic of soft plastic polymeric materials not reaching their yield point under tensile conditions. At rupture, the material shows some characteristic signs of macroscopic plasticity.

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