Chemistry

Express Method for Cefazolin Determination in Small Samples Sensors Planar Potentiometric

The unmodified and modified by polyaniline and nanoparticles planar potentiometric sensors on the basis of tetradecylammonium associates with a complex silver (I) – cefazolin are created. Optimum ratios of components in carbon-containing ink are established: 30–32% carbon powder, 16–18% polyvinylchloride, 48–50% dibutylphthalate and 1–3% of electrode active compound (EAC). Planar sensors of two types are examined: electrode active compounds, electrode active compound and modifiers were added into in carbon-сontaining ink.

The Influence of the Composition of Subphase and External Conditions on the Formation and Properties of Langmuir Monolayer

The specifity of the formation of arachinic acid monolayers (used as models of cell membranes) by the Langmuir method on a subphase containing L-ascorbic and D-isoascorbic acids with a concentration of 10-2, 10-3 M at a temperature of 25, 37 and 41°C was studied. The influence of the isoforms of ascorbic acid, the composition and temperature of the subphase on the mechanical properties of monolayers (specific area, compressibility, collapse pressure) was experimentally found.

Receiving Oil Sorbents from Renewable Agricultural Raw Materials

A method is proposed for obtaining a promising cellulosecontaining oil sorbent based on the buckwheat shell and millet shell, suggesting its modification by compounds structuring the polymer followed by heat treatment. These modification methods contribute to the creation of carbon structures with controlled porosity, as well as an increase in the yield of carbonized structures after heat treatment. Sorption properties of materials based on modified plant raw materials are investigated.

Prospects for the Development of Biomimetic Hybrid Materials Based on the Layer-by-Layer Assembly Technique

Natural composite structures, such as horn bones and nacre (or socalled mother-of-pearl), are characterized by a structural organization ordered at the nanoscale. This material architecture has attracted a wide interest order to develop new hybrid composite materials with tunable mechanical properties. The сurrent review aimed to establish the prospects for the development of artificial methods for synthesis of mechanically strong biomimetic materials.

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.

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