Полупроводниковые свойства полимерных пленок на основе комплекса никеля с лигандом саленового типа

Complexes of metals with Schiff bases are considered as promising materials for creating energy storage and photovoltaic devices. In this work, the semiconducting properties of a polymer nickel film with a salen-type ligand (poly-Ni(CH3O-Salen)) were studied by spectrophotometric and Faraday impedance spectroscopy. The Mott-Schottky analysis showed that the polymer film is a semiconducting material with a fairly narrow band gap, high charge carrier density and p-type conductivity. Using the method of Faraday impedance spectroscopy, the limiting stage of the oxygen photoelectroreduction reaction, the process of charge transfer from the film to molecular oxygen, has been established.

POLYMERIZATION BY INTERACTION a-HALOACRYLIC ACIDS WITH TERTIARY AMINES

Приведены результаты самопроизвольной полимеризации а -хлоракриловой и а -бромакриловой кислот с третичными аминами при невысокой температуре. В результате самопроизвольной полимеризации при взаимодействии а -галоидакриловых кислот с третичными аминами образуются полимеры, содержащие четвертичные аммониевые группы. С целью подтверждения данного предположения были проведены ЯМР- и ИК-спектроскопические исследования продуктов самопроизвольной полимеризации. Показано, что сопутствующая реакция кватернизации, спонтанной полимеризации, имеет место как в смеси реагентов, так и в присутствии растворителя, т.е. и при смешении непредельного амина и галоидного алкила. Изучены кинетические закономерности реакции полимеризации и показано, что реакция кватернизации, являющаяся лимитирующей стадией процесса самопроизвольной полимеризации, протекает по S 2 - механизму. Описываются первые попытки получения новых нанокомпозиционных материалов на основе синтезированных сополимеров и модифицированного монтмориллонита. Анализ литературных данных показывает, что особенности получения нанокомпозитов на основе Na - монтмориллонита и водорастворимых сополимеров ранее не изучались. The results of spontaneous polymerization of а -chloroacrylic and а -bromoacrylic acids with tertiary amines at a low temperature are presented. As a result of spontaneous polymerization during the interaction of а -halodacrylic acids with tertiary amines, polymers containing quaternary ammonium groups are formed. In order to confirm this assumption, nuclear magnetic resonance and infrared spectroscopic studies of the products of the spontaneous polymerization were carried out. Spontaneous polymerization proceeds, consisting of two stages: the quaternization reaction and the polymerization reaction. The kinetic regularities of the polymerization reaction were studied and it was shown that the quaternization reaction, which is the limiting stage of the spontaneous polymerization process, proceeds according to the S 2 - mechanism. It has described the first attempts to obtain new nanocomposite materials based on synthesized copolymers and modified montmorillonite. Analysis of the literature data shows that the features of the preparation of nanocomposites based on Na - montmorillonite and water-soluble copolymers have not been previously studied.

Model for ring closure in ER tubular network dynamics

Tubular networks of endoplasmic reticulum (ER) are dynamic structures whose steady-state conformations are maintained by a dynamic balance between the persistent generation and vanishing of the network elements. While factors producing the ER tubules and inter-tubular junctions have been investigated, the mechanisms behind their elimination remained unknown. Here we addressed the ER ring closure, the process resulting in the tubule and junction removal through constriction of the network unit-cells into junctional knots followed by the knot remodeling into regular junctions. We considered the ring closure to be driven by the tension existing in ER membranes. We modeled, computationally, the structures of the junctional knots containing internal nanopores and analyzed their tension dependence. We predicted an effective interaction between the nanopores facilitating the knot tightening and collapse of additional network unit cells. We analyzed the process of the pore sealing through membrane fission resulting in formation of regular junctions. Considering the hemi-fission as the rate-limiting stage of the fission reaction, we evaluated the membrane tensions guarantying the spontaneous character of the pore sealing. We concluded that feasible membrane tensions explain all stages of the ER ring closure.

Study of the mechanism of pre-burned ash leaching by hydrochloric acid

The use of hydrochloric acid for processing aluminum-containing raw materials has a number of advantages over other acids, which include: easy decomposition of aluminum compounds with the transfer of aluminum into solution; low solubility of silica in HCl, the possibility of complete separation of the solid residue without significant losses of acid, etc. The paper considers the possibility of using the method for processing ash and slag dumps accumulated in large volumes in the country. Based on the thermodynamic analysis of reactions of interaction between ash components and hydrochloric acid, the behavior of aluminum, iron and nonferrous metal compounds during leaching is studied. It was shown that the preliminary roasting of ash with calcium chloride provides a high extraction of aluminum in the solution from the cinder. Based on experimental studies, the influence of time, temperature and acid consumption on the degree of aluminum extraction into the solution has been established. At optimal conditions of leaching conducted at S:L = 1:3, T = 60 ºC, τ = 60 min extraction of aluminum in a solution as chloride amounted to 99.92 %. At the same time the extraction of silica in solid sediment due to the maximum transfer of impurities in the solution was 99.8 %. The mechanism of the leaching process is proposed. The values of activation energy and the order of the reaction, indicating the complex 3-step character of the reactions, have been calculated. It is established that the limiting stage during leaching is the dissolution of anorthite.

Reduce the Degradation of Polyhydroxyalkanoates: Feeding in the Oxygen-limiting Section Increases the Accumulation of PHAs

To solve the problem that the content of polyhydroxyalkanoates (PHAs) in the aerobic section of the traditional anaerobic-aerobic process continues to decrease, two different feeding modes in the oxygen-limiting section were explored under the anaerobic-oxygen limiting process(for reducing the energy consumption of aeration). Based on 16SrRNA sequence analyses, the results show that the abundance of Hydrogenovora(9.57%), Zoogloea(6.73%), Thaurea(1.49%) and other bacterial genera in the microbial community had increased after enrichment. PHAs were synthesized in the oxygen-limiting stage of both one-time feeding and batch feeding mode. The maximum content of PHA reached 52.17% when C/N increased to 150 in the one-time feeding mode, and that reached 42.04% in batch feeding mode when C/N was 100. The one-time feeding mode shows a more significant accumulation potential of PHAs than the batch feeding mode. The content of PHAs shows an increasing trend with the increase of C/N ratio, and a high C/N ratio may lead to sludge bulking and other problems, making the sludge system unsteady.

Determination of corrosion characteristics of steel protected by a latex coating in Nyquist coordinates

This paper investigates the corrosion process of steel St3 protected by latex coating 69Б-2к produced by Kapitel Ltd (Irkutsk). Electrochemical impedance spectroscopy of steel samples with a threefold latex coating was carried out by a PGSTAT302 + FRA2 potentiostat-galvanostat equipped with NOVA 1.8. Corrosion studies were carried out under thermostating (25 ± 0.2°C) of the working environment. The corrosion rate was determined by gravimetric tests with the recording of mass changes over a controlled period of time (up to 10 h). A 3% sodium chloride solution was used as the electrolyte. In most cases, the mechanism of the corrosion process can be reliably described by an equivalent electrochemical circuit with Warburg and Cotangent Hyperbolic elements, which simulates the reaction at the electrodeelectrolyte interface. According to the conducted visual, gravimetric and electrochemical studies of the St3 steel surface protected with the 69B-2k latex coating, the impedance remains almost unchanged for a prolonged period of time. It is obvious that the surface process is associated with the limiting stage of solvent diffusion through the protective layer. Thus, the electrochemically determined corrosion rate was low and amounted to ~ 0.164 mm/year (for reference samples – 0.75 mm / year). Our studies confirmed high protective qualities of latex 69B-2k. The corrosion properties of the coating under study are related to its composition, the components of which not only exhibit good adhesion, but are also active with respect to other interactions, including chemical interactions of the components with each other and with metal surface crystallites. The model calculation of the process, carried out using the developed equivalent electrochemical circuit, describes experimental curves in Nyquist coordinates almost comprehensively.

Kinetic Characteristics of Electrodeposition of Ni-Co-Al2O3 Composite Coating

The kinetic features of electrodeposition process of a wear-and corrosion-resistant composite electrochemical nickel-cobalt-aluminum oxide coating were investigated. Potentiodynamic studies showed that in the process of the CEC formation at the cathode the electrode polarization decreases, and the value of the limiting current density increases by more than twice. Consequently, the rate of the CEC electrodeposition process increases and the range of operating current densities expand in comparison with the control coating with the Ni-Co alloy. Temperature-kinetic, chronopotentiometric methods, values of the temperature coefficient of the reaction rate and the diffusion coefficients of nickel ions were used to determine the mechanism of CEC electrodeposition. As the result of determining the nature of limiting stage of the electrodeposition process of CEC nickel-cobalt-aluminum oxide, it was found that it is caused by such two coupled processes proceeding at comparable rates, as electrophoretic transfer of electroactive particles to the cathode and overgrowing of dispersed particles adsorbed on the cathode surface with electrodeposited metals.

Study of the Process of Wastewater Treatment with Activated Caron from Dimethylamine and Dimethylformamide in their Joint Presence

The regularities and mechanism of adsorption of dimethylformamide and dimethylamine by industrial activated carbon in their joint presence from aqueous solutions are considered. The characteristics of equilibrium adsorption, the limiting stage, and the mass transfer coefficient have been determined. The main parameters of the adsorption column process and the mode of continuous cleaning are calculated by the method of mathematical modeling.

Kinetic Features of the Hydrogen Sulfide Sorption on the Ferro-Manganese Material

The kinetics of hydrogen sulfide sorption by the surface of a ferromanganese material containing in its composition a mixture of iron (II) and (III) oxides FeO × Fe2O3, takanelite (Mn, Ca) Mn4O9 × 3H2O and quartz SiO2, and which is samples of unrefined ferromanganese ore, was studied in this work. Sorption rate constant and activation energy constant values were calculated. The catalytic effect of iron (III) oxide was established, the presence of which in natural material contributes to a decrease in the H2S sorption activation energy. Based on the results of X-ray phase and chromatographic analysis methods, a chemical (redox) reaction of the conversion of hydrogen sulfide into elemental sulfur and H2O was revealed. The overall process rate is expressed in terms of the physical sorption stage and chemical transformation of the components; the influence of the rate of the third stage—reaction products desorption—on the overall rate of the process is taken into account. The limiting stage of the process is determined—a chemical reaction. The relation between the heat and the activation energy of the chemical transformation is used according to the Bronsted—Polanyi rule for catalytic processes. It was found that with an increase in the chemisorption heat, the activation energy of the chemisorption stage decreases and, as a consequence, its rate increases. The sorption process parameters were calculated—the Fe2O3 coverage degree with the initial substances and reaction products providing the maximum sorption rate, which can be a criterion for evaluating the catalytically active sites of the catalyst surface for carrying out catalytic reactions.

Anti-inflammation biomaterial platforms for chronic wound healing

Nowadays, there has been an increase in the number of people with chronic wounds, which has resulted in serious health problems worldwide. The rate-limiting stage of chronic wound healing has...