The Use of Mathematical Modelling Methods in the Creation of Composite Materials Based on Carbon Fibre Materials

The report provides data on the electrochemical modification of carbon-graphite fibers as the basis for the creation of composite materials. The results of studies of the electrodeposition of metals on pre-electrochemically modified carbon fiber materials (CFM) in order to obtain composite materials based on them are presented. The use of CFM for the creation of composite materials is associated with the possibility of deposition of metals, alloys or their compounds on the surface of their constituent fibers. Electrochemical treatment in aqueous solutions of electrolytes is a promising method for modifying the surface properties of carbon materials, including in order to improve their adhesive properties. Preliminary electrochemical modification of carbon fiber materials in indifferent solutions of electrolytes made it possible to obtain composite and nanocomposite materials with good adhesion of the electrodeposited metal to the surface of the fibers of carbon materials.When metals are deposited on carbon fiber materials, it is necessary to solve the problem of applying a uniform metal deposit or with a certain profile in the thickness of the material. In this case, it is effective to use methods of mathematical modeling of metal deposition processes in a flowing three-dimensional electrode. Depending on the selected modes of deposition of metal sediment on the CFM, some electrochemical parameters of the process and system may be dependent on both the time of the process and the thickness coordinate of the electrode. This is especially true for the value of the resistivity of the solid phase of the system, that is, carbon-graphite fibrous material. Other electrochemical parameters, such as the specific electrode surface, the exchange current and the transfer coefficient of the electrochemical reaction, the porosity of the material, etc., can also change during the electrodeposition of the metal on the CFM. It is proposed to take into account the change in the characteristic properties of modified carbon fiber materials in the mathematical modeling of the processes of electrodeposition of metals on carbon fiber materials in order to determine the technological parameters to improve the efficiency of the properties of composite materials. In order to implement mathematical models used in the calculation of electrochemical processes in the volume and on the surface of carbon fiber materials, a set of programs based on modern computational methods and programming languages has been developed.

All-Russian Seminar on the Study of the Structure of Liquids and Solutions (In Memory of O.Ya. Samoilov)

This publication is dedicated to the memory of Oleg Yakovlevich Samoilov, who passed away in June 1980. Having entered the Institute of General and Inorganic Chemistry of the USSR Academy of Sciences after the university bench in 1942, Oleg Yakovlevich worked his way up from a junior researcher to the head of a laboratory, having defended his candidate and at the age of 37 his doctoral dissertation and soon received the academic title of professor. His area of interest was the nature of the liquid state, and in this area he opened the way to new views on the structure of liquids and the nature of the thermal motion of their particles, reflected in the monograph "The structure of aqueous solutions of electrolytes and hydration of ions", immediately translated abroad to major foreign languages, and at the seminar organized by him at the Institute for the Study of the Structure of Liquids and Solutions, which he directed from 1962 to the last days of his life, and which continues to exist to this day. The entire content of the seminar is reflected in this publication.

3D Supramolecular Chiral Crystal Structures of Radical Anion Salts of (−)-NDI-Δ and Possible Magnetic Phase Diagrams

Supramolecular chiral crystals of radical anion salts of a rigid triangular chiral electron acceptor, (−)-naphthalene diimide (NDI)-Δ, were electrochemically grown in propylene carbonate (PC) solutions of electrolytes (M·ClO4, M =...

Спектры электролюминесценции и структура анодного оксида алюминия при его формировании в химически чистой воде и спиртах

For a film of aluminum oxide (Al2O3) formed in distilled water (H2O), a linear growth was revealed during the high-voltage anodization time of 2000 s, and it was found that its electroluminescence (EL) is reliably recorded at an Al2O3 thickness of about 120 nm. It is shown that in DV and its deuterium-containing analogue, deuterium water (D2O), the electrolysis formation of Al2O3 is possible. cellular-nanoporous structure, identical to that formed in aqueous solutions of electrolytes. It was found that the presence of such a structure in the oxide is not a prerequisite for the generation of its EL. The EL spectrum of Al2O3 in H2O and D2O, as well as in “water-like” electrolytes: ethylene glycol, N, N-dimethylethanolamine, and isopentanol, was recorded for the first time. In the investigated range of 400–700 nm, significant differences in the luminescence in water and the above alcohols are revealed. For EL, the short-wavelength component with a wavelength of the order of 440 nm dominates in water, and in alcohols, the long-wavelength component with a maximum at 625 nm. In this case, nonstationarity of luminescence is observed both in the spectral composition and in the intensity of individual parts of the spectrum for the entire time of aluminum anodization.

Water-absorbing materials based on polymer hydrogel and bentonite

The article deals with the production, sorption and rheological properties of composite materials based on polymer hydrogel and bentonite. It is shown that bentonite prevents the collapse of the hydrogel in aqueous solutions of electrolytes and leads to an increase in the moisture content after the collapse. After several repeated cycles of swelling in water, followed by drying at 60 and 110 °C, the degree of swelling of the composite is higher than that of the hydrogel. In the temperature range from 20 to 40 °C, the polymer hydrogel and the composite are able to withstand at least ten cycles of swelling and drying without changing the degree of swelling.