Solid State Phenomena Vol. 320

Abstract: Unlike traditional materials, the development of high-performance foamed concrete with a compressive strength of up to 20 MPa and a density of up to 1400 kg/m³ allows the use of foamed concrete as a constructive material with additional functions including good thermal insulation properties, sound insulation and capillary porosity needed to ensure hydrothermal conditions. Unlike autoclaved aerated concrete, foamed concrete can also be used in monolithic construction.The studies of high strength foamed concrete were performed by using mostly local mineral components and mixing technology by using planetary activator which provides a fundamentally new mixing mode that combines intensive mixing, foaming and activation of components. To realize the experimental part of the research, turbulence type foamed concrete mixer SPBU-LUKS was used.

Abstract: In this study different pathways for obtaining activated carbon with catalytical activity were analysed. Industrially fast pyrolysis is an efficient way of lignocellulosic biomass processing, since in this process various important high value chemicals are obtained. Biochar is obtained as the by-product in fast pyrolysis process from which activated carbon can be acquired with further chemical activation. Different methods for chemical activation of biochar were tested with the obtained activated charcoals being used as a catalyst in esterification reactions to evaluate their potential use as a heterogenic catalyst. Highest catalytical activity was observed when biochar was pre-treated with sulfuric acid at 80 °C for 24 hours. The obtained activated charcoal could be used as a catalyst for up to five times with no noticeable decrease in catalytic activity.

Abstract: The work is focused on obtaining hybrid pigments by adsorption of anionic dyes on positively charged montmorillonite. Modification of the sodium form of montmorillonite by chromium hydroxocomplexes was provided to ensure effective adsorption of anionic dyes on the surface of mineral particles. A high level of adsorption of anionic dyes as a result of steric factor was revealed. It was shown that the adsorption of dyes depended on the pH of the medium and was characterized by a maximum level at pH 4.5 – 6.0. The scheme of obtaining hybrid pigments, which were characterized by good сovering ability, resistance to stratification, especially saturated and intense colour was proposed.