Acid-basic surface properties of dispersed fillers based on metal oxides TiO₂, Al₂O₃, CaO and Fe₂O₃

Abstract

The dispersed oxide fillers of different chemical composition were investigated: rutile (TiO2), alumina (Al2O3), calcite (CaO) and hematite (Fe2O3). The mineral composition, surface morphology, particle size and specific surface of the fillers were investigated using modern physicochemical methods. It has been established that the acid-alkaline properties of the active surface centers (ASC) and hydroxyl-hydrate layer (HHL) depend on the chemical and mineral nature of the fillers. It is established that with decreasing acidity of the oxide, the desire for its surface to adsorb water molecules from the air increases. As the alkalinity of the oxide increases, the thickness of both the hydroxyl and hydrate surface layers increases in proportion. It is shown that the acid-alkaline properties of the surface correlate with the acid-alkaline properties of the oxides included in the fillers.

Ways to increase the production efficiency of hardwood blanks

“…Conditions (4-6) are based on the parameters: equipment (devices), ΔT ୰ୣୱ ; products, C ୬୭୧ୱୣ ; heating, T ୟୠୱ ; defects, ߂ܶ or ‫.ܥ‬ Thus, in order to establish the most effective method of industrial wood thermal stimulation of oak wood initial moisture, we determined the signal-to-noise ratio criterion, S, using equations (1-2) and verified the fulfillment of conditions (3)(4)(5)(6), for which a number of experimental studies were performed. For the experiment, uncut industrial wood from oak timber was selected in an amount of 720 pieces with an average initial moisture content (40…50%), an actual thickness of 30 mm and a length of 1.7 m. Fig.…”

“…Production of high-quality materials, determination of their properties today special attention is paid [1][2][3][4][5][6]. The full technological cycle is characteristic feature of the production of hardwood timber blanks in Ukraine -from round timber to finished intermediate products of final moisture content, since the manufacturing of such products from industrial wood is low cost-effective.…”

Acid-Alkaline Surface Properties of Powders: Potentiometric Research Methods

“…The regularities of interactions on the surface of the phase separation in any case can be described as reactions between acids and alkalis by Brønsted (protic reactions) or Lewis (aprotic reactions). It is believed that a hydroxyl-hydrate layer is formed on the surface of dispersed materials, which consists of chemically bound water molecules, which form the first lower hydroxyl layer of OH-groups (Brønsted centers) and subsequent hydrate layers of water molecules that are more distant from the solid surface, connected with the hydroxyl layer due to hydrogen and other physicochemical bonds [1][2][3].…”