Goncharuk E. Electrophysical and structural properties of individual and biphase oxides with silica, titania and alumina

Objects: water dispersions of pyrogenic oxides. The purposed is to establish of mechanism of influencing of the nature of a surface and morphology of highly disperse oxides on structure of their water dispersions, on electrokinetic and physical characteristics of dispersions, definition of their adsorptive capacity in relation to ions of heavy metals and photocatalytic activity, definition of a role by surface of hydration shells. Methods: atom force microscopy; measurement of electrical conductivity on constant and alternating current; dielectric relaxation spectroscopy; thermostimulated depolarization; photon correlation spectroscopy; a potentiometry; adsorptive methods; optical methods; research of a kinetics of wetting; research of a kinetics of photocatalytic reactions; rheological and structural-mechanical researches. Established, that the nature and concentration of active centers of a surface determine intensity of its interaction with water and structure of near-surface hydrated layers. The wetting heat of highly dispersive silica is determined by a hydration of surface OH-groups, and the availability of bridge fissile centers in binary oxides increases a hydrophylic nature of their surface as contrasted to individual. The correlation between adsorptive properties of binary oxides in relation to ions of metals and contents of the second oxide (Al2O3, TiO2) in surface layer is established. Established, that total volume and the mean pore radius in aggregates of highly disperse oxides decreases with increase of specific surface. Photocatalytic properties of titaniasilica, obtained the pyrogenic method and method of a chemical vapor deposition, compared and establishes correlation between modification TiO2, size of its crystallites and photocatalytic properties. It is demonstrated that the structural-mechanical property of investigated systems are determined both nature of a surface, and morphology of oxides. It is shown that interparticle interactions and structure of dispersions that at an adsorption of macromolecules on pyrogenic silica in a large degree are determined by the nature of polymer.