Andriyko L. Physical-chemical properties of fumed oxides modified by poly(vinyl alcohol), poly(ethylene glycol) and lecithin

The thesis is devoted to determination and investigation of physico-chemical and adsorption properties of initial silica, silica/alumina and silica/titania modified by poly(vinyl alcohol), poly(ethylene glycol) and lecithin. It was shown that the properties of oxide/PVA nanocomposites are stabilize in the form of powders as well as of dispersions. Adsorption poly(vinyl alcohol), poly(ethylene glycol) and lecithin on the surface of silica, silica/alumina and silica/titania is irreversible. It was shown the surface modification of fumed silica, silica/alumina and silica/titania stabilized their water suspensions. The surface modification of fumed silica and silica/alumina by poly(vinyl alcohol) leads to increase number of water clusters with low number of hydrogen bonds and destruction of the bulk water clusters. The obtained results testify that the adsorption modification of fumed silica surface by poly(vinyl alcohol) and poly(ethylene glycol) allows to reduce significantly its hemolysis activity and to raise its biocompatibility.