Roik N. Designing of the centers for adsorption of cholic acid on a surface of highly dispersed silica

The fundamental problems of designing of the centers for cholic acid adsorption by direct modification of silica surface with quaternary ammonium groups has been considered in the dissertation. The chemical immobilization of tetraalkylammonium halogen groups with various chemical composition on a surface of highly dispersed amorphous silicas has been realized by use of quaternization, hydrosilylation and copolymerization reactions. The structure of modified layer of organosilicas and the limits of its thermal and chemical stability has been found using IR spectroscopy, thermal analysis with programmed heating and chemical analysis of surface compounds. Constants of anion exchange, aggregation and stability have been calculated. It has been shown that the chemical grafting of quaternary ammonium groups on a silica surface results in improving of main adsorption parameters of cholic acid in comparison with hydroxylated silica and cholestyramine.