In Ukrainian

Abstract

Synthesis of mesoporous silicas of MCM-41 type with chemically immobilized β cyclodextrin-containing groups was realized by template sol-gel method in the presence of functional silane. The influence of reaction mixture composition used at β cyclodextrin-silane synthesis (molar ratio β cyclodextrin:3 aminopropyltriethoxysilane: 1,1'-carbonyldiimidazole) on chemical structure and arrangement of mesopores of resulting organosilica materials was proved. The enhancement of ethoxysilyl constituent in β cyclodextrin-silane used in sol-gel condensation leads to the formation of silicas with higher content of chemically immobilizedβ cyclodextrin-containing groups and less arranged mesopores. Structure of obtained materials was determined using chemical analysis, infrared spectroscopy, low-temperature nitrogen adsorption-desorption, X-ray diffraction, and transmission electron microscopy. With the aim to elucidate the contribution of β cyclodextrin-containing groups in the removal of azo dyes, sorption of methyl red and alizarin yellow on synthesized silicas was studied from phosphate buffer solutions in dependence of contact duration, equilibrium concentration, and pH of medium. The results were analyzed using Langmuir, Freundlich and Redlich-Peterson equations. It has been found that equilibrium sorption of methyl red and alizarin yellow on parent silica and silica with chemically immobilized β cyclodextrin containing groups is described by the Redlich-Peterson model.