Investigation of the Structure of Surface Hydroxyl Groups on Silica

Chemical Reaction and Molecular Adsorption Method

Abstract

Classification of types of surface hydroxyl groups and structure of hydrogen-bonded hydroxyl groups on Aerosil silica have been investigated. The fraction of isolated hydroxyl groups on the surface could be estimated by the reaction of dimethyldichlorosilane molecules with surface hydroxyl groups at a low concentration. The structure of the hydrogen-bonded hydroxyl groups on the surface was examined through the change in FT-IR spectra with CO physisorption at 77K. The analysis of CO physisorption provided information on the structure of hydrogen-bonded hydroxyl groups by estimating of the amount of terminal hydroxyl groups.