Reactions of silica gel with alkylaluminum compounds and titanium tetrachloride

Abstract

The amount of gases (methane, ethane, isobutane and hydrogen chloride) evolved in a reaction of silica gel was measured. The gel was heated up to 20–900°C, with an excess of alkylaluminum compounds and titanium tetrachloride. A linear decrease of the amounts with activation temperature in the range 200–900°C was observed. These compounds can be used for OH determination as OH group signals in near infrared spectra are not detected after the reaction. Alkylaluminum deposition on silica gel from heptane solutions was measured. Besides the chemical reaction with OH groups a chemisorption on silica gel surface was observed and its extent was measured. This phenomenon is discussed in terms of alkylaluminum chemisorption on surface siloxane bonds of silica gel.