Gas chromatography study of the acid catalyzed hydrolysis of tetraethylorthosilicate [Si(OC 2H 5) 4

Abstract

The acid catalyzed hydrolysis reaction of tetraethylorthosilicate [TEOS] was monitored using gas chromatography. In these experiments TEOS was hydrolyzed using molar ratios of H 2O:TEOS of 1:1 and 4:1 at temperatures of 21, 45, and 65°C. In all cases the pH of the solution was between 0.5 and 1. The extent of hydrolysis was indirectly measured by monitoring the volume percentage of ethanol generated. It was found that for all of the conditions studied the amount of ethanol generated reached a peak within 20–25 min after initiation of the reaction and then remained constant with time. Our results indicate that for the conditions studied, the 4:1 ratio led to roughly 77% of full hydrolysis and the 1:1 ratio led to roughly 20%.