Aqueous sol-gel route to barium aluminosilicate glass-ceramics

The rapid hydrolysis of some alkoxides creates problems in alcohol-based sol-gel processes. This paper describes a simple aqueous sol-gel process for the synthesis of barium aluminosilicate gels and gel-derived glasses, in which the problem of the rapid hydrolysis of aluminum isopropoxide (the source of aluminum) is solved by a precipitation-peptization process that is cost effective. Tetraethylorthosilicate, aluminum isopropoxide, and barium acetate are used as the starting materials, and water is the solvent. The molecular network, crystallization behavior, weight-loss, and thermal characteristics of the gel and the gel-derived glass have been detected by Raman spectroscopy, XRD, DTA, and TGA.