Sol-Gel Route to Barium Aluminosilicate (BAS) Glass-Ceramics

A new idea was proposed for solving the problems caused by different hydrolysis rate of alkoxides in Sol-Gel processes. The new idea is that the highest-hydrolysis-rate alkoxide is supposed to be hydrolysized slowly and homogeneously at first under a controllable condition, and meanwhile, its hydrolysis intermediates polymerize with lower-hydrolysis-rate alkoxides. Based on this new idea, a Sol-Gel process with lower cost and a simple procedure was developed for synthesizing BAS glass-ceramics. XRD, DTA and Laser Raman Spectrum were used to detect the molecular structures and crystallization behaviors of a gel and a gel-derived glass. The as-prepared gel is amorphous with (Si, Al)-O network structures. The temperature of maximum-nucleation-rate of the amorphous is about 938°C, and the temperature of maximum-crystal-growth is about 1164°C.