关键词: 微晶, 玻璃, 溶胶-凝胶过程, 方法

Abstract: The influence of water addition sequence and water quantity, quantity and acidity and basicity of alkoxides, solvent quantity and temperatur eduring gelling process on the forma tion ofgel, gelation time and structure of gel glasses were studied for the sol-gel process fabricating BASglasses. The composition ranges of the glasses (wt%) are BaO: 24～48, Al2O3: 10～30, SiO2:34～50 and Li2O: 0～5。The results show that the homogeneous transparentgels can be gained bya partial hydr olysis of tetraethy silicate and optimum parameters of hydrolysis process, when themolration of water to alkoxides is more than 6～ 8, and when tetraethyl silicate is more than40mol% or aluminum is opropoxide is less than 40mol%. The gel glasses have over 80% framenet work structure and the degee of broken bond is below 12%. The gelation time decreases withthe increase of water quantity and with the rise in temperature during gelation.

Key words: microcrystals, glass, sol-gel processes, procedures