Study on Drying Process of 3Al<,2>O<,3>2?SiO<,2>, Mullite Gel

摘要

Monophasic mullite gel with composition 3Al<,2>O<,3>2SiO<,2> was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide and tetraethylorthosilicate as reagents. Gels with different drying control chemical additives (DCCAs) and polyvinylpyrrolidone (PVP) as spinning assistant were dried at several temperatures. The influences of temperatures, DCCAs and PVP in the drying process were investigated. The optimum drying temperature was 70℃. N, N- Dimethylformamide (DMF) was chosen as the preferable DCCA in the drying process. PVP decreased solvent volatilization speed and prevented gel crack at a certain extent.