Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with differe...Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with different drying control chemical additives(DCCAs) and polyvinylpyrrolidone(PVP) as spinning assistant were dried at several temperatures. The influences of temperature, DCCAs and PVP in the drying process were investigated. N,N-dimethylformamide(DMF) was the optimum DCCA at 70℃ in the drying process. PVP decreased the solvent volatilization speed and prevented gel crack to a certain extent. FTIR results revealed that free water, ethanol, and isopropanol were completely removed by the drying procedure.展开更多
文摘Monophasic mullite gel with composition 3Al2O3·2SiO2 was prepared by the sol-gel method using aluminium nitrate nonahydrate, aluminium-tri-isopropoxide, and tetraethylorthosili-cate as reagents. Gels with different drying control chemical additives(DCCAs) and polyvinylpyrrolidone(PVP) as spinning assistant were dried at several temperatures. The influences of temperature, DCCAs and PVP in the drying process were investigated. N,N-dimethylformamide(DMF) was the optimum DCCA at 70℃ in the drying process. PVP decreased the solvent volatilization speed and prevented gel crack to a certain extent. FTIR results revealed that free water, ethanol, and isopropanol were completely removed by the drying procedure.
