PVP辅助常压干燥制备SiO2气凝胶的研究

Preparation of SiO2 aerogels by PVP assisted ambient pressure drying route

以聚乙烯吡咯烷酮(PVP)为干燥控制化学添加剂,采用常压干燥法制备SiO2气凝胶,采用FTIR、XRD、SEM和BET等测试手段表征气凝胶结构与性能。结果表明:引入PVP时制备出的SiO2气凝胶为非晶态二氧化硅,其开裂程度小,凝胶结构中存在大量纳米孔道,比表面积为363.45 m2·g-1,平均孔径为10.6 nm,SiO2气凝胶具有较好的保温隔热性能,150℃时导热系数为0.05 W/m·K。

SiO2 aerogels were prepared by ambient pressure drying route with polyvinylpyrrolidone(PVP)as drying control chemical additive.The aerogels were characterized by FTIR,XRD,SEM and BET.The results show that the SiO2 aerogel as-prepared with introducing PVP is amorphous silicon dioxide,and its cracking degree is small.There are a large number of nano channels in the gel structure,the specific surface area is 363.45 m2·g-1,and the average pore diameter is 10.6 nm.SiO2 aerogels have better thermal insulation performance,and the thermal conductivity is 0.05 W/m·K at 150℃.