以有序介孔二氧化硅颗粒SBA-15 为添加剂,利用酸碱两步法制备 SBA-15/SiO2气凝胶硅- 硅复合材料. 研究SBA-15添加量对气凝胶复合材料的形成过程和性能的影响,采用扫描电镜和氮气吸附-脱附对样品的结构进行表征,并测试其力学性能和热导率. 结果表明:少量有序介孔二氧化硅材料SBA-15的加入能大大缩短二氧化硅气凝胶形成时间,提高气凝胶复合材料的力学性能,并保持较低的热导率,而材料的比表面积仅略有下降.
A mesoporous SBA-15/silica composited aerogel was prepared by a two-step acid-alkali method with SBA-15 as an additive. The effects of the amount of SBA-15 on the formation process and the performance of the composited aerogel were investiga-ted. The microstructure of the composited aerogel was characterized by scanning electron microscopy and N2 adsorption- desorption isotherms, and the mechanical properties and thermal conductivity were tested. It is found that as a small amount of SBA-15 is added, the gelation time of silica greatly shortens, the mechanical properties improves, the thermal conductivity still keeps small, while the specific surface area slightly decreases.