溶剂顺序及配比对常压制备SiO_2气凝胶的影响

Effect of the Solvent Sequence and Ratio on the SiO_2 Aerogel Being Prepared under Ambient Pressure

以硅溶胶为硅源,在氨水催化下硅溶胶变为凝胶,凝胶经溶剂替换和改性后在常压干燥条件下制备了SiO_2气凝胶。研究了不同溶剂顺序及配比对SiO_2气凝胶的影响。用扫描电镜对SiO_2气凝胶的形貌进行了表征,用比表面积及孔径分析仪对气凝胶的基本性质进行了分析,用综合热分析仪对气凝胶进行了热稳定性分析,结果表明,当乙醇、正己烷、三甲基氯硅烷的体积比为10:10:1时,气凝胶的气孔分布较为均匀,三维网络结构以及性能较好。

Silica sol was used as the silica source, and it turned into a gel under the catalysis of ammonia. Then SiO2 aerogel was prepared under ambient pressure after the solvent exchange and modifcation. The efect of the solvent sequence and ratio on the as-prepared SiO2 aerogel was studied. Scanning electron microscope was used to characterize the SiO2 aerogel morphology. Specifc surface area and pore size analyzer was used to analyze the basic parameters of SiO2 aerogel. Comprehensive thermal analyzer was used to analyze the thermal stability of SiO2 aerogel. The results showed that, when EtOH/n-hexane/TMCS was 10 ： 10 ： 1, the porosity distribution of SiO2 aerogel was more uniform. The three-dimensional network structure and comprehensive performance were better than others.