块状低密度C/SiO_2复合气凝胶的制备

Preparation of monolithic C/SiO_2 composite aerogels with low density

采用溶胶凝胶法结合CO_2超临界干燥工艺制备间苯二酚甲醛/SiO_2(RF/SiO_2)复合气凝胶,RF/SiO_2气凝胶高温炭化得到块状低密度C/SiO_2复合气凝胶研究反应物质量分数对溶胶凝胶过程和热处理过程的影响,考察不同热处理温度对C/SiO_2复合气凝胶孔结构的影响。结果表明:反应物质量分数为13%时,RF/SiO_2气凝胶受热处理工艺的影响较小,炭化温度升高至1200℃对C/SiO_2气凝胶网络结构有明显的改善作用。

Resorcin-formaldehyde/SiO2 composite （RF/SiO2 ） aerogels were synthesized by the sol-gel method and CO： supercritical fluid drying. C/SiO2 composite aerogels were formed from the RF/SiO2 aer- ogels after carbonization. The influence of reactant concentration on sol-gel and thermal treatment proces- ses was investigated. The effect of heat treatment temperature on pore structure of C/SiO2 aerogels was discussed. Results showed that the heat treatment had the least impact on RF/SiO2 aerogels with the re- actant concentration of 13%, and increasing the carbonization temperature to 1 200 ℃ had an obvious improvement to the network structure of C/SiO2 aerogels.