摘要
以短切石英纤维、硅溶胶、B4C粉烧结制备多孔刚性骨架,以正硅酸乙酯、去离子水和乙醇配制SiO2溶胶,多孔骨架浸渍SiO2溶胶后经超临界干燥制备了SiO2气凝胶/多孔骨架复合材料。对隔热瓦的高温热导率、比表面积和孔径分布进行了测试并且观察了微观形貌。结果表明:SiO2气凝胶复合的石英纤维刚性隔热瓦具有纳米孔结构,平均孔径为39.5nm,在600℃和800℃,其热导率分别仅为0.0335W/(m.K)和0.0404W/(m.K),与未复合气凝胶的刚性骨架相比,高温热导率下降了40%～50%。此外,SiO2气凝胶填充了隔热瓦骨架中的大部分的宏孔,抗弯强度提高了30%,并且使刚性隔热瓦的脆性有一定改善。
A short silica fiber porous skeleton consisting of colloidal silica and B4C powder was sintered.The porous skeleton was dipped into SiO2-sols prepared using tetraethyloxysilane(TEOS),deionized water and ethanol.The skeleton was supercritical dried to obtain SiO2-aerogels/short silica fiber porous skeleton composite.The high-temperature thermal conductivity,specific area and pore diameter distribution of the composite were determined,and its microstructure was observed.The results reveal that the composite h...
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2009年第2期234-237,共4页
Journal of The Chinese Ceramic Society
基金
国家部委基金资助项目
关键词
短切石英纤维
氧化硅气凝胶
纳米多孔
热导率
抗弯强度
short silica fiber
silica-aerogel
nanoporous
thermal conductivity
flexural strength
