柔韧性块体疏水二氧化硅气凝胶的制备及表征  

Synthesis and Characterization of Block Hydrophobic Silica Aerogels with Flexibility

作　　者：胡银[1] 张和平[1] 黄冬梅[2] 何松[1] 毕海江[1] 杨晖[1] 程旭东[1] 

机构地区：[1]中国科学技术大学,火灾科学国家重点实验室,合肥230027 [2]中国计量学院质量与安全工程学院,杭州310018

出　　处：《硅酸盐学报》2013年第8期1037-1041,共5页Journal of The Chinese Ceramic Society

基　　金：国家重大基础研究计划(973计划)(2012CB719701)资助

摘　　要：以甲基三甲氧基硅烷为前驱体,乙醇为溶剂,盐酸和氨水为过程催化剂,采用溶胶–凝胶两步法制备气凝胶固体。经老化及常压干燥制得试管状、饼状疏水性气凝胶,该气凝胶块体具有一定柔韧性及弹性,经一定外力压缩可恢复至原状。通过对气凝胶样品进行弹性恢复测试、疏水性测试、比表面积、热重和透射电镜等分析,测得样品弹性变化率为31.25%,疏水接触角为127°,比表面积为457.79m2/g,平均孔径为14.24 nm,在空气中的耐温点可提高至251.15℃。扫描电子显微镜分析结果表明,样品具有连续多孔结构,且粒子堆积有序,为空间三维网络结构,其骨架疏松。Hydrophobic monolith silica aerogels were synthesized using different ratios of precursor and catalysator by a two-step （acid-base） sol–gel process. The main raw materials used were methyltrimethoxysilane（MTMS） as prescurs, alcohol as solvent, hydrochloric acid and ammonia water as catalyst. The shape of the block silica aerogels appears either tube-shape or pie-shape, determined by various containers used. The sample has superior flexibility and elasticity. The aerogel samples were characterized by elastic recovery test, hydrophobic test, specific surface area analysis, thermogravimetry and transmission electron microscopy, respectively. The results show that the change rate of the elasticity is 31.25%, the contact angle with water is 127°, the specific surface area is 457.79 m^2/g, the average pore size is 14.24 nm, the heat resistance point is 251.15 ℃, and the sample appears a continuous porous and loose skeleton structure.

关 键 词：气凝胶块体 甲基三甲氧基硅烷 疏水性 柔韧性 

分 类 号：O684[理学—化学]