Mechanical Properties of Silica Aerogels Prepared from a Mixture of TEOS and Organo-alkoxysilanes of Type R_1SiX_3  

作　　者：杨海龙 孔祥明 ZHANG Yanrong WU Chunchao CAO Enxiang 

机构地区：[1]Department of Civil Engineering, Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Tsinghua University

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2014年第1期201-207,共7页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the National Natural Science Foundation of China(No.50802050);Science and Technology Research Project of Chinese Ministry of Railways

摘　　要：Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility of silica aerogels was significantly improved by incorporation of organo-alkoxysilanes. When MTES and TEOS were combined as precursors of silica areogels, with the increased amount of MTES, the apparent elastic modulus and apparent compressive strength monotonously rose. At the same organo- alkoxysilanes to TEOS ratio, the size of alkyl groups of the organo-alkoxysilanes had little effect on the mechanical properties. In series of MTES and TEOS, the lowest elastic modulus of silica skeleton and the highest compressive strength of silica skeleton were observed at MTES to TEOS ratio of around 50：50. At a certain organo-alkoxysilanes to TEOS ratio, the elastic modulus of silica skeleton increased and the compressive strength of silica skeleton decreased with the size increase of the alkvl grouns.Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility of silica aerogels was significantly improved by incorporation of organo-alkoxysilanes. When MTES and TEOS were combined as precursors of silica areogels, with the increased amount of MTES, the apparent elastic modulus and apparent compressive strength monotonously rose. At the same organo- alkoxysilanes to TEOS ratio, the size of alkyl groups of the organo-alkoxysilanes had little effect on the mechanical properties. In series of MTES and TEOS, the lowest elastic modulus of silica skeleton and the highest compressive strength of silica skeleton were observed at MTES to TEOS ratio of around 50：50. At a certain organo-alkoxysilanes to TEOS ratio, the elastic modulus of silica skeleton increased and the compressive strength of silica skeleton decreased with the size increase of the alkvl grouns.

关 键 词：silica aerogels mechanical properties organo-alkoxysilanes silica skeleton FLEXIBILITY SOL-GEL 

分 类 号：O627.41[理学—有机化学]