SiO2气凝胶的疏水性改性研究

采用三甲基氯硅烷（TMCS）对硅溶胶制备的湿SiO2气凝胶进行表面疏水改性处理，研究了TMCS与孔洞中水的摩尔比对气凝胶的疏水改性作用与性能，用红外光谱法检测了疏水性改性的SiO2气凝胶，发现气凝胶表面的-OH被-OR基团取代，以此构建SiO2气凝胶的疏水性改性机理及模型，试验结果表明，TMCS与孔洞中水的摩尔比控制在0．35左右时可获得不开裂、完好的、具有憎水性特征的二氧化硅气凝胶。

Study on the Hydrophobic Modification of Silica Aerogels

Hydrophobic SiO2 aerogels prepared via sol-gel process using silica sol were modified trimethylchloro-silane （TMCS） for hydrophobic modification. The influences of the molar ratio of TMCS with pore water on hydrophobic modification and performanee were investigated. Infrared spectroscopy of the hydrophobic modified SiO2 aerogel showed that the -OH on aerogel surface have been replaced by-OR group. And Mechanism and model for hydrophobic modification of SiO2 aerogel were constructed.The results showed that： The SiO2 aerogel has high surface area, the porous nanometer structure, and the granule size in 30-40 nm; It has the good hydrophobic energy after the hydride surface modification processing, when the radio of TMCS and water is about 0.35, we can obtain the SiO2 aerogels which do not crack and have the complete hatred river characteristics.