摘要
以正硅酸乙酯为先驱体,丙三醇为干燥控制化学添加剂(DCCA),通过酸碱两步溶胶-凝胶法制备了二氧化硅气凝胶,同时利用六甲基二硅氮烷(HMDZ)和正己烷的混合液对湿凝胶进行表面疏水改性。测试分析了所制备气凝胶的密度、疏水性、比表面积和形貌。结果表明,经过表面改性的SiO2气凝胶具有良好疏水性,与水的接触角约为139.4°,比表面积为952m2/g,平均孔径为5～10nm,孔隙率达94.2%,且其密度仅为0.127g/cm3。
Using tetraethylorlhosilicate（TEOS） as precursor, glycerol as dry control chemical agent as well as hexmethyldisilazane（HMDZ） and hexane as a suface modifying agent, silica aerogels were synthesized by the two step sol--gel method. The physical properties such as density, hydrophobicity, specific surface area and appearance were measured. The results show that silica aerogels made by surface modification has good hydrophobie property whose contact angle is 139.4°, surface area is 952m^2/g, mean pore diameter is 5-10nm, porosity is 94.2% and densily is only 0. 127g/cm^3.
基金
催化材料科学国家民委-教育部重点实验室开放基金(CHCL09005)
关键词
二氧化硅气凝胶
常压干燥
疏水
表面改性
silica aerogels, ambient drying, hydrophobic, surface modification
