摘要
以价廉的水玻璃为原料,通过六甲基二硅氧烷和三甲基氯硅烷混合改性剂对制备的SiO2水凝胶进行表面改性,避免了溶剂交换,并常压干燥得到疏水的SiO2气凝胶。研究了改性剂用量对气凝胶疏水性和结构的影响。疏水气凝胶与水的接触角在100～130°范围内。常压干燥制备的气凝胶具有典型的气凝胶结构特征,孔洞尺寸、密度和比表面积分别在5～6.5nm,100～160kg/m3和500～720m2/g范围内,颗粒尺寸小于100nm。疏水气凝胶在空气和氮气中的热稳定性分别为284℃和490℃。
Hydrophobic silica (SiO2) aerogels were prepared from cheap water glass, directly modified with surface modifier of hexamethyldisiloxane/trimethylchlorosilane (HMDSO/TMCS) without solvent exchange and via ambient drying. The effect of surface modifier concentration on the structure and properties of the SiO2 aerogels was investigated. The contact angles between hydrophobic aerogels and water are 100-130°. The pore diameter, the densities and the specific surface area of the SiO2 aerogels are in the range of 5-6.5 nm, 100-160 kg/m3 and 500-700 m2/g, respectively. The SiO2 aerogels prepared at ambient drying has a typical aerogels structure. The particle diameter of SiO2 aerogels is less than 100 nm. The thermal stability of SiO2 aerogels in air and N2 is 284°C and 490°C, respectively.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2005年第6期727-731,共5页
Journal of The Chinese Ceramic Society
基金
航天基金(2002HT006)资助项目。
