二氧化硅凝胶的疏水改性及表征

摘要

以正硅酸乙酯为原料,经溶胶-凝胶过程制备二氧化硅溶胶,再利用二甲基二乙氧基硅烷(DDS)对其进行改性,制备疏水性二氧化硅凝胶.用红外光谱、接触角,热重分析及原子力显微镜等测试方法对试样的结构、疏水性、热稳定性及形貌进行分析.结果表明,改性后的样品是表面存在疏水基团-CH3的疏水凝胶；热稳定性较好,600℃之后没有明显的质量损失,热处理温度定于400℃可保证其疏水性；表面均一平整,孔隙率较高.%A hydrophobic silica gel was prepared by sol-gel process using tetraethoxy silicone(TEOS) as raw material, and modifying the surface chemically by diethoxydimethylsilane (DDS). The structure, hydrophobicity, thermal stability and surface morphology of the silica membrane were characterized by means of IR,angle of contact,TG-DTG and AFM. The results showed that the hydrophobic group-CH3 was on the surface of silica gel modified; the thermal stability was good, there was no significant mass loss after 600 °C, at a sintered temperature of 400 °Cthe silica membrane draw a good hydrophobicity; the surface with large-porosity was regularly smooth.