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以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTOS)为共聚硅源,加入N,N-二甲基甲酰胺(DMF)为化学干燥控制添加剂,三甲基氯硅烷(TMCS)和γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)为原位疏水改性剂,通过溶胶-凝胶法,常压干燥制备出低密度的疏水SiO2气凝胶。用扫描电子显微镜(SEM)、N2-吸附仪、傅里叶变换红外分析(FT-IR)、X射线衍射、热分析仪对其结构和性能进行表征。结果表明:所制备出的SiO2气凝胶比表面积高达870.99 m2/g、孔体积为1.74 cm3/g,密度为0.244 g/cm3,气孔率为88.9%,可在430℃下保持疏水性,孔径分布集中在11 nm,为典型的中孔纳米材料。
Using tetraethyl orthosilicate (TEOS) and methyltriethoxysilane (MTOS) as the copolymerization silicon source, N, N-dimethylformamide (DMF) was added as a chemical drying control additive, trimethylchlorosilane TMCS) and γ-methacryloxypropyltrimethoxysilane (KH-570) as in-situ hydrophobic modifiers, low density hydrophobic silica airgel was prepared by sol-gel method and dried under atmospheric pressure . Their structures and properties were characterized by scanning electron microscopy (SEM), N2-adsorption, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction and thermal analysis. The results show that the specific surface area of the prepared aerogels is up to 870.99 m2 / g, the pore volume is 1.74 cm3 / g, the density is 0.244 g / cm3, the porosity is 88.9%, and the hydrophobicity can be maintained at 430 ℃. The distribution is concentrated at 11 nm, which is a typical mesoporous nanomaterial.