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以乙烯基三乙氧基硅烷(VTES)为先驱体,无水乙醇(EtOH)作溶剂,采用Sol-Gel酸碱两步法常压制备疏水SiO2气凝胶材料。使用X射线衍射仪、傅立叶红外光谱仪对SiO2气凝胶的结构进行表征,并通过视频光学接触角测定仪测出气凝胶对水的接触角范围为115°～150°,呈现好的疏水性能。同时研究表明,不同EtOH/VTES摩尔比以及不同酸、碱催化剂浓度对气凝胶的体积收缩率、体密度有较大影响。试验所获得的样品体密度大致分布在0.13～0.43g/cm3范围,体积收缩率分布在20%～70%之间。
Hydrophobic SiO2 aerogels were prepared by a two-step Sol-Gel acid-base method using vinyltriethoxysilane (VTES) as precursor and anhydrous ethanol (EtOH) as solvent. The structure of SiO2 aerogels was characterized by X-ray diffractometer and Fourier transform infrared (FTIR) spectroscopy. The contact angles of aerogels to water were measured by video optical contact angle measuring instrument with a range of 115 ° -150 °, showing good hydrophobicity . At the same time, it has been shown that different molar ratios of EtOH / VTES and different concentrations of acid and base have a great effect on volume shrinkage and bulk density of aerogels. The bulk density of the samples obtained in the experiment is generally distributed in the range of 0.13 ~ 0.43g / cm3, and the volumetric shrinkage is distributed in the range of 20% -70%.