【摘要】 采用溶胶 凝胶技术 ,结合碱性催化和低表面张力溶剂交换以及非活性CH3基团置换修饰 ,在常压条件下成功地制备了孔隙率为 77%、折射率为 1.12纳米多孔SiO2 气凝胶薄膜 .采用氨和水蒸气混合气体热处理技术提高薄膜的耐磨性、附着力等力学特性 .使用透射电镜 (TEM)、扫描电镜 (SEM)分别观察了溶胶的颗粒结构和薄膜表面形貌 .应用傅里叶转换红外光谱仪 (FTIR)研究了薄膜经表面基团修饰前后的红外吸收光谱以及后处理对薄膜红外ω4 (TO3)吸收峰位置和半宽度的影响 .采用椭偏仪测量薄膜的厚度和折射率 .耐摩擦和附着力测试表明 :混合气体热处理显著地增强了SiO2 气凝胶薄膜纳米结构 .薄膜结构增强归因于混合气体热处理产生的SiO2 颗粒间更多的Si—O—Si键连接更多还原

【Abstract】 Scratch resistant silica aerogel films with a 77% porosity and 1.12 refractive index at ambient pressure is reported using the exchange of solvent and modification of \_CH 3 group. The silica films were prepared in a sol gel process by a dip coating method, and then were post annealed in air and a mixed gas atmosphere. The films were characterized with transmission electron microscope, scanning electron microscope, Fourier Transform infrared spectroscope, an ellipsometer, and the abrasion test, respectively. With the post annealing, the frequency shift of FTIR absorption ω 4 (TO 3) peak of the films to a lower wave number results from a decrease in the average Si—O—Si bridging angle. An increase in the full width at half maximum (FWHM) of the ω 4 peak is ascribed to a wide distribution of the bridging angle because of the formation of strained Si—O—Si bonds caused by the post annealing. The abrasion and adhesion tests indicate that the mixed gas treatment noticeably strengthens the silica network. The increase in strength is attributed to more Si—O—Si bond cross linkages between silica particles formed by the mixed gas treatment.更多还原