溶胶凝胶法制备超疏水二氧化硅涂膜及其表面润湿行为

采用溶胶-凝胶法以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为前驱体制备超疏水SiO2涂层。红外光谱(FTIR)和热重分析(TGA)表征合成SiO2的化学组成,通过透射电镜(TEM)和扫描电镜(TEM)观察制备SiO2的结构形貌,扫描电镜(SEM)和原子力显微镜(AFM)观察SiO2涂膜的表面形貌,通过测试水接触角(WCA)讨论SiO2涂层的表面微观结构与其表面疏水性能的关系。结果表明以TEOS和MTES为共前驱体可以制备得到表面带-CH3基团的SiO2溶胶,SiO2溶胶在老化过程中纳米SiO2粒子由于自组装作用形成草莓状微米-纳米双微观结构,这种结构赋予SiO2涂膜表面不同等级的粗糙度,使得水滴与涂膜表面接触时能够形成高的空气捕捉率和较小的粗糙度因子,与SiO2表面疏水性的-CH3基团共同作用形成类荷叶超疏水结构。

Preparation of Superhydrophobic Silica Films by Sol-Gel Method and Its Wettability

Superhydrophobic silica surfaces were obtained by sol-gel method using TEOS and MTES as procures. FRIR and TGA were used to analyze the chemical components of the prepared silica. TEM and TEM were used to observe the morphology of silica before and after aging. SEM and AFM were used to analyze the surface morphology of the silica surfaces. The relationship between the surface morphology and hydrophobicity was studied by testing the WCA of the prepared silica coatings. The result shows that nano silica particle with -CH₃ group can be obtained by sol-gel method using TEOS and MTES as precursors, the micro-nano dual size structure silica particles were formed duo to self-assemble effect during aging process. This special structure plays an essential role in trapping air between the substrate surface and the liquid droplets. Combining with the low energy surface of -CH₃ group of the silica, a superhydrophobic surface with high contact angle and low contact angle hysteresis was prepared.