疏水型SiO_2光学增透膜的制备

Preparation of Hydrophobic Optical Silica Thin Film with Sol-gel Method

以正硅酸乙酯（ＴＥＯＳ）为有机醇盐前驱体，采用溶胶－凝胶技术，通过酸／碱二步法控制实验条件，结合三甲基氯硅烷（ＴＭＣＳ）对胶粒表面的修饰过程，制备出结构可控的疏水型ＳｉＯ２薄膜．采用椭偏仪、ＦＴＩＲ、接触角测试仪、ＳＥＭ等对薄膜的折射率、红外特性、接触角以及表面形貌等进行了测量．研究结果表明，疏水型ＳｉＯ２薄膜的折射率在１．３３～１．１８之间连续可调；ＳｉＯ２胶粒表面的亲水性－ＯＨ中的Ｈ已部分被非活性－Ｓｉ（ＣＨ３）３基团取代；接触角由表面未修饰膜的４０°左右增加到表面修饰膜的１２０°左右．

Preparation of hydrophobic SiO2 thin film is reported. The solution is prepared by a acid/base 2-step method and then modified by TMCS (trimethylchlorosilane). Ellipsometry, FTIR, SEM, and contact angle instrument were used to measure the physical properties of the thin films. The results show that the refractive index of thin film is controlled between 1.33 and 1.18, OH groups on the surface of SiO2 particles have been partly replaced by CH3 groups, the contact angle is increased to 120 degree of modified films from 40 degree of unmodified films.