耐环境性SiO2/SiO2-TiO2 增透膜的设计与制备

根据膜层设计理论设计出以K9玻璃为基体的耐环境性的双层增透膜, 这种增透膜在特定波长处具有超高的透过率. 以盐酸为催化剂, 分别以正硅酸乙酯和钛酸丁酯为前驱体制备了SiO2和TiO2溶胶, 将SiO2和TiO2溶胶按一定比例混合得到SiO2-TiO2复合溶胶. 通过改变复合溶胶中SiO2的含量调节复合膜的折射率, 通过改变提拉速度控制薄膜的厚度. 实验结果表明, 双层增透膜在550 nm处的透过率达到99.9%. 增透膜经较强机械摩擦后峰值透过率基本保持不变, 表明该增透膜具有优良的耐摩擦性. 进一步采用六甲基二硅氮烷对增透膜表面进行修饰, 修饰后增透膜的接触角增大至98.3°, 增透膜的疏水性及环境稳定性得到较大提高.

Design and Preparation of SiO2/SiO2-TiO2 Antireflective Coating with Excellent Environmental Resistance

Double-layer antireflective(AR) coatings on K9 glass with excellent environmental resistance and abrasion-resistance were designed and prepared.Using tetraethylorthosilicate(TEOS) and titanium tetraisopropoxide(TTIP) as precursor,respectively,SiO 2 and TiO 2 sols were prepared via sol-gel process with hydrochloric acid as catalyst.SiO 2-TiO 2 composite films were prepared by mixing the SiO 2 and TiO 2 sols and then dip-coating on the substrates.The refractive indices of the composite films were controlled by adjusting the SiO 2/TiO 2 ratio and the thickness was controlled by adjusting the dip-coating speed.It was found that the maximum transmittance of the double-layer AR coatings reached 99.9% and could be adjusted to match a specific wavelength.The transmittance did not decrease after abrasion test,indicating an excellent abrasion-resistance of the AR coating.Hydroxyl terminated hexamethyldisiloxane(HMDS) treatment was further performed to improve the hydrophobicity,the environmental resistance and durability of the AR coatings.