溶胶-凝胶法制备疏水型超低折射率膜层材料

Sol-gel Preparation of Hydrophobic Silica Coating-materials with Ultralow Refractive Index

以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为共同前驱体,羟丙基-β-环糊精(HPCD)为致孔剂,水和乙醇为溶剂,氨水为催化剂,采用溶胶-凝胶法制备了HPCD-Si O2溶胶.溶胶经过六甲基二硅氮烷(HMDS)改性后,制得疏水型超低折射率膜层,其最低折射率可达1.05,静态水接触角从66.4°上升至128.7°.以羟丙基-β-环糊精为致孔剂制得的膜层孔径约为4 nm,因而膜层不会因为孔径接近光波长的1/4而引起散射.与传统的致孔剂泊洛沙姆(F127)等相比,羟丙基-β-环糊精具有致孔效率高及折射率更低等优点,在模板剂领域具有广泛的应用前景.

Using methyltriethoxysilane（MTES）, tetraethylorthosilicate（TEOS） as co-precursors and hydroxypropyl-β-cyclodextrin（HPCD） as porogen,ultralow refractive index films were prepared based on a base-catalysed sol-gel process. After further modification by hexamethylisilazane（HMDS）,the lowest refractive index of these silica coatings obtained from the hybrid sol were 1. 05 and the static water contact angles of the coatings increased from 66. 4° to 128. 7°. The data showed that the films prepared with HPCD as porogen got a pore diameter around 4 nm. Compared with those templates such as poloxamer（F127）,HPCD not only perform well in decreasing the refractive index of films,but also eliminate light scattering caused by mesopore of the film,will have potential value in the field of surfactant-templated methods.