Growth of hydrophilic/hydrophobic Optical Thin Film on Optical Plastics by Plasma Chemical Vapor Deposition

• Main Author: 王俊堯
• Other Authors: Franklin Chau-Nan Hong
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/23565925504124221448

碩士 === 國立成功大學 === 化學工程學系 === 87 === Abstract The quality of optic plastics has been greatly improved recently. Due to its light weight and high toughness, plastics is gradually replacing glass in many optical application. However, optic plastics suffers a major problem in scratch-resistance. Therefore, a hard coating on the relatively soft plastics surface is required. This study is aimed at depositing on the optic plastics an adherent hard coating with controllable surface properties, like hydrophillicity and hydrophobicity. Plasma enhanced chemical vapor deposition (PECVD) has been employed to deposit hard films on polycarbonte (PC) and polymethylmethacrylate (PMMA) substrates using hexamethyldisiloxane (HMDSO) and methyltrimethoxysilane (MTMS) as reactants. Our results show that the films deposited using HMDSO are highly hrdrophobic. IR ad ESCA show that methyl groups reside in the deposited films, accounting for the hydrophobicity of the films. By flowing O2 with HMDSO, the films become hydrophillic. IR and ESCA show that methyl groups are etched away from the film and the film structure become close to that of SiO2, accounting for the hydrophillicity of the films. Beside, both the hydrophobicity and hydrophillicity of the films can be greatly enhanced by increasing surface roughness of polymer substrates. By utilizing the heterogeneous nature of polymer surface, plasma etching using O2 or O2/HMDSO is quite effective in creating a rough surface. All the films deposited on PC substrates exhibit good adhesion, with no film detachment under all peeling test conditions. However, the adhesion on PMMA is strongly dependent on the film structure. The adhesion becomes very poor while adding O2 in the HMDSO. An interfacil layer deposited by using HMDSO only, before depositing the top hydrophillic layer by using HMDSO/O2 mixture, improves the film adhesion, but is yet not satisfactory.