Properties of silicious film on polycarbonate substrate prepared by vacuum ultraviolet irradiation: Effect of intermediate silane layer

We studied the effect of vacuum ultraviolet irradiation (VUV) on siliceous coatings of polycarbonate substrates derived by the sol-gel method, with the aim of improving the abrasion resistance of the substrate surface. The experimental conditions to insert an intermediate silane layer between siliceous film and polycarbonate substrate were examined in order to enhance the abrasion resistance and adhesion strength, using four kinds of silane coupling reagents, i.e., 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilne, phenyltriethoxysilne and ethyltriethoxysilane. After the formation of intermediate silane layer on the PC substrate, siliceous film was further prepared on it by VUV irradiation of the spin-coated sol solution containing methyltriethoxysilane and colloidal silica. Among the silanes examined in this research, 3-aminopropyltrimethoxysilne notably played a role as an appropriate intermediate layer for the enhanced abrasion resistance of siliceous-coated polycarbonate substrate. The average transmittance was kept as high as 70% even after abraded 140 turns.