Synthesis and characterization of poly(methyl methacrylate)-silica hybrid optical thin films

A series of poly(methyl methacrylate) (PMMA)-silica hybrid thin films was prepared by the in situ sol-gel process combined with spin coating and multi-step baking. The investigated acrylic monomers were methyl methacrylate (MMA) and 3-(trimethoxysilyl) propyl methacrylate (MSMA). The alkoxide monomers for the preparation of the silicate segment were tetraethoxysilane (TEOS). methyltriethoxysilane (MTES), and phenyltriethoxysilane (PTES). The prepared hybrid materials show good thermal stability and no phase separation. The AFM study suggests that the prepared hybrid thin films have excellent planarization. The refractive indices of the prepared hybrid thin films in the wavelength range of 190-900 nm can be controlled by the side group on the Si atom as well as by content of the inorganic moiety. The extinction coefficients of the studied films were almost zero in the wavelength range of 190-900 nm indicating very high optical transparence.