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ABSTRACT: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 190-900nm 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. Poly(methyl methacrylate)(PMMA)-silica hybrid material is an interesting organic-inorganic material.10-14 Coltrain et al. studied the morphologies and properties of the hybrid materials prepared by various acrylic polymers and tetraethoxysilane (TEOS) or tetramethoxysilane (TMOS). 11 They discovered that the macroscopic phase separation of the hybrid materials is controlled by the backbone of the acrylic segment with the growing silica network. Huang et al. used the in situ sol-gel process to prepare the acrylic-silica hybrid materials. 12 · 13 They obtained transparent hybrid materials and found that phase behavior is significantly affected by interactions between the side chain of the polymer segment and silica network. Wei et al. examined monolithic PMMA-silica hybrid materials. 14 They demonstrated the dependence of surface roughness on silica content. Although previous studies have examined the structures and properties of acrylic polymer-silica hybrid materials, the thin film properties of the hybrid materials have not been fully explored yet. For practical applications of the hybrid materials in electro-optical devices, a thin film material with controlled film thickness and optical properties is required. Slow evaporation at a low temperature for a long time reported in the literature was used to prepare the hybrid materials. Hence, hybrid materials with uncontrollable film thickness and a large portion of monomer and solvent residues were found in the PMMA-silica hybrid materials. 10 · 12 · 13 Therefore, a fundamental study for developing PMMA-silica hybrid thin films should be made. KEY WORDSIn this study, a series of PM MA-silica hybrid thin films was prepared by the in situ sol-gel process combined with spin coating and multi-step baking, as shown in Figure 1. The in situ sol-gel process avoids selfcondensation' of the MSMA moiety or reaction with moisture, which has been proven in the literature. 12 · 13 Multi-step baking was used to prevent void formation and film shrinkage due to evaporation of solvent and monomer residues. The used acrylic monomers were...

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Prescription errors are prevalent in ambulatory care in Taiwan, and differential practice standards exist between community and hospital services. This disparity needs to be reconciled by pertinent initiatives to enhance community-hospital and pharmacist-general practitioner communication and interprofessional educational efforts to improve medication use and safety.