本研究在室温下采用溶胶-凝胶法於非质子溶剂(DMAc和DMF)中合成二氧化钛奈米粒子(约5 nm)；且合成的二氧化钛溶胶可长期存放(30天)。将可溶性聚亚醯胺与二氧化钛溶胶依适当比例混合後，藉由旋转涂布及多段烘烤(至300 oC)程序制备高折射率聚亚醯胺-二氧化钛混成薄膜。由FE-SEM可观察到混成薄膜相当平坦，且二氧化钛以奈米尺度均匀分布在混成薄膜中，可以避免散射的问题。藉由调控二氧化钛的含量，在633 nm的折射率可由1.63提升至2.16，显示具备应用於抗反射涂料及光波导的潜力。
In this study, TiO2 sols with very small particle sizes (~5 nm) were synthesized in an aprotic solvent, N,N-dimethylacetamide (DMAc) and N,N- dimethylformamide (DMF), via sol-gel reaction at room temperature. The TiO2 sol showed long-term storage stability (30 days) and can provide operating control for the preparation of high–refractive–index polyimide-TiO2 hybrid thin films. By means of spin coating and multistep baking (up to 300 oC), the hybrid thin films were prepared from the solutions composed of soluble polyimide and TiO2 sol. The FE-SEM images showed a smooth and uniform morphology of the hybrid thin films. TiO2 domains were in the nanometer range, thus avoiding the light scattering. The refractive indices at 633 nm of the prepared hybrid thin films increase from 1.63 to 2.16 with increasing TiO2 content, which suggested the potential application to anti-reflective coatings and optical waveguides.
