Tunable Thickness and Refractive index of Mesoporous Silica Thin Films using Swelling Agent

초록

Large-pore mesoporous silica thin films were synthesized by incorporating poly(propylene oxide) as a swelling agent with Pluronic F127 block copolymer. The influence of the various synthesis parameters, such as the addition of poly(propylene oxide), the condensation catalyst(HCl,NH3), and the aging time, was systematically explored, especially their influence on the mesostructure, thickness and refractive index. The cumulative effect of these parameters is demonstrated and we obtain materials with uniform pore size with pore diameter of mesopore about 12.5nm. However, in the higher content of poly (propylene oxide) sample, there was evidence that broad distribution of pole entrance size with large diameter. The silica synthesized under typical conditions os a well-ordered cubic Im3m structure with a good quality of cagelike pore structure. The refractive index of 12.1 and total porosity of 59%(vol) were obtained from cubic thin films.