| Materials with two-dimensional ordered macroporous not only has large surface areaand high porosity, but also has characteristics, such as pore structure with two-dimensionalperiodic arrangement and uniform pore size distribution, which enable it to be used asphotonic crystal material for designing and regulating the micro-structure andperformance of functional material. This article prepared nanometer titanium dioxidephotonic crystal material with two-dimensional macroporous structure using colloidalcrystal template and its photoelectric properties were studied.Firstly, according to orthogonal test program, poly(methyl methacrylate)(PMMA)microemulsion ball was prepared by soap-free emulsion polymerization process, whichwas confirmed by infrared analysis. By differential thermal analysis and thermal weightloss test, the complete removing temperature of PMMA was determined to be at400℃and scanning test was conducted to determine the optimum scheme. By changing singlevariable, such as the monomer concentration and initiator concentration, the particle sizeof microemulsion ball was found to increase with increasing monomer concentration andto decrease with increasing initiator concentration. The colloidal crystal template wasassembled with PMMA microemulsion ball, which had opal structure.By sol-gel method and according to orthogonal table, nano pure titanium dioxide andlanthanum-doped titanium oxide sol precursors were prepared and the precursors werefully filled in the gaps of PMMA colloidal crystal template using a dip-coating method.Then heat treatment method was applied for removing PMMA template and fixing thecrystal style, getting two-dimensional photonic crystal with ordered macroporous structure.PMMA with different particle size were used as templates to prepare two dimensionallyordered macroporous TiO2films of different pore size, which verified the controllability ofphotonic crystal size. By comparasion of doped lanthanum-doped and pure TiO2, it wasfound that after doping lanthanum atoms, the macroporous film collapsing anddeformation phenomena were reduced and the macroporous film had better surfacemorphology. The preparared TiO2dry gel was heat-treated at different temperature and XRD,Raman and so on were used for materials characterization of microstructure morphology.Titanium dioxide powder and macroporous titanium film were conducted with BET testrespectively. It was found the specific surface area of large porous film increaed nearlyone time than that of the power. |
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