三联噻吩衍生物功能化SiO2反蛋白石光子晶体荧光薄膜的制备及应用

将单分散聚苯乙烯微球乳液与SiO₂溶胶均匀混合后, 于恒温恒湿条件下, 竖直沉积共组装制备得到蛋白石型光子晶体薄膜, 然后利用牺牲模板法制得SiO₂反蛋白石光子晶体薄膜. 该薄膜依次经过浓硫酸与过氧化氢混合液、 3-氨丙基三甲氧基硅烷的甲苯溶液、 三联噻吩的三氯甲烷溶液和硼氢化钠的甲醇溶液处理后, 得到三联噻吩衍生物功能化的SiO₂反蛋白石光子晶体. 结果表明, 制备得到的光子晶体薄膜在512 nm处有荧光发射, 经紫外辐射后荧光猝灭, 甲醛气氛下458 nm处又出现新的荧光发射峰. 在甲醛气氛下20 s即可观察到荧光发射, 空气氛围下可恢复, 10次循环仍可保持强的荧光发射, 可重复性良好. 以无反蛋白石光子晶体结构的三联噻吩衍生物的平滑膜与甲醛作用的体系作为参比, 以330和400 nm聚苯乙烯微球为模板制备的三联噻吩功能化反蛋白石光子晶体, 在甲醛气氛中发射的荧光分别增强47.5和78.6倍. 这是由于光子晶体光子禁带的红带边和蓝带边与荧光发射波长相重叠, 产生了慢光子效应, 极大地增强了发射的荧光强度.

Preparation and Application of Triplethiophene Derivative Functionalized SiO2 Inverse Opal Photonic Crystal Fluorescent Films

The as-prepared SiO₂ inverse opal photonic crystal（IOPC） was sequentially treated with the mixture of concentrated sulfuric acid and hydrogen peroxide， toluene solution of 3-aminopropyl trimethoxy silane， chloroform solution of trithiophene derivative（denoted as 3T） and methanol solution of sodium borohydride to obtain a 3T-functionalized SiO₂ IOPC. The resulting photonic crystal（PC） film emits fluorescence at 512 nm and the fluorescence quenches at UV radiation. A new fluorescence emission can be observed at 458 nm when the IOPC film is subsequently exposed to formaldehyde atmosphere. The fluorescence can be observed in 20 s in formaldehyde vapor and will quench in air atmosphere. The IOPC film can maintain strong fluorescence after ten cycles when alternately exposed to formaldehyde vapor and air， showing a good repeatability. Taking trithiophene derivative smooth film without IOPC structure as a control sample， the fluorescence of 3T-functionalized IOPC films fabricated from polystyrene microspheres templates of 300 and 400 nm was enhanced by 47.5 and 78.6 times in formaldehyde vapor， respectively. This is because the fluorescence emission wavelength is overlapped with the red and blue band-edge of the PC’s photonic stopband， resulting in the slow photon effect and enhancing the fluorescence intensity remarkably. The fabricated 3T-funtionalized SiO₂ IOPC in this work provides a novel strategy for the preparation of photonic crystal fluore-scent film sensors.