基于PEGPEA-高灵敏仿生光子晶体薄膜制备及应用

Preparation and application of highly sensitive biomimetic photonic crystal thin films based on PEGPEA

摘要:

采用乳液聚合结合改良的Sto ?ber方法制备单分散聚苯乙烯（PS）@SiO2核壳纳米微球，然后将PS@SiO2颗粒分散在聚(乙二醇)苯基醚丙烯酸酯（PEGPEA）的前体中，形成非密集颗粒阵列后快速光聚合捕获规则阵列，制备一种机械变色的光子晶体薄膜。采用SEM、光纤光谱仪对光子晶体薄膜的结构、光学性能、力致变色性能进行了表征和测试，考察了PS@SiO2颗粒的体积分数和粒径对光子晶体结构色的影响，并对光子晶体薄膜的力致变色机理进行推测。结果表明，紫外光照的热处理，改变了PS@SiO2颗粒的微观秩序，使之形成蛋白石光子晶体结构；光子晶体结构色随着PS@SiO2颗粒体积分数的增加或粒径的减小由红色向蓝色渐变；光子晶体薄膜具有的结构色反射率>60%、拉伸应变70%、灵敏度2.16 nm/%、响应速度1.9 nm/ms，反射波长调谐范围（Δλ）＝152 nm；在100次拉伸/释放循环实验和25 ℃下维持拉伸状态3 d恢复后，光子晶体薄膜结构色保持不变。PS@SiO2纳米微球独特的核壳结构具有弹性和可拉伸性，PS提高了纳米微球与弹性体基质的折射率差，可以提高反射率，会使光子晶体薄膜结构色更明亮。在拉伸过程中，胶体颗粒通过跟随细长晶格的位置可以保持不变。粒子的可忽略不计的重排使得光子晶体薄膜在应变下的色移完全可逆，因此变形是弹性的，没有残余应变。

Abstract:

Monodisperse polystyrene(PS)@SiO2 core-shell nanometer microspheres are prepared by emulsion polymerization combined with an improved Sto ?ber method, PS@SiO2 particles are then dispersed in the precursor of poly(ethylene glycol) phenyl ether acrylate (PEGPEA), forming a fast photopolymerization capture regular array after forming a non-dense particle array, and preparing a mechanically discolored photonic crystal film. The structure, optical properties and photochromic properties of photonic crystal thin films were characterized and tested by SEM and optical fiber spectrometer. The influence of the volume fraction and particle size of PS@SiO2 particles on the structure color of photonic crystal thin films was investigated, and the mechanism of photochromic effect of PS@SiO2 particles on the structure color of photonic crystal thin films was predicted. The results show that the heat treatment by ultraviolet light changes the microstructure order of PS@SiO2 particles and causes them to form the structure of opal photonic crystal. The structure color of photonic crystals gradually changes from red to blue with the increase of PS@SiO2 particle volume fraction or the decrease of particle diameter. Photonic crystal thin film has structural color reflectivity> 60%, tensile strain 70%, sensitivity 2.16 nm/%, response speed 1.9 nm/ms, reflection wavelength tuning range(Δλ)=152 nm. After 100 stretch/release cycles and 3 d recovery at 25 ℃, the structure color of the photonic crystal film remained unchanged. The unique core-shell structure of PS@SiO2 nano-microspheres has elasticity and stretchability. PS improves the refractive index difference between the nano-microspheres and the elastomer matrix, can improve the reflectivity, and can make the structure color of the photonic crystal thin film brighter. During the stretching process, the colloidal particles can remain constant by following the position of the elongated lattice. The negligible rearrangement of the particles makes the color shift of the photonic crystal film completely reversible under strain, so the deformation is elastic and there is no residual strain.