Preparation And Solvent Response Characteristics Of Photonic Crystal Films Based On Epoxy Resin

With the continuous improvement of photonic technology,optical functional materials have gradually become an important component of new efficient functional materials.As one of the advanced optical functional materials,responsive photonic crystal materials’surface structural color can be regulated according to the external environment stimulation,which has achieved important research significance in the fields of physical and chemical sensing,color display and biomedicine.In this paper,the solvent response characteristics of the epoxy resin photonic crystal film was studied,the structural color changes of the different solvents infiltrated films were discussed and the color recovery effects were analyzed.In addition,a kind of rewritable photonic crystal anti-counterfeiting label was prepared based on the solvent response characteristics of the films,which has certain application value.The main content of this paper is as follows:Firstly,the classification of photonic crystals and responsive photonic crystals was introduced,the research progress of solvent responsive photonic crystal materials at home and abroad was summarized,and the significance of studying the solvent response characteristics of photonic crystal materials was expounded.In addition,the characteristics of photonic band gaps,photonic crystal opal and inverse opal structures were introduced,and the chromogenic mechanism and regulatory mechanism of the responsive photonic crystals’structural color were analyzed based on the Bragg’s diffraction law.The swelling mechanism of three-dimensional porous structures was clarified.Secondly,the monodisperse silica microspheres with uniform particle size and silica opal array structure were prepared,and the epoxy resin inverse opal photonic crystal films with good flexibility and robustness were prepared by filling with epoxy resin materials and etched the microspheres.According to the analysis of chromaticity diagram and reflectance spectrum,the films exhibit outstanding optical performance due to its high saturation and brightness.Then,the structural color changes of the epoxy resin inverse opal photonic crystal films were studied after being infiltrated by dimethyl sulfoxide（DMSO）,ethanol（C₂H₅OH）,and acetone（C₃H₆O）three solvents.The mechanism of the solvent response discoloration and the films’microstructure changes were analyzed,and the results showed that DMSO had the best structural color recovery effect compared with the other two solvents.Finally,the structural color recovery properties of the epoxy resin photonic crystal film infiltrated by DMSO was further investigated.In addition,a kind of repeatable photonic crystal anti-counterfeiting label was prepared based on the film’s different structural color responses of the three solvents,which has certain application prospects.