Preparation And Application Research Of Photonic Crystal Hydrogel Based On Polystyrene Template

Inverse opal photonic crystals hydrogel materials have been widely used in sensor, the detection of biological molecules, optical switch and optical catalysis,owing to combine the unique band structure of photonic crystal and the intelligent of hydrogel. In this paper, on the basis of the preparation of well monodispersed, controllable particle size of polystyrene(PS) microspheres, further assembled into PS colloidal crystals, respectively, the PAM and PAM/PMAA inverse opal photonic crystal hydrogel membrane was prepared by using acrylamide(AM), methyl acrylic acid(MAA) as the monomer, and then their preparation method and the response was explored, the main conclusions are as follows,(1) Both PS microspheres and modified PS microspheres were prepared by using soap-free emulsion polymerization method. The monodispersity and particle size of the PS microspheres could be controlled by the influences of the dosage of monomer, initiator and solvent.(2) The Face centered cubic(FCC) structure colloidal crystals were prepared by vertical deposition method with modified PS microspheres. PS colloidal crystals with a complete and colorful three dimensional ordered structure could be assembled at 1% solid content of emulsion under 60℃.(3) The "sandwich" method was used to prepare the PAM inverse opal photonic crystal hydrogel films with different degrees of crosslinking using PS colloidal crystals as templates. SEM microscopy and optical fiber spectrometer indicated that the film had a regular three-dimensional ordered porous inverse opal structure and with increasing of the size of the template size, maximum diffraction wavelength of PAM inverse opal photonic crystal hydrogel showed a red shift phenomenon.PAM inverse opal photonic crystal hydrogel films showed a response to p H and solvent. When the diameter and crosslinking degree of the film is 226 nm and 2%, along with the increase of p H, the maximum diffraction wavelength showed red shift of the film, when p H=8.49, the wavelength came to the maximum(λmax=121nm). Further increase of p H, the maximum diffraction wavelength had a blue shift phenomenon. The films showed blue shift with increasing the amount of alcohol especially ethanol.(4) The PAM/PMAA inverse opal photonic crystal hydrogel films were prepared by "sandwich" method and the influences of different degree of crosslinking, different MAA content on the films were investigated. It was found that the PAM/PMAA inverse opal photonic crystal hydrogel films had obvious response to p H and solvent, and with a greater response to methanol and ethanol which were compared to the PAM inverse opal films.(5) The co-deposition method was used to prepare PAM inverse opal photonic crystal hydrogel films with the mixture of PS microspheres and AM precursor solution, which combining the preparation of the colloidal crystal template and liquid in?ltration into the preassembled porous structure in one-step. It was conducive to prepare a more three-dimensional ordered porous inverse opal structure and the films surface cover could be avoided. It was indicated that the inverse opal structure photonic crystal with 3m L of precursor liquid showed more perfect three dimensional ordered structure under 50℃.