| Structural color has been widely concerned by domestic and external researchers with the advantages of high brightness, high saturation, never fading, iridescent phenomenon, excellent adhesion, scratch resistance and environmental friendliness. High saturation structural color agent has broad application prospects, and it will penetrate and replace the existing color agent in the field of display, anti-fake, security, detection, aerospace and new high technology products. It has high academic research value and application potential.It is possible to emerge a complete photonic band gap when the dielectric constant ratio reaches a certain threshold in photonic crystal. Complete photonic band gap is conducive to the regulation of visible light and the improvement of the color saturation and brightness of the structural color under natural light. In the opal structure, this threshold is about 4, but in artificially constructed inverse opal structure, threshold is much lower than 4, also due to the spherical symmetry of the face centered cubic lattice points caused by the degenerate, the opal photonic crystals is difficult to complete photonic band gap, which limits its application in structural aspects of color agent, so that the inverse opal photonic crystal structure is applied to color agent potential.This paper takes the preparation of inverse opal structure zirconia photonic crystal and analysis the morphology and color phenomenon as the goal. Polystyrene (PS) microspheres were synthesized, then PS microspheres formed colloidal crystals by self-assembly. The zirconia sol with high dielectric constant is added in the space of the PS colloidal crystals template, and the high dielectric ratio of the zirconia-air photonic crystal is formed by the calcinations to remove template.The samples were characterized by IR, XRD, SEM, UV-VIS and other testing methods, and the colour generation results were captured by digital camera. The main research work is the synthesis of PS microspheres and particle size analysis, the preparation of PS colloidal crystal template and preparation process of inverse opal zirconia photonic crystal. The specific research work includes the following parts:Submicron PS microspheres were synthesized by the soap free emulsion polymerization method, its particle size distribution and the functional group information of the IR spectrum was analyzed. The effect of addition amount of potassium hydrogen carbonate, sodium styrene sulfonate and initiator and reaction time on the particle size of PS microspheres and the surface morphology of the microspheres were discussed. Finally, the forming mechanism of polystyrene microspheres was analyzed.PS colloidal crystals were prepared by evaporation self assembly technology. The effect of microspheres concentration, self assembly temperature, the height of emulsion and assembly area on the microstructure and color generation of PS colloidal crystals was studied. The primary and secondary factors and the level of the influence of the above factors on the results were confirmed by the orthogonal experiment.Inverse opal zirconia photonic crystal was prepared by colloidal crystal template method. The effect of the precursor concentration, mass ratio of PS colloidal crystal template to precursor, dipping times, calcination temperature and holding time on the phase and microstructure of inverse opal zirconia photonic crystal was studied. The primary and secondary factors and the level of the influence of the above factors on the results were confirmed by the orthogonal experiment.The effect of the the different calcination atmospheres on the microstructure and colour generation of inverse opal zirconia photonic crystal was studied. The reason of the high saturation of the structural color of the calcined samples in the reducing atmosphere was analyzed. It is proved that reverse opal zirconia photonic crystal which is prepared by PS colloidal crystal template method has great application potential. |
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