| Since the concept of photonic crystals have been proposed, domestic and foreign scholarshave done a lot of photonic crystal research. Now photonic crystals are applied in many areas.According to the characteristics of photonic crystals, bright structural color appears if the bandgap of photonic crystals is in the range of visible light. The structure color with high brightnessand iridescent effect will never fade. Besides the conventional staining techniques have manyweaknesses, the dyeing and finishing industry has always related with high consumption of waterand heavy pollution. So if this structure color can be applied to textiles dyeing, it can not onlyavoid the environmental pollution caused by traditional textile dyeing, but also make color systemplenty because of the structure color with iridescent effect. Therefore, research about assemblyphotonic crystal on textiles has great practical significance.This subject was put forward based on this context, and relative theory research andexperiments were designed. The research mainly included the following four aspects: Firstly, thephysical phenomenon of three-dimensional photonic crystal structure was analyzed to find asimple method of calculating the band gap. Three typical three-dimensional photonic crystals weresimplified into one-dimensional photonic crystals by equal volume method. The equivalentnumerical result was calculated by transfer matrix method, and then the spectral reflectance curveswere achieved under different structure parameter, which could play an important role on structurecolor analysis. Secondly, colloidal SiO2nanoparticles were prepared by sol-gel method. Differentsize particles were obtained by varying the experimental conditions and the ratio of reactants.Then the photonic crystals were achieved by vertical self-assembly method using colloidal SiO2nanoparticles. The photonic crystals were assembled on the base materials which had beenprepared by hydrophilic treatment. Then some performances were tested to analyze theexperimental results. Based on the results, the optimal experimental conditions were determined.Finally, according to the above experiments, the photonic crystals could be found on the polyesterfabric under the best experimental conditions. So the application of photonic crystal structurecolor in textiles was basically realized. Some major conclusions were shown as the following:(1) Three-dimensional photonic crystals were simplified into one-dimensional photoniccrystals by equal volume method. The equivalent numerical result was calculated by transfermatrix method. It turned out to be effective because3-D and1-D nearly have same spectralreflectance curves. As the increase of particle size, the band gap moved to the longer wavelength.The center wavelength was on the same place when the thickness increased. The structure colorchanged along with the incidence angle. Besides, the FCC structure fitted best.(2) It was necessary to control the particle size of SiO2colloidal spheres to realize thedifferent structure colors. SiO2colloidal spheres were prepared using sol-gel method. Thediameter range of200nm-400nm was achieved by changing the ratio of ammonium hydroxide andTEOS and the PDI all lower than5%.(3) Three primary colors of the photonic crystal structure were obtained on a glass slide andthe PET substrate by vertical self-assembly. The structure was best under the situation oftemperature of45℃, concentration of1%by changing the experimental conditions. The testedspectral reflectance curve showed that the center wavelength was in the right place and was clear.The structure color changed along with the incidence angle.(4) On the base of the previous experiments, self-assembled photonic crystals were found onpolyester fabric under optimal experimental conditions. It showed that photonic crystals preferredto be self-assembled in the folds of the fabric, and filament fabric had a better effect than staplefabric. |
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