| Structural color materials have wide application prospects in the fields of display and sensing,anti-counterfeiting and identification,decoration and coatings,due to their special optical and color properties.To date,the most important artificial approach to construct structural color materials is three-dimensional colloidal photonic crystals,which are self-assembled from monodispersed colloidal microspheres.However,the existing polymer photonic crystal structures still have some problems to be solved.For example,The species of available monodispersed polymer microspheres that are able to build photonic crystals are limited and their refractive index are low.The existing polymer structural colors possess low color saturation and poor stability of heat resistance.In this thesis,three kinds of new polymer colloidal microspheres were designed and synthesized,based on the polycondensation and crosslinking reaction.By increasing the refractive index and visible light absorption capacity of the polymer microspheres,the structural color visibility and saturation are improved.The heat resistance of the structural color material is improved by improving the thermostability of the polymer microspheres.Finally,polymer photonic crystal structural color materials with high color saturation and high thermal stability are obtained.Polythiourethane resin with refractive index of 1.673 is designed and synthesized through the polycondensation reaction between 4,4'-thiobisbenzenethiol and toluene-2,4-diisocyanate,based on the higher molar refractive index effect of sulfur and benzene ring.The polythiourethane resin is processed into polymer microspheres with narrow size distribution and controllable particle size from 157 nm-287 nm via nanoprecipitation method.Three photonic crystal structures with red,orange and green structural colors are obtained from the self-assembled polythiourethane microspheres with particle sizes of 267 nm?243 nm and 208 nm.This study enriched the variety of high refractive index resin microspheres for polymer structural color materials.By introducing multi-sulfur bonds into the polysulfide macromolecular chain,the polymer microspheres are endowed with good light absorption properties and high refractive index.Thus,the interference light is effectively eliminated and the structural color saturation is enhanced.Monodispersed polysulfide microspheres are synthesized in a ethanol/water system,in the presnece of F-127,based on the polycondensation and crosslinking reaction of sodium disulfide and 1,2,3-trichloropropane.The particle size can be tuned in the range of 70 nm-387 nm.Moreover,the polysulfide microspheres have high refractive index up to 1.858 and strong visible light absorption propery.Red,orange and green structural color films with high color saturation and wide viewing angle are constructed from the assembling of polysulfide microspheres with particle size of 260 nm?226 nm and 211 nm.This study solved the problem of poor color visibility of the existing polymer photonic crystals.The thermal stability of polymer microspheres can be improved by phenol-formaldehyde condensation and crosslinking reaction of polyphenol and aldehydes.Monodispersed sulfur-containing thiophenol formaldehyde(STPF)microspheres are synthesized using polyfunctional 4,4'-thiodiphenol and formaldehyde as monomers and F-127 as surfactant,through a hydrothermal process.The particle size can be tuned in the range of 142 nm-337 nm.The STPF microspheres are endowed with good thermostability due to the existence of crosslinking network structure.Photonic crystal arrays with bright structure color of red,orange and green are constructed from the STPF microspheres with average particle size of 278 nm,265 nm and 231 nm.The three STPF structural color films have robust heat resistance and thermal cycling stability,and only undergo 10 nm,8 nm and 8 nm of blue peak shift under 250 ? high temperature.This study solved the problem of poor thermostability of the existing polymer photonic crystals. |
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