Patterning Of Photonic Crystals With Structural Colors On The Textile Substrates And Their Application In Anti-counterfeiting Printing

The structural colors is different from the pigment colors.It produces visual effects through the selective reflection of light by the physical structure,and has the advantages of high brightness,non-fading and iridescent.At present,the color development of photonic crystals structure has attracted more and more attention from researchers.In this project,the screen printing method was used to construct P(St-MAA)photonic crystals on textile substrates,and the filling method was used to improve the stability of P(St-MAA)photonic crystals;also through the design of the combination of Si O₂ photonic crystals and P(St-MAA)photonic crystals,the anti-counterfeiting printed matters was prepared by inkjet printing technology,and its preliminary application was carried out.This research would provide certain strategic support for the construction of highly stable photonic crystals color-generating structures on textile substrates and the functional application of photonic crystals.The research work was:(1)First synthesized monodisperse P(St-MAA)colloidal microspheres,and then used it as the structural elements to construct patterned photonic crystals on polyester substrates by screen printing method,and explored the effects of self-assembly conditions(colloidal microsphere concentration,self-assembly temperature and drying time)on the structural colors effects of photonic crystals.(2)The structural colors of P(St-MAA)photonic crystals prepared based on the screen printing method was easy to reduce when subjected to external forces such as washing,folding and friction,the Si O₂ sol is selected as a filler for P(St-MAA)photonic crystals.The crystals is filled to enhance the stability,thereby avoiding the problem of structural colors reduction.Explored the effects of filling conditions(sol concentration,filling time and drying temperature)on the structures and colors effects of Si O₂-P(St-MAA)composite photonic crystals,evaluated the stability of composite photonic crystals,and establishd a filling method to improve the stability of photonic crystals Sexual model.(3)Based on the Bragg diffraction equation,designed an anti-counterfeiting printed matters composed of Si O₂ colloidal microspheres and P(St-MAA)colloidal microspheres,and realized its initial application.The influence of synthesis factors on the particle size and monodispersity of Si O₂ colloidal microspheres was explored,the self-assembly conditions for obtaining regular Si O₂ photonic crystals were optimized,and the influence of different solvents on the imaging effects of the prepared anti-counterfeiting printed matters was explored.The research results showed that:(1)When the colorant concentration was 65%,the drying temperature was 30?,and the drying time was 4 min,the screen printing method can construct a P(St-MAA)photonic crystals with a three-dimensional face-centered cubic structure on a polyester substrates.The resulting patterned photonic crystals have bright colors and strong iridescent effects,and the structural hue would change with the decrease of the particle size of the P(St-MAA)colloidal microspheres,following the law of blue shift.(2)When the Si O₂ sol concentration was 30%,the filling treatment was 5 min,and the drying temperature was 60?,Si O₂-P(St-MAA)composite photonic crystals with brighter structural colors and obvious iridescent effects can be prepared;After the designed water washing,folding and friction tests,the structural colors of the Si O₂-P(St-MAA)composite photonic crystals on the substrates did not significantly decrease,indicating that its stability was good;The Si O₂ microspheres firmly fill the gaps between adjacent P(St-MAA)colloidal microspheres and strengthen the connection between the P(St-MAA)colloidal microspheres,thereby significantly improving the stability of the composite photonic crystals.(3)When the dosages of ammonia,water and ethyl orthosilicate were 0.04?0.07 g/m L,0.07?0.1 g/m L and 0.1 g/m L respectively,monodisperse Si O₂ colloidal microspheres can be prepared;when the concentration of Si O₂ colloidal microspheres was 3%and the self-assembly temperature was 60?,Si O₂ photonic crystals with excellent structural colors effects can be prepared;anti-counterfeiting printed matters was in air-water,air-ethanol and air-carbon tetrachloride environments When applied,the anti-counterfeiting effects can be exerted,but the anti-counterfeiting effects was not good in the environments of air-ethyl acetate and air-N,N-dimethylformamide.