Preparation And Modifications Research Of Structural Color Coatings On Calcium Silicate Board

Structural color is the color generated by the interaction of the light and the micro-nanostructure.Because it does not contain colorants and it is not easy to fade,there is a great development prospect in many areas,in particular color display area.Typically,the researchers conducted the preparation and applications of photonic crystal structural colors on the surface of glass or fabrics,and very a few people tried to apply structural colors to other substrates such as wood,composite panels.This thesis is proposed to prepare and study structural color coatings on the calcium silicate board（CSB）.Due to the presence of interference light,the color of the structural color coatings generated from the microspheres such as polystyrene（PS）or silicon dioxide are whitish and low-contrast.At the same time,in the process of preparing structural color coatings from microspheres self-assembling,there are weak interaction force and transverse stress caused by microsphere shrinkage,which make the coatings easy to carck.In addition,structural color coatings are poorly stabilized mechanically,and are easy to lose color when they are exposed to the liquid such as water,which will seriously limit the application scenarios of structural color materials.In order to address the problems above,this work prepared structural color coatings on the CSB,and explored the methods to improve the color contrast,inhibite the generation of crack and enhance mechanical stability of structural color coatings.（1）Mixing the substance such as carbon black（CB）with the PS dispersion to prepare non-iridescent structural color coatings.When the CB was 5 wt%in the CB dispersion,the effects of two dispersants,lucramul DA345 and DA 360,and their dosage on the structural color coatings prepared were screened and discussed;the experiments showed that the addition of lucramul DA345 was of no effect,and the appropriate amount addition of DA360 could make the color of coatings prepared uniform;the optical photographs,reflection spectrum indicated that the color performance of resulting coatings were better when DA360 was 1 wt%in the CB dispersion liquid（C₂）.Then,the effects of C₂ and PS with different mass ratios of blending on the resulting coatings performance were explored,founding that the comprehensive performance of non-iridescent coatings formed by the PCD dispersion was better when C₂ and PS mass ratio of 5%.The polyethylene glycol 400（PEG400）was introduced into the system,and the effects of its blending with PCD at different volume ratios on the performance of coatings generated were studied.We found that the crack of PCDP coatings formed by the PCDP dispersion was narrower and the color performance was better when the volume ratio of PEG400 and PCD was 1/8.One component waterborne polyurethane varnish（WPU）was brushed onto the surface of the coatings formed by PCDP dispersion to enhance mechanical stability.The effects of two-component waterborne polyurethane varnish and WPU on the color rendering properties of PCDP coatings were tested.The different brushing times of WPU only affected the total thickness of the coatings that had been brushed the varnish,but basically did not affect the optical properties and pencil hardness of the coatings,and all pencil hardness were 3B.After painting,the friction resistance of the PCDP coatings was improved,and the paint layer could prevent the direct contact between water or oil with the lower coatings from making the PCDP coatings lose color.（2）PS dispersion modified by polydopamine（PS@PDA）was blended with polyacrylate dispersion（PA）to prepare non-crack PS@PDA/PA non-iridescent structural color coatings.The influence of dopamine hydrochloride（DA）dosage on the color contrast and reflective spectra of PS@PDA coatings was discussed,founding that the optimum mass ratio of DA and PS was30%.The effects of the blending of PA with PS@PDA at different volume ratios on the color performance and cracks of PS@PDA/PA coatings were studied;optical photos,reflection spectra and scanning electron microscope（SEM）showed that the non-iridescent coatings prepared had no cracks and had better color properties when the volume ratio of PA and PS@PDA was 1/7;the addition of PA not only did not affect the disorder of the microspheres arrangement,but also enhanced the interaction force between the PS@PDA microspheres.A single component waterborne acrylic varnish（WA）was brushed onto the surface of the PS@PDA/PA coatings to enhance mechanical stability of coatings.We explored the influence of the number of brushing the WA on the coatings,it was found that optical performance of the coatings was basically not affected by the number of times and all the pencil hardness were B.The friction resistance of the PS@PDA/PA coatings after being brushed the varnish was improved,and the lacquer layer could prevent liquids such as water from directly contacting with the microspheres.The prepared PS@PDA/PA structural color coatings on the CSB had a certain mechanical stability and stainability,which could be applied to the fields such as color decoration.