Preparation And Application Of Multichromatographic Thermochromic Microcapsules

Generally,the color change of thermochromic materials mainly changes between the same hue or different color depths.Too monotonous color changes limit its further development.In order to expand the color spectrum of thermochromic materials,this topic will microencapsulate thermochromic materials as basic materials for follow-up research.Three types of microcapsules have been prepared in this subject,namely:thermally induced blue to yellow colorless microcapsules,thermally induced blue to yellow microcapsules,monochromatic microcapsules,and thermally induced blue to yellow microcapsules as representative the preparation conditions of the microcapsules(emulsification time,emulsification power,core-wall ratio,dye amount)were optimized,and the microcapsules were characterized by XRD,XPS,FTIR,TG and other methods.The thermally induced blue colorless microcapsules and the thermally induced blue colorless microcapsules are mixed with monochromatic microcapsules to obtain a variety of multi-chromatographic thermally sensitive colorless microcapsules.The microcapsules obtained by color matching are arranged on the textile by a coating process to prepare a multi-chromatographic thermochromic coating fabric.Finally,the relationship between color parameters(?E,?L,?a,?b)and time(t)in the discoloration process of discoloration textiles with different environmental temperatures and coating amounts is analyzed.The results of this study are mainly summarized in the following aspects:(1)Thermally induced blue-to-yellow microcapsules,thermally-induced blue-to-yellow microcapsules,and monochromatic microcapsules all present a regular spherical structure with an average particle size distribution of about 4?m;preparation of thermally induced blue to yellow microcapsule the optimal process is:core-wall ratio 3.5:1,emulsification time 1 min,dye dosage 0.14 g;emulsification power 85%.(2)Through XRD,XPS,FTIR tests,the discoloration mechanism of the thermochromic system is proved,and there is a tautomerism phenomenon in the discoloration system;it also proves that the discoloration system is successfully coated by the wall material to form microcapsules;TG The test proves that the microcapsule has good thermal stability,and the starting point of thermal weight loss is about 140?;the color parameter test proves that the microcapsule has excellent discoloration performance,and the color difference?E is above 50.(3)Under different color matching schemes,thermochromic coated fabrics with different color changing effects are obtained.The reflectance and K/S value curves are significantly different.The total color difference?E before and after the color change is above 20,which is significantly expanded the color chromatogram of thermochromic coated fabrics.(4)Thermochromic coating with different coating amount(58 g/m~2,142 g/m~2,275 g/m~2),different ambient temperature(25?,30?,35?,40?,45?)The relationship between the color parameters(?E,?L,?a,?b)and time(t)in the process of layer fabric discoloration all accords with the quasi-first order kinetic equation,and the degree of fit R~2 is basically above 0.9.