基于SiO_(2)微胶囊的多色谱温敏变色棉织物制备及其性能

Preparation and properties of multichromatic thermochromic cotton fabrics using SiO_(2) microcapsules

为解决温敏变色织物颜色变化范围较窄的问题,以正硅酸四乙酯(TEOS)为硅源,荧烷-二苯砜-脂肪醇为芯材,采用溶胶-凝胶法制备多种颜色的SiO_(2)壳温敏变色微胶囊,拼混后上染棉织物,得到随温度变化可产生连续色谱变色的棉织物。对微胶囊的微观形貌、热稳定性、变色时间、变色温度、颜色变化等性能进行研究。结果表明:微胶囊大小分散均匀,热稳定性良好,热降解温度高于200℃,加热-冷却循环50次后,K/S值变化仅为0.01,且棉织物热响应颜色变化仍明显;不同变色温度的红、黄、蓝3种微胶囊复配整理到棉织物上后,得到的多色谱温敏变色棉织物可实现阶梯变色,变色性能良好且变色效果明显。

Objective Low-temperature reversible thermochromic textiles are not only fashionable and attractive,but also applicable for temperature indication and anti-counterfeiting,showing the potential economic and social benefits of thermochromic textiles.However,the majority of thermochromic textiles are currently available for single-color change,e.g.from colored to colorless or colored to colored.In order to broaden the color change range of thermochromic textiles and achieve multichromatic thermochromic color change,SiO_(2) shell thermochromic microcapsules with various colors were prepared and finished on cotton fabrics to obtain multichromatic thermochromic cotton fabrics.Method In this research,tetraethyl orthosilicate was used as the silica source and fluorane-diphenyl sulfonealiphatic alcohol as the core material to prepare multi-color SiO_(2) shell thermochromic microcapsules by sol-gel method.After blending and dyeing cotton fabrics,cotton fabrics with continuous chromatographic color change with temperature change were obtained.Scanning electron microscopy was adopted to observe the morphological features of microcapsules.The chemical structure of the microcapsules was characterized employing infrared spectroscopy.The thermal stability of the microcapsules was tested with a thermogravimetric analyzer.The color change of thermochromic cotton fabrics was characterized by colorimeter.Results The SiO_(2) shell thermochromic microcapsules prepared by sol-gel method had uniform size dispersion and smooth surface(Fig.2).The average particle size was about 0.9μm(Fig.3).The microcapsules demonstrated excellent thermal stability,where thermal degradation temperature was shown up to 200℃(Fig.5),much higher than daily service temperature.The microcapsules are finished onto the surface of the cotton fabric using the dip-roll method.After 50 heating-cooling cycles,the change of K/S value is only 0.01,showing the thermochromic microcapsules possess excellent thermal cycling durability(Fig.7).The color change of cotton fabric in response to heat was still obvious.The excellent thermal stability and cycling durability could be attribute to fluorene,the developing agent,with sensitive color development,good stability and abundant color.The singlecolor change of thermochromic cotton fabric was obvious(Fig.9),and the reflectance demonstrated an overall upward shift with temperature increasing,with the cotton fabric changing from colored to colorless(Fig.8).It was possible to obtain thermochromic textiles with different color change temperatures by changing the solvent phase change point(Tab.1).After different color-change thermochromic microcapsules of red,yellow and blue compound were coated onto the cotton fabric,the obtained multichromatic temperature sensitive color change cotton fabric was able to achieve step color change(Fig.10).The color change performance of polychromatic color-change cotton was reliable and color change effect was obviously.Conclusion Thermochromic microcapsules with SiO_(2) shell have been successfully prepared by sol-gel method on fluorane-diphenyl sulfone-aliphatic alcohol core material.The prepared thermochromic microcapsules indicate superb microscopic morphology and uniform size dispersion.The prepared thermochromic fabric has good thermal stability and thermal cycling durability and can meet the requirements of daily use,which broadens the temperature variation range of thermochromic cotton textiles.The prepared multichromatic thermochromic textiles can respond to temperature from 20 to 55℃.Since the prepared thermochromic cotton fabric can achieve gradient color change,it can be utilized to indicate the temperature.It is expected that the multichromatic thermochromic cotton fabrics would be employed in the fields of food safety for temperature indication to indicate suitable storage temperature.It also can be used on anti-counterfeiting and building for environmental temperature indication.However,further increase of the temperature sensing accuracy of thermochromic materials still need further attention.Compared to inorganic thermochromic materials,organic thermochromic materials is non-toxic,and excellent in temperature sensitivity and color density.However,the color change performance of organic reversible thermochromic materials in the high temperature region is still a major problem,which is a hot spot in future research.