Highly fatigue-resistant photochromism of wool surface printed with spiropyran/chitosan microcapsules

A smart photochromic chitosan microcapsule, which was prepared by emulsification-chemical crosslinking technique utilizing spiropyran compound EDN as core material and chitosan as shell material, was printed onto wool fabric through screen-printing process. The photochromic microcapsule was adhered onto the surface of wool fabric via the adhering and crosslinking system. The microcapsule exhibited an approximately spherical shape with a size of 3 similar to 4 mu m, and could withstand high temperature around 300 degrees C. The time of the color development and fading stability of the microcapsule dispersions were 4.25 s and 26.00 s, respectively, which were only 0.25 s and 4.00 s slower than that of the photochromic spiropyran dispersion, respectively. When the amount of microcapsule was 8wt% and the amount of adhesive DH-BS was 15wt%, the printed fabric had remarkable photochromic responsibility and good colorfastness. The printed wool fabric presented high fatigue resistance, and the K/S, L*, a* values of the printed wool fabric were nearly no change during 25 consecutive UV/Vis irradiation cycles.

Automated summary

The smart photochromic chitosan microcapsule printed on wool fabric showed good resistance to high temperatures and significant photochromic response, with excellent colorfastness. Additionally, it exhibited a nearly spherical shape with a size of 3 to 4 micrometers and stable color development and fading properties.