Thermochromic wool fabric prepared via grafting thiol-modified thermochromic microcapsule

In this study, a reversible thermochromic wool fabric with excellent color fastness was prepared by reacting thiol-modified thermochromic microcapsules with the fabric. Treatment with tris (2-carboxyethyl) phosphine hydrochloride (TCEP) resulted in the appearance of a large number of thiol groups on the surface of the wool fabric, enabling the formation of disulfide bonds with thiol-containing microcapsules. The effective introduction of thiol groups onto the microcapsule surface and their incorporation onto the wool fibers was confirmed by FTIR analysis. DSC measurements revealed that the color transition temperature of the thiol-modified microcapsules was 48.98 °C. The photos of the color-changing process of the microcapsule solution and the variations in color parameters during the heating-cooling cycles demonstrated the excellent color-changing characteristics of the microcapsules. The covalent bonding between the thiol-modified microcapsules and the wool fabric contributed to its high color fastness. When the dosage of 3-mercaptopropyltriethoxysilane was 10% of tetraethyl orthosilicate, the fading fastness of the thermochromic wool fabric reached grade 3, while the staining fastness reached grade 5. The wet rubbing and dry rubbing fastness were at grade 3 and grade 4, respectively. Even after undergoing 30 cycles of heating and cooling experiments, the K/S value of the thermochromic wool fabric remained stable. Graphical Abstract