Covalently anchored photonic crystal skins for robust structural colors on textiles

Photonic crystals (PCs) offer an environmentally sustainable alternative to conventional textile dyes, exhibiting exceptional colorfastness properties. Nevertheless, the development of durable, wash-resistant PCs on porous colored basalt fibers (BFs) remains technologically challenging. In this work, we report an advanced fabrication strategy employing ZnS@PDA core-shell nanoparticles via stepwise spray coating, which forms covalent polyurethane linkages between the fabrics and PC-coatings through reactions of isophorone diisocyanate (IPDI) with polydopamine. Precise modulation of fabric hydrophilicity enables the formation of a distinctive single-fiber-encapsulated architecture that preserves textile breathability through its non-film morphological characteristics. Comprehensive laundering evaluations demonstrate outstanding colorfastness performance, with ΔE values consistently maintained below 2.0 across diverse media including aqueous solutions, detergents, and acidic/alkaline environments. The developed methodology establishes a universal platform for fabricating robust structural-colored technical textiles with multifunctional capabilities, thereby facilitating their implementation in next-generation smart wearable systems and specialized fabric applications.