Preparation and Performance Characterization of Photothermal‐Luminescent Fabric Based on <scp>PDA</scp> Modification and <scp> SrAl ₂ O ₄ </scp> Composite Coating

ABSTRACT The integration of photothermal conversion and long‐afterglow luminescence into a single textile platform presents a promising strategy for developing intelligent outdoor apparel, but depending on the properties of different functional materials, the preparation of multifunctional coatings with luminescent, and thermal effects remains challenging. Herein, a hierarchical functionalization approach to fabricate a photothermal‐luminescent fabric was developed. A polydopamine (PDA) layer was first deposited onto nylon taffeta via in situ polymerization to serve as an efficient photothermal conversion layer and a versatile adhesive interface. Subsequently, a waterborne polyurethane (WPU) coating containing SiO 2 /KH570 co‐encapsulated SAO phosphors was applied to impart long‐afterglow luminescence. The resulting composite fabric (SAO‐PDA‐PU) exhibits a remarkable equilibrium temperature of 60.3°C under 1000 W/m 2 illumination, significantly outperforming the original fabric (43.3°C). The SiO 2 encapsulation layer effectively shields SAO from moisture, ensuring excellent and stable green afterglow emission even in humid environments. Furthermore, the fabric demonstrates superior practicality for outdoor use, possessing excellent hydrophobicity (with a water contact angle ~114°), high hydrostatic pressure resistance of ~5 kPa, and efficient self‐cleaning capability. This work provides a viable and efficient pathway for designing next‐generation multifunctional textiles for applications in personal thermal management and nighttime safety protection.