Preparation and Properties of Photothermal Fibers by Melt Spinning and Their Durability

ABSTRACT Cesium tungsten bronze (Cs x WO 3 ), renowned for its high visible‐light transmittance and strong near‐infrared absorption, can be integrated with fibers to produce high‐performance photothermal materials. In this study, Cs x WO 3 was blended with polyamide 6/66 (PA6/66), and PA6/66‐Cs x WO 3 fibers were produced via melt spinning. Woven fabrics constructed from these fibers exhibit excellent photothermal properties. Surprisingly, after washing or rubbing has a negligible impact on the Cs x WO 3 content within the woven fabrics. Under 1000 W/m 2 xenon irradiation for 6 min, the maximum woven fabrics temperatures can reach up to 62.8°C, 70.1°C, and 71.1°C for pristine, washed, and rubbed samples, respectively. Notably, near‐infrared absorption and photothermal conversion performance were significantly enhanced after washing and rubbing; this is, the observed temperature increase effect of more than 11% demonstrates that it improves photothermal efficiency after washing and rubbing. Clothing made from PA6/66‐Cs x WO 3 fibers exhibit superior photothermal performance compared with ordinary clothing. These findings highlight the potential of PA6/66‐Cs x WO 3 woven fabric, with their high photothermal conversion efficiency and robust durability, for applications in cold environments, such as winter thermal apparel.