A Bioinspired Photon‐Gated Phase‐Change Textile for Two‐Stage Heat‐Flux Regulation of Building Envelopes

ABSTRACT Passive cooling textiles for buildings must do more than reflect sunlight; they must also buffer transient heat under real outdoor conditions. Here we report a continuous coaxial wet‐spinning strategy for fabricating a microencapsulated phase‐change material (mPCM)‐integrated radiative‐cooling meta‐fabric (MFRP), consisting of a thermoplastic polyurethane (TPU)/hexagonal boron nitride (h‐BN)/barium sulfate (BaSO 4 ) photon‐regulating sheath and a TPU/mPCM latent‐heat core. The spatially separated architecture integrates broadband solar reflection, atmospheric‐window emission, and phase‐change thermal buffering within one fiber platform. The optimized meta‐fabric shows high solar reflectance (95.44%), strong atmospheric‐window emissivity (96.21%), and a melting enthalpy of 102.28 J/g. In a representative sunny‐day test, MFRP reduced the chamber temperature by up to 10.36°C relative to the blank control; three‐day cement‐panel measurements further yielded an average peak‐temperature reduction of 7.51°C ± 2.17°C relative to bare cement. Energy‐balance analysis and climate‐scale modelling further indicate promising cooling‐energy and carbon‐reduction potential in hot and cooling‐dominated regions. These results establish wet‐spun radiative cooling/phase‐change material meta‐fabrics as continuously processable exterior textile candidates for passive building thermal management.