Biomimetic Hierarchical Fabric with Thermochromic-Superhydrophobic Dual-Functionality for Adaptive Radiative Cooling and Self-Cleaning

Passive radiative cooling textiles confront the trilemma of balancing chromatic aesthetics, self-adaptive radiative cooling, and environmental durability. Herein, inspired by hierarchical structures of taro-leaf, biomimetic thermochromic radiative cooling fabric (TRCF) is developed through an innovative evaporation/vapor-induced phase separation (E-VIPS) technique. This phase separation strategy integrates poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), polyurethane (PU), and thermochromic microcapsules (TCMC) into multi-scale porous networks featuring rough surface topography and optical structure. The resultant fabric demonstrates temperature-modulated visible reflectance enhancement (ΔR = 6.56–14.67%). Notably, the prepared yellow, red, and blue TRCF exhibit high solar reflectance of 95.5%, 90.9%, and 89.9%, with strong infrared emissivity of 91.4%, 90.6%, and 92.4%. Actual outdoor cooling tests show that the yellow, red, and blue TRCF achieve sub-ambient cooling performance with temperature reductions of approximately 7.8 °C, 5.5 °C, and 2.2 °C, respectively, relative to the substrate. In addition, the biomimetic microstructure's rough structure endows the material with exceptional superhydrophobicity for durability, while retaining self-cleaning functionality after 30 cycles of abrasion. This work pioneers a pathway toward adaptive, multifunctional textiles for sustainable outdoor thermal management.