Mie Scattering-Enhanced Fluorinated Polyether Ether Ketone Nanofibrous Films for Efficient Radiative Heat Dissipation

This study develops a high-performance radiative cooling (RC) composite film based on electrospinning fluorinated polyether ether ketone, incorporating titanium dioxide (TiO2) and hexagonal boron nitride (h-BN) as functional fillers to achieve exceptional spectral selectivity with a solar reflectance of 96.51% and mid-infrared emissivity of 95.12%. The three-dimensional porous fibrous network endows the film with outstanding RC performance, achieving a maximum sub-ambient temperature reduction of 14.63 °C under direct sunlight and a temperature reduction of 8.66 °C relative to the bare vehicle model in small-scale outdoor vehicle tests, thereby validating the significant cooling advantage of the electrospinning film under real-world service conditions. The synergistic effect of the porous fibrous network and intrinsically low-surface-energy matrix imparts self-cleaning functionality to the film (water contact angle of 151.46° and sliding angle of approximately 5°), while solar reflectance degradation remains below 3% after the aging test, demonstrating long-term outdoor service reliability. EnergyPlus building energy simulations confirmed that the film achieved annual energy savings exceeding 6% in tropical arid cities, with positive net energy savings across the vast majority of global climate regions. This film provides a comprehensive design paradigm for high-performance multifunctional RC materials, with broad application prospects for low-carbon building energy conservation and outdoor thermal management.