Biobased Fibrous Films Enabling Synergistic Thermal Conduction and Radiative Cooling for Personal Thermal Management

Personal thermal management materials are increasingly in demand under intensifying outdoor heat exposure and global warming. However, simultaneously achieving efficient radiative cooling, rapid thermal conduction, mechanical flexibility, and sustainability within a simple wearable architecture remains challenging. Here, biobased PLA/Al2O3 composite fibrous films were fabricated by electrospinning for synergistic thermal conduction and radiative cooling. By regulating the Al2O3 loading and film thickness, optical scattering, thermal emissivity, and thermal conduction were coordinately optimized. The optimized PFA-30 film with a thickness of 400 μm exhibited 95.7% solar reflectance, 95.47% average emissivity within 8–13 μm, and a thermal conductivity of 0.46 W·m–1·K–1. In outdoor tests, PFA-30 delivered a maximum daytime temperature reduction of 9.8 °C and an average daytime reduction of 3.8 °C relative to ambient temperature. This work establishes a versatile platform for sustainable wearable thermal management systems, advanced smart textiles, and next-generation energy efficient personal cooling technologies.