High Performance Transmission-Type Daytime Radiative Cooling Film with a Simple and Scalable Method.

Transmission-type radiative cooling textiles represent a vital strategy for personal thermal management. However, traditional preparation methods based on heat-induced phase separation face significant challenges regarding cost, environmental impact, and optical performance. Herein, a novel preparation method is devloped by blending mid-IR transparent solid styrene ethylene butylene styrene (SEBS) with solid polyethylene (PE), enabling the creation of pores through dissolving SEBS. Consequently, large-scale production of transmission-type radiative cooling films at the meter scale are achieved, exhibiting 95% solar reflectivity and 80% mid-IR transmittance. Moreover, this method reduces costs by 68% and diminishes CO2 emissions by 92%. Under sunny and cloudy conditions (solar irradiance ≈730 and 280 Wm- 2, respectively), the film-covered simulated skin demonstrates sub-ambient cooling effects of ≈4 and 3 °C. Given its exceptional passive cooling capabilities, low-cost, and scalability, this film holds great potential for industrial and personal applications.