Eco‐Friendly Packaging Film Utilizing Radiative Cooling for Energy‐Free Food Preservation Under Solar Radiation

ABSTRACT Intense solar radiation and the high temperatures it generates tend to result in significant food loss during transportation, storage, and retailing. Although low‐temperature preservation is a key strategy for mitigating these losses, its application is constrained by high energy consumption and carbon emissions. Here, we report a bilayer polymeric packaging film based on energy‐free radiative cooling, which consists of biodegradable Poly(ε‐caprolactone) (PCL) and is fabricated through a continuous preparation process integrating solution coating with electrostatic spinning. The fabricated film demonstrates an average solar reflectance () of ~96.3% and an average thermal emittance () of ~94.0%, thereby achieving excellent subambient cooling performance and significantly mitigating temperature increases within the packaging environment under intense solar irradiation. Furthermore, the film exhibits excellent water vapor barrier performance, as high‐moisture fruits packaged in it produced little visible shrinkage after 5 days of outdoor storage. Additionally, the manufacturing process enables the preparation of large‐scale products. Such scalable, biodegradable and flexible packaging film demonstrates significant potential for application in food fresh‐keeping and contributes to promoting green and sustainable development within the cold chain industry.