A flexible PDMS@ZrO2 film for highly efficient passive radiative cooling

Passive daytime radiative cooling (PDRC) technology can make objects cooling down without energy consumption by radiating out heat through the atmospheric transparent window (ATW, 8-13 mu m) and simultaneously reflect incident sunlight to avoid heated. In this work, a flexible radiative cooling film (FRCF) was fabricated by embedding zirconium dioxide (ZrO2) particles into polydimethylsiloxane (PDMS). It exhibited a high emissivity over 0.95 in ATW and a high reflectance beyond 0.92 in range of visible light. It achieved better cooling performances and yields an average temperature drop of 16.1 degrees C compared to the air around the film under the solar intensity of 735 W/m2. Because of its good cooling performance, great flexibility and acid resistance, this FRCF will have a wide application of radiative cooling in buildings and equipment.