Design and preparation of flexible double-layered daytime radiative cooling composite film with antifouling property

Energy and environmental concerns are becoming more prominent with the widespread use of high-power-consuming cooling devices. Radiative cooling has lately gained popularity as a new energy-saving and environmentally beneficial technique. Here, we fabricated a double-layered radiative cooling composite film by coating a metal aluminum (Al) sheet with a SiO 2 /TiO 2 /PDMS (STP) using the tape casting method. In the STP coating layer, polydimethylsiloxane (PDMS) is employed as the matrix material, and SiO 2 /TiO 2 particles are dispersed evenly in it. The SiO 2 /TiO 2 /PDMS/Al (STP-Al) composite film shows 91% sunlight reflectivity and 83% atmospheric transparent window emissivity. An outdoor cooling test revealed that the STP-Al can provide a cooling effect of 5.3 ᵒC in direct sunlight with an intensity of 523 W m −2 . Furthermore, it has excellent anti-fouling properties and superior strength, enabling it to be used outdoors for an extended time. Due to its superior performance and easy preparation procedures, it can be fabricated on a large scale and has a broad range of practical applications in daily life. • Double-layered radiative cooling composite film by coating metal Al sheet with a SiO 2 /TiO 2 /PDMS. • Composite film shows 91% sunlight reflectivity and 83% atmospheric transparent window emissivity. • Excellent anti-fouling property and superior strength, enabling it to be used outdoors for an extended period of time.