Hierarchical-porous coating coupled with textile for passive daytime radiative cooling and self-cleaning

Passive daytime radiant cooling (PDRC) technology is an energy-free and ecologically beneficial cooling solution compared to conventional electric cooling. The limited cooling efficiency and impossibility of mass manufacture, however, severely restrict its popularization and application. This study uses a combination of template and etching techniques to construct a hierarchically porous Poly (vinylidene fluoride-co-hexafluoropropene) (P(VDF-HFP) coating with controlled pore size and porosity. Coated textiles have strong solar reflectances (0.93) and infrared emittances (0.98) thanks to the organization of specific micro-nano multi-level pore size and high porosity, which results in a subambient temperature drop of around 9.0 °C. Due to its porous structure, the coated textile possesses a considerable bit of flexibility and self-cleaning capabilities. The present work paves a new way for the mass production of radiate cooling textiles with a controlled coating structure and exceptional cooling performance. • Radiation cooling textiles are prepared by stencilling and etching to form layered porous structures. • The coated textile has a solar reflectivity of 93% and an ultra-high atmospheric transparent window emissivity of 98%. • Sub ambient cooling of 9.3 °C can be achieved during daylight hours with the coated textile. • In addition to the radiative cooling properties, the coated textiles are also self-cleaning.