Efficient radiative cooling and super-hydrophobic ZnO/P(VDF-HFP)-PDMS coated fabric

Radiative-cooled textiles are attracting attention because they can spontaneously lower the microenvironmental temperature of the human body. The radiative cooling and hydrophobic fabric was prepared by two-step dip-coating on PET fabric with a ZnO/P(VDF-HFP) as radiative cooling coating and a PDMS hydrophobic wear-resistant layer. The effect of morphology (sheet, hexagonal prism, flower, and rod) of ZnO nanomaterial on the radiative cooling property of the coated fabric was examined. Among the four types of ZnO, the ZnO sheets have the highest sunlight reflectivity of 0.827. Besides, P(VDF-HFP) is a binder that loads ZnO onto PET fibers and enhances the solar reflectivity of coated fabric by reflecting visible light. Hence, the ZnO sheet/P(VDF-HFP)-PDMS (Z S PP) coated fabric possessed a solar reflectance of up to 91.3 % under the synergistic effect of ZnO sheets and P(VDF-HFP), and due to specific functional groups (e.g. C–F, C–Si) in the hybrid coating, and its mid-infrared emissivity reached 93.2 %. As a result, the Z S PP coated fabric were 7.1 °C cooler than the PET fabric under direct sunlight, with an average cooling efficiency of 72.6 W·m −2 . The coated fabric demonstrated well-hydrophobic and durability properties due to the PDMS, making them much more suitable for use in complex outdoor environments.