Durable and robust broadband radiative cooling coatings for multi-temperature scenarios

Abstract

Passive daytime radiative cooling presents a promising avenue for revolutionizing cooling solutions by reflecting sunlight and radiative heat to outer space without consuming energy. Previous studies often focus on a single temperature scenario, neglecting the complexity of real-world applications in which the target object may have heat sources. Here, we have successfully prepared a Cooling Paint for Multi-Temperature Scenarios (CPMTS) by incorporating nanometer boron nitride into the photocured monomer Tricyclodecane Dimethanol Diacrylate (DCPDA). CPMTS exhibits excellent broadband thermal emittance (∼0.955), reflectance (∼0.778, from 300 nm to 2.5 μm), and thermal conductivity (∼0.51 W m−1 K−1). Notably, it achieves a maximum cooling of 20.1 °C and 8.8 °C under ∼790 W m−2 and ∼507 W m−2 of solar irradiation in the absence and presence of a 1 W heat source continuously heating, respectively. Continuous and significant radiative cooling performance has been observed on cloudy days or at night. CPMTS shows excellent radiative cooling performance in practical application scenarios. Excellent ageing resistance, adhesion, stability, and color matching ability make CPMTS expected large-scale application through spray or brush. This research provides a potential solution for cooling in real-world diverse temperature scenarios. The obtained radiative cooling coatings demonstrate scalability and durability in practical applications.