Improved abrasion-resistant coatings using designed inorganic particles for durable radiative cooling

Passive radiative cooling materials offer electricity-free cooling by strongly reflecting sunlight and emitting thermal radiation to outer space, presenting a significant potential to reduce energy consumption and carbon emissions . Among these, particle-filled coatings stand out for their ease of processing, cost-effectiveness, and superior cooling performance, making them a promising solution for building cooling applications. However, the practical outdoor application of current particle-filled coatings is hindered by their inadequate abrasion resistance , impacting the coating’s service life significantly. In this study, an efficient daytime cooling coating composed of ZrO 2 particles and silicone acrylate with superior abrasion resistance is presented. By experimentally optimizing the composition, particle size, and volume fraction, this coating achieved a solar reflectivity of 95.7%, an emissivity of 0.978, and an abrasion resistance significantly exceeding that of existing commercial outdoor coatings, at 5310 m ⋅ N/mm 3 compared to the typical 134 m ⋅ N/mm 3 . Even under extensive wear, the coating’s reflectivity only diminished by 0.7%, far less than the 3.8% reduction observed in commercial alternatives, demonstrating its durability under harsh conditions. Moreover, in humid daytime summer conditions, these coatings demonstrate an average temperature reduction of 2.6 °C and a maximum of 7.7 °C below ambient temperature. This work provides new insights in designing durable radiative cooling coatings, paves the way for their practical application in more outdoor applications settings.