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

Abstract

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 ZrO2 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/mm3 compared to the typical 134 m⋅N/mm3. 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.

Xiaokun Song

PhD

Manyao Zhang

PhD

Qibin Zhao

Associate Professor

My research focuses on soft functional materials in which mesoscale structure controls optical and physical properties. I have worked extensively on colloidal and particle-assembled photonic materials, developing scalable processing methods to organize soft particulate systems into structurally coloured films and coatings. A central theme of my work is how external mechanical fields, such as shear, bending, stretching, and cyclic deformation, can drive microstructural ordering, lattice transitions, and structure-dependent optical responses. More broadly, I am interested in programmable soft photonic materials and functional coatings, where colloidal assembly, deformation processing, and soft-matter physics can be used to create adaptive optical, thermal, sensing, or mechanically encoded material functions.