Superhydrophobic self-cleaning solar reflective orange-gray paint coating

A method of fabricating an industrially scalable, widely applicable, and easily repairable superhydrophobic self-cleaning cool orange-gray coating using commercially available materials and following a simple industrial procedure is introduced. Grinding the coating surfaces using an appropriate emery paper creates microgrooves with suitable widths and exposes micro- and nanoparticles on the coating surface. Both factors together endow the coating surfaces with superhydrophobic self-cleaning properties. The hydrophobicity of the coating possesses good resistance to alkali, acid and mechanical abrasion. Grinding the coating surfaces using emery papers also increases the solar reflectance of the coating. The cooling effect of the superhydrophobic coating, which has a solar reflectance of 0.815, is estimated to be 23 °C relative to concrete on a typical clear summer sunny day. Although the superhydrophobic self-cleaning property and solar reflectance of the coating may be compromised by artificial accelerated weathering, the superhydrophobic self-cleaning property can be easily and fully reestablished and the inclined solar reflectance may be partially restored after the coating surfaces are ground using an appropriate emery paper.