Facile preparation method of robust superhydrophobic coatings based on double layers and multistage complementary structures

This study designed a novel double-layer structured superhydrophobic coating with exceptional wear resistance and dynamic impact resistance. Sand particles were employed as "armor" and a hydrophobic adhesive layer was employed as the bonding layer. The synergistic effect of the chemical components and optimized rough structures enhances the coating’s resistance to external stress and wear. Results shows that the coating maintains its superhydrophobicity after 150 cycles of sandpaper abrasion under a 300 g load, accompanied by a decrease of only 6 % of the contact angle. Also, the coating exhibits remarkable impact resistance to water impact, retaining contact angles above 153° and 151° after 16 hours of water droplet penetration and 12 hours of water jet impact, respectively. Additionally, the coating maintains its superhydrophobicity after chemical attack. UV aging and high-low temperature cycling tests indicate good outdoor environmental adaptation characteristics. Furthermore, the prepared samples exhibit excellent durability and stability after 180 days of outdoor exposure. These outstanding properties can be attributed to the robust double-layer, double-scale structure of the composite coating, as well as the low surface energy and mechanical stability provided by the modifiers. With its exceptional mechanical properties, excellent chemical durability, and strong adaptability to outdoor conditions, the double-layer superhydrophobic composite coating demonstrates remarkable durability and excellent practicality. It holds significant potential for practical applications, particularly in challenging environments.