Low temperature-curable superhydrophobic surface with ultra-mechanical durable and anti-corrosion properties through structural engineering of coniferous ZnO

Abstract

Superhydrophobic surfaces (SHS) receive considerable attention because of their wide applications, such as building materials, biomedical materials, and different metallic coatings. This study reports a simple and cost-effective approach for fabricating a robust superhydrophobic surface consisting of 1H,1H,2H,2H-perfluorooctyltriethoxysilane-modified SiO2 and coniferous ZnO nanoparticles dispersed in fluoroethylene vinyl ether (FEVE/FS@ZnO) on a stainless steel substrate. The prepared SHS coatings were curable at room temperature and easy to handle. They exhibited unique hierarchical and re-entrant structures, reducing surface energy and resulting in a long lifetime, significant adhesion enhancement, and superhydrophobic and self-cleaning properties. The highest water contact angle (CA) and roll-off angle were 156° and 3°, respectively, achieved at an optimized ZnO:fluoroalkylsilane mass ratio of 10:0.6. The SHS coatings also showed a significant anti-corrosion effect in a corrosion solution (3.5 wt% NaCl solution) and high stability against various acidic (H2SO4, pH = 1) and basic (NaOH, pH = 13) solutions. In addition, the SHS coating layer exhibited improved durability and stability in sandpaper abrasion and tape peel tests, with a CA of 153° after 130 sandpaper abrasion cycles. These results provide a pathway for the future development of multifunctional coating materials. The robust FEVE/FS@ZnO SHS coating with superhydrophobic and self-cleaning properties could be applied to various functionalized solid surfaces.