Superhydrophobic coating based on organic/inorganic double component adhesive and functionalized nanoparticles with good durability and anti-corrosion for protection of galvanized steel

Abstract

The excellent wetting resistance properties of superhydrophobic materials mean that they have a wide range of potential applications. However, there are problems that need to be solved urgently regarding mechanical stability, corrosion resistance and complex synthesis. Herein, we prepared a robust and durable superhydrophobic coating using an inorganic aluminum phosphate (AP) adhesive. This contained organic polydimethylsiloxane (PDMS) and silica/halloysite composite nanotubes (HNTs) modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES). The as-prepared F-SiO2/HNTs-AP@PDMS coating shows good superhydrophobicity (water contact angle = 158°), mechanical strength and durability. Superhydrophobicity was maintained even after 150 complete sandpaper wear cycles and 200,000 water droplet impact measurements. In particular, electrochemical impedance spectroscopy (EIS) results showed that the Rct value of the superhydrophobic coating was significantly increased by five orders of magnitude. After exposure to a corrosive environment for 10 days, the Rct value is still far higher than that of uncoated galvanized steel, indicating that it provides excellent long-term protection for metals. We believe this work not only provides a reference for the large-scale preparation of superhydrophobic materials, but also provides a strategy for the long-term protection of galvanized steel.