SiC-armoured triple-layered superhydrophobic coating with super-robustness and anti-corrosion durability

Abstract

Continuously enhancing the mechanical stability and durability of superhydrophobic corrosion-resistant materials is a great challenge for researchers. In this paper, we developed a SiC armoured triple-layered superhydrophobic coating with super-robustness on Q235 carbon steel substrates. The triple-layered coating was achieved by sequentially applying an epoxy (EP) resin adhesive layer, a SiC-armored skeleton structure, and a superhydrophobic F-Al2O3@EP layer. The resulting coating demonstrated outstanding non-wetting superhydrophobicity, featuring a static water contact angle (WCA) of 157.7 ± 0.5° and a sliding angle (SA) of 3.7 ± 0.6°. Moreover, the designed triple-layered superhydrophobic coating exhibits ultra-low interfacial adhesion force and demonstrates self-cleaning ability. Its mechanical stability was significantly heightened, enduring more than 2700 sandpaper abrasion cycles, 2200 tape-peeling cycles, and 3000 g sand impact resistance. Additionally, the coating displayed superior corrosion resistance with eight orders of magnitude enhanced charge transfer resistance (Rct), 590 mV positive shift corrosion potential (Ecorr), and six orders of magnitude lower corrosion current density (Icorr) in a 3.5 wt% NaCl solution. Impressively, the SiC armoured triple-layered superhydrophobic coating demonstrated prolonged marine anti-corrosion performance, enduring immersion in a 3.5 wt% NaCl solution for over 1200 h and exposure to the outdoor marine atmospheric environment for more than 3360 h. We believe the development of superhydrophobic materials with high stability and durability contributes to their widespread adoption and multifunctional applications.