One-step fabrication of robust PDMS-MWCNTs composite superhydrophobic coatings with hierarchical micro-nanostructures for anticorrosive applications

Superhydrophobic coatings hold considerable promise for safeguarding metals against corrosion. However, realizing coatings with excellent superhydrophobicity, mechanical strength and corrosion resistance remains a great challenge. In this study, a robust superhydrophobic surface was achieved through the laser processing of multi walled carbon nanotubes (MWCNTs)/polydimethylsiloxane (PDMS) coatings, resulting in a water contact angle (WCA) of approximately 165°. Notably, the coating demonstrated outstanding abrasion resistance in sandpaper abrasion, steel wool abrasion, and falling sand tests. The friction coefficient of the coating is only 0.25. In addition, the robust superhydrophobic coating also has good anti-corrosion. The lowest-frequency impedance value of the composite coatings increases seven orders of magnitude compared with that of carbon steel, and the corrosion inhibition efficiency ( η ) is 99.83 %. The outstanding corrosion resistance is primarily ascribed to the formation of a dual synergistic barrier by PDMS-MWCNTs, providing effective protection for carbon steel.