Superhydrophobic, corrosion resistance, and antibacterial coating with delayed release of Ag ions

The degradation failure of organic coatings in the marine environment is often caused by microbiologically influenced corrosion. This study assembled multilayer antibacterial hybrids onto NaOH etched basalt scales via mussel-inspired depositions of PDA and AgNPs followed by post-modification with 1-Dodecanethiol. 1-Dodecanethiol could suppress the formation of mature biofilms and maintain bacteria in dispersed states, which further promotes the bacterial-killing effect of AgNPs. Meanwhile, 1-Dodecanethiol slowed down the release rate of Ag ions so that an utterly dead biofilm would not be formed on the surfaces of the coatings. The bacterial adhesion to the surface of the superhydrophobic coatings exhibited substantially reduced after 14 days of immersion in PAO1 inoculated medium. Moreover, owing to the sustained release of Ag ions, the as-prepared coatings showed excellent long-term bactericidal activity. The EIS measurements demonstrated that the superhydrophobic coatings promoted corrosion resistance effectively.