Nanowall enclosed architecture infused by lubricant: A bio-inspired strategy for inhibiting bio-adhesion and bio-corrosion on stainless steel

Microbiologically influenced corrosion (MIC) severely deteriorates metal material in seawater environment. Finding versatile coatings to inhibit bioadhesion and biocorrosion is a critical option to avoid degradation by microorganisms. Inspired by Nepenthes pitcher, this study prepares lubricant-infused surface (LIS) by using a three-step method: electrodeposition, vapor deposition, and oil infusion. First, Co(OH)2 is built on stainless steel (SS) via electrodeposition. The wrinkled nanowall circumvents the partition architecture, thus producing a highly porous structure. Second, through dodecanethiol modification, the combination of anchored hydrophobic moiety and porous structure creates a lotus-inspired superhydrophobic (SHP) surface. Third, oil infusion produces LIS. The independent partition architecture increases the anchoring effect to oil phase, thereby enhancing the stability. After immersion for 28 days in an abiotic seawater environment, the corrosion current density of SS covered by LIS SS is as low as 2.52 × 10−10 A/cm2, which is approximately five orders of the magnitude lower than that of bare SS. After immersion in sulfate-reducing bacteria (SRB) suspension for 6 days, the cell adhesion density on LIS decreases by one order of magnitude compared with that on bare SS, thereby showing high bio-adhesion inhibition capability. The decrement of bacteria adhesion steadily decreases the MIC to SS. After exposure to SRB suspension for 10 days, the corrosion current density of LIS SS is only 1.06 × 10−8 A/cm2, which is lower than that of SHP coating under the same immersion periods. Therefore, the bio-inspired LIS for SS is a promising way to inhibit bioadhesion and biocorrosion in seawater environment.