Green biolubricant infused slippery surfaces to combat marine biofouling

Hypothesis: Marine biofouling is a global, longstanding problem for maritime industries and coastal areas arising from the attachment of fouling organisms onto solid immersed surfaces. Slippery Liquid Infused Porous Surfaces (SLIPS) have recently shown promising capacity to combat marine biofouling. In most SLIPS coatings, the lubricant is a silicone/fluorinated-based synthetic component that may not be fully compatible with the marine life. We hypothesized that eco-friendly biolubricants could be used to replace synthetic lubricants in SLIPS for marine anti-fouling. Experiments: We developed SLIPS coatings using oleic acid (OA) and methyl oleate (MO) as infusing phases. The infusion efficiency was verified with confocal microscopy, surface spectroscopy, wetting efficiency, and nanocontact mechanics. Using green mussels as a model organism, we tested the anti-fouling performance of the biolubricant infused SLIPS and verified its non-cytotoxicity against fish gill cells. Findings: We find that UV-treated PDMS infused with MO gives the most uniform infused film, in agreement with the lowest interfacial energy among all surface/biolubricants produced. These surfaces exhibit efficient anti-fouling properties, as defined by the lowest number of mussel adhesive threads attached to the surface as well as by the smallest surface/thread adhesion strength. We find a direct correlation between anti-fouling performance and the substrate/biolubricant interfacial energy.