Marine biofouling is a major problem deteriorating the service performance and lifespan of marine infrastructures. Developing a durable, long-term and environmental-friendly antifouling coating is therefore of significant importance but still a critical challenge in maritime engineering. Herein, we developed two types of long-term durable antifouling coatings by plasma spraying. The one is a composite Cu-X coating (X is a kind of metal with more positive potential than Cu) with novel micron-sized alternating Cu/X laminated-structure This coating was designed to controlled release Cu ions by galvanic dissolution of Cu laminates from the Cu/X micro-galvanic cell in aqueous solution, and therefore to achieve long-term, self-polishing and environmental-friendly antifouling capability with high mechanical durability simultaneously. The other is a micro/nano bimodal porous-structured slippery liquid infused porous surfaces (SLIPS) coating. The effect of spraying parameters on the coating microstructure and long-term antifouling performances were investigated and the underlying mechanisms were revealed.
In the case of the Cu-X coating, results showed that remarkable antifouling efficiency against bacteria survival and adhesion up to ~100% was achieved. Cu/X micro-galvanic cell was confirmed to be formed within Cu-X coating and responsible for the Cu ions release and its excellent antifouling performance. For the SLIPS coating, it demonstrated superior reduction rates of 87 %, 92 %, and 94 % for the settlement of E. coli, Chlorella, and P. tricornutum, respectively, after 20 days of incubation assay. These two novel coatings would provide new and effective antifouling strategies in maritime engineering.

plasma spraying; antifouling; Cu-X coating; SLIPS; long-term durability