Synergistic antifouling performance of Cu/MXene composite nanofluid-infused SLIPS coatings with self-cleaning and self-replenishing capabilities for marine applications

Biofouling in marine environments poses a severe threat to artificial facilities such as ship hulls, underwater structures, marine ranches, cross-sea bridges, and offshore wind power piles. Copper-containing antifouling coatings dominate the current market, but the excessive release of copper ions remains an urgent issue. Recently, slippery liquid-infused porous surfaces (SLIPS) have shown excellent potential in resisting fouling. However, the easy loss of lubricating liquids in complex marine environments limits their long-term stability. Therefore, developing novel antifouling coatings with long-term stability and environmental friendliness is crucial. To tackle these challenges, a SLIPS antifouling coating (Cu/MXene@uPDMS-oil) based on Cu/MXene composite nanofluid and a polydimethylsiloxane (PDMS) matrix was designed and fabricated. The addition of MXene nanosheets not only promotes the dissolution of copper ions but also enables the controlled release of copper ions through the labyrinth effect, thereby solving the problem of “initial rapid release followed by a slow release” in copper-based coatings. Furthermore, the low surface energy of PDMS, the intrinsic antifouling property of MXene, and the toxic effect of copper ions synergistically enhance the antifouling performance significantly. The inhibition rates against bacteria, Chlorella , and conchs reach 100%, 99.46%, and 100%, respectively. Notably, the introduction of copper particles and MXene into the nanofluids increases the viscosity of the silicone oil system, making it more difficult for silicone oil to be eluted from the coating surface. This endows the Cu/MXene@uPDMS-oil coating with excellent stability and prolongs its antifouling lifespan. In addition, the coating exhibits good hydrophobicity, self-cleaning property, and self-replenishing capability. This research provided a new idea and feasible approach for the development of long-term and environmentally friendly next-generation marine antifouling coatings.