Enhancing marine concrete durability: A novel silicone-based slippery coating for antifouling and corrosion resistance^☆

Complex corrosive marine environments significantly impair the durability of marine structures. Slippery coatings are known to provide effective protection against marine corrosion and biofouling. However, the complex surface topography and molecular structure of concrete restrict the application of these coatings in marine environments. In this study, a silicone-based slippery coating (S-SC) with a reliable bonding strength to concrete and effective marine protective capabilities was designed and fabricated. The coating can be applied to concrete surfaces via a simple brushing process, with lubricating oil spontaneously exuding through intermolecular forces within the coating to form a slippery surface. Moreover, after depletion of the lubricating oil on the S-SC surfaces, the oil continues to exude spontaneously to the coating surface, enabling self-healing of the slippery performance. The presence of the film of lubricating oil on the S-SC surfaces enabled the effective inhibition of seawater penetration, thereby mitigating erosion by the chloride ions in seawater. Bacterial adhesion experiments demonstrated that S-SC effectively inhibited the adhesion of marine bacteria, thereby suppressing biofouling. Protein adhesion experiments demonstrated that S-SC effectively reduced the adhesion of protein molecules to prevent the formation of early-stage biofilms associated with marine biofouling. In summary, a durability-enhancing protective coating was designed and fabricated for marine concrete structures, which offers a new protective strategy to improve the durability of these structures.