Preparation and synergistic antifouling effect of self-renewable coatings containing quaternary ammonium-functionalized SiO nanoparticles.

Confronting the complexity of marine biofouling, no single ecofriendly technology has been reported for efficient anti-biofouling. Combination of multiple antifouling factors should be one of the strategies for strengthening the anti-biofouling performance. Here we synthesized quaternary ammonium modified SiO nanoparticles (QAS-SiO) and incorporated them into self-polishing polymer (SP) to get the coatings combining self-renewal ability, micro-nano structured topography, and bactericidal function. The coatings acquired underwater superoleophobic surface after immersion in artificial seawater due to their micro-nano structured surface together with the hydrolyzed SP. In comparison with unmodified SiO, QAS-SiO had better compatibility with SP and caused less increment of self-polishing rate. Synergistic antifouling effect was interestingly observed between self-renewal ability and bactericidal function in both the laboratory assay based on the adhesion of Shewanella loihicas and natural field trial. The micro-nano structured topography contributed to underwater superoleophobicity but did not exhibit its impact on antifouling performance. QAS-SiO can also slightly inhibit the adhesion of diatoms and reduce the settlement of plantigrades of the mussel. In addition, we also demonstrated the coatings with lower quantity of biofilm exhibited less settlement of plantigrades of mussel.