Slime-resistant marine anti-biofouling coating with PVP-based copolymer in PDMS matrix

Poly(dimethylsiloxane) (PDMS) has been widely used as the fouling-release coatings due to its low surface energy. However, for marine anti-biofouling applications, current PDMS-based materials with hydrophobic property still suffer from marine slime attachment. Therefore, the design of novel amphiphilic coatings by modifying PDMS with hydrophilic polymers has been widely explored. In this work, based on poly(N-vinylpyrrolidone) (PVP), a novel hydrophilicity-active poly(N-vinyl-2-pyrrolidone-co-methyl methacrylate-co-butyl acrylate-co- 2-hydroxyethyl methacrylate) (PNMBH) was synthesized using a robust free radical polymerization method. Next, amphiphilic coatings were prepared by crosslinking different amounts of PNMBH with PDMS at room temperature. The resultant PNMBH-PDMS coatings were characterized with water contact angle tests, presenting their increased hydrophilicity and the optimal PNMBH content (10%). Moreover, the anti-biofouling performance of these coatings was evaluated using proteins (bovine serum albumin and fibrinogen), bacteria (Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus), and marine diatom (Navicula parva). Compared with pristine PDMS coating, PNMBH-PDMS coatings could reduce ∼82% adhesion of fibrinogen, ∼97% adhesion of Staphylococcus aureus, and ∼97% adhesion of diatom, the major composition of marine slime. More importantly, PNMBH-PDMS coatings were also tested in the marine field, and results showed their excellent anti-biofouling performance for at least 4 months in the ocean. This work developed a novel amphiphilic coating with appealing marine anti-biofouling performance and might provide new opportunities for marine coating applications.