Dynamic multi-level microstructured antifouling surfaces by combining quaternary ammonium modified GO with self-polishing copolymers

Marine biological fouling is the undesirable accumulation on the surfaces of submerged objects and causes environmental and economic consequence to ships and marine facilities. However, traditional coatings achieve antifouling by releasing toxic heavy metal antifouling agents, causing ecological problems. And the static antifouling performance of self-polishing antifouling coating is not good. To overcome the shortcoming, a novel antifouling strategy to build a self-renewing multi-level microstructure on the coating surface was developed by dispersing GO-based quaternary polymer brushes in a self-polishing fluoro/silyl acrylate copolymer. Quaternized GO exhibits excellent dispersibility in the silyl-based acrylate copolymer. A dynamic self-renewing surface is realized for the coating via a self-polishing effect that exposes the filler inside the coating at the surface. The multi-level microstructure of the sharp edge of GO and quaternized "spear" structure destroys the cell wall of organisms. And a "water-shield" on amphoteric ion surface on quaternized GO inhibits adhesion of organisms. The antibacterial and anti-algae tests demonstrated the excellent antifouling effect of the coating at only 0.1% (mass) filler content, with anti-algae ratio against Nitzschia closterium (N. closterium), Phaeodactylum tricornutum (P. tricornutum) and Halamphora sp. of 83.7%, 52.4%, and 65.8%, respectively. The proposed preparation method is simple and potentially applicable to large-scale production for antifouling application.