Bioinspired rosin-borneol eco-friendly antifouling coatings with self-renewable and self-generatable amphiphilic surface

The release of toxic and persistent substances in conventional antifouling paints has elicited substantial environmental concerns, underscoring an urgent requirement for eco-friendly alternatives. This study presents the successful synthesis of an eco-friendly antifouling coating, denoted as PSBZ-X-Y, through the grafting of a hydrolysable borneol-modified zwitterionic precursor, DEA-IBOA, onto a bio- derived rosin resin. The PSBZ-X-Y coating exhibits a controlled self-renewable rate (50–400 μg/cm 2 ·d) tuned by varying DEA-IBOA modified rosin content, which enhances the coating's durability and regulates the release of borneol. Molecular dynamics (MD) simulations and surface structure analyses, including ATR-FTIR and XPS, reveal that hydrolysis of DEA-IBOA leads to the release of the natural antimicrobial agent borneol and thus facilitates the in-situ generation of zwitterionic surfaces. Amphiphilic surfaces and natural antimicrobial borneol as eco-friendly approaches synergistically enhance the antifouling properties of natural rosin, which in turn promotes the sustainability of amphiphilic surfaces due to its self-renewal capability. Consequently, the coating exhibits remarkable resistance to protein adhesion (FITC-BSA adhesion rate: 0.4 %), bacterial biofilm formation (absorbance of biofilm: 1.3), and diatom attachment (150 cells/mm 2 ), as well as remarkable antifouling properties in real marine environments. More importantly, the hydrolyzed products generated during the coating renewal process demonstrate no adverse effects on the marine ecosystem, thus contributing to eco-friendly antifouling systems based on natural products.