Bio-Derived Dual-Temperature Antifouling Coating Enabled by Oyster-Shell Valorization

Abstract Marine biofouling imposes serious challenges to sustainability by increasing fuel consumption, maintenance costs, and ecological risks across maritime operations. Conventional antifouling coatings typically rely on toxic biocides, which persist in marine environments and harm non-target organisms. This study presents a biocide-free, eco-friendly coating derived from thermally activated oyster shells, modified via silane and stearic acid treatment. Incorporated into a siloxane matrix with ZnO and TiO₂, the coating demonstrates long-term hydrophobicity and antifouling efficacy through field tests in seawater over 12 months.