Full-Ocean-Depth-Oriented Poly(oxime-urethane) Coating: Construction and Protective Mechanism for Integrated Antifouling and Anticorrosion
Peng Zhang, Shu Tian, Ruiqi Li, Guangming Lu, Qunji Xue, Liping Wang
Abstract
Full-ocean-depth (FOD) environment, characterized by extreme pressure, salinity, and biological complexity, presents severe challenges for surface antifouling and anticorrosion. High-performance coatings capable of withstanding such coupled extreme conditions are urgently needed. Herein, an integrated antifouling/anticorrosion poly(oxime-urethane) (PUDF) coating with a tunable microphase-separated structure was developed by incorporating the intrinsically antifouling unit (2,5-diformylfuran dioxime, DFFD) and the reactive high-barrier nanosheets (carboxyl-functionalized graphene oxide GO-COOH). The coating showed excellent biointerface resistance, suppressing protein and bacterial biofilm adhesion by 98 and 99%, respectively, and achieving 100% bactericidal efficacy against marine bacteria. After 2 months of immersion at both shallow-sea (2 m, East China Sea) and deep-sea (7730 m, Philippine Sea) sites, no macrofouling organisms or deep-sea microbial adhesion were observed. Cross-linking GO-COOH within the PUDF matrix enhanced microphase separation and mechanical robustness, enabling exceptional resistance to coupled corrosion. Under a combined condition of 15 MPa, 3.5 wt % NaCl, and 10 6 cells mL –1 Pseudomonas aeruginosa, the coating exhibited impedance two orders of magnitude higher than pristine PUDF. Microbial community analysis and density functional theory (DFT) simulations further elucidated the disruption of purine biosynthesis/nucleotide metabolism antifouling and low-adsorption/high-barrier anticorrosion synergistic protection mechanisms. This study offers a theoretical and practical basis for designing integrated protection materials for FOD applications.