Engineering long-lasting marine antifouling coatings with curcumin-grafted SiO2/PDMS nanocomposites via RAFT polymerization

Biofouling poses a great challenge to marine facilities and causes serious economic losses, making the development of green and non-toxic anti-fouling coatings a high priority. In this study, leveraging the broad-spectrum bacteriostatic and economic properties of the natural product curcumin (Cur), it was chemically grafted onto the surface of xanthate-functionalized silica nanoparticles with the hydrophilic monomer vinylpyrrolidone (NVP) using a reversible addition-fragmentation chain transfer (RAFT) polymerization strategy. The resulting modified particles were incorporated as active fillers into a terminal hydroxy-polydimethylsiloxane (PDMS) matrix, successfully constructing a functional coating labeled PDMS/SiO 2 -X. This coating exhibits a synergistic antifouling mechanism combining self-polishing, static antifouling agent mitigation and dynamic fouling release. The presence of modified silica significantly improves the mechanical properties of the coating. The low surface energy surface imparts excellent fouling-release characteristics, while the hydrolysis of ester bond enables the sustained release of Cur to achieve efficient bacterial inhibition. Additionally, NVP effectively resists protein adhesion by forming a hydration layer. A 180-day real-sea field test verifies the long-lasting and stable antifouling performance of the coating. This work provides a new idea for developing highly efficient and environmentally friendly marine antifouling coatings.