Amphiphilic Poly(SBMA-co-EGDEA) Coatings for Marine Antifouling: Insights into Design Criteria for Hydrophobic Monomers

Marine biofouling poses significant economic and environmental challenges, highlighting the need for effective antifouling coatings. We report amphiphilic poly(SBMA-co-EGDEA) copolymer coatings that resist both marine diatom adhesion and sediment adsorption. The coatings were synthesized via surface-initiated ATRP and RAFT polymerization using hydrophilic sulfobetaine methacrylate (SBMA) and hydrophobic ethylene glycol dicyclopentenyl ether acrylate (EGDEA). Interestingly, EGDEA exhibited a partial negative charge when coated on a surface, as confirmed by computational analyses. Since marine sediments are typically negatively charged and adhere strongly to hydrophilic surfaces, EGDEA's combination of hydrophobicity and negative charge effectively minimized sediment adsorption while maintaining resistance to diatom adhesion. Experimental results further showed that coatings with higher EGDEA content exhibited superior antifouling performance. These findings highlight the unique role of EGDEA in amphiphilic copolymers and provide valuable design insights for next-generation marine antifouling coatings.