Zwitterion-Enhanced Hydration Layer Construction in Acrylic Zinc Resin for Marine Antifouling

Endowing marine coatings with multiple anti-fouling capabilities holds significant application value yet is technically challenging. Herein, zwitterion moieties were introduced into a self-polishing acrylic resin to form a dense hydration-layer barrier that provides static antifouling performance, thus synergistically combining dual antifouling mechanisms. By varying the alkyl chain length of the zwitterion moieties (C1, C8, C10, and C12), the antifouling performance was optimized, with the C8 chain length affording high antibacterial efficiencies of 99.9% and 99.8% against E. coli and S. aureus, respectively, and antialgae efficiencies of 78.6%, 73.3%, and 83.0% against P. tricornutum, C. vulgaris and N. closterium, respectively. More importantly, the developed coating exhibited excellent anti-biofouling performance over 70 days in a real marine environment. This work demonstrates a novel self-polishing/hydration layer barrier synergistic antifouling strategy, providing new insights for the future development of high-performance marine anti-fouling coatings.