Fluorine‐Free Amphiphilic Copolymers for Broad‐Spectrum Marine Biofouling Deterrence

Abstract Biofouling, the accumulation of living organisms on submerged surfaces, remains a critical challenge in marine and industrial settings. Amphiphilic coatings offer promising antifouling performance by presenting both hydrophilic and hydrophobic domains, but often rely on environmentally persistent perfluoroalkyl substances (PFAS). This study introduces a fluorine‐free amphiphilic copolymer synthesized via initiated Chemical Vapor Deposition (iCVD), incorporating 1,3,5,7‐tetramethyl‐1,3,5,7‐tetravinyl cyclotetrasiloxane (V4D4) as the hydrophobic component and pyridinium‐based zwitterions as the hydrophilic moiety. V4D4 enables an unprecedented conversion rate of pyridine to zwitterionic sulfobetaine, reaching 69.5% at a 240 nm depth into the film from a diffusion‐limited vapor derivatization reaction, pointing to the network flexibility afforded by V4D4. The coating reduces Pseudomonas aeruginosa attachment by over 90% compared to aluminum surfaces and decreases Cellulophaga lytica biofilm formation by 55% compared to a zwitterionic benchmark under dynamic flow. Against the model diatom Navicula incerta , it achieves 99.7% removal after water jetting, outperforming a commercial fouling‐release paint, Intersleek® 1100SR. The high fouling‐release performance is attributed to its low Young's modulus, promoting deformation under shear. Additionally, the coating exhibits chemical stability in alkaline conditions that degrade PFAS‐based counterparts. These findings present a durable, high‐performance, and environmentally responsible alternative to PFAS‐based amphiphilic copolymers as the next‐generation antifouling technologies.