Radical cation-initiated surface polymerization on photothermal rubber for smart antifouling coatings.

Biofouling on surfaces of various materials has aroused considerable attentions in biomedical and marine industry. Surface grafting based on covalent surface-initiated polymerization offers a popular route to address this problem by providing diverse robust polymer coatings capable of preventing the biofouling under complex environments. However, the existing methods to synthesize polymer coatings are complicated and rigorous, or require special catalysts, greatly limiting their practical applications. In this work, we report a radical cation-based surface-initiated polymerization protocol to graft the surafce of darkened rubber of trans-polyisoprene (TPI) with thermo-responsive smart polymer, poly(N-isopropylacrylamide) (PNIPAM) via a simple iodine doping process. A series of characterizations were performed to provide adequate evdiences to confirm the successful grafting. Combining thermal sensitivity of PNIPAM with the photothermal conversion ability of the darkened rubber, effecient bacterial killing and antifouling as a result of temperature-controlled iodine release and switchable amphiphilicity of PNIPAM are successfully achieved.