Hydroxyl-Hydration-Promoted Antifouling Performances of Amphiphilic Nanoparticle-Doped Poly(caprolactone-polydimethylsiloxane) Coatings

In this study, amphiphilic copolymers with biocompatible and electrically neutral poly(2-hydroxyethyl methacrylate) (PHEMA) as a hydrophilic block and poly(lauryl methacrylate) (PLMA) as a hydrophobic block were synthesized, which were then incorporated into the coating matrix poly(ε-caprolactone)-<i>b</i>-poly(dimethylsiloxane) (PCL-PDMS) for the fabrication of marine coatings. With the hydrolysis of PCL in water, the self-assembled amphiphilic copolymer may be exposed on coating surfaces with the PHEMA block extending to water. Experimental results proved that the hydration effects of hydroxyl groups in the PHEMA block enhanced the surface hydrophilicity and accelerated the weight loss rate. More importantly, the antibacterial rate of the coating against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> can reach 98.41 and 97.67%, respectively, in comparison with those of 55.36 and 51.97%, respectively, for the PCL-PDMS matrix. Additionally, the marine field tests elucidated that the amphiphilic polymers with longer PHEMA chains exhibit stronger antifouling capability in the marine environment. And the marine field tests evidenced that the developed PLMA-<i>b</i>-PHEMA incorporated coatings can withstand biofouling for up to 5 months.