Effects of surface-active block copolymers with oxyethylene and fluoroalkyl side chains on the antifouling performance of silicone-based films.

Elisa Martinelli, Deniz Gunes, Brandon M Wenning, Christopher K Ober, John A Finlay, Maureen E Callow, James A Callow, Alessio Di Fino, Anthony S Clare, Giancarlo Galli

Index: Biofouling 32 , 81-93, (2016)

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Abstract

Block copolymers made from a poly(dimethyl siloxane) (Si) and a poly(meth)acrylate carrying oxyethylene (EG) or fluoroalkyl (AF) side chains were synthesized and incorporated as surface-active components into a silicone matrix to produce cross-linked films with different surface hydrophilicity/phobicity. Near-edge X-ray absorption fine structure (NEXAFS) studies showed that film surfaces containing Si-EG were largely populated by the siloxane, with the oxyethylene chains present only to a minor extent. In contrast, the fluorinated block was selectively segregated to the polymer-air interface in films containing Si-AF as probed by NEXAFS and X-ray photoelectron spectroscopy (XPS) analyses. Such differences in surface composition were reflected in the biological performance of the coatings. While the films with Si-EG showed a higher removal of both Ulva linza sporelings and Balanus amphitrite juveniles than the silicone control, those with Si-AF exhibited excellent antifouling properties, preventing the settlement of cyprids of B. amphitrite.