Oligopeptide-modified hydrophobic and hydrophilic polymers as antifouling coatings

Abstract

Amphiphilic block copolymers have been extensively studied for their antifouling and fouling-release properties. Herein the authors report amphiphilic polymers based on two triblock copolymers with opposite-polarity backbones: polystyrene-block-poly(dimethylsiloxane-stat-vinylmethylsiloxane)-block-polystyrene (PS-b-P(DMS-stat-VMS)-b-PS), which contains a hydrophobic middle block, and polystyrene-block-poly[(ethylene oxide)-stat-(allyl glycidyl ether)]-block-polystyrene (PS-b-P(EO-stat-AGE)-b-PS), which contains a hydrophilic middle block. These two triblock copolymers were modified with two different non-natural oligopeptide segments: one non-fluorinated and one fluorinated. These oligopeptides were attached to the triblock copolymers by using thiol–ene ‘click’ chemistry. The modified polymers were coated onto treated glass slides and the surfaces were characterized using contact angle measurements. Near-edge X-ray absorption fine structure studies were used to show the delivery of oligopeptide segments to the film surface, even in cases when those surface groups were in competition with PDMS blocks. The coatings were tested for antifouling and fouling-release properties against sporelings of the green alga Ulva linza and cells of the diatom Navicula incerta. The modified PS-b-P(DMS-stat-VMS)-b-PS coatings performed well against the U. linza sporelings, and the PS-b-P(EO-stat-AGE)-b-PS coating performed well against both biofoulers.