Resistance to protein sorption as a model of antifouling performance of Poly(siloxane-urethane) coatings exhibiting phase separated morphologies

Abstract

In this study, bovine serum albumin (BSA) adsorption measurements were used as a model test to investigate the anti-biofouling performance of hybrid poly(siloxane-urethane) coatings. Different coatings were obtained from isophorone diisocyanate trimer, polycaprolactone triol and hydroxy-terminated poly(dimethylsiloxane). The copolymers showed a phase separated structure that depended on the mixing time and casting temperature. Two types of adsorption measurements were performed: (a) static adsorption measurements, immersing the film in a BSA solution and determining the BSA concentration of the remaining solution by UV; (b) measuring the adsorption using a quartz crystal microbalance with dissipation monitoring (QCM-D). According to static adsorption measurements, the BSA adsorption was reduced when the coatings showed a phase separated structure. In addition, QCM-D measurements, and particularly the dissipation data, showed that in nanostructured coatings the protein adsorption occurred in a conformation that prevented water retention. The latter could be the origin of the fouling resistance ability of these copolymers.