Evaluating fouling‐resistance and fouling‐release performance of smart polyurethane surfaces: An outlook for efficient and environmentally benign marine coatings

Various environmentally friendly approaches have been studied in recent years for effectively controlling biofouling on marine structures. Among these, two distinct and successful approaches are (1) the use of hydrophilic surfaces that control biofouling by resisting the adhesion of fouling organisms and (2) the use of hydrophobic elastomeric surfaces that function by facilitating their easy removal. In this study, we attempted to investigate amphiphilic surfaces for their effectiveness in controlling marine biofouling. Polyurethane surfaces containing tethered hydrophilic, hydrophobic, and amphiphilic moieties were designed and synthesized. The wetting behaviors of these surfaces, as a function of the external environment, were studied by dynamic contact angle (DCA) measurements and their morphologies by atomic force microscopy (AFM). The results from DCA measurements and AFM postulate interesting characteristics of the amphiphilic surfaces. Bioassays with the green fouling alga Ulva showed that the amphiphilic surfaces had fouling‐resistance and fouling‐release potential and provide an insight into the scope of the development of smart marine coatings.