Marine biofouling is the accumulation of marine species on surfaces submerged in seawater leading to unwanted problems for man-made surfaces such as hulls of ships and aquaculture nets. Historically, the amount of biofouling was regulated using metal based coatings whose usage have been disused lately due to adverse toxic effects. Alternative environmentally friendly coatings are currently avidly being pursued. Nanopatterned polymer thin films were investigated as potential candidates for marine antifouling coatings. Polystyrene- block-poly(2-vinyl pyridine) and polystyrene-block-poly(methyl methacrylate) diblock copolymer thin films self-assembled using vapor solvent annealing into cylinders perpendicular to the substrate composed of poly(2-vinyl pyridine) or poly(methyl methacrylate) respectively with diameters between 30 nm to 82 nm and center-to-center spacing between 46 nm to 113 nm in a polystyrene matrix on various substrates such as silicon or nylon. Polystyrene- block-poly(2-vinyl pyridine) copolymers were also mixed with the photoinitiator benzophenone and irradiated with ultraviolet light to crosslink the polymer chains and decrease the surface hydrophobicity. In the case of polystyrene-block-poly-(methyl methacrylate), the yield of these nanopatterned films increased with the modification of the vapor annealing method. A low temperature vapor annealing technique was developed in which the annealing occurs at 2 °C. In another strategy, polystyrene and poly(2-vinyl pyridine) homopolymers were nanopatterned with alternating lines and grooves with widths between 200 nm and 900 nm and depths between 15 nm to 100 nm using Thermal Nanoimprint Lithography. Poly(2-vinyl pyridine) films were synthesized as brushes using surface initiated Atom Transfer Radical Polymerization to produce robust polymer films. The chemical and/or the topographical heterogeneity of the polymer surfaces influenced the settlement of Ulva linza algae zoospores. Overall, the incorporation of nanoscale features enhanced the antifouling properties of the samples. Further exploration of these types of coatings is highly encouraged.
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