Influence of modified graphene oxide on the antifouling performance of waterborne polyurethane coatings containing amphiphilic honeycomb surface

Abstract

The coating with amphiphilic honeycomb surface containing modified graphene oxide was constructed by a three-step method for improved antifouling properties. Graphene oxide is modified with potassium hydroxide and γ-aminopropyltriethoxysilane, and then the product is dispersed in water and ethanol. Isophorone diisocyanate, polyethylene glycol, and γ-aminopropyltriethoxysilane are used to construct an amphiphilic prepolymer. The honeycomb surface is constructed during the evaporation of water and ethanol and the mixing of the modified graphene oxide and prepolymer. The amphiphilic honeycomb surface gives the coating fouling resistance and fouling release, while the modified graphene oxide gives the coating fouling degradation. The coating’s amphiphilicity, microstructure, and antifouling properties are characterized by the contact angle, confocal laser scanning microscope, scanning electron microscopy, benthic diatom, and bacterial adhesion. The results show that the coatings form an amphiphilic surface with a honeycomb microstructure and exhibit good antifouling properties. The water, diiodomethane, and 1-bromonaphthalene contact angle can be less than 20°. The size and depth of the honeycomb microstructure are about 600 nm and 100–200 nm. Compared with traditional polyurethane and waterborne silicone coatings, the resistance to benthic diatom and bacteria is increased by at least 28 and 400 times, respectively.