Zinc-graphite composite coating for anti-fouling application

In this paper, an anti-fouling composite coating was fabricated by blending zinc-graphite alloy powders with epoxy-silicone resin and characterized by EDS, SEM, XRD and ion titration. Compared with stainless steel and epoxy-silicone resin coating, the composite coating significantly inhibited the deposition of CaCO₃ fouling. Only a small amount of fouling was observed on the surface of composite coating after it was immersed in CaCl₂/ NaHCO₃ solution. The galvanic corrosion of zinc-graphite powders could release Zn²⁺ ions, which can reduce partially the nucleation and crystal growth rate of CaCO₃ on the surface of composite coating. It was found that the morphologies of CaCO₃ fouling changed from calcite to aragonite as the existence of composite coating. Meanwhile, CaCO ₃ fouling was prone to precipitate in bulk solution rather than on the surface of composite coating.