Fabrication of a robust graphene oxide-nano SiO2-polydimethylsiloxane composite coating on carbon steel for marine applications

Abstract

Abstract Here we report a simple approach to produce corrosion resistant, anti-biofouling and durable graphene oxide-nano-SiO2-polydimethylsiloxane composite coating on carbon steel (CS) through an anodic electrophoretic deposition combined with dip coating. The corrosion resistance of the composite coatings was evaluated by electrochemical impedance and potentiodynamic polarization technique after exposure to 3.5\xa0wt% NaCl solution. The composite coating (GSP) showed a six-order higher charge transfer resistance and polarization resistance values compared to uncoated CS due to the lower permeation of chloride ions through the GO-nano-SiO2 interlayer and the effective filling of micro-pores by nano-SiO2. The Si–OH group enhanced the chemisorption of PDMS to GO-nano-SiO2 interlayer surface that provided a strong adhesion. The cross hatch tape test of GSP coating indicated good adhesion of the coating with the substrate. Epifluorescence and confocal laser scanning microscopic analysis showed a reduced density of bacterial cell and biofilm formation on GSP coated specimens. This new approach is found to be useful to fabricate a robust corrosion resistant and anti-biofouling composite coating for marine applications.