Application of layer-by-layer assembled graphene oxide nanosheets/polyaniline/zinc cations for construction of an effective epoxy coating anti-corrosion system

By a layer by layer deposition approach the grafted graphene oxide (GO) particles were grafted by zinc doped polyaniline (PAni) and then distributed in the epoxy matrix to provide active inhibition/barrier properties simultaneously. The modified/unmodified nanosheets were examined by X-ray diffraction (XRD) analysis and Raman spectroscopy. The corrosion prevention effect of GO-PAni-Zn/epoxy composite was studied by EIS and salt spray test. Results revealed that the GO nanosheets dispersion quality and interfacial interactions were improved after applying PAni-Zn layer, leading to significant improvement in the epoxy coating barrier properties against diffusion of sodium chloride solution. In addition, according to EIS test results the active inhibition properties of the epoxy film was promoted after addition of zinc doped polyaniline compound. GIXRD results confirmed deposition of an inhibitor film on metal surface within the scratched part of epoxy composite coating filled with GO-PAni-Zn particles. In addition, the coating surface damage during salt spray test was significantly decreased through addition of GO-PAni-Zn as demonstrated by SEM/contact angle tests.