Self-assembled graphene oxide-graphene hybrids for enhancing the corrosion resistance of waterborne epoxy coating

Graphene (Gr), with robust barrier properties against corrosion ions, holds great potential application in waterborne epoxy coating for corrosion resistance, but hard to be realized for its intrinsic hydrophobicity. In comparison, graphene oxide (GO), with oxygen-containing functional groups on its surface, can be well dispersed in water but suffer the modest barrier properties for its defect can't effectively resist the permeability of corrosion ions. Herein, GO-Gr hybrids have been used in waterborne epoxy coating to overcome their shortcomings and enhance their advantages via the π-π interactions. The structure and morphology of the GO-Gr hybrids were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), X-ray photoelectronic spectroscopy (XPS), Raman spectra, UV–vis absorption spectroscopy and transmission electron microscopy (TEM). Furthermore, the corrosion resistances of pure epoxy coating, GO/epoxy, and GO-Gr/epoxy were evaluated via electrochemical experiment and salt spray test. The results revealed that the GO-Gr/epoxy exhibited the highest corrosion resistance among these coatings owning to the synergistic effect of GO and Gr.