Superior corrosion resistance and self-healable epoxy coating pigmented with silanzied trianiline-intercalated graphene

In this study, novel aniline trimer (AT) functionalized graphene sheets (SAT-G) was prepared by intercalation and silanization of trianiline precursor. Fourier transform infrared spectroscopy (FTIR), Raman and UV-vis spectra indicated that the π-π interaction was formed between the silanized aniline trimer (SAT) and graphene (G). Meanwhile, scanning electron microscope (SEM), transmission electron microscope (TEM), and scanning probe microscope (SPM) confirmed the successful decoration of graphene surface by AT. As a result, the silanized aniline trimer could effectively increase the dispersion of graphene in epoxy matrix. The long-term anti-corrosion ability of epoxy matrix was greatly enhanced via adding proper SAT-G (0.5 wt%). Local electrochemical impedance spectroscopy (LEIS) studies manifested that the local impedance of artificial defect was greatly improved. The excellent anti-corrosion performance was attributed to two parts: (1) the well-dispersion graphene could fully exhibit its barrier property; (2) the silanized aniline trimer with intact electroactivity could induce the formation of passive film, which was composed by Fe₃O₄ and Fe₂O₃. The combine action between the barrier property of graphene and the self-healing capacity of silanized aniline trimer contributed to the superior corrosion resistance of SAT-G based epoxy coating.