Corrosion protection performance of epoxy coating containing alumina/PANI nanoparticles doped with cerium nitrate inhibitor on Al-2024 substrates

Abstract

Abstract Alumina/polyaniline hybrid nanoparticles doped with cerium nitrate corrosion inhibitor was synthesized via a chemical polymerization method. The morphology and structure of the synthesized nanoparticles were investigated by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and X-Ray diffraction (XRD) techniques. Incorporation of alumina/polyaniline nanocomposite particles doped with cerium nitrate into epoxy coating on aluminum alloy 2024-T3 resulted in a protective system with superior corrosion protection performance confirmed by potentiodynamic scanning method (PDS) and electrochemical impedance spectroscopy (EIS). The corrosion current density of the nanocomposite coating was (7.35 ± 0.22)×10−9 A/cm2, which was reduced by two orders of magnitude compared with that of the control epoxy sample. Moreover, the embedding of cerium nitrate doped alumina/polyaniline nanoparticles into epoxy coating provides active protection against corrosion. The low frequency impedance values of the scratched area of this coating after 6 days immersion was three orders of magnitude higher than that of the control sample.