An investigation of the electrochemical action of the epoxy zinc-rich coatings containing surface modified aluminum nanoparticle

•Aluminum nanoparticle was modified with amino trimethylene phosphonic acid.•2wt% of zinc dust in zinc-rich paint was substituted by aluminum nanoparticles.•Surface modified aluminum nanoparticle improved the cathodic period of protection.•Aluminum nanoparticles enhanced the corrosion protection of the zinc-rich coating. Aluminum nanoparticle was modified with amino trimethylene phosphonic acid (ATMP). The surface characterization of the nanoparticles was done by X-ray photo electron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and thermal gravimetric analysis. The influence of the replacement of 2wt% of zinc dust in the standard zinc-rich epoxy coating by nanoparticles on the electrochemical action of the coating was studied by electrochemical impedance spectroscopy (EIS) and salt spray tests. The morphology and phase composition of the zinc rich paints were evaluated by X-ray diffraction (XRD) and filed-emission scanning electron microscopy (FE-SEM). Results showed that the ATMP molecules successfully adsorbed on the surface of Al nanoparticles. Results obtained from salt spray and electrochemical measurements revealed that the addition of surface modified nanoparticles to the zinc rich coating enhanced its galvanic action and corrosion protection properties.