This work reports the corrosion behavior of novel epoxy based double-layer nanocomposite coatings designed to mitigate corrosion in the marine environment. Zirconia (ZrO2) nanoparticles were used as a carrier to load separately amine-based self healing agent, polyethyleneimine (PEI), and corrosion inhibitor, imidazole (IM). The loaded zirconia (ZrO2) nanoparticles with IM and PEI were doped into the epoxy matrix separately (1 wt. %) and applied on polished steel substrate to form pre and top layers of nanocomposite coatings, respectively. The successful modification of Zirconia nanoparticles was confirmed through various characterization techniques. Transmission electron microscopy (TEM) analysis confirms the almost globular morphology of the zirconia nanoparticles with a particle size of 15-25 nm. The chemical bonding interactions among various species were confirmed through Fourier-transform infrared spectroscopy (FTIR). The synergistic effect of self-healing agent and corrosion inhibitor in epoxy-based double-layer nanocomposite coatings demonstrated the pH and time dependence release of inhibitor and self-healing agent. A comparative electrochemical impedance spectroscopy (EIS) analysis conducted in 3.5 wt.% sodium chloride solution reveals that epoxy-based double layer nanocomposite coatings demonstrate improved corrosion resistance performance as compared to the blank epoxy coatings and single layer epoxy reinforced coatings. This enhanced corrosion resistance of epoxy-based double-layer nanocomposite coatings can be ascribed to the efficient release of loaded IM and PEI into the ZrO2 nanoparticles in response to the external stimuli (crack and pH change). The obtained results demonstrate that epoxy based double-layer nanocomposite coatings reported herein can be potentially considered to circumvent corrosion in the oil & gas and marine applications.
Share this page on your timeline