Surface modification of ZrO2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating

The surface of ZrO₂ nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO₂ nanoparticles were used as an additive. The grafting performance and microstructure of the nano-ZrO₂/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO₂/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaCl solution using electrochemical impedance spectroscopy (EIS). Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO₂ nanoparticles. The epoxy coating containing 2 wt% modified ZrO₂ nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.