Studies on coatings containing nano‐zinc oxide for steel protection


Zinc oxide (ZnO) nanoparticles (NPs) were synthesized using the coprecipitation method. The resulting NPs were characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The surface morphology of the coatings has been characterized by scanning electron microscopy (SEM). SEM images show a uniform and homogeneous distribution of ZnO-NPs in polyurethane (PU) coatings while aggregates appear in epoxy coatings. Using tensile stress–strain test, the effect of the addition of ZnO-NPs on the mechanical properties of PU and epoxy coatings was examined. The addition of ZnO-NPs has enhanced the Young's modulus and the tensile strength of PU and epoxy coatings. Through the open-circuit potential and electrochemical impedance spectroscopy measurements, the anticorrosive properties of PU- or epoxy-coated mild steel panels containing ZnO-NPs have been investigated in 0.5 M NaCl solution. Nyquist impedance plots for PU and epoxy coatings in PU- or epoxy-coated mild steel panels containing ZnO-NPs were tested in the absence and presence of ZnO-NPs have different responses. It has been shown that the dispersion of ZnO-NPs significantly improves the anticorrosive performance of PU coatings. A PU coating containing 700 mg/kg ZnO-NPs is recommended to achieve better mechanical properties and corrosion resistance.

Journal/Conference Information

Materials and Corrosion,DOI: DOI: 10.1002/maco.202012010, Volume: 72, Issue: 5, Pages Range: 859-867,