The effect of graphene oxide nanosheets functionalized by Polyaniline Nanofibers doped with zinc cations on the corrosion resistance of epoxy coating on mild steel

摘要

The effect of graphene oxide nanosheets functionalized by Polyaniline Nanofibers doped with zinc cations on the corrosion resistance of epoxy coating on mild steel N.Taheri, B. Ramezanzadeh*[1], M.Mahdavian Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654, Tehran, Iran, Corresponding email address: Recently the graphene oxide nanosheets (GONs) have highly attracted the researchers' attention due to its extraordinary physical, electrical, chemical and barrier properties. Owing very high surface area the incorporation of GONs into the organic coatings gives an excellent metal protection due to the effective barrier properties. However, this system cannot provide any active corrosion protection when there is a slight mechanical damage to the coating. To overcome this problem, the GONs were modified by a highly crystalline and conductive polyaniline (PANI) nanofibers doped with zinc cations. The GONs functionalization by PANI was done through an in situ polymerization of aniline in the presence of GO as an oxidant. The zinc cations were added to the GO/aniline mixture to obtain a very conductive Emeraldine salt (ES) form of PANl-Zn with high capability of inhibition efficiency. By field-emission scanning electron microscopy (FE-SEM) the morphology, by Fourier transform infrared spectroscopy the chemical structure, and by X-ray diffraction (XRD) analysis the phase composition of GO/PANI-Zn were characterized. Finally, the influence of GO/PANI-Zn on the corrosion protection performance of epoxy nanocomposites was studied by electrochemical impedance spectroscopy (EIS) and salt spray test. Results revealed that inclusion of 0.1 wt.% GO/PANI-Zn into the epoxy coating remarkably enhanced its barrier and active corrosion inhibition performance.