Synthesis of graphene oxide-based nanofillers and their influence on the anticorrosion performance of epoxy coating in saline medium

Abstract

The present study investigated the anticorrosion performance of epoxy coating by the incorporation of two different functionalized graphene oxides as nanofillers in saline media. GO was functionalized with 2-Aminothiazole (AT) and 2-amino-4-(1-Naphthyl)Thiazole (ANT) and modified compounds were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Raman spectroscopy, and Scanning electron microscopy (SEM). 0.2 wt% of neat epoxy and epoxy nanocomposites (GO-AT/EP and GO-ANT/EP) were coated on mild steel substrate by a spin coating method and the formation of a protective film on the steel surface was confirmed using SEM, Atomic Force Microscopy (AFM) and contact angle test. The electrochemical impedance spectroscopy was employed to study the corrosion protection properties of nanocomposite coatings in 3.5% NaCl medium. The results signify the better anticorrosion performance of nanocomposite coatings due to their two-dimensional sheet structures, uniform dispersion and exfoliation in the epoxy matrix, hydrophobic nature and stopping up tiny pores properties. The GO-ANT/EP coating exhibited higher coating resistance (6.598 × 107 Ω cm2) than GO-AT/EP (1.017 × 105 Ω cm2) and pure epoxy (1270 Ω cm2) coating. The crowded structure of GO-ANT helps in forming highly crosslinked compact epoxy coating and therefore displays excellent corrosion protection efficiency than other coatings.