Ionic liquid-assisted production of hydrophobic nanocomposite coating for mild steel corrosion prevention in saline medium

A dicationic ionic liquid, [BisOct (MIM)(2)][2Br], was successfully synthesized and used for the hydrothermal preparation of rod-shaped nanostructured ZnO with a basic hexagonal wurtzite growth unit. A hydrophobic nanocomposite coating of ZnO with polystyrene (ZnO/PS) was fabricated and characterized using Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The effect of nanocomposite coatings with different percentages of ZnO (1, 3, and 5 wt.%) was explored for mild steel corrosion protection in NaCl (3.5 wt.%) saline solution using electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), and FE-SEM. The EIS results showed a significant increase in the charge transfer resistance, with the highest value of 4.83 x 10(5) omega cm(2) in the presence of PS/ZnO-5, which acted as an efficient passivating barrier for the diffusion of corrosive ions. The results revealed that embedding ZnO nanorods significantly enhanced the corrosion-protection properties of the PS coating. The results of this study may contribute to the design of anticorrosive coatings for industrial applications. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

A dicationic ionic liquid was synthesized and used for the hydrothermal preparation of rod-shaped nanostructured ZnO. A hydrophobic nanocomposite coating of ZnO with polystyrene was fabricated, showing promising corrosion protection properties for mild steel.