Surface protection of mild steel using benzimidazole derivatives: experimental and theoretical approach

Abstract

Interaction of organic molecules with the surface of metals plays important role in many applications. In particular, surface protective applications need much explanation from both experimental and theoretical point of view. Herein, we have investigated the surface adsorption characteristics and corrosion inhibition behavior of two new benzimidazole derivatives namely 2-(2-Bromophenyl)-1H-benzimidazole (BPBA) and 2-(2-Bromophenyl)-1-methyl-1H-benzimidazole (BPMA) on mild steel in 0.5 M HCl solution using experimental and theoretical approach. Electrochemical and weight loss experiments were used to elucidate the corrosion inhibition potentials of BPBA and BPMA. Attenuated total reflectance-Fourier transform infrared spectroscopy, contact angle, scanning electron microscopy, and X-ray photoelectron spectroscopy measurements were performed to confirm the adsorption of BPBA and BPMA on mild steel surface. Computer simulations were further employed to provide additional insights into the mechanism of interaction between the inhibitors and the steel surface. All the results confirmed that BPMA is a better corrosion inhibitor for mild steel than BPBA in 0.5 M HCl. This new inhibitors could find application industrially during processes such as oil well acidizing for steel protection against corrosion.

Keywords:

• steel
• benzimidazoles
• DFT
• Monte Carlo simulation
• acid corrosion

Acknowledgments

The authors would like to acknowledge the support received from King Abdulaziz City for Science and Technology (KACST) for funding this work under the National Science Technology Plan (NSTIP) grant number 13-ADV1737-04. Also, the support provided by the Deanship of Scientific Research (DSR) and the Center of Research Excellence in Corrosion (CORE-C), at King Fahd University of Petroleum & Minerals (KFUPM) is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the King Abdulaziz City for Science and Technology (KACST) under the National Science Technology Plan (NSTIP) [grant number 13-ADV1737-04]. Also, the support provided by the Deanship of Scientific Research (DSR) and the Center of Research Excellence in Corrosion (CORE-C), at King Fahd University of Petroleum & Minerals (KFUPM).