ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

To evaluate an ionic liquid for anticorrosive impact on iron–carbon steel: synthesis, computational and experimental mechanism

Yadav Bhaskaran, P. D. Pancharatana, Raj Kishore Sharma, Gurmeet Kaur, Suman Lata, and Gurmeet Singh

Department of Chemistry, University of Delhi, Delhi, India

E-mail: sumanjakhar.chem@dcrustm.org

Received: 24 August 2020  Accepted: 29 August 2020

Abstract:

An ionic liquid (IL) comprising imidazolium moiety, specified as 3-(2,5-difluorobenzyl)-1-methyl-1H-imidazol-3-ium bromide [DFBMIm]Br is synthesized and applied, herein, for corrosion mitigation of iron–carbon (Fe–C) steel or mild steel in 0.5 M H₂SO₄ matrix. The studies were conducted after characterization of the synthesized IL with NMR and IR spectroscopy, for potentiodynamic polarization techniques and impedance spectroscopy for procuring the nature of IL for corrosion control, supplemented by SEM, X-ray (EDX) and AFM for getting knowledge about surface changes. Besides, DFTs, MD, adsorption kinetics and thermodynamical investigations for deep insights of adsorption mechanisms were computed. The IL shows good protection (with 99.39% efficiency through polarisation and 99.49% efficiency using EIS method), each as percent inhibition at 0.01 M and 298 K. Theoretical parameters using Jaguar—quantum mechanical engine for DFT and its comparison with Gaussian 09 program studies for the IL are also presented. Moreover, the interactions of the liquid over the metal substrate using Schrodinger–MS Suite for MD findings are corroborated with the estimable mechanism. Importantly, the electrical double layer-based model is also presented, specifically to support the practical observations for appreciable efficiency.

Keywords: Fe–C steel; Ionic liquid; EDL model; DFTs and MD; Corrosion mechanism

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01341-9

Chemical Papers 75 (2) 789–803 (2021)