Environmentally Benign Water-Soluble Sodium L-2-(1-Imidazolyl) Alkanoic Acids as New Corrosion Inhibitors for Mild Steel in Artificial Seawater

Jiyaul Haque; Mohammad F Ridwan Zulkifli; Nabilah Ismail; Mumtaz A Quraishi; Mohd Sabri Mohd Ghazali; Elyor Berdimurodov; Wan Mohd Norsani Bin Wan Nik

doi:10.1021/acsomega.3c00366

Environmentally Benign Water-Soluble Sodium L-2-(1-Imidazolyl) Alkanoic Acids as New Corrosion Inhibitors for Mild Steel in Artificial Seawater

ACS Omega. 2023 Jul 5;8(28):24797-24812. doi: 10.1021/acsomega.3c00366. eCollection 2023 Jul 18.

Authors

Jiyaul Haque^{1

2}, Mohammad F Ridwan Zulkifli¹, Nabilah Ismail³, Mumtaz A Quraishi², Mohd Sabri Mohd Ghazali³, Elyor Berdimurodov⁴, Wan Mohd Norsani Bin Wan Nik¹

Affiliations

¹ Faculty of Ocean Engineering Technology and Informatics, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Malaysia.
² Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, India.
³ Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Malaysia.
⁴ Faculty of Natural Science, Karshi State University, Karshi 180119, Uzbekistan.

Abstract

Three novel natural amino acid-derived sodium L-2-(1-imidazolyl) alkanoic acids (IZSs), namely, sodium 2-(1H-imidazol-1-yl)-4-methylpentanoate (IZS-L), sodium 2-(1H-imidazol-1-yl)-3-phenylpropanoate (IZS-P), and sodium 2-(1H-imidazol-1-yl)-4-(methylthio)butanoate (IZS-M), were investigated as corrosion inhibitors. The IZSs were synthesized following the green chemistry principles, and their structure was characterized using FTIR and NMR techniques. The corrosion study results reveal that a moderate concentration of IZSs (having low solution conductivity) showed potential corrosion inhibition for mild steel in artificial seawater. At longer immersion, IZS-P forms a uniform protective film and exhibits the potential inhibition efficiency of 82.46% at 8.4 mmol L^-1. Tafel polarization results reveal that IZS-P and IZS-M act as mixed types with an anodic predominantly corrosion inhibitor. The electrochemical impedance spectroscopy results signify that IZSs inhibit mild steel corrosion through the formation of an inhibitor film on the metal surface, which was further confirmed by the FTIR, SEM, EDX, and XPS studies. DFT result shows that in IZS-P, the benzylic group (-CH₂-Ph) has greater electron distribution compared to isobutyl (-CH₂CH(CH₃)₂) in IZS-L and methythioethyl group (-CH₂CH₂SCH₃) which supported the corrosion inhibition performance at longer immersion [IZS-P (82.46%) > IZS-M (67.19%) > IZS-L (24.77%)].