A thermodynamical, electrochemical, theoretical and surface investigation of diheteroaryl thioethers as effective corrosion inhibitors for mild steel in 1 M HCl
By Chandrabhan Verma and M.A. Quraishi and Ambrish Singh
Published in Taiwan Institute of Chemical Engineers
Elsevier Inc
2015
Abstract
The inhibition effect of three diheteroaryl thioethers (DHATs) namely 5,5’-thiobis (4-phenylthiazol-2amine) (DHAT-1), 4,4’-(5,5’-thiobis(2-aminothiozole-5,4-diyl)) diphenol (DHAT-2) and 4,4’-(5,5’-thiobis(2-aminothiazole-5,4-diyl))bis (benzene-1,3-diol) (DHAT-3) on mild steel corrosion in 1 M HCl was studied by weight loss, electrochemical, scanning electron microscopy (SEM), atomic force microscopy (AFM) and theoretical calculation methods. Among the studied compounds DHAT-3 exhibited maximum inhibition efficiency (η%) of 96.99% at 11.2 × 10–5 mol/L concentration. The potentiodynamic studies revealed that investigated DHATs act as mixed type inhibitors. Adsorption of the DHATs on the mild steel surface in 1 M HCl obeys the Langmuir adsorption isotherm. The results of theoretical calculation, SEM and AFM studies were found to be consistent with the weight loss and electrochemical results.