AC impedance measurement of cystine adsorption at mild steel/sulfuric acid interface as corrosion inhibitor |
| |
Authors: | Muzaffer Özcan |
| |
Institution: | (1) Department of Science and Technology Education, Cukurova University, 01330 Adana, Turkey |
| |
Abstract: | Alternating current (AC) impedance measurements of mild steel/sulfuric acid interface in the absence and in the presence of
various concentrations of cystine (Cys–Cys) have been carried out in the 100 kHz–10 mHz frequency range. The results revealed
that Cys–Cys is a good and effective inhibitor for mild steel corrosion in 0.5 M H2SO4 and its percent inhibition efficiency changes with its concentration. Changes in impedance parameters indicated the adsorption
of Cys–Cys on the mild steel surface, which was verified by scanning electron microscope (SEM) and atomic force microscope
(AFM) photographs. Adsorption of Cys–Cys on mild steel surface was found to obey the Langmuir adsorption isotherm with a standard
free energy of adsorption of −33.2 kJ/mol. Energy gaps for the interactions between mild steel surface and Cys–Cys molecule were found to be close
to each other showing that Cys–Cys owns capacity to behave as both electron donor and electron acceptor. |
| |
Keywords: | Corrosion Inhibitor Adsorption Cystine AC impedance Quantum chemical calculations |
本文献已被 SpringerLink 等数据库收录! |