African Journal of
Pure and Applied Chemistry

  • Abbreviation: Afr. J. Pure Appl. Chem.
  • Language: English
  • ISSN: 1996-0840
  • DOI: 10.5897/AJPAC
  • Start Year: 2007
  • Published Articles: 335

Full Length Research Paper

Eco-friendly chalcones derivatives as corrosion inhibitors for carbon steel in hydrochloric acid solution

A. S. Fouda1*, M. A. Elmorsi2 and A. Elmekkawy1
  1Department of Chemistry, Faculty of Science, El-Mansoura University, El-Mansoura-35516, Egypt. 2Department of Chemistry, Faculty of Science, Tanta University, Tanta- 31511, Egypt.
Email: [email protected]

  •  Accepted: 18 September 2013
  •  Published: 31 October 2013

Abstract

 

The inhibiting effect of some chalcones derivatives on the corrosion of carbon steel in 1 M HCl was studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The results showed that the inhibition efficiency increases with increasing the inhibitor concentration, while it decreases with increasing the temperature. The adsorption of chalcones derivatives on the carbon steel surface obeys Langmuir adsorption isotherm. Some thermodynamic parameters were calculated and discussed. The values of free energy of adsorption for investigated inhibitors were calculated. Polarization curves showed that chalcones derivatives are mixed-type inhibitors but the cathode is more polarized than the anode. The variation in inhibition efficiency depends on the type of the substituent groups in the benzene ring. It was found that the presence of donating group (such as OCH3) better facilitates the adsorption of molecules on the surface than in the case with withdrawing groups (such as – Cl and NO2). The data obtained from the four different methods were in good agreement.

 

Key words: Carbon steel, HCl, corrosion inhibition, electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM), chalcones derivatives.

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