TY  - JOUR
AU  - Lebrini, M.
AU  - Robert, F.
AU  - Vezin, H.
AU  - Roos, C.
PY  - 2010//
TI  - Electrochemical and quantum chemical studies of some indole derivatives as corrosion inhibitors for C38 steel in molar hydrochloric acid
T2  - Corrosion Sci.
JO  - Corrosion Science
SP  - 3367
EP  - 3376
VL  - 52
IS  - 10
PB  - PERGAMON-ELSEVIER SCIENCE LTD
KW  - Steel
KW  - EIS
KW  - Raman spectroscopy
KW  - Polarization
KW  - Acid inhibition
N2  - A comparative study of 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane) as inhibitors for C38 steel corrosion in 1 M HCl solution at 25 degrees C was carried out. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of different concentrations of these inhibitors. The OCP as a function of time were also established. Cathodic and anodic polarization curves show that norharmane and harmane are a mixed-type inhibitors. Adsorption of indole derivatives on the C38 steel surface, in 1 M HCl solution, follows the Langmuir adsorption isotherm model. The Delta G degrees(ads) values were calculated and discussed. The potential of zero charge (PZC) of the C38 steel in inhibited solution was studied by the EIS method, and a mechanism for the adsorption process was proposed. Raman spectroscopy confirmed that indole molecules strongly adsorbed onto the steel surface. The electronic properties of indole derivates, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR). (C) 2010 Elsevier Ltd. All rights reserved.
SN  - 0010-938X
N1  - ISI:000281315500026
ID  - Lebrini_etal2010
ER  -