enhanced corrosion resistance of mild steel in molar hydrochloric acid solution by...

Enhanced corrosion resistance of mild steel in molar

hydrochloric acid solution by

1,4-bis(2-pyridyl)-5H-pyridazino[4,5-b]indole: Electrochemical,

theoretical and XPS studies

F. Bentiss a,c, F. Gassama b, D. Barbry b, L. Gengembre d,H. Vezin e, M. Lagrenee a, M. Traisnel f,*

aLaboratoire de Cristallochimie et Physicochimie du Solide, CNRS UMR 8012 ENSCL,

BP 90108, F-59652 Villeneuve d’Ascq Cedex, Franceb Laboratoire de Chimie Organique EA 2692, Bat. C4, USTL, F-59652 Villeneuve d’Ascq Cedex, France

c Laboratoire de Chimie de Coordination et d’Analytique, Universite Chouaib Doukkali,,

Faculte des Sciences, B.P. 20, El Jadida, Moroccod Laboratoire de Catalyse, CNRS UMR 80100, Bat. C3, USTL, F-59652 Villeneuve dAscq Cedex, France

eLaboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Bat C3,

F-59655 Villeneuve d’Ascq Cedex, Francef Laboratoire des Procedes d’Elaboration des Revetements Fonctionnels, UPRES EA 1040 ENSCL,

BP 90108, F-59652 Villeneuve d’Ascq Cedex, France

Received 9 January 2005; accepted 30 March 2005

Available online 6 June 2005

www.elsevier.com/locate/apsusc

Applied Surface Science 252 (2006) 2684–2691

Abstract

The inhibition effect of the new pyridazine derivative, namely 1,4-bis(2-pyridyl)-5H-pyridazino[4,5-b]indole (PPI) against

mild steel corrosion in 1 M HCl solutions was evaluated using weigh loss and electrochemical techniques (potentiodynamic

polarisation curves and impedance spectroscopy). The experimental results suggest that PPI is a good corrosion inhibitor and the

inhibition efficiency increased with the increase of PPI concentration, while the adsorption followed the Langmuir isotherm. X-

ray photoelectron spectroscopy (XPS) and theoretical calculation of electronic density were carried out to establish the

mechanism of corrosion inhibition of mild steel with PPI in 1 M HCl medium. The inhibition action of this compound was,

assumed to occur via adsorption on the steel surface through the active centres contained of the molecule. The corrosion

inhibition is due to the formation of a chemisorbed film on the steel surface.

# 2005 Elsevier B.V. All rights reserved.

Keywords: Corrosion inhibition; Mild steel; Pyridazine; HCl solution; Adsorption

* Corresponding author. Tel.: +33 320 436 658; fax: +33 320 436 658.

E-mail address: [email protected] (M. Traisnel).

0169-4332/$ – see front matter # 2005 Elsevier B.V. All rights reserved.

doi:10.1016/j.apsusc.2005.03.231

F. Bentiss et al. / Applied Surface Science 252 (2006) 2684–2691 2685

Fig. 1. Molecular structure of PPI.

1. Introduction

Acid solutions are generally used for removal of

undesirable scale and rust in several industrial

processes. The use of inhibitors is one of the most

practical methods for protection against corrosion in

acid solutions because they prevent metal dissolution

and acid consumption [1] and, during the past decade,

many inhibitors have been studied in different media

[2–8]. The mechanism of their action can be different,

depending on the metal, the medium and the structure

of the inhibitor. One possible mechanism is the

adsorption of the inhibitor, which blocks the metal

surface and thus do not permit the corrosion process to

take place. The existing data show that most organic

inhibitors get adsorbed on the metal surface by

displacing water molecules and form a compact

barrier film. Availability of lone pairs and p electrons

in inhibitors molecules facilitate electron transfer

from the inhibitor to the metal, the strength of the

resulting chemisorption bond depends on electronic

density on the donor atom of the functional group and

also on the polarisability of the group. It is well known

that heterocyclic compounds containing nitrogen

atoms are good corrosion inhibitors for many metals

and alloys in various aggressive media. The inhibiting

effect of some derivatives of indole on the corrosion of

mild steel or copper in acidic media has been reported

[9,10] as well as these of some pyridazine derivatives

[11].

The present work reports the use of a new

heterocyclic derivative, the 1,4-bis(2-pyridyl)-5H-

pyridazino[4,5-b]indole (PPI) which have the parti-

cularity to possess both indole and pyridazine parts,

as corrosion inhibitor in 1 M HCl medium. The

presence of several nitrogen atoms in PPI is an

opportunity to understand and explain the mechan-

ism of the inhibition and the type of adsorption on

the metal surface. The influence of PPI on the

corrosion inhibition in 1 M HCl solution was

investigated by weight loss measurements, electro-

chemical techniques: potentiodynamic polarisation

method and electrochemical impedance spectro-

scopy (EIS) and by X-ray photoelectron spectro-

scopy (XPS). Molecular modelling has been

conducted in attempt to correlate the corrosion

inhibition properties with the calculated quantum

chemical parameters [12,13].

2. Experimental details

2.1. Materials

The synthesis of the inhibitor, namely 1,4-bis(2-

pyridyl)-5H-pyridazino[4,5-b]indole (PPI) has been

described elsewhere [14–17]. PPI was prepared

through an inverse electron-demand Diels-Alder

reaction between 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine

and indole. Its molecular formula is shown in Fig. 1.

Mild steel strips composed of (wt%): 0.09% P, 0.38%

Si, 0.01% Al, 0.05% Mn, 0.21% C, 0.05% S, and

balance Fe were pre-treated prior to the experiments

by grinding with emery paper SiC (grades 600 and

1200), then cleaned in ultrasonic bath with ethanol,

rinsed with doubly distilled water and finally dried at

room temperature. The solutions (1 M HCl) were

prepared by dilution of an analytical reagent grade

37% HCl with doubly distilled water. The concentra-

tion range of PPI employed was 1 � 10�5 M to

1 � 10�4 M.

2.2. Weight loss measurements

Gravimetric experiments were carried out in a

double glass cell equipped with a thermostated cooling

condenser. The solution volume was 100 ml. The steel

specimens used have a rectangular form (length =

2 cm, width = 1 cm, thickness = 0.06 cm). The max-

imum duration of tests was 24 h at 30 8C � 1 8C in non-

de-aerated solutions. At the end of the tests, the

specimens were carefully washed in ethanol under

ultrasound and then weighed. Duplicate experiments

were performed in each case and the mean value of the

F. Bentiss et al. / Applied Surface Science 252 (2006) 2684–26912686

weight loss is reported. Weight loss allowed calculation

of the mean corrosion rate in mg cm�2 h�1.

2.3. Electrochemical techniques

Electrochemical experiments were carried out by

means of impedance equipment (Tacussel-Radiometer

PGZ 3O1) and controlled with Tacussel corrosion

analysis software (Voltamaster 4). Electrochemical

experiments were carried out in a standard glass three-

electrode cell with a capacity of 500 ml for polarisa-

tion curves and a polymethyl methacrylate (PMMA)

cell with a capacity of 1000 ml for electrochemical

spectroscopy measurements.

2.3.1. Polarisation curves

The electrochemical tests were performed as

follows: the disc formed working electrode exposing

surface of 1 cm2, the platinum counter-electrode and

the reference saturated calomel electrode (SCE) filled

in a Luggin’s capillary bridge were placed in a

conventional three-electrode glass cell. The solutions

under continuous agitation were deaerated by bub-

bling with a nitrogen stream at 30 8C. The potential

applied to the working electrode ranges from �800 to

0 mV at a rate of 500 mV s�1. The procedure adopted

for the polarisation measurements was the same as

described elsewhere [18]. Inhibition efficiencies were

determined from corrosion currents calculated by the

Tafel extrapolation method and fitting the curve to the

polarisation equation.

2.3.2. Electrochemical impedance spectroscopy

(EIS)

Impedance spectra were obtained using TACUS-

SEL RADIOMETER PGZ 3O1 Frequency Response

Analyser in a frequency range in the frequency range

100 kHz to 10 mHz with 10 points per decade at the

corrosion potential after 24 h of immersion. Tests were

performed in a PMMA cell with a capacity of 1000 ml.

Square sheets of mild steel of size (5 cm � 5 cm �0.06 cm), which exposed a 7.55 cm2 surface to the

agressive solution, were used as the working electrode.

All tests have been performed at 30 8C in non-de-

aerated solutions under unstirred conditions. After the

determination of steady-state current at a given

potential, sine wave voltages (10 mV) peak to peak

were superimposed on the rest potential. The

impedance data were analysed and fitted using

graphing and analysing impedance software, version

(Voltamaster 4).

2.4. X-ray photoelectron spectroscopy (XPS)

Rectangular mild steel specimens of dimensions

5 cm � 2 cm � 0.6 cm were immersed in 1 M HCl

with 1 � 10�4 M of PPI at 30 8C during 24 h. After

removal from acid solution, the sample was rinsed

with ethanol and then dried at room temperature. A

pure sample of PPI has also been analysed for

comparison. Surface analyses were performed with an

VG ESCALAB 220 XL spectrometer, using a

monochromated Al Ka X-ray source (1486.6 eV).

The experimental details of this analysis have been

previously reported by Bentiss et al. [18].

2.5. Theoretical calculations

Geometry optimisation was performed at the DFT

B3LYP level theory using 6-31G** basis set with

Gassian-98 program. The highest occupied molecular

orbital (HOMO) and the lowest unoccupied molecular

orbital (LUMO) were mapped with the second

function of the total electronic density using full

SCF matrix.

3. Results and discussion

3.1. Weight loss measurements

The weight loss of rectangular steel specimens

sized 5 cm � 2 cm � 0.05 cm in 1 M HCl without and

in the presence of various concentrations of inhibitor

was determined after 24 h of immersion in acid at

30 8C without bubbling. Values of the inhibition

efficiency E (%) obtained and corrosion rate are given

in Table 1. In this method, the inhibition efficiency can

be calculated by the relation:

Eð%Þ ¼�Wcorr �WcorrðinhÞ

Wcorr

�� 100 (1)

where W and Winh are the values of weight loss of steel

after immersion in solutions without and with inhi-

bitor, respectively.


Table 1

Corrosion rates of mild steel and inhibition efficiencies for various

concentrations of PPI in 1 M HCl after 24 h of immersion at 30 8C

Concentration

(M)

Corrosion

rate (mg cm�2 h�1)

Inhibition

efficiency E (%)

Blank 5.939 –

1 � 10�5 2.091 64.8

2 � 10�5 1.539 74.1

6 � 10�5 0.456 92.3

8 � 10�5 0.386 93.5

1 � 10�4 0.356 94.0

Table 2

Kinetic parameters for the corrosion of mild steel in 1 M HCl

containing various concentrations of PPI at 30 8C

Concentration

(M)

Ecorr

(mV/SCE)

Icorr

(mA cm�2)

bc

(mV dec�1)

E

(%)

Blank �476 534 157 –

1 � 10�5 �468 252 186 53.0

2 � 10�5 �458 107 182 79.9

6 � 10�5 �453 97 178 81.8

8 � 10�5 �450 77 180 85.5

1 � 10�4 �444 50 184 90.6

It can be clearly noticed that the corrosion rate

values of mild steel decrease when the inhibitor

concentration increases. The inhibition efficiency

increases with the concentration of PPI reaching a

maximum value (94%) at 10�4 M.

3.2. Polarisation curves

Both anodic and cathodic polarisation curves for

mild steel in 1 M HCl at various concentrations of PPI

at 30 8C are shown in Fig. 2. The extrapolation of the

Tafel straight line allows the calculation of the

corrosion current density (Icorr). The values of Icorr,

the corrosion potential (Ecorr) and the cathodic and

anodic Tafel slopes (bc), E (%) as function of PPI

concentrations are given in Table 2. In this case, the

inhibition efficiency is defined as follows:

Eð%Þ ¼ Icorr � IcorrðinhÞIcorr

� 100 (2)

where Icorr and Icorr(inh) are the corrosion current

density values without and with the addition of inhi-

bitor, respectively.

Fig. 2. Polarisation curves for mild steel in 1 M HCl containing

different concentration of PPI.

It is clear that the addition of PPI hindered the

acid attack on the steel electrode and a comparison

of curves, showed that, with respect to the blank,

increasing the concentration of the inhibitor gave rise

to a consistent decrease cathodic and anodic current

densities. Its presence caused an ennoblement of the

corrosion potential of mild steel and a change of the

cathodic Tafel slope (bc) (Fig. 2). As it is shown in

Fig. 2, the cathodic current–potential curves give rise

to parallel Tafel lines, which indicate that hydrogen

evolution reaction is activation controlled and that the

addition of the PPI does not modify the mechanism of

this process [19]. The results demonstrate that the

hydrogen reduction is inhibited and that the inhibi-

tion efficiency increases with inhibitor concentration.

In the anodic range, the polarisation curves of mild

steel show that the addition of PPI decreases current

densities in a large domain of potential. This result

suggest that this compound act as a mixed-type

inhibitor of the corrosion of mild steel in hydro-

chloric acid medium. It can be noticed that for

potential higher than �300 mV/SCE, the inhibitor

start to desorb. This potential can be defined as

the desorption potential. Similar behaviour have

been already reported for other organic compounds

[20,21].

E (%) increased with inhibitor concentrations

reaching a maximum (76.2%) for the higher con-

centration of PPI. The polarisation curves study also

confirms the inhibiting character of PPYobtained with

weight loss measurements, however, E (%) values

determined using polarisation curves were smaller

than those obtained by weight loss measurements.

The kinetic parameters for the corrosion of mild

steel in 1 M HCl indicate satisfactory inhibiting

efficiencies even at very low concentration (73.0% at

10�5 M). At higher concentrations (10�4 M) the


Table 3

Impedance parameters for the corrosion of mild steel in 1 M HCl

containing various concentrations of PPI after 24 h of immersion at

30 8C

Concentration

(M)

Rt

(V cm�2)

Cdl

(mF cm�2)

Erest potential

(mV/SCE)

E

(%)

Blank 20.2 785.1 �473 –

1 � 10�5 41.0 489.4 �448 50.5

2 � 10�5 69.5 229.1 �452 70.8

6 � 10�5 137.4 145.9 �457 85.3

8 � 10�5 170.1 125.8 �472 88.1

1 � 10�4 200.0 93.6 �453 90.2

inhibition efficiency is found to be higher when the

weight loss measurements or the EIS methods are

used: 94 (Table 1) and 90.2% (Table 3) respectively

instead of 90.6% (Table 2) obtained by the polariza-

tion curve. This difference was probably caused by the

shorter immersion time in the case of polarisation

curve measurements.

3.3. Electrochemical impedance spectroscopy

(EIS)

The impedance diagrams obtained after 24 h of

exposure of the samples at 30 8C in inhibited and

uninhibited solutions containing various concentration

of PPI are shown in Fig. 3. It is apparent from these

plots that the impedance response of mild steel in

uninhibited HCl solution has significantly changed

after the addition of PPI in the corrosive solution. This

indicates that the impedance of inhibited substrate

increases with increasing inhibitor concentration and

consequently the inhibition efficiency increases.

Fig. 3. Nyquist diagrams for mild steel of PPI after 24 h of

immersion in 1 M HCl containing different concentrations.

When the complex plane impedance contains a

‘‘depressed’’ semicircle with the center under the real

axis, such behaviour characteristic for solid electrodes

and often referred to as frequency dispersion have

been attributed to different physical phenomena such

as roughness and inhomogeneities of the solid surfaces

[22], impurities, dislocations, grain boundaries

[23,24], fractality [23,25], distribution of the active

sites, adsorption of inhibitors [18], formation of

porous layers [26]. Similar diagrams were described

elsewhere [12,13] for steel electrode with and without

organic inhibitors in 1 M HCl. In addition to the high

frequency loop, a low inductive frequency loop was

also observed (Fig. 3), indicating that a Faradaic

process is taking place on the free electrode sites. This

low inductive loop is generally attributed to the

adsorption of species resulting from the iron dissolu-

tion and the adsorption of hydrogen [27–29].

The impedance parameters such as the double layer

capacitance (Cdl), the charge-transfer resistance (Rt),

E (%) and the rest potential (Erestpot) derived from

Nyquist diagrams are given in Table 3. The charge-

transfer resistance Rt, values are calculated from the

difference in impedance at lower and higher frequen-

cies as suggested by Haruyama and Tsuru [30]. To

obtain the double-layer capacitance (Cdl), the fre-

quency at which the imaginary component of the

impedance is maximum (�Z00max) is found and Cdl

values are obtained from the equation.

f ð�Z 00maxÞ ¼

1

2pCdlRt

(3)

The inhibition efficiency is calculated as follows:

E% ¼�R�1 � R�1

R�1

�� 100 (4)

where Rtcorr and Rtcorr(inh) are the charge transfer

resistance values without and with inhibitor, respec-

tively.

The analysis of the electrochemical parameters

shows that the charge-transfer resistance increases with

the concentration of PPI. Seeing that, for a same

immersion time, the values of the double layer

capacitance (Cdl) decrease with increasing concentra-

tion of inhibitor. The double layer between the charged

metal surface and the solution is considered as an

electrical capacitor. The adsorption of the PPI on the


Fig. 5. N 1s XPS core-level spectra of steel surface exposed to 1 M

HCl + 10�4 M PPI solution during 24 h at 30 8C.

electrode decreases its electrical capacity because they

displace the water molecule and others ions originally

adsorbed on the surface. The decrease of this capacity

with increasing PPI concentrations may be attributed to

the formation of a protective layer at electrode surface.

Inhibition efficiency is found to increase with PPI

concentration. The inhibition efficiencies calculated

from ac impedance results show the same trend as those

obtained from dc polarisation and weight loss

measurements.

3.4. Theoretical calculations and surface

analysis results

When the frontier molecular orbital are analysed

(Fig. 4), it is observed that the highest occupied

molecular orbital (HOMO), is located for the most part

on the benzene ring of the indole system and on

nitrogen N1 and N2; these atoms are the active sites

for a nucleophilic attack and consequently the

favourable place for the interaction with the metallic

surface as it is observed in the XPS spectrum (Fig. 5)

of the adsorbed PPI.

The protection provided by PPI to mild steel in HCl

solutions was retained when specimens dipped in

acids containing the organic molecules were trans-

ferred into fresh HCl without inhibitor. PPI have a

strong tendency to stick to the steel surface. The PPI

molecules absorbed on the metal surface as it can be

supposed by the EIS studies which show a decreasing

of double layer capacitance values (Cdl).

Fig. 4. HOMO and LUMO map of PPI with respectively alpha (red)

and beta orbitals (green). (For interpretation of the references to

colour in this figure legend, the reader is referred to the web version

of the article.)

The presence of the PPI on the steel surface was

monitored using the characteristic N 1s signals (Fig. 5)

[30]. The XPS spectra were obtained for the steel

exposed to PPI as well as for the steel exposed to PPI

in 1 M hydrochloric acid medium. For comparison

purposes, the XPS spectra were also obtained for pure

PPI (Fig. 6, Table 4). Considering an isolated PPI

molecule, a two component N 1s peak is expected,

the two components being in the ratio 1:4 according

to the two PPI nitrogen species ( NH, N–) at

different bonding energies 399.9 and 399 eV, respec-

tively [31–33].

The XPS spectra show three peaks (Fig. 6, Table 4).

We may attribute the two majors peaks at a BE about

399.03 and 399.16 eV for the nitrogen’s 1–4 and 3–5,

respectively (Fig. 1) and the minor peak at a BE

399.9 eV at the nitrogen 2 (Fig. 1) [31,32]. The XPS

spectrum of the steel surface shows that PPI is present

but the relative proportions of the nitrogen species are

quite different from these observed with pure PPI. The

spectrum exhibits three major components at BE

398.05, 399.25 and 400.06 eV which can be attributed

[33] at the N–H adsorbed of indole part of the

molecule, N– pyridyl substituents and pyridazine

part of the molecule and NH indole respectively


Table 4

Bending energies of redox states of PPI and atomic concentration from surface XPS

Sample Bending energies (eV)

N2ads NHads N– N– NH –N+–H

Pure PPI 399.03 399.16 399.9

Concentration (%) 40 40 20

Steel and PPI 396.97 398.05 399.25 400.06 401.35

Concentration (%) 9 29 23 31 7

References [25] [25] [22–23] [22–23] [24] [24]

(Fig. 5, Table 4). Two small peaks are also observed at

BE 396.97 eV (N2ads), which comes from a partial

degradation of PPI [34] and 401.35 eV characteristic

of apparition of positively charged nitrogen, showing

that there has been oxidation or protonation [33].

3.5. Adsorption isotherm

Adsorption isotherms are very important in under-

standing the mechanism of organo electrochemical

reactions [35]. In order to obtain the isotherm, the

fractional coverage values Q, as a function of inhibitor

concentration, must be obtained. It is preferable to

Fig. 6. N 1s XPS core-level spectra of pure PPI.

evaluate the adsorption isotherm with AC impedance

study because the imposed sine wave voltages, at

10 mV peak to peak, does not disturb the surface,

therefore not desorption occurs in this case. Q can be

obtained from the impedance measurements as

described elsewhere [35]. A simple model connects

Cdl to Q: impedance measurements

Cdl;Qð1 �QÞCdlðQ¼0Þ þQCdlðQ¼1Þ (5)

where Cdl,Q is the Cdl with inhibitor, Cdl(Q=0) is the Cdl

without inhibitor, and Cdl(Q=1) is the Cdl of an entirely

covered surface. After rearrangement, the Q for differ-

ent concentrations of the inhibition in acidic media is:

u ¼Cdlðu¼0Þ � Cdl;u

Cdlðu¼0Þ � Cdlðu¼1Þ(6)

Q can also be evaluated from corrosion rate using the

equation:

u ¼ W �Winh

W(7)

In this study, attempts were made to fit these Q

values to various isotherms (Langmuir, Temkin,

Fig. 7. Langmuir adsorption plots for mild steel in 1 M HCl

containing different concentrations of PPI from capacitance values.


Frumkin,. . .). These models have been used for other

inhibitor systems [36]. By far the best fit was obtained

with the Langmuir isotherm (Fig. 7).

The plot of Cinh/Q versus Cinh yielded a straight

line, where Cinh is the inhibitor concentration (Fig. 7).

This was observed, clearly proving that the adsorption

of the PPI from 1 M HCl solutions on the steel surface

corresponds to the Langmuir isotherm model where,

Q ¼ bCinh

1 þ bCinh

ðLangmuir isothermÞ (8)

and where ‘‘b’’ designates the adsorption coefficient.

The strong correlation (r = 0.99) for the Langmuir

adsorption isotherm plot confirmed the validity of this

approach.

4. Conclusions

PPI inhibits the corrosion of mild steel in 1 M HCl

medium. The additions of inhibitor modified slightly

the cathodic Tafel slope and the Ecorr potential

increase with increasing concentrations. This shows

that PPI is more anodic than cathodic inhibitor. The

XPS spectrum shows that PPI is present on the steel

surface. The relative proportion of nitrogen species is

quite different from those observed with pure PPI; a

part of nitrogen is oxidised and other part is reduced.

Inhibition of corrosion by PPI is due to the formation

of chemisorbed film on the steel surface. Adsorption

of this inhibitor on the steel surface from HCl solution

follows the Langmuir isotherm.

Acknowledgements

The authors would like to thank the FEDER, the

CRNS, the ‘‘Region Nord-Pas de Calais’’ and the

‘‘Ministere de l’Enseignement Superieur et de la

Recherche Scientifique’’ for the their financial support

for the acquisition of the XPS spectrometer.

References

[1] J.M. Sykes, Br. Corros. J. 25 (1990) 175.

[2] G. Schmitt, Br. Corros. J. 19 (1984) 165.

[3] J.O’M. Bockcis, B.O. Yang, J. Electrochem. Soc. 138 (1991)

2237.

[4] C. Pillali, R. Narayan, Corros. Sci. 23 (1983) 151.

[5] F.B. Growcock, V.R. Lopp, Corros. Sci. 28 (1998) 397.

[6] M. Bartos, N. Hackeman, J. Electrochem. Soc. 139 (1992)

3429.

[7] F. Zucchi, G. Trabanelli, G. Brunoro, Corros. Sci. 33 (1992)

1135.

[8] S.L. Granesse, Corrosion 44 (1998) 322.

[9] G. Moretti, G. Quartarone, A. Tassan, A. Zingales, Werkst.

Korros. 45 (1994) 5.

[10] G. Moretti, G. Quartarone, A. Tassan, A. Zingales, Electro-

chim. Acta 41 (1996) 1971.

[11] A. Chetouani, A. Aouniti, B. Hammouti, N. Benchat, T.

Benhadda, S. Kertit, Corros. Sci. 45 (2003) 1675.

[12] F. Bentiss, M. Traisnel, H. Vezin, M. Lagrenee, Ind. Eng.

Chem. Res. 39 (2000) 3732.

[13] M. Lagrenee, B. Mernari, N. Chaibi, M. Traisnel, H. Vezin, F.

Bentiss, Corros. Sci. 43 (2001) 951.

[14] M. Takahashi, H. Ishida, M. Kohmoto, Bull. Chem. Soc. Jpn.

49 (1976) 1725.

[15] S.C. Benson, C.A. Palabria, J.K. Snyder, J. Org. Chem. 52

(1987) 4610.

[16] N. Haider, R. Wanko, Heterocycles 38 (1994) 1805.

[17] F. D. Gassama, Thesis UST Lille (2001).

[18] F. Bentiss, M. Traisnel, L. Gengembre, M. Lagrenee, Appl.

Surf. Sci. 152 (1999) 237.

[19] S. Kertit, B. Hammouti, Appl. Surf. Sci. 93 (1996) 59.

[20] W.J. Lorenz, F. Mansfeld, Corros. Sci. 21 (1981) 647.

[21] L. Elkadi, B. Mernari, M. Traisnel, F. Bentiss, M. Lagrenee,

Corros. Sci. 42 (2000) 194.

[22] K. Juttner, Electrochem. Acta 35 (1990) 1501.

[23] Z.B. Stoynov, B.M. Grafov, B. Savova-Stoynove, V.V. Elkin,

Electrochemical Impedance, Nauka, Moscow, 1991.

[24] F.B. Growcock, J.H. Jasinski, J. Electrochem. Soc. 136 (1989)

2310.

[25] A.H. Mehaute, G. Grepy, Solid State Ionics 910 (1989) 17.

[26] S. Veleva, A. Popova, S. Raicheva, in: Proceedings of the 7th

European Corrosion Inhibitors, Ferrara, 1990, p. 149.

[27] K.F. Khaled, N. Hackerman, Electrochim. Acta 48 (2003) 2715.

[28] J. Bessone, C. Mayer, K. Juttner, W.J. Lorenz, Electrochim.

Acta 28 (1983) 171.

[29] I. Epelboin, M. Keddam, H. Takenouti, J. Appl. Electrochem. 2

(1972) 71.

[30] T. Tsuru, S. Haruyama, Boshoku Gijutsu, J. Jpn. Soc., Corros.

Eng. 27 (1978) 573.

[31] F. Bentiss, M. Traisnel, L. Gengembre, M. Lagrenee, Appl.

Surf. Sci. 161 (1999) 237.

[32] C. D. Wagner, W. M. Riggs, L. E. Davis, J. F. Moulder,

Perking-Elmer Corporation, Physical Electronics Division.

[33] E.T. Kang, K.G. Neoh, K.L. Tan, Surf. Interf. Anal. 19 (1992) 33.

[34] K.L. Tan, B.T.G. Tan, E.T. Kang, K.G. Neoh, J. Mater. Sci. 27

(1992) 4056.

[35] N. Hackerman, E. McCafferty, In: Proceedings of the 5th

International Congress on Metallic Corrosion, Houston,

1974, p. 542.

[36] S. Bilgic, N. Caliskan, Appl. Surf. Sci. 152 (1999) 107.

enhanced corrosion resistance of mild steel in molar hydrochloric acid solution by...

Documents