Inhibition of copper corrosion by isatin in aerated 0.5 M H2SO4

doi:10.1016/S0010-938X(02)00134-8

Corrosion Science

Volume 45, Issue 4, April 2003, Pages 715-733

https://doi.org/10.1016/S0010-938X(02)00134-8 Get rights and content

Abstract

The corrosion inhibition of commercial copper by means of isatin was studied in aerated 0.5 M H₂SO₄ in the temperature range 25–55 °C using weight-loss, potentiodynamic and spectrophotometric tests, and determination of double layer capacitance. Inhibition efficiencies up to 94% in the concentration range of 1×10⁻⁴–7.5×10⁻³ M of isatin were obtained. The corrosion rates estimated with weight-loss measurements were higher than those correspondingly determined with the potentiodynamic test, especially at higher concentrations of inhibitor. This is in accord with other researches that have pointed out the limitation of the Tafel line extrapolation method in the determination of corrosion rates. The kinetics of cuprous and cupric ion formation and UV–visible spectra support the formation hypothesis of a complex between copper and isatin. The adsorptive behaviour of isatin on copper 0.5 M H₂SO₄ was also investigated.

Introduction

The chemical industry employs copper and its alloys extensively for condensers, evaporators, fractionating columns, etc. Copper does not displace hydrogen from acid solutions and it is therefore unattacked in non-oxidising acid environments. Nevertheless, most acidic solutions contain dissolved air that enables some corrosion to take place. Many organic molecules are used to inhibit copper corrosion [1], [2], [3], [4], [5], [6].

The primary step in the action of organic corrosion inhibitors in acid solutions is usually adsorption at the metal–solution interface. The adsorption process depends on the electronic characteristic of the molecules (adsorbate), the chemical composition of the solution, nature of the metal surface, temperature of the reaction and on the electrochemical potential at the metal–solution interface [7]. The adsorption requires the existence of attractive forces between the adsorbate and the metal. According to the type of forces, adsorption can be physisorption or chemisorption or a combination of both [8]. Physisorption is due to electrostatic attractive forces between inhibiting organic ions or dipoles and the electrically charged surface of the metal. Chemisorption is due to interaction between unshared electron pairs or π electrons with the metal in order to form a coordinate type of bond. It may take place in presence of heteroatoms (P, Se, S, N, O), with lone-pair electrons and/or aromatic rings in the adsorbed molecules [9], [10], [11], [12], [13].

Isatin is an indole derivative having two carbonyl groups in the 2 and 3 positions. The carbonyl group in the 3-position behaves like a ketone that is very reactive, the other has amidic behaviour [14]. Infrared evidence supports the following structure for isatin and gives no evidence for the enol form [15]:

In the present study the inhibition mechanism, efficiency and adsorptive behaviour of isatin on the corrosion of commercial copper were investigated in aerated 0.5 M H₂SO₄ solutions in the temperature range 25–55 °C.

Section snippets

Experimental

Copper corrosion inhibition in presence of isatin in aerated 0.5 M H₂SO₄ was investigated by means of potentiodynamic, gravimetric and spectrophotometric tests and determination of the double layer capacitance at the metal–solution interface.

Isatin was dissolved at concentrations in the range 1.0×10⁻⁴–7.5×10⁻³ M in aerated 0.5 M H₂SO₄ solutions. Commercial copper specimens (99.994% purity) were discs of 13 mm in diameter. Impurity contents (wt.-ppm): 26.3S, 9.4Ag, 7.9Fe, 7.7Ni, 7.1P, 1 (Sb, As,

Results and discussion

Fig. 2 shows some typical anodic and cathodic polarisation curves carried out at 35 °C in aerated 0.5 M H₂SO₄ in the absence and presence of various concentrations of isatin. From the polarisation curves the following electrochemical parameters were determined and listed in Table 2, Table 3: corrosion potential (E_corr), corrosion current density (i_corr) determined by extrapolation of the anodic Tafel line to the corrosion potential, limiting current density for oxygen reduction (i_L), potential

Conclusions

•
Isatin was found to be an effective inhibitor for commercial copper corrosion in aerated 0.5 M H₂SO₄ at higher concentrations in the temperature range 25–55 °C.
•
Some evidence was found for a different corrosion mechanism for copper in solutions containing isatin in contrast to aerated uninhibited solutions of 0.5 M H₂SO₄.
•
The difference between gravimetric and potentiodynamic corrosion rates emphasizes the limitation of the Tafel line extrapolation method in the determination of corrosion rates.
•

References (43)

M. Ohsawa et al.
Corros. Sci.
(1979)
J.W. Schultze et al.
Electrochim. Acta
(1987)
H. Vaidyanathan et al.
Corros. Sci.
(1971)
J.W. Schultze et al.
Electrochim. Acta
(1987)
R.C. Paul et al.
J. Inorg. Nucl. Chem.
(1969)
S. Trasatti
J. Electroanal. Chem.
(1971)
D. Altura et al.
Corrosion
(1972)
R.J. Chin et al.
Corrosion
(1973)
S.L.F.A. Da Costa et al.
Corrosion
(1989)
J.B. Cotton, Proc. 2nd Int. Congr. Met. Corrosion, New York, 1963 NACE, Houston, Texas, 1966, p....

G. Schmitt

Brit. Corros. J.

(1984)

V. Molokanov et al.

Corrosion

(1998)

G. Trabanelli

D.P. Schweinsberg et al.

Corros. Sci.

(1988)

J. Penninger et al.

Werkst. und Korros.

(1987)

H.A. El-Rahman

Corrosion

(1991)

M.M. Singh et al.

Corrosion

(1994)

R. Fusco et al.

D.G. O’Sullivan et al.

J. Chem. Soc.

(1956)

W.H. Ailor

G. Quartarone et al.

Corrosion

(1998)

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Inhibition of copper corrosion by isatin in aerated 0.5 M H2SO4

Abstract

Introduction

Section snippets

Experimental

Results and discussion

Conclusions

Corros. Sci.

Electrochim. Acta

Corros. Sci.

Electrochim. Acta

J. Inorg. Nucl. Chem.

J. Electroanal. Chem.

Corrosion

Corrosion

Corrosion

Brit. Corros. J.

Corrosion

Corros. Sci.

Werkst. und Korros.

Corrosion

Corrosion

J. Chem. Soc.

Corrosion

Inhibition of copper corrosion by isatin in aerated 0.5 M H₂SO₄