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Journal of Applied Electrochemistry

, Volume 31, Issue 9, pp 973–978 | Cite as

Inhibitory mechanism of low-carbon steel corrosion by mimosa tannin in sulphuric acid solutions

  • S. Martinez
  • I. Štern
Article

Abstract

Mimosa tannin was investigated as inhibitor of low-carbon steel sulphuric acid corrosion in concentrations from 10−5 to 10−1 mol L−1, at the temperature of 298 K in the solutions of pH 1, 2 and 3. The inhibitor effectiveness increases with increase in concentration. The adsorptive behaviour of mimosa tannin in solutions of pH 1 and 2 may be approximated, both by Temkin and Frumkin type isotherms, probably due to the chemisorption of tannin molecules on the metal surface. The free energies of adsorption are in the range from −35.1 to −39.5 kJ mol−1. At pH 3, a Freundlich type isotherm is obeyed, probably due to the physisorption of ferric-tannate that forms at this pH, both on the metal surface and in the bulk electrolyte. The free energy of adsorption at pH 3 is −11.8 kJ mol−1. The activation energy of the iron dissolution process at pH 1 was found to be 51.4 kJ mol−1 and decreased to 48.0 kJ mol−1 on the addition of 1.25 × 10−2 mol L−1 mimosa tannin. The addition of the same amount of mimosa tannin into solutions of pH 2 and 3, increased the activation energy of iron dissolution from 15.6 to 34.3 kJ mol−1 and from 12.0 to 19.2 kJ mol−1, respectively.

activation energy adsorption energy adsorption isotherm inhibitor steel tannin 

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References

  1. 1.
    A.J. Seawell, J. Oil Col. Chem. Assoc. 61 (1978) 439.Google Scholar
  2. 2.
    M. Favre and D. Landolt, Proceedings of the 7th European symposium on 'Corrosion Inhibitors', Ann. Univ. Ferrara (1990), p. 787.Google Scholar
  3. 3.
    J. Iwanow and Yu.I. Kuznetsow, Proceedings, op. cit. [2], p. 795.Google Scholar
  4. 4.
    S. Martinez and I. Štern, Chem. Biochem. Eng. Q. 13 (1999) 191.Google Scholar
  5. 5.
    R.M. Saleh, A.A. Ismail and A.A. El Hosary, Br. Corros. J. 17 (1982) 131.Google Scholar
  6. 6.
    I.H. Farooqi, A. Hussaiin, M.A. Quaraishi and P.A. Saini, Anti-Corros. 46 (1999) 328.Google Scholar
  7. 7.
    I.L. Rozenfeld, 'Corrosion Inhibitors' (McGraw-Hill, New York, 1981), p. 97.Google Scholar
  8. 8.
    A.E. Stoyanova, E.I. Sokolova and S.N. Raicheva, Corros. Sci. 39 (1997) 1595.Google Scholar
  9. 9.
    M.M. Osman, A.M.A. Omar and A.M. Al-Sabagh, Mat. Chem. Phys. 50 (1997) 271.Google Scholar
  10. 10.
    W. Durnie, R. De Marco, A. Jefferson and B. Kinsella, J. Electrochem. Soc. 146 (1999) 1751.Google Scholar
  11. 11.
    B.I. Podlovchenko and B.B. Damaskin, Elektrohimia 8 (1972) 297.Google Scholar
  12. 12.
    B.E. Conway, 'Principles of Electrode Processes' (Ronald Press, New York, 1965), p. 78.Google Scholar
  13. 13.
    D.D. Do, 'Adsorption Analysis: Equilibria and Kinetics' (Imperial College Press, London 1998), p. 10.Google Scholar
  14. 14.
    A.E. Martell and M. Calvin, 'Chemistry of Metal Chelates Compounds' (Prentice-Hall, New York, 1953), p. 28.Google Scholar
  15. 15.
    S.H. Pine, 'Organic Chemistry' (McGraw-Hill, New York, 1987), p. 100.Google Scholar
  16. 16.
    M. Favre and D. Landolt, Proceedings op. cit. [2], p. 787.Google Scholar
  17. 17.
    P.J. DesLauriers, Mater. Perform. 26 (1987) 35.Google Scholar
  18. 18.
    E. Knowles and T. White, J. Oil. Colour Chem. Assoc. 41 (1958) 10.Google Scholar
  19. 19.
    M. Metikoš-Huković, R. Babić, Z. Grubač and S. Brinić, J. Appl. Electrochem. 26 (1996) 443.Google Scholar
  20. 20.
    D. Altura and K. Nobe, Corrosion 29 (1973) 433.Google Scholar
  21. 21.
    F. Bentiss, M. Traisnel, L. Gengembre and M. Lagrenee, Appl. Surf. Sci. 152 (1999) 237.Google Scholar
  22. 22.
    T. Szauer and A. Brandt, Electrochim. Acta 26 (1981) 943.Google Scholar
  23. 23.
    S. Sankarapapavinasan, F. Pushpanaden and M. Ahmed, Corros. Sci. 32 (1991) 193.Google Scholar

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • S. Martinez
    • 1
  • I. Štern
    • 1
  1. 1.Department of Physical Chemistry, Faculty of Chemical Engineering and TechnologyUniversity of ZagrebZagrebCroatia

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