Servicios Personalizados
Revista
Articulo
Indicadores
- Citado por SciELO
- Accesos
Links relacionados
- Similares en SciELO
Compartir
Portugaliae Electrochimica Acta
versión impresa ISSN 0872-1904
Port. Electrochim. Acta v.27 n.4 Coimbra 2009
Inhibitive and Adsorption Properties of Ethanol Extract of Seeds and Leaves of Azadirachta Indica on the Corrosion of Mild Steel in H2SO4
N. O. Eddy,* P. A. P. Mamza
Department of Chemistry, Ahmadu Bello University, Nigeria
Received 18 December 2008; accepted 4 March 2009
Abstract
The corrosion of mild steel in H2SO4 was studied using gravimetric, gasometric and IR methods. The results indicate that the rate of corrosion of mild steel in H2SO4 increases with increase in the concentration of the acid and that ethanol extracts of the seeds and leaves of Azadirachta indica inhibit the corrosion of mild steel in H2SO4.Inhibition efficiencies of the leaves and seeds extract range from 82.62 to 94.24% and from 60.55 to 84.78%, respectively. The inhibition potential of these extracts is attributed to the presence of tannin, saponin, glycoside, anthraquinone, flavonone and other phytochemicals in the extracts. IR study confirms that the inhibitors are adsorption inhibitors and the adsorption of the inhibitors on mild steel surface is exothermic, spontaneous and consistent with the assumptions of Flory-Huggins adsorption isotherm. Based on the values of the activation, free energy of adsorption and the variation of inhibition efficiency with temperature, a physical adsorption mechanism is proposed for the adsorption of ethanol extract of leaves and seeds of Azadirachta indica on the surface of mild steel.
Keywords: corrosion, inhibition, Azadirachta indica leaves and seeds
Full text only in PDF format
Texto disponível em PDF
References
1. M. Abdallah, Portugaliae Electrochimica Acta 22 (2004) 161. [ Links ]
2. L. Anauda, R.A. Sathiyanathan, S.B. Maruthamuthu, M.C. Selvanayagam, S.B. Mohanan and N.B. Palaniswamy, Indian J. Chem. Tech. 12 (2005)
3. H. Ashassi-Sorkhabi, B. Shaabani, B. Aligholipour and D. Seifzadeh, Appl. Surf. Sci. 252 (2006) 4039.
4. M.A. Bendahou, M.B.E. Benadellah, B.B. Hammouti, Pigment and Resin Technol. 35 (2006) 95.
5. A. Bouyanzer and B. Hammouti, Pigment and Resin Technol. 33 (2004) 287.
6. A. Chetounani, B. Hammouti and M. Benkaddour, Pigment and Resin Technol. 33 (2004) 26.
7. E.E. Ebenso, U.J. Ibok, U.J. Ekpe, S. Umoren, J. Ekerete, O.K. Abiola, N.C. Oforka and S. Martinez, Trans. SAEST 39 (2004) 117.
8. N.O. Eddy, Inhibition of corrosion of mild steel by some antibiotics, Ph.D. Thesis, University of Calabar, 2008.
9. N.O. Eddy and E.E. Ebenso, African J. Pure Appl. Chem. 2(6) (2008) 1.
10. N.O. Eddy and S.A. Odoemelam, Pigment and Resin Technol. 38(2) (2009) 111.
11. A.O. Odiongenyi, S.A. Odoemelam and N.O. Eddy, Portugaliae Electrochimica Acta 27(1) (2009)33. [ Links ]
12. E.E. Ebenso, N.O. Eddy and A.O. Odiongenyi, Afri. J. Pure and Appl. Chem. 2 (2008) 107.
13. N.O. Eddy, P. Ekwumemgbo and S.A. Odoemelam, Inter. Journal Physical Sciences 3 (2008) 1.
14. N.O. Eddy, S.A. Odoemelam and A.O. Odiongenyi, J. Appl. Electrochem. DOI 10. 1007/s10800-008-9731 (2008).
15. N.O. Eddy, S.A. Odoemelam and N.W. Akpanudoh, J. Chem. Technol. 4 (2008) 1.
16. A.Y. El-Etre, Corros. Sci. 45 (2003) 2485.17. A.Y. El-Etre, Appl. Surface Sci. 252 (2006) 8521.
18. A.Y. El-Etre, M. Abdallah and Z.E. El-Tantawy, Corros. Sci. 47 (2005) 385.
19. S.A. Odoemelam and N.O. Eddy, J. Surface Sci. Technol. 24 (2008) 1.
20. I.G. Ndukwe, M.O. Achimugu and N.F. Amako, J. Pest, Diseases and Vector Mgt. 6 (2005) 391.
21. S.A. Odoemelam and N.O. Eddy. J. Materials Science 4 (2008) 1.
22. E.E. Oguzie, Corros. Sci. 49 (2007) 1527.
23. P.C. Okafor, V.I. Osabor and E.E. Ebenso, Pigment and Resin Technol. 36 (2007) 299.
24. R.A.I. Sathiyanathan, M.M.C. Essa, S.B. Maruthamuthu, M.A. Selvanayagam and N.B. Palaniswamy, J. Indian Chemical Society 82 (2005) 357.
25. M.G. Sethuraman and P.B. Raja, Pigment and Resin Tech. 34 (2005) 327.
26. D.S. Sheatty, P. Shetty and H.V.S. Nayak, Journal Chidean Chemical Society 51 (2006) 849.
27. H. Shokry, M. Yuasa, I. Sekine, R.M. Issa, H.Y. El-Baradie and G.K.G. Gomma, Corros. Sci. 40 (1998) 2173.
28. S.A. Umoren, I.B. Obot and E.E. Ebenso, E-Journal of Chemistry. 5 (2008) 355.
29. S.K. Rajappa, T.V. Venkatesha and B.M. Peaveen, Bull. Mater. Sci. 31 (2008) 37.
*Corresponding author. E-mail adress: nabukeddy@yahoo.com