0.5), but values of inhibition efficiency tend to decrease with increasing concentration of the acid. The adsorption of clarithromycin on zinc surface is endothermic, spontaneous and is best described by Langmuir adsorption isotherm. Calculated values of activation energies and free energies of adsorption indicate that the adsorption of clarithromycin on zinc surface supports the mechanism of physical adsorption.]]>
E.C. Ogoko,1 S.A. Odoemelam,1 B.I. Ita,2 N.O. Eddy3,*
1 Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
2 Department of Chemistry, University of Calabar, Calabar, Cross River State, Nigeria
3 Department of Chemistry, Ahmadu Bello University, Zaria, Kaduna State, Nigeria
Received 30 May 2009; accepted 28 October 2009
Abstract
]]> The corrosion of zinc in 0.01 to 0.04 M H2SO4 was studied using gravimetric and gasometric methods of monitoring corrosion. The results obtained indicate that clarithromycin is a good adsorption inhibitor for the corrosion of zinc in H2SO4. The inhibition efficiency of clarithromycin increases with increasing concentration but decreases with increasing temperature. There was no significant difference between the inhibition efficiencies of clarithromycin obtained at various concentrations of H2SO4 (P>0.5), but values of inhibition efficiency tend to decrease with increasing concentration of the acid. The adsorption of clarithromycin on zinc surface is endothermic, spontaneous and is best described by Langmuir adsorption isotherm. Calculated values of activation energies and free energies of adsorption indicate that the adsorption of clarithromycin on zinc surface supports the mechanism of physical adsorption.Keywords: corrosion, inhibition, clarithromycin
Full text only in PDF format
Texto disponível em PDF
References
1. A.Y. El-Etre, Appl. Surface Sci. 252 (2006) 8521.
2. K.C. Emregul and M. Hayvali, Corrosion Sci. 48 (2006) 797.
3. H. Wang, X. Wang, H. Wang, L. Wang and A. Liu, J. Mol. Model. 13 (2007) 147.
]]> 4. R.A.I. Sathiyanathan, M.M.C. Essa, S.B. Maruthamuthu, M.A. Selvanayagam and N.B. Palaniswamy, J. Indian Chemical Society 82(4) (2005) 357.5. M.G. Sethuraman and P.B. Raja, Pigment and Resin Tech. 34(6) (2005) 327.
6. S.K. Rajappa, T.V. Venkatesha and B.M. Praveen, Bull. Mater. Sci. 31(1) (2008) 37.
7. J. Dobryszycki and S. Biallozor, Corrosion Sci. 43(7) (2001) 1309.
8. M. Masamitsu, Coating Technol. 34 (10) (1999) 378.
9. A.A. Ahmed and S. Abdel-Hakam, Anti-corrosion methods and Materials 36(3) (1989) 4.
10. K. Aramaki, Corrosion Sci. 44(4) (2002) 871.
11. Y.K. Agrawal, J.D. Talati, M.D. Shah, M.N. Desai and N.K. Shah, Corrosion Sci. 46 (2004) 633.
12. S. Rajendran, J. Jeyasundari, P. Usha, J.A. Selvi, B. Narayanasamy, A.P.P. Regis and P. Rengan, Portugaliae Electrochimica Acta 27(2) (2009) 153. [ Links ]
13. S.A. Odoemelam and N.O. Eddy, Mater. Sci. 4(1) (2008) 1.
]]> 14. B. Muller, M. Schubert and G. Kinet, Pigment and Resin Technol. 28(5) (1999) 279.15. R.T . Vashi and Champaneri, Indian J. Chem. Technol. 4 (1997) 180.
16. R. Solmaz, G. Kardas, B. Yazici and M. Erbil, Protections of Metals 4(16) (2005) 581.
17. K. Orubite-Okorosaye and N.C. Oforka, J. Appl. Sci. Environm. Mgt. 8(1) (2004) 57.
18. A.S. Fouda, H.A. Mostafa and M.N. Moussa, Portugaliae Electrochimica Acta 22 (2005) 275. [ Links ]
19. A.S. EL-Gaber, A.S. Fouda, A.M. El Desoky, Ciência & Tecnologia dos Materiais 20(3/4) (2008) 71. [ Links ]
20. S.T. Arab and A.M. Turkustuni, Portugaliae Electrochimica Acta 24 (2006) 53-69. [ Links ]
21. M.M. Attar and J.D. Scantlebury, JCSE 8(1) (2005) 97.
22. M.M. Ahmed, Portugaliae Electrochimica Acta 24 (2006) 1. [ Links ]
23. O.K. Abiola, N.C. Oforka, E.E. Ebenso and N.M. Nwinuka, Anti-Corrosion Methods Materials 54(4) (2007) 219.
]]>24. A.O. Odiongenyi, S.A. Odoemelam and N.O. Eddy, Portugaliae Electrochimica Acta 27(1) (2009), 33. [ Links ]
25. P.C. Okafor and E.E. Ebenso, Pigment and Resin Technol. 36 (3) (2007) 134.
26. P.C. Okafor, V.I. Osabor and E.E. Ebenso, Pigment and Resin Technol. 36(5) (2007) 299.
27. P.C. Okafor, M.I. Ikpi, I.E. Uwah, E.E. Ebenso, U.J. Ekpe and S.A. Umoren, Corros. Sci. doi:10.1016/j.corsci.2008.05.009.
28. M. Abdallah, Portugaliae Electrochimica. Acta 22 (2004) 161. [ Links ]
29. E.E. Ebenso, N.O. Eddy and A.O. Odiongenyi, Afri. J. Pure Appl. Chem. 4(11) (2008) 107.
30. M.A. Bendahou, M.B.E. Benadellah and B.B. Hammouti, Pigment Resin Technol. 35(2) (2006) 95.
31. M. Abdallah, Corrosion Sci. 44 (2002) 717.
32. M. Abdallah, Corrosion Sci. 46 (2004) 1981.
33. N.O. Eddy, S.A. Odoemelam and A.J. Mbaba, Afri. J. Pure Applied Chem. 2(12) (2008) 132.
]]> 34. N.O. Eddy, U.J. Ibok, E.E. Ebenso, A. El Nemr and E.H. Ashry, J. Molecular Modelling. DOI 10.1007/s00894-009-0472-7.35. E.E. Ebenso, N.O. Eddy and A.O. Odiongenyi, Portugaliae Electrochimica Acta 27(1) (2009) 13. [ Links ]
36. S.A. Odoemelam, E.C. Ogoko, B.I. Ita and N.O. Eddy, Portugaliae Electrochimica Acta 27(1) (2009) 57. [ Links ]
37. N.O. Eddy, S.A. Odoemelam and P.A. Ekwumemgbo, Scientific Research and Essay 4 (1) (2009) 033.
38. N.O. Eddy, S.A. Odoemelam and N.W. Akpanudoh, Research J. Pure Applied Sciences 4(12) (1963)1973.
39. S.A. Umoren, I.B. Obot and E.E. Ebenso, E-Journal of Chemistry 5 (2008) 355.
40. H. Shokry, M. Yuasa, I. Sekine, R.M. Issa, H.Y. El-Baradie and G.K.G. Gomma,. Corrosion Sci. 40(12) (1998) 2173.
41. D.S. Sheatty, P. Shetty and H.V.S. Nayak, Journal. of Chidean Chemical Society 51(2) (2006) 849.
42. K.K. Sharma and L.K. Sharma, A Textbook of Physical Chemistry. 4th edition, Vikas Pub, House PVT Ltd, India.
43. M.G. Sethuran and P.B. Raja, Pigment Resin Technol. 34(6) (2005) 327.
]]> 44. A. Chetounani, B. Hammouti and M. Benkaddour, Pigment Resin Tech. 33 (2004) 26.
* Corresponding author. E-mail address: nabukeddy@yahoo.com
]]>