Abstrakt

Inhibitive Effect of Aqueous Extract of Aloe Vera and Sodium Molybdate-Zn2+ System on Carbon Steel

R.Epshiba , A.Peter Pascal Regis , S.Rajendran

The Inhibition efficiency (IE) of various concentrations of a SM(Sodium molybdate)-Zn2+-Aloe vera system in controlling corrosion of mild steel immersed in well water was evaluated by a weight–loss study. The formulation consisting of 100 ppm of SM and 25 ppm of Zn2+ and 10ml of aloe vera extract showed 97% IE. A synergistic effect was noticed between SM-Zn2+-Aloe vera system. In the presence of aloe vera, SM-Zn2+ system has excellent inhibition efficiency. Polarization studies reveal that SM-Zn2+-Aloe vera system functions as a anodic inhibitor. AC impedance spectra suggest that a protective film is formed on the metal surface. FTIR spectra reveal that the protective film consists of Fe2+-SM complex and Fe2+-Aloe vera complex and Zn(OH)2.