Corrosion Inhibition of Zinc on HCl using Nypa fruticans Wurmb Extract and 1,5 Diphenyl Carbazone

Abstract

The corrosion inhibition of zinc in hydrochloric acid by extract of Nypa Fruticans Wurmb was studied using weight loss techniques. Maximum inhibition efficiency (and surface coverage) was obtained at an optimum concentration. However increase in temperature decreased the inhibition efficiency at the temperature range studied. The inhibition action of Nypa Fruticans Wurmb extract compared closely to that of 1, 5 Diphenyl Carbazone (DPC). Optimum inhibition efficiency for zinc in the presence of Nypa Fruticans Wurmb extract was 36.43% and 40.70% with DPC. The phenomenon of physical adsorption has been proposed from the activation energy values (19.33 kJ mol^-1 and 21.11 kJ mol^-1) with Nypa Fruticans Wurmb extract and DPC respectively. A first order kinetics has been deduced from the kinetic treatment of the results. The heat of adsorption, Qad range from (-33.63 to - 58.52 kJ mo l^-1) for both additives studied. Mean ΔGoads values (-7.82 to 8.68 kJ mol^-1) are negative and suggestive of adsorption on metal surface. The data obtained from this study fits well into the Langmuir isotherm. Evidence is hereby provided to show that Nypa Fruticans Wurmb extract and DPC inhibits the corrosion of zinc comparatively.


Journal of Applied Sciences and Environmental Management Vol. 8 (1) 2004:57 - 61