Alcoholic extract of “Gymnema Sylvestre” leaves on mild steel in acid medium Quinquefasciatus say
Deivanayagam P, Malarvizhi I, Selvaraj S
Effect of “Gymnema Sylvestre” leaves extract on corrosion of mild steel in 1.0 N hydrochloric acid was investigated by mass loss measurement with various period of contact and temperature. The observed results indicate that the corrosion inhibition efficiency was increased with increase of inhibitor concentration and decreased gradually with rise in temperature. The maximum percentage of inhibition efficiency attained 96.92%. The thermodynamic parameters (viz; Ea, Qads ΔHads, ΔGads, ΔSads) were evaluated for corrosion process, which suggest that the adsorption is exothermic, spontaneous and Physisorptions. The inhibitor follows Langmuir adsorption isotherm. The corrosion products formed on the metal surface was analyzed by using various spectroscopic studies UV, FT-IR and EDX techniques and the film formation also confirmed by SEM image.
Deivanayagam P, Malarvizhi I, Selvaraj S. Alcoholic extract of “Gymnema Sylvestre” leaves on mild steel in acid medium Quinquefasciatus say. International Journal of Advanced Science and Research, Volume 1, Issue 5, 2016, Pages 21-27