International Journal of Advanced Science and Research

Authors
Deivanayagam P, Malarvizhi I, Selvaraj S

Abstract
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; E_a, Q_ads ΔH_ads, ΔG_ads, ΔS_ads) 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.