Corrosion inhibition of mild steel with aqueous extract of Calotropis procera L. leaves in 1m HCl solution

The inhibition of mild steel (MS) in 1 M HCl solution with aqueous extract of Calotropis procera L. leaves (AECPL) was studied by weight loss method at 303-333K temperatures. It was found that inhibition efficiency increased with increase in concentration of extract and decreased with increase in temperature. Maximum 60.86%inhibition efficiency was observed at 303 K and at 8% (v/v) concentration of extract. Adsorption of extract at mild steel surface follows Langmuir adsorption isotherm. Physiorption is proposed by the values of Gibbs free energy, variation in inhibition energy with temperature and with activation energy values trend. Negative Gibbs energy reveals the spontaneity of inhibition process in extract at studied temperatures.