Abstract

ADSORPTION BEHAVIOUR AND CORROSION INHIBITION PROPERTIES OF AQUEOUS EXTRACT OF LEAVES OF NERIUN OLENDER L. IN HYDROCHLORIC ACID SOLUTION

Priya Bhardwaj*, Seema Agarwal and S. Kalpana

ABSTRACT

The inhibition of mild steel (MS) in 1 M HCl solution with aqueous extract of Nerium olender L.leaves (AENOL) 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 83.76%inhibition efficiency was observed at 303 K and at 10% (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 values of Gibbs energy reveals the spontaneity of inhibition process in extract at studied temperatures.

Keywords: Nerium oleander L., Corrosion, Langmuir adsorption isotherm, Mild steel, Weight loss method.