Derris Indica Leaves Extract as a Green Inhibitor for the Corrosion of Aluminium in Alkaline Medium

Neha K Nambiar,1,2

D. Brindha,3

Parthipan Punniyakotti,1

B.R.Venkatraman3 

Subramania Angaiah1*Email

1Electro-Materials Research Laboratory, Centre for Nanoscience and Technology, Pondicherry University, Puducherry-605014, India.

2Department of Chemistry, CHRIST (Deemed to be University), Bengaluru-560029, India.

3PG & Research Dept. of Chemistry, Periyar EVR College, Trichy – 620023, India.

Abstract

The corrosion inhibitive effect of Derris indica leaves extract (DILE) on aluminium in 1M NaOHis investigated at different temperatures. For this purpose, weight loss studies and electrochemical methods including Tafel polarization and electrochemical impedance spectroscopy technique (EIS) are employed. Surface analysis of the treated and untreated aluminium coupons are done by using metallurgical microscopy. About 60.2% of maximum corrosion inhibition efficiency is attained with an optimum inhibitor concentration of 1.2 g/L. Both weight loss and electrochemical studies confirmed that DILE plays a crucial role in the formation of a protective layer over metal surfaces. Also,electrochemical measurements revealed that DILE behaves as a mixed type of corrosion inhibitor. The kinetic parameters and thermodynamic parameters are calculated using Arrhenius theory and transition state theory. Langmuir adsorption isotherm was found to be the best fit and physical adsorption mechanism was proposed.

Derris Indica Leaves Extract as a Green Inhibitor for the Corrosion of Aluminium in Alkaline Medium