Abstract

CORROSION INHIBITION OF ALUMINIUM IN ALKALINE MEDIUM USING CYANODON DACTYLON LEAVES EXTRACT

*K. Lakshmi Prabha, Shameela Rajam

ABSTRACT

Corrosion inhibition effect of cyanodon dactylon leaves (CDL) extract on aluminium in 1N NaOH medium has been investigated by weight loss, gasometric and electrochemical techniques. Inhibition efficiency of 76% was achieved with 800ppm CDL at 30°C. The polarization studies showed that CDL acts as mixed type inhibitor. The Nyquist plot showed that in presence of CDL extract charge transfer resistance increases and double layer capacitance decreases. Adsorption of CDL extract on aluminium surface follows Langmuir adsorption isotherm. The protective film formed on the surface of the aluminium was confirmed by SEM studies

Keywords: Aluminium , Cyanodon dactylon leaves extract, weight loss, potentiodynamic polarization studies, Mixed type inhibitor.