GREEN INHIBITION OF COPPER CORROSION BY AMMOIDES VERTICILLATA OIL IN 1M NITRIC ACID: WEIGHT LOSSAND RAMAN SPECTROSCOPIC MAPPING STUDIES

Abstract

The present study was designed to predict and analyse the effect of the essential oil of Ammoides verticillata (A.E.O) originating from the city of Souahlia (Tlemcen), which is located in northwest Algeria and its major compound on the inhibition of copper corrosion in 1 M HNO3. According to the analysis gas chromatography coupled to mass spectrometry (GC-MS), the essential oil studied is dominated by carvacrol (67.89%). The effect of concentration and temperature on the corrosion behaviour of copper and the inhibitory efficiency has been studied by the gravimetric method. The results obtained show that A.E.O and carvacrol alone present a good inhibition for copper in 1 M HNO3. The inhibitory efficiency reaches a maximum value of 63% at 1.5 g/L for A.E.O and 79% at 0.1 g/L for carvacrol. The adsorption of A.E.O and carvacrol alone on the copper surface follows the Langmuir and Frumkin isotherm respectively. Synergy parameter proves that there is a competitive adsorption between iodide ions and A.E.O. The immersed copper surface was analysed by Raman spectroscopy.