A Study of the corrosion inhibition of aluminum in ethanol-gasoline blend by using Annona muricata leaves extract

Abstract

The effect of Annona muricata leaves extract as an inhibitor of green corrosion of aluminum was investigated 20% cane ethanol and 80% gasoline blend solution for 91 days of immersion. It was evaluated using gravimetric and electrochemical techniques such as electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and electrochemical noise (EN). The studies revealed that Annona muricata extract is an efficient corrosion inhibitor, reaching its highest efficiency at concentrations of 20 and 25 ppm. This decrease in the corrosion rate is because the inhibitor adsorbs to the aluminum surface by physisorption according to the Langmuir adsorption isotherm and demonstrated a more notable protective effect Fourier transform infrared spectroscopy (FTIR) and gas chromatography coupled with mass spectrometry (GC-MS) analyzes were performed, which showed the presence of phenolic compounds, lauric acid, palmitic acid, linoleic acid, vitamin E and other compounds with antioxidant properties. The morphology of the aluminum surface was examined by scanning electron microscopy (SEM), showing the existence of a protective layer of Annona muricata extract that reduces pitting corrosion susceptibility of aluminum.