The purpose of this paper is to study the inhibition potential of ethanol extract of Citrus Sinesis Seed (CSS) on the corrosion of mild steel in 1M HCl using phytochemical screening, conventional weight loss, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and Quantum chemical analysis. The experimental results revealed that the Inhibition efficiency of the Citrus Sinesis seed extract increases with extracts concentration but decreases with time and temperaturein. The inhibition efficiency increases gradually reaching a maximum value of 96.72% within the first 2 hours at a concentration of 1.0g/l. the extract acts as an inhibitor because of its phytochemical composition and is adsorbed spontaneously on the surface of aluminium according to Langmuir adsorption isotherm. The mechanism of physical adsorption is proposed from the inhibition efficiency with temperature and the values of some kinetic and thermodynamic parameters were obtained. FTIR results showed that the inhibition mechanism was an absorption process through the functional groups present in the seed extract. Surface morphology also revealed that corrosion product confirmed the protection offered by the extract on the surface of the metal immersed in the acid media. Quantum chemical studies confirmed that inhibition was due to adsorption of active molecules leading to formation of a protective layer on surface of mild steel.
Keywords: Corrosion, Mild steel., Weight Loss, corrosion inhibitors, scanning electron microscopy quantum analysis
