Adsorption proprieties and inhibition of mild steel corrosion in HCl solution by the essential oil from fruit of Moroccan Ammodaucus leucotrichus

The essential oil from the fruits of ammodaucus leucotrichus (al oil) was studied by gas chromatography (gc) and gas chromatography-mass spectrometry (gc/ms). 10 components were identified accounting 94.7% of the total oil,which peryllaldehyde (73.5%) and limonene (12.5%) were the major compounds. the inhibitive effect of this essential oil on the corrosion of mild steel in 1m hcl solution was investigated by weight loss measurement as well as potentiodynamic polarization and electrochemical impedance spectroscopy (eis) techniques. from loss measurements,is clear that inhibition efficiency values increased with increase in inhibitor concentration but decreased with increase in temperature. polarization measurements showed that the studied inhibitor is mixed type with significant reduction of cathodic and anodic current densities. the results of eis measurements indicated that the corrosion of steel is mainly controlled by the charge transfer process. various activation and adsorption thermodynamic parameters are evaluated and discussed. linearity of langmuir isotherm adsorptions indicated the monolayer formation of inhibitor on mild steel surface.