Utilization of hydrophobic ionic liquid as corrosion inhibitor for carbon steel

Abstract

This thesis focuses on the investigation of hydrophobic ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate, [bmim]PF6 as corrosion inhibitors on carbon steel immersed in hydrochloric acid media. It has been found that the combination of imidazolium cations and hexafluorophosphate anions resulted in improvements in inhibition. It has proposed that this inhibition arose due to the reactivity of PF6- in presence of [bmim]+ in corrosive solution. The performance of this inhibitor has been measured through open circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy. Morphology has been investigated by using scanning electron microscopy. Langmuir adsorption isotherm has followed the [bmim]PF6. The experimental results revealed that [bmim]PF6 protect the carbon steel surface by reducing both cathodic and anodic reactions. The maximum inhibition efficiency of 86.44% has achieved at the concentration of 50 mM. All results expressed that [bmim]PF6 in hydrochloric acid corrosive solution produced strong protective film at the carbon steel surface.