Gravimetric, electrochemical and surface study on the good’s buffer ionic liquid as corrosion inhibitor for carbon steel in acidic medium

Abstract

This corrosion study assessed the inhibition performance of carbon steel in 1 M of hydrochloric acid (HCl) using Good’s buffer ionic liquids (GBIL) namely 1-Butyl-3-methylimidazolium 2-(N-Morpholino) propane, [BMIM][MOPS] using electrochemical impedance, potentiodynamic polarization, and weight loss (gravimetric) measurements. GBIL are synthesized by the combination of Good's buffer as anion and various organic bases as the cation. The gravimetric measurements exhibit higher reduction in weight for carbon steel exposed to the acidic environment in the absence of corrosion inhibitor (CI) as compared to carbon steel immersed in the presence of inhibitor molecule. Potentiodynamic polarization study indicates that the synthesized inhibitor acted as a mixed type inhibitor. The inhibition efficiency increases with increase in the concentration of [BMIM][MOPS]. Corrosion protection efficiency ranging from 88% to 90% was featured at 800 ppm of CI in the HCl medium. The adsorption of [BMIM][MOPS] on the carbon steel surface was described by the Langmuir's adsorption isotherm. The scanning electron micrographs inspected the morphology of the carbon steel surface exposed to the solution without and with the presence of inhibitor. The result showed that compound effectively suppressed corrosion by the appearance of an improved surface structure of carbon steel with increasing concentration of [BMIM][MOPS].