Comparison of the Corrosion Inhibiting Properties of Imidazole based Ionic Liquids on API X52 Steel in Carbon Dioxide Saturated NaCI Solution

摘要

The aim of this work is to investigate the corrosion inhibiting efficiency of four imidazolium ionic liquids in carbon dioxide saturated NaCI Brine solution by using electrochemical and surface analysis testing methods. The four compounds are 1-Ethyl-3-methylimidazolium chloride (Emc), 1-Butyl-3-methylimidazolium chloride (Bmc), 1-Hexyl-3-methylimidazolium chloride (Hmc), and 1-Decyl-3-methylimidazolium chloride (Dmc). Under the testing conditions, compound Dmc showed the highest inhibition efficiency. After 24 hours of immersion time in the inhibiting solution, the inhibiting efficiency reached 99%; SEM photos showed that the steel surface was well protected from uniform corrosion. The solution with Dmc showed an Open circuit potential (OCP) 70 mV higher than the one in blank solution. The testing results of Hmc also show inhibition properties in some degree. Compound Emc and Bmc showed no obvious corrosion-prevention properties, though the OCP changes indicated a slight influence. Scanning Electron Microscope (SEM) was used to characterize and support steel surface changes following the chemical (inhibitor) addition and electrochemical testing.