Performance of imidazolium based ionic liquids as corrosion inhibitors in acidic medium: A review

Abstract

Corrosion is an acknowledged worldwide issue which has led to depletion of natural resources, reduction in efficiency and economic losses. The increased complexity and use of diverse materials have further extended it to a serious concern. Use of inhibitors as environment modifiers is nowadays playing an important role in supressing or mitigating the corrosion process. In the past two decades ionic liquids have emerged as promising green corrosion inhibitors. Among various chemical variants of ionic liquids those incorporating imidazole as the nucleus have been reported extensively due to their excellent corrosion resistant behavior on mild steel and other metals. This article reviews the recent developments in imidazolium based ionic liquids as corrosion inhibitors in acidic media on metals and alloy such as aluminum, copper, zinc and mild steel. Details of investigated data and techniques for characterization and their significance are also highlighted with respect to these ionic liquids. Outcomes of reported studies including maximum inhibition efficiency with varying metal and corrosive media have been summarized and analyzed. A critical analysis reveals that most of the imidazolium ionic liquids exhibit good corrosion inhibition behavior in sulphuric acid towards examined mild steel.

Keywords

• Imidazolium based ionic liquids (ImILs)
• Corrosion inhibitor (CI)
• Inhibition efficiency (IE)
• Metallic surface
• Adsorption
• Potentiodynamic polarization