INNOVATIVE APPLICATIONS OF IONIC LIQUIDS AS “GREEN” ENGINEERING LIQUIDS

Abstract

Over the past decade, ionic liquids (ILs) have become one of the fastest growing “green” media for chemists and engineers due to their superb physicochemical properties. The applications of these remarkable salts in reactions and extraction processes have been extensively investigated and reviewed. This review, however, highlights recent advances of ILs as versatile “green” engineering liquids in a variety of industrial applications including heat transfer fluids, azeotrope-breaking liquids, lubricants, electrolytes, liquid crystals, supported IL membranes, plasticizers, and more. This review is not intended to be comprehensive, but rather to discuss the potentials of ILs for diverse industrial applications.

Keywords:

• Electrochemistry
• Engineering fluid
• Green technology
• Heat transfer fluid
• Industrial application
• Ionic liquid

Acknowledgments

This project was partially supported by the NIH-EARDA grant (No. 5 G11 HD 32861-08) and the NIH-MBRS grant. This article greatly benefitted from the very constructive comments by three anonymous reviewers.

Notes

^a Data from (Lide, 2003).

^b Data from manufacturer's specifications.

^c Data from Van Valkenburg et al. (2005), where EMIM = 1-ethyl-3-methylimidazolium, BMIM = 1-butyl-3-methylimidazolium, DMPI = 1,2-dimethyl-3-propylimidazolium, Tf₂N = bis(trifluorosulfonyl)imide (CF₃SO₂)₂N⁻.

^d Data from Holbrey et al. (2003), where C₆MIM = 1-n-hexyl-3-methylimidazolium.

^e Data from Moens et al. (2003), where C₈MIM = 1-n-octyl-3-methylimidazolium.

^f Data from Wu et al. (2001).