So far, tremendous efforts have been made by many researchers to develop methodologies for the production of pure Ionic Liquids (ILs), as pure ILs currently have become highly demandable in many sophisticated applications including catalysis, electrochemistry, fuel cells, batteries as solvents, electrolytes, working fluids, separation media, etc. Recently, our lab has introduced ITD (Ion Transfer Device), a modified electrodialyzer that has been used in many important analytical applications, can quantitatively transfer ions under the influence of an applied potential differences. Herein, we, for the first time, report a novel approach to synthesize highly pure ILs in a continuous flow in-line mode of production using an especially designed three-layered Anion Exchange Device (AED); a suited ITD, that can mix cations and anions quantitatively which is crucial for IL synthesis. Effects of current, concentrations and flow rates of solutions on the IL synthesis were studied carefully. Applying suitable conditions, we could successfully generate a series of ILs using several cations and anions to synthesize both hydrophilic and hydrophobic ILs with a purity of more than 98.5% to ~99.5%. The effect of the purity of source materials and the effect of water evaporation from the generated aqueous IL solution on the purity of the final product also has been studied. The purity of source materials greatly affected the purity of produced ILs while the evaporation of water simultaneously removed volatile impurities which eventually improved the quality of the final product. ‘Mixed-Ionic Liquids’ that got important applications too, could easily be generated using our method. Requiring no other solvents than water in the whole synthesis made the process essentially ‘green’. We carefully evaluated the purity with Ion Chromatography for the evaluation of the synthesized Ionic Liquids.

In-line electrodialytic synthesis of highly pure ionic liquids

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.