Solvent extraction of cesium ions from aqueous solution to hydrophobic ionic liquids without the introduction of an organophilic anion in the aqueous phase was demonstrated using calixarene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) as an extractant. The selectivity of this extraction process toward cesium ions and the use of a sacrificial cation exchanger (NaBPh4) to control loss of imidazolium cation to the aqueous solutions by ion exchange have been investigated.
Luo, H. M., Dai, S., Bonnesen, P. V., Buchanan, A. C., Holbrey, J., Bridges, N. J., & Rogers, R. (2004). Extraction of cesium ions from aqueous solutions using calixarene-bis(tert-octylbenzo-crown-6) in ionic liquids. Analytical Chemistry, 76(11), 3078-3083. https://doi.org/10.1021/ac049949k