Separation of Fission Products Based on Ionic Liquids: Anion Effect
The applications of ionic liquids (ILs) as new separation media have been actively investigated recently. The most commonly studied class of ILs for such applications is based on dialkyl imidazolium cations. In comparison with conventional molecular solvents, ILs exhibit enhanced distribution coefficients for a number of complexing neutral ligands in extraction of metal ions from aqueous solutions. The effect of the alkyl chain length of imidazolium cations on the distribution coefficients of solvent extraction using crown ethers was the subject of a number of the previous investigations. The distribution coefficients have been found to decrease with the alkyl chain length of the IL cations. This observation implies that the extraction process also involves the exchange of the IL cations with metal ions. The longer the alkyl chain lengths of the IL cations are, the more hydrophobic the IL cations are and the more difficult to be transported into aqueous phases via ion exchange. Accordingly, the ion-exchange process is another unique property of IL-based extractions involving charged species. Here, we report the investigation about the effect of the variation of IL anions on the solvent extraction of metal ions using crown ethers as extractants. The elucidation of different solvation effects involved in ionic liquids could lead to optimized separation media for these novel solvents.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC) (US)
- DOE Contract Number:
- AC05-0096OR22725
- OSTI ID:
- 825838
- Resource Relation:
- Conference: 227th American Chemical Society Meeting, Anaheim, CA (US), 03/28/2004--04/01/2004; Other Information: PBD: 28 Mar 2004
- Country of Publication:
- United States
- Language:
- English
Similar Records
Extraction Separation of Rare-Earth Ions via Competitive Ligand Complexations between Aqueous and Ionic-Liquid Phases
Extraction of Tetra-oxo Anions into a Hydrophobic, Ionic Liquid-Based Solvent Without Concomitant Ion Exchange