Separations, solvation, and coordination of actinides in ionic liquids

In this work, the potential of using Ionic Liquids (ILs) in biphasic separation of actinides has been investigated taking a two way approach: getting a better understanding of ILs behavior in liquid/liquid and solid/liquid separations of actinides, and investigating the coordination environment of actinide ions in the presence of ILs in order to assess how these ionic solvents affect the coordination environment of the metal ions and subsequently could influence the liquid/liquid separation of metal ions.; The results presented here demonstrate for the first time, that separation schemes for the extraction of actinides into ILs can utilize the same extraction mechanism found in traditional solvents while preserving the same metal ion coordination. These findings offer new perspectives for designing targeted IL-based separations by balancing the combination of IL and ligand used. The results from the coordination studies indicate that when ions such as NO 3-, Cl-, or SO42- are the only ligands bound to the uranyl center, the metal ion coordination adopted is affected by the presence of ILs. However, in the presence of strong and sterically demanding ligands, the coordination environment of the metal ions is the same in ILs as it is in molecular solvents. The investigation of extraction mechanisms of actinide ions in IL/aqueous systems and the coordination environments of these metal ions in ILs has shed more light into the potential which ILs possess for these separation systems. Despite the ionic character of ILs, it is possible to attain advantageous actinide separation schemes in these new solvent media.