Award Date

8-2011

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Radiochemistry

Department

Chemistry

First Committee Member

Kenneth Czerwinski, Chair

Second Committee Member

David Hatchett

Third Committee Member

Alfred Sattelberger

Graduate Faculty Representative

Ralf Sudowe

Number of Pages

188

Abstract

Room temperature ionic liquids (RTILs) are salts that are liquids from as low as -96 °C to up to 100 °C. RTILs are of high interest in many fields of study because of their negligible vapor pressure, high electrochemical stability, high conductivity, and wide electrochemical windows. These diverse solvents have recently been used in organic synthesis, as extraction solvents, and as electrochemical solvents. It is as a direct result of the multifunctional capabilities of these RTIL solvents that they are examined in this work. The ability to probe the chemistry of lanthanides and actinides is based on the unique properties of the cation/anion pair used in the RTIL solutions. The ionic solvent allows studies to be performed under conditions that minimize hydrolysis of the actinide species of interest. In addition, the RTIL solutions can be utilized in the potential dependent electrodeposition of f-elements in their metallic form. However, lanthanide and actinide species cannot always be added into the RTIL directly. Methods of introducing several f-species into the RTIL solvent will be explored. Complexes containing the N(SO 2 CF3 )2 anion were synthesized for this work. The synthesis and resulting mechanisms of addition of f-species into the RTIL will be discussed. Electrochemical analysis of the soluble species will be presented. Separation of the f-species from the RTIL solvent onto the surface of the electrode via potential mediated electrodeposition will be explored. The nature of each deposit was evaluated with scanning electron microscopy and the accompanying energy dispersive spectroscopy. These results will be presented. Finally, conclusions will be reviewed regarding the feasibility of the use of RTIL solvents as a tool in future separations of lanthanides and actinides from spent nuclear waste and other mixed systems.

Keywords

Actinide elements; Electrochemistry; F-elements; Ionic liquids; Ionic solutions; Radiochemistry; Rare earth metals; Room temperature ionic liquids

Disciplines

Analytical Chemistry | Chemistry | Physical Chemistry | Radiochemistry

Language

English


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