Thesis
Preorganization of diglycolamide extractants for the improved separation of trivalent f-elements
University of Iowa
Master of Science (MS), University of Iowa
Autumn 2023
DOI: 10.25820/etd.006846
Abstract
In the pursuit of enhancing the separation efficiency of trivalent actinides and lanthanides, specifically within the ALSEP process, this study delves into the exploration of scaffold preorganization in diglycolamide (DGA) ligands. Such preorganization is expected to impact the kinetic inertness and radiation resistance of f-element-extractant complexes. A key innovation involves the incorporation of a pyridine moiety into the DGA backbone, offering additional coordination sites and potentially improving metal-ion selectivity through chelation changes. This research led to the synthesis and structural characterization of six novel DGA ligands: N,N,N’,N’ tetra-hexyl pyridine diglycolamide, N,N,N’,N’ tetra-hexyl benzene diglycolamide, N,N,N’,N’ tetra-octyl pyridine diglycolamide, N,N,N’,N’ tetra-octyl benzene diglycolamide, N,N,N’,N’ tetra-decyl pyridine diglycolamide, and N,N,N’,N’ tetra-decyl benzene diglycolamide were synthesized and structurally characterized by 1H and 13C NMR analysis. Two asymmetric analogs of the novel ligands, N,N’- dimethyl N,N’- dihexyl pyridine diglycolamide and N,N’- dimethyl N,N’- dihexyl benzene diglycolamide, were synthesized and analyzed to investigate the role of asymmetry of the alkyl chain on solubility and selectivity. Initial liquid-liquid extraction experiments focused on lanthanides, particularly the critical elements neodymium (Nd) and dysprosium (Dy). Mixtures were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES), allowing for the determination of distribution factors for lanthanide ions and the exploration of initial separation factors for each lanthanide pair. This study not only contributes to a deeper understanding of separation processes vital to critical materials and the nuclear fuel cycle but also provides valuable insights into the design of more efficient extractants for trivalent elements.
Details
- Title: Subtitle
- Preorganization of diglycolamide extractants for the improved separation of trivalent f-elements
- Creators
- Janadhi Lawanya Ananda Nakath Durage
- Contributors
- Korey P Carter (Advisor)Scott R Daly (Committee Member)James B Gloer (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Chemistry
- Date degree season
- Autumn 2023
- Publisher
- University of Iowa
- DOI
- 10.25820/etd.006846
- Number of pages
- ix, 37 pages
- Copyright
- Copyright 2023 Janadhi Lawanya Ananda Nakath Durage
- Language
- English
- Date submitted
- 12/03/2023
- Description illustrations
- illustrations, tables, graphs
- Description bibliographic
- Includes bibliographical references (pages 25-29).
- Public Abstract (ETD)
- In the realm of critical materials processing, the efficient separation of rare earth elements used in modern applications poses a significant challenge. This study aims to enhance the rare earth separation processes, particularly in the context of critical materials essential for various applications. A key innovation involves refining the structural composition of certain molecules known as DGA ligands, which are currently being used for separation of rare earth elements, with the aim to improve their ability to separate elements more effectively. New DGA ligands have been synthesized and rigorously evaluated for their performance to separate selected rare earth elements. Our research has primarily focused on lanthanides, elements of critical importance in progression of technologies that depend on these fundamental elements. We have employed specialized instrumentation to comprehensively analyze the results. This research contributes to a deeper understanding of critical material separation processes and holds the promise of driving advancements in the future.
- Academic Unit
- Chemistry
- Record Identifier
- 9984546848502771
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