Element specific smart media for fast, low cost, radionuclide analyses

Merrikin, Danielle Amber 2021. Element specific smart media for fast, low cost, radionuclide analyses. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF - Accepted Post-Print Version Download (16MB) | Preview
	PDF (Cardiff University Electronic Publication Form) - Supplemental Material Restricted to Repository staff only Download (624kB)

Abstract

Analysis of low-level waste (LLW) within the nuclear industry is currently constrained by the use of environmentally unfriendly and toxic scintillant cocktails, time-consuming work-ups and high sample disposal costs. The work described herein hoped to address these issues via development of analysis utilising the Scintillation Proximity Assay (SPA). Chapter 1 introduces the theory and techniques underpinning the work presented in the rest of the thesis. Chapter 2 describes the synthesis of a series of novel oxazoles with a range of photophysical properties suitable for use as secondary scintillants. Incorporation into oil-in-water microemulsions, a greener alternative to industry standards, showed that they were effective scintillants for the detection of Sr-90 and Ni-63, in some cases outperforming the industrially used secondary scintillant POPOP. Chapter 3 describes the encapsulation of the oxazoles into polystyrene/silica core/shell particles suitable for use in SPA, with aqueous dispersions also shown to scintillate in the presence of Ni-63 and Sr-90. Chapter 4 describes the surface functionalisation of the nanoparticles with TMS-EDTA and their subsequent scintillation efficiency. Although preliminary results showed that the scintillation efficiency was not greatly increased via the resultant closer proximity of the radionuclide to the bead, surface analysis confirmed sequestration of a range of metal ions. Thus the work described herein paves the way for further explorations of metal-specific chelator functionalisation, potentially leading to element specific sequestration and analysis from a complex mixture of radionuclides. Chapter 5 describes the synthesis of rhenium(I) tricarbonyl complexes bearing novel oxazole-based ligands. The varied photophysical characteristics displayed by both ligands and complexes were studied in depth, with computational analysis used to further inform experimental observations. Chapter 6 investigated the internal core-shell particle environment and hence its role in the photophysics of encapsulated dopants, via encapsulation of known lanthanide complexes with environment sensitive photophysical properties.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Chemistry
Funders:	EPSRC, NNL, NDA
Date of First Compliant Deposit:	27 January 2022
Last Modified:	31 Jan 2023 14:17
URI:	https://orca.cardiff.ac.uk/id/eprint/146995

Actions (repository staff only)

Edit Item