Metal-organic framework composites for nuclear waste clean-up

Long-lived environmentally-mobile radionuclides such as 99Tc (technetium) pose a significant groundwater contamination issue and present a serious challenge for the clean-up of nuclear sites such as Sellafield. This can be addressed using solid-phase adsorbents configured as permeable reactive barrier (PRB) materials that have high selectivity for the dominant 99TcO4- anion, trapping this from contaminated groundwaters. In a recently established multi-disciplinary project between Southampton chemistry and the National Oceanography Centre Southampton (NOCS) we are investigating the potential of microporous materials known as metal-organic frameworks (MOFs) as PRBs for technetium removal. MOFs are high surface area porous solids based on the linking of metal-ions and organic linkers and constitute a modular materials platform ensuring they have highly tuneable structures and functionality for the optimisation of their properties for given applications. In this project you will prepare and characterise a range of new and existing MOFs and directly evaluate their technetium uptake properties, and it is expected that a number of technetium uptake mechanisms will be investigated. In order to increase their practical utility as PRBs the best performing MOFs will be configured as composite materials such as membranes and columns through which contaminated groundwater can flow. The successful candidate will spend time in both chemistry and NOCS and will develop broad skills in materials synthesis and characterisation and analytical methods relevant to the nuclear industry.