Together with colleagues at the JRC Ispra, my research group has shown that the motion of small nanoparticles at low concentrations is independent of their size, density and material , [see ‘Slow moving nanoparticles‘ on December 13th, 2017]. This means that commercially-available instruments for evaluating the size and number of nanoparticles in a solution will give erroneous results under certain conditions. In a proposed PhD project, we are planning to extend our work to develop an instrument with capability to automatically identify and size nanoparticles, in the range from 1 to 150 nanometres, using the three-dimensional optical signature, or caustic, which particles generate in an optical microscope, that can be several orders of magnitude larger than the particle , [see ‘Toxic nanoparticles?‘ on November 13th, 2013]. The motivation for the work is the need to characterise particles present in solution in legacy ponds at Sellafield. Legacy ponds at the Sellafield site have been used to store historic radioactive waste for decades and progress is being made in reducing the risks associated with these facilities . Over time, there has been a deterioration in the condition of the ponds and their contents that has resulted in particles being present in solution in the ponds. It is important to characterise these particles in order to facilitate reductions in the risks associated with the ponds. We plan to use our existing facilities at the University of Liverpool to develop a novel instrument using simple solutions probably with gold nanoparticles and then to progress to non-radioactive simulants of the pond solutions. The long-term goal will be to transition the technology to the Sellafield site perhaps with an intermediate step involving a demonstration of the technology on pond solutions using the facilities of the National Nuclear Laboratory.
The PhD project is fully-funded for UK and EU citizens as part of a Centre for Doctoral Training and will involve a year of specialist training followed by three years of research. For more information following this link.
 Coglitore, D., Edwardson, S.P., Macko, P., Patterson, E.A., & Whelan, M.P., Transition from fractional to classical Stokes-Einstein behaviour in simple fluids, Royal Society Open Science, 4:170507, 2017.
 Patterson, E.A., Whelan, P., 2008, ‘Optical signatures of small nanoparticles in a conventional microscope’ Small, 4(10):1703-1706.
 Comptroller and Auditor General, The Nuclear Decommissioning Authority: progress with reducing risk at Sellafield, National Audit Office, HC 1126, Session 2017-19, 20 June 2018.