Non-thermal plasmas (NTPs) are cold enough to touch, but produce both intense UV radiation and highly reactive chemical species. As such, they are a fascinating and useful example of matter far from thermodynamic equilibrium, capable of carrying out chemical reactions that cannot be achieved by other means, and fundamentally altering the properties of materials and liquids exposed to them. Atmospheric pressure NTPs in contact with liquid represent a particularly exciting problem to study due to the simultaneous interaction of multiple phases of matter over extreme time, space and energy scales; yet, despite this incredible complexity offer enormous application potential. If the underlying fundamental physics and chemistry of NTPs in liquids were better understood, applications in reformation of hydrocarbons, rapid sterilisation of medical equipment, and the synthesis of exotic materials could be envisaged. However, despite some progress in the last decade, a full understanding of these systems remains largely elusive, particularly regarding what chemical species are present, and for how long.
A particularly attractive method of generating NTPs in a liquid is to generate the plasma in a bubble. A plasma bubble has a plasma-liquid interface with a large surface-to-volume ratio, enabling transfer of reactive species to the liquid phase. The size of the bubble has been postulated to affect the rate of this transfer. However, the complexity of the reactions and species present is extremely challenging to model. We propose a new approach to study NTPs: the use of microfluidic chips to generate plasma bubbles of defined size. As the bubbles will be continuously produced, we can use spatial resolution in combination with time resolved spectroscopy across the system (collaboration with Dr Timothy Easun, Cardiff University) to generate maps of where chemical species are within the bubbles and liquid. We will use this to gain fundamental understanding of NTPs in liquids, such as the effect of changing bubble size; the lifetime and propagation of species of interest; and the effect of introducing additives to the liquid. We will then seek to use this knowledge to control the presence of reactive species in the liquid, with the aim of on-demand delivery of chemical reactivity. The student will be trained in microfluidic methods, plasma generation and diagnostics, and Raman spectroscopy via a collaboration with Dr Timothy Easun. Depending on the background and interests of the successful candidate, we will seek to develop the system towards generating new fundamental knowledge, new functional materials through plasma treatment, and/or new applications and technology transfer.
The project will be jointly supervised by Dr Slater (Chemistry and Materials Innovation Factory), Dr Walsh (EEE), and Dr Easun (Cardiff University, Chemistry), and will be based primarily in the Slater Group.
Our group, established in Sept 2017, is active in organic supramolecular and materials synthesis. We use flow chemistry methods coupled with analytical and chromatography techniques, particularly LC-MS, to screen for, optimise, and scale up new materials. We are keen participators in outreach and have taken part in the Science Museum’s ‘SciLates’ programme in London and the 2017 Royal Society Summer Science Exhibition. We are building strong links with industry and have been funded by the University of Liverpool’s EPSRC Impact Acceleration Account to develop commercial aspects of our work. We have also been funded by and are active participants of the EPSRC Dial-a-Molecule and Directed Assembly Grand Challenge Networks. Researchers in the group are encouraged and supported to develop their own careers, whether in academia or elsewhere.
Applications are encouraged from highly motivated candidates who have, or expect to have, at least a 2:1 degree or equivalent in Chemistry or Physics.
Teaching duties may be available and will be discussed at interview.
Applications should be made as soon as possible but no later than 1st March 2019. Informal enquiries are also encouraged and should be addressed to Anna Slater ([email protected]
To apply please visit: https://www.liverpool.ac.uk/study/postgraduate-research/how-to-apply/