Unravelling interfacial dynamics at the plasma-liquid boundary

Plasma-Treated-Liquids (PTL) have emerged as promising solutions for many global societal challenges. Preliminary studies showed remarkable success of PTL in treating antimicrobial infections, which costs the UK economy approximately £3 billion annually. In addition, PTL-based technologies in the food industry showed an ability to extend the shelf-life of many products by several days, which could potentially save UK consumers £6 billion per year by reducing food waste.

Despite these exciting preliminary results, there are major challenges impeding the widespread adoption of such PTL technology. One of which is understanding the interaction between the plasma and the treated liquid. This interaction occurs through a plasma-liquid interface which is difficult to study experimentally due to the very small scales in space and time of the interaction. Another challenge is the multi-physics aspect of this interaction, where the plasma interacts with the treated liquid mechanically, chemically, electrically, and thermally. The different aspects of the plasma-liquid interaction are not independent, for example the mechanical interaction affects the chemical interaction, and the electrical interaction affects the mechanical interaction. This multi-physics coupling makes understanding the plasma-liquid interactions even more challenging.

The aim of this project is to build an advanced numerical model describing plasma-liquid interfaces, linking the plasma conditions to the properties of the treated liquid, and to compare the model's results to measurable parameters to benchmark it experimentally. The proposed model will implement a novel mathematical approach to resolve the small scales in space and time of the interaction. In addition to combining state-of-the-art numerical methods from multiple disciplines to resolve the strong multi-physics coupling of the problem. Then to use the developed model to understand the complex interactions at plasma-liquid interfaces, encountered in many of the devices under development for tackling the previously mentioned societal challenges, thus accelerating the translation of PTL technology.

Treating liquids with plasmas alters their chemical properties, allowing them to gain properties which can be utilised in a variety of advanced applications. One of the major problems impeding the development of mature technologies based on plasma-treated liquids is a missing link between the plasma conditions and the properties of the treated liquids. The aim of the proposed project is to provide such a link, for the first time. The immediate impact of this project will become evident in the academic community, where many international research groups are focusing on plasma-liquid interactions from experimental perspective, and face challenges in understanding these interactions beyond what can be observed experimentally. The project will impact their work by providing information on the interactions that are not accessible otherwise, enabling them to obtain a clearer picture of the interactions. Over the long term, the outcomes of this project will be translated into economic and societal impact by accelerating the development of mature technologies based on plasma-treated liquids, in areas such as surface decontamination, medicine, food treatment, and environmental waste management. As such, successful implementation of this project will lead to significant impact into EPSRC prosperity outcomes "A healthy nation, a productive nation and a resilient nation". In addition to the impact of the findings of the project, conducting the project will have a major impact on the career of the PI as it will be his first independent project, thus launching his career as an international researcher. Finally, the project offers an opportunity for a PDRA, to be recruited to work on the project, to expand his/her background by working on a highly multidisciplinary project, such an expansion will be an important addition to his/her career portfolio, increasing his/her employability and potential for academic success.