PhD Studentship - A curious example of Hierarchical Aggregation: Computational Modelling, Theory and a Practical Application

This 4-year PhD project is fully funded; students who are eligible to pay tuition fees at the Home rate are eligible to apply (more details can be found here). The successful candidate will receive an annual tax-free stipend set at the UKRI rate (£21,805 for 2026/27) plus an uplift of £5000 per annum and tuition fees will be paid. We expect the stipend to increase each year. The Research and Training Grant will be £2,500 per annum.

The start date is October 2026. 

We recommend that you apply early as the advert may be removed before the deadline.

Most phases of matter consist of individual molecules organised into bulk structures. Ice, for example, is a regular lattice of water molecules. Self-assembling, hierarchical systems are different. Here molecules combine to form complexes, the complexes form clusters and these clusters then arrange themselves into the phase. This is intriguing and is what we want to study.

An example lies in the liquid-liquid of extraction of plutonium, which is important to energy, defence, space power and waste disposal. For example, closing the nuclear fuel cycle by reprocessing spent nuclear fuel to remove plutonium reduces the volume and heat load of high-level waste.  

The extraction process involves the transfer of plutonium ions, dissolved in nitric acid, to plutonium complexes in an organic phase. At high loadings, these plutonium complexes stick together to form an extended gel-like structure called the third phase. Third phase formation is, however, a processing disaster and must at all costs be avoided. An ability to predict and control third-phase formation is essential and this study will help in doing that. 

This project has both fundamental and applied aspects. It will involve the use of atomistic Molecular Dynamics simulation to shed light on how and why this third phase forms. We will investigate which organic solute is best at preventing third phase formation. Finally, we will develop new molecular thermodynamic models to describe third phase formation. These will then be fed into process-level flowsheet models.

The UK-National Nuclear Laboratory (UK-NNL) is supporting this project. In addition to acquiring training in computational modelling and theory, the successful candidate will also gain insights into the working of the nuclear industry. 

This project is part of the Nuclear Doctoral Focal Award in Radiation Protection, Nuclear Safety and Environmental Sustainability (RAPTOR). The successful candidate will be part of a cohort of PhD students across four universities (Manchester, Liverpool, Surrey, Suffolk) working in a national programme with 18 industrial partners. During the first months of this PhD, training will be provided UK experts in radiation protection, environmental assessment and radioactive waste management, nuclear safety and security, and social value and societal impact. 

Applicants should have, or expect to achieve, at least a 2.1 honours degree or a master’s (or international equivalent) in Chemical Engineering or a related science/engineering discipline. Only UK students are eligible for this PhD scholarship.

We strongly recommend that you contact the main supervisor, Prof Andrew Masters, for this project before you apply. Please include details of your current level of study, academic background and any relevant experience and include a paragraph about your motivation to study this PhD project.