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Department of Chemical Engineering and Biotechnology

Former CEB PhD student, Dr Clare Rees-Zimmerman, was awarded the biennial prize by the Institute of Mathematics and its Applications for work published during her PhD with our Colloidal Dispersions group.

Rees-Zimmerman presented her paper, which explores the drying processes of particle films, at the 2023 British Applied Mathematics Colloquium in Bristol, alongside 8 other finalists.  

The paper models how particles of different sizes arrange themselves in a film as it dries, with the aim being to understand how to carefully control the process for engineering applications. The paper demonstrates how a phenomenon called ‘diffusiophoresis’ can explain experimental observations of small particles preferentially accumulating at the top surface.

In her paper, Rees-Zimmerman derives asymptotic (approximate analytical) solutions to characterise the fast evaporation regime, in which it’s possible to achieve a top layer of the film made almost entirely of small particles.

The findings could be used across a range of industries, wherever expensive components are only required at the top surface, including biocidal or catalytic coatings. For other coatings, such as car paints, which consist of many layers that currently need to be applied one at a time, Rees-Zimmerman’s work could be used to develop self-layering coatings, reducing the total drying time.

I’m delighted to have been awarded this prize,” said Rees-Zimmerman. “It is an honour to have my work recognised as interesting applied maths in its own right, whilst my motivation for doing the work was to address a practical engineering problem! I’m very grateful for the education I’ve received at CEB, developing my analytical skills, as well as for the support of my PhD supervisor, Professor Alex Routh, who kept me busy writing this paper during covid.” 

Since graduating from her PhD at CEB, Rees-Zimmerman has taken up a Junior Research Fellowship with Christ Church College, Oxford, working with the Oxford Colloid Group in the Physical and Theoretical Chemistry Laboratory, University of Oxford.

Her fellowship will focus on developing a new class of three-phase composite functional materials – coatings with highly tuneable properties with a range of promising applications, from reactor materials to tissue engineering. The required theoretical work will also advance understanding of multiphase flow.

Read the award-winning paper

Rees-Zimmerman, C., & Routh, A. (2021). Stratification in drying films: A diffusion–diffusiophoresis model. Journal of Fluid Mechanics, 928, A15. doi:10.1017/jfm.2021.800


© Ian Wallman/Christ Church College, Oxford