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Department of Chemical Engineering and Biotechnology


Particles, Soft Solids and Surfaces (PS3G) Group

Our interests lie in developing the understanding of processing of pastes, particles and complex fluids (e.g. foods). We apply that knowledge to manufacture, at industrial scale, products with desired microstructure or function, or, equally importantly, to resolve problems encountered in processing such materials.

The group is now led by Ian Wilson and Sarah Rough following the departure of Bart Hallmark in August 2021. The group was formed in January 2013 by the (friendly) merger of two of the groups in the Department of Chemical Engineering and Biotechnology with interests in structured materials and processing: the Paste and Particle Processing group (P3G) and the Polymer Fluids group, to form the Paste, Powder and Polymer Processing Group, hence P4G.

In June 2022 the name changed to PS3G to reflect the current expertise in the group.

Prof. Wilson has worked extensively on applications in food processing, heat exchanger fouling, cleaning and decontamination. Dr Rough has a long-standing interest in particle technology and paste engineering. Dr Hallmark worked on polymers and modelling and simulation of flows from micro- to plant scale. There has been much work on complex fluids, both visco-plastic and visco-elastic.

The group's activities range from fundamental theoretical, numerical and experimental investigations to applied and proof-of-concept studies. The research page gives a full listing of ongoing and past projects.



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Determination of quality parameters for consumer goods (baked cakes!)

Scanning Electron Microscopy (SEM) image of a cellulose membrane, before fouling

Extrudates of microcrystalline cellulose water-based paste (3 mm die diameter). The difference in appearance is due to the extrusion velocity - a higher velocity induces surface fractures

Academic collaborators within other groups at Cambridge include:

Active external academic collaborators:

Sponsorship and funding comes from a range of sources, including ESPRC and industry. This support is gratefully acknowledged: more information about sponsoring bodies is available on the Networks and Collaborators page.

PS3G also hosts the Fluid Dynamic Gauging website: this technique was developed within the P3G group.

The former P3G or Polymer Fluids Group websites can be viewed for more information.