Oxford Colloid Group

What is rheology?

Rheology is ‘the science of the flow and deformation of materials’.  It involves the study and determination of many key structural characteristics of materials both at rest and in flow, such as calculating yield stress (the value of the stress at which a material starts to behave plastically, rather than elastically) or viscosity.

Rheology is not only of significant interest in academia, but also in industry. For example, it is a key consideration in the formulation of a product and assessing its shelf-life. For a product to be commercialised, it needs to have a suitable yield stress and viscosity, whilst also being stable for long enough to allow the customer to use it within a certain timeframe.

What do we do in the group?

A collaborative focus is to find a clay which can be used as an alternative to a thickener currently used in industry, whilst also preserving the rheological characteristics of the final product. We are also keen to model the rheological response of such new combinations of thickener to predict the rheological characteristics when subjected to different environmental conditions.

We additionally study the ageing of clay-based gels (i.e. the time-evolution of rheological properties) and are particularly interested in how these changes are linked to the evolution in microstructure. We combine standard rheological techniques with imaging techniques such as Cryo-SEM and X-ray tomography.

Cryo-SEM image of a 10% bentonite (clay) gel

Key People

 

Last updated 08/02/2022