Characterising dynamics

Characterising dynamics can give key information for the way a product changes when a formulation or process change is underway. Flow behaviour, consumer experience and product stability all depend on the product sensitivity to dynamics. The following are techniques that can be used to characterize motion within complex fluids.

Diffusing Wave Spectroscopy (DWS)

With DWS the dynamics of turbid soft matter can be gathered and analysed over time. DWS can be used to determine the size of emulsion droplets and bubbles to characterize coalescence over a period of time. Changes in diffusivity due to aggregation (e.g. the early signs of gel collapse) can also be identified through DWS.

Dynamic Differential Microscopy (DDM)

Scientists within the Complex Fluids research group have developed DDM to characterise the motility of micro-organisms such as algae and bacteria.


To understand a product or formulation we need to link the microstructure and the dynamics with the macroscopic properties. Our rheo-imaging facility has a fast confocal microscope (up to 100 fps) coupled to an Anton-Paar rheometer. Simultaneous measurement allows us to measure the rheological response of material and correlate this with changes in microstructure.


Using our suite of rheometers, we can apply stress and strain controlled deformation through continuous flow, creep, stress relaxation and oscillatory rheology from small strain through to LAOS mode. Interfacial rheology to understand viscoelastic properties at interfaces (e.g. for proteins, lipids, colloids or surfactants at interfaces).