Concentrated suspensions undergo a wide range of rheological behavior, such as shear thinning, shear thickening, and yielding. Fundamental understanding of these varied behavior is necessary to control them for use in industrial processes or varied product applications. The shear thickening is especially important as it can damage process equipment where concentrated suspensions are used. It also has been linked to improved ballistic and stab performance in composites with Kevlar fabrics.

My research has worked to provide fundamental understanding of the microstructural particle rearrangements under shear flow that cause the varied rheological behavior, primarily through small angle neutron scattering (SANS), ultra small angle neutron scattering (USANS), rheology, particle characterization, and microscopy. These measurements are compared to simulations and micromechanic theories are used to calculate rheological parameters from the microstructure measurements. These measurements help confirm the theory and provide insight toward controlling shear thinning and shear thickening.

Separately, we have been working on understanding the effect of rheology and particle properties for the STF-Armor application. This work has helped us to understand the underlying mechanism for improvement of Kevlar by addition of concentrated suspensions.