Characterization of Particulate Suspensions using Optical Rheometry

Optical rheometric methods are being used in this project to characterize the structure and dynamics of suspensions during flow. The methods being employed are primarily scattering methods: scattering dichroism and small angle light scattering. These are being applied to a wide range of problems that include:

1. determinations of the aspect ratio of colloidal particles,
2. flow induced structure in strongly flocculated suspensions,
3. orientation dynamics of a concentrated nematic suspension, and
4. the influence of interparticle interactions on the microrheology of dense suspensions.

The platform for these measurements is a newly developed facility based upon the principle of light transmission at oblique angles of incidence within a commercial stress rheometer.