Jason Rich

Education:

Research Interests:

Colloidal gels are an important class of soft materials that are found throughout nature and in industrial products such as paints, consumer products, cosmetics, and drilling fluids. They typically consist of a suspension of colloidal particles that undergoes dynamical arrest through the formation of a fractal-like network. The arrested microstructure gives rise to unique rheological properties, such as viscoelasticity, yield stress, shear banding, etc. An example of an important gel-forming material is an aqueous dispersion of the discotic synthetic clay Laponite®, often used as a rheological modifier in industrial applications. I study the mechanical properties of this material at macroscopic scales using bulk rheology. Additionally, I use microrheology techniques to probe the local, microscale rheology during gelation. These methods involve tracking the motion of embedded probe particles subject to thermal agitation (via multiple particle tracking microrheology) or active forces (with a magnetic tweezer).

Typical trajectories of a Brownian probe particle diffusing in an aqueous Laponite® dispersion at various age times.		Single-pole magnetic tweezer setup for studying nonlinear rheological properties at the microscopic scale (design c/o Jan Lammerding).

I am co-advised by Professor Gareth H. McKinley in the Department of Mechanical Engineering.

Other research interests:
Polymer Rheology and Dynamics
Soft Glassy Materials
Magnetorheological (MR) Suspensions

Journal Articles: