(533f) Microstructure of Colloids in Sheared Boger Fluids

Microstructures of high volume fraction colloidal suspensions in Boger Fluids are measured using high speed confocal microscopy.  Unlike pure hydrodynamic interactions, wall effects have a large effect on the kinematics of the flow and the microstructure.  What is unclear is why low weight fraction high molecular weight polymers have a significant effect on structure even when the polymer is localized.  Through fluorescence imaging, the polymer phase is seen to remain coiled and isotropic in low shear regions of the flow and extended in the flow direction in high shear.  Results demonstrating the effect of weight fraction, molecular weight, and relaxation time of the polymer phase will be shown.