(161b) Theoretical Model for the Aspect Ratio-Based Separation of Ellipsoidal Particles in Field-Flow Fractionation

We have developed a new theoretical model for describing the separation behaviors of ellipsoidal particle in flow field-flow fractionation (Fl-FFF), which is a particle separation technique which utilizes a parabolic channel flow and a cross-flow field. Previous model on the aspect ratio-based separation of rod-like particles [Alfi & Park, J. Sep. Sci. (2014) 37:876-883; Park & Mittal, Chromatography (2015) 2: 472-487], has been extended for prolate ellipsoids, which has a lower aspect ratio of less than 5. As in the previous model, the cross-sectional concentration distribution is derived considering the particle orientation and the configuration near the accumulation wall. The derived concentration distribution is then used for the evaluation of the retention ratio, which is equivalent to the normalized elution time. The effects of the aspect ratio, axial flow rate, and cross flow rate on the retention ratio will be presented to explain the elution order. Comparison with the experimental data will also be discussed.