Research involving polymer gels with embedded nanoparticles of varying properties is quite attractive because of the multitude of potential applications, including separation of biomacromolecules, tissue scaffold growth, as well as the analysis of the efficiency and control of drug delivery. The presence of nanoparticles within gels has the potential to modify not only the gel morphology but also the electrokinetic properties of the gels; therefore, these nanoparticles may influence both the electrophoretic transport as well as electro-osmotic flows.

This project focuses on idealized capillary models whose characteristics are useful domains to mimic the gel morphology in the aforementioned nanocomposite gels. Such domains allow for the use of a nonuniform cross section and electrostatic potential along the capillary walls in order to capture the electrophoretic and electrostatic behaviors between the nanoparticles and the gel. Additionally, this communication will report details and illustrations of the modeling of the electroosmotic transport within the gels, and on the effect of various system parameters such as the convergent-divergent channel cross sections, electrostatic potential, and aspect ratio, among others. The research has effectively used the electrokinetic hydrodynamics (EKHD) concepts as introduced by Arce and Oyanader ([1], unpublished, [5]) coupled with the spatial averaging approach originally introduced by ([2],[3],[4]).

[1] Arce, P. and Oyanader, M. “Electrokinetic Hydrodynamics: An Introductory Graduate level Course.” To be submitted to Chemical Engineering Education.

[2] Slattery, J. C., Momentum, Energy and Mass Transfer in Continua, Krieger, New York, 1981.

[3] Whitaker, S., Chem. Eng. Sci. 1985, 40, 1387.

[4] Cwirko, E. H.; Carbonell, R. G., . J. Colloid Interface Sci. 1989, 129, 513.

[5] Pascal, Jennifer, Arce, Pedro and Oyanader, Mario. “Electrokinetic-Hydrodynamics (EKHD): An Efficient Framework for Systematic Research.” AIChE Poster Presentation, 2008.