Assessing the role of the gel microvoid scale, geometry, and shape on the optimal time of separation in electrophoresis

Recent experiments at the Nanocomposite Gel Research Group at Tennessee Technological University (TTU) and by others have shown an important effect on the motion of proteins driven by an electric field when nanoparticles are embedded into the gel matrix. Features of these nanocomposite gels are dramatically altered at the nanometer scale due to the presence of the nano-inclusions. Understanding the effects of morphological characteristics of these nanocomposite gels on electrophoretic separations is an exciting prospect that could allow for the creation of new nanostructures with tunable sizes and shapes. To realize the full potential of morphology for achieving controlled synthesis of a broad range of useful nanomaterials, insights into the effects of morphology on transport which are not currently clear, would be highly beneficial. The approaches here are based on the use of idealized geometrical domains which can serve as an important initial step to understand the role of both morphology (size and shape of micro-capillary domains) and operational parameters (magnitude and direction of electrical field) of the nanocomposite gel on the separation efficiencies.;In this research, the importance of geometry bias on the evaluation of macroscopic transport properties such as effective diffusivity and effective velocity are illustrated by a steady state analytical model developed by considering two simple idealized units connected in series to form an expansion. These properties can aid in understanding the performance of the nanomaterial. Later numerical simulations (based on finite element) are performed for the pore visualized as having several idealized discrete units connected in series under transient conditions and with the injection at the center which is practically relevant. The effects of electrical field in the orthogonal direction and Poiseuille or pressure driven flow on the optimal times of separation are then investigated.;This work also introduces a novel approach to investigate the morphological effects of nanocomposite on gel electrophoresis by integrating the numerical simulations (based on finite element method), and population-based search algorithms such as differential evolution. Simulations were performed to study the solute transport by electromigration-diffusion in a microchannel with an axially varying cross-section. Morphological parameters such as channel shape and size, as well as operational parameters such as electric field in the axial and orthogonal directions were considered and found to have considerable effects on the electrophoretic separation resolution.