Up-scaling electrical based separations by electrokinetic-hydrodynamics (EKHD) and the role of scaling in learning transport phenomena concepts
Jennifer Anne Pascal, Tennessee Technological University, United States
Doctor of Philosophy, Tennessee Technological University . Awarded
Electrical-based separations have applications in clinical diagnostics, drug delivery and environmental remediation, to name a few. Because of the advancements made in micro and nanotechnology, there are a myriad of devices and techniques available to perform electrokinetic separations of biomolecules, such as proteins, DNA and antibiotics. Some of these include electrical field flow fractionation (EFFF), micro/nanofluidic devices, and nanocomposite polymer gels. Many of these systems can be viewed as porous media consisting of various capillary geometries. Therefore, the current research aims at fundamentally understanding the transport phenomena and role of the various scales within these electrical-based separations systems. Specifically, the focus of this research is on using the electrokinetic-hydrodynamics (EKHD) approach to model the transport within idealized microdomains that can potentially exist in these systems and have an effect on the separation efficiency. This approach uses geometrical scaling arguments to obtain effective transport parameters (i.e., effective velocity and effective diffusivity) using information from the microscopic scale that predict the overall behavior of the system at the macroscopic scale. These transport parameters can then be used to compute optimal separation times within the systems. In addition, another goal of the current work is to develop systematic approaches that can improve Chemical Engineering students' understanding of transport phenomena.
This work is divided into four main parts. The first part describes some of the real world applications related to electrical-based separations and the methodologies and approaches that have been commonly utilized to model the transport in these systems. In addition, Part I summarizes research related to common misconceptions of engineering students in transport phenomena and emphasizes the importance of students having a deep understanding of the fundamental concepts in transport phenomena. Part II of this work is devoted to the application of the EKHD approach to determine optimal separation times in EFFF systems with Couette flow. Furthermore, the dynamics of these systems are studied in order to gain more insight into the separation process. The third part of this research is focused on using the EKHD approach to understand the effect of morphology on separations by studying the transport in microvoids of idealized geometries (e.g., diverging rectangular, annular) under the influence of electrophoresis and electroosmosis. Finally, Part IV is focused on enhancing Chemical Engineering students' learning of transport phenomena through various scaling illustrations and applications.
Pascal, J.A. Up-scaling electrical based separations by electrokinetic-hydrodynamics (EKHD) and the role of scaling in learning transport phenomena concepts. Doctor of Philosophy thesis, Tennessee Technological University.
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