Date of Award
Doctor of Philosophy (PhD)
R. Kenneth Marcus
Carlos D Garcia
Sarah W Harcum
At the heart of the chromatography technique, the stationary phase is the essential component that dictates multiple aspects of the separation process. Diverse chemistry of the stationary phases, in combination with the choice of appropriate base support materials, allows chromatography to be used in a wide range of applications ranging from the high-performance separations of trace analytes in complex biological samples for chemical detection and quantification to the large-scale purification of a recombinant protein from a complex media. Traditional chromatographic stationary phases mostly utilize porous materials for the high surface area and versatility for chemical modification. However, in many cases, these materials suffer from high operating back-pressure and inefficient mass transfer. Joining the efforts to investigate alternative phases, Marcus research group (Clemson University) has investigated the potentials of capillary-channeled polymer (C-CP) fibers for the past 15 years. These fibers are characterized by eight capillary channels running down the length of the fiber, allowing the fibers to interdigitate to form well-aligned micrometer-sized channels when packed into a column format. It is the unique shape that allows separations to be conducted at high linear velocities (>75 mm s−1) with high column permeability (<0.14 MPa cm−1). The highly efficient fluid movement through the narrow channels composed of non-porous C-CP fibers gives rise to favorable mass transfer rates, facilitating fast protein separations and processing. Moreover, another advantage of C-CP fiber supports over other commercial sorbents is that these fibers are quite stable over a wide pH range and are fairly inexpensive (<$ 100 lb−1). Additionally, packing a C-CP fiber column is a simple process that can be conveniently performed without any special equipment.
The concepts of using natural and synthetic polymer fibers as chromatographic stationary phases are not new. Potential advantages cited include low costs, ease in column fabrication, low operation backpressure, facile solute mass transfer, and a general ease of tailoring fiber surfaces to affect high levels of chemical specificity. There have been several surface modification techniques reported for polymer fibers in the literature. However, many of these modification methods can be detrimental to the physical properties of the polymer by destroying the polymer backbone. In order to further exploit the advantageous fluidic properties of C-CP fiber columns without compromising the fiber integrity, milder modification approaches have been a focus of this group recently, including covalent coupling and direct ligand adsorption methods. The research studies reported in this work focus on the development of functionalized C-CP fiber for a variety of affinity chromatography applications. The ultimate goal is to investigate non-invasive modification schemes that do not compromise the mechanical strength and fluidic properties of C-CP fibers. Affinity ligands are immobilized on the fiber surface through one of the following schemes:
1. Scheme 1: Physical adsorption of recombinant protein A (rSPA) ligands on polypropylene (PP) C-CP fibers for immunoglobulin (IgG) capture
2. Scheme 2: Microwave-assisted grafting polymerization of Glycidyl Methacrylate (GMA) onto nylon C-CP fibers as a ligand binding platform with applications in Immobilized Metal-ion Affinity Chromatography (IMAC) protein separations and uranium capture
3. Scheme 3: Polydopamine-coated C-CP fiber for phosphopeptides capture and analyses
Trang, Hung Khiem, "Development of Functionalized Capillary-Channeled Polymer (C-CP) Fibers as Stationary Phase for Affinity Chromatography" (2019). All Dissertations. 2532.