Date of Award
Doctor of Philosophy (PhD)
Marcus, R. Kenneth
Christensen , Kenneth A
Chumanov , George
Pennington , William T
High Performance Liquid Chromatography (HPLC) is a key component in the purification and separation of biological samples. Stationary phases in HPLC are generally silica based porous particles or monoliths designed with high surface area and high capacities in mind. However, in the field of macromolecule separations, specifically proteins, the porous based stationary phases have inherent issues that include slow mass transfer, high operating back pressures, and analyte carryover. Recent research has looked to non-porous polymeric materials as stationary phases in HPLC to overcome these challenges. Specifically, fibrous based polymer stationary phases exhibit significant benefits for macromolecules that include improved mass transfer, decreased operating pressures, and improved chemical robustness.
Capillary-Channeled Polymer (C-CP) fibers have been under investigation in the Marcus laboratory for their application as stationary phases in HPLC. C-CP fibers are extruded from standard textile polymers through a spinneret. The spinneret shape provides the unique structure of the fibers, which consists of eight channels that run the length of the fiber. These C-CP fibers have been successfully employed for macromolecule separations due to the increased surface area over cylindrical fibers, an improved mass transfer due to their non-porous nature, and reduced back pressures allowing for operation at higher linear velocities.
C-CP fibers come in a variety of base polymers; polyester, polypropylene, and nylon, providing a wide array of chemical interactions (ionic, pi-pi, hydrophobic) and therefore separation mechanisms to occur. However, the ability to generate HPLC stationary phase surfaces with a high degree of analyte specificity is desired. The focus of this research is on modification of C-CP fibers, specifically to generate a high density functional group surface for analyte selective interactions. All three available base polymers of C-CP fibers were evaluated for their ability to undergo chemical modification while maintaining the structural integrity and characteristics of the fibers. Several modification approaches, including plasma grafting, covalent modification, and lipid adsorption, were utilized and their performance evaluated in order to obtain metal or protein selective HPLC stationary phases.
Pittman, Jennifer, "SURFACE MODIFICATIONS OF CAPILLARY-CHANNELED POLYMER (C-CP) FIBERS FOR APPLICATIONS IN HIGHLY SELECTIVE SEPARATIONS" (2012). All Dissertations. 919.