Thesis
One-step crosslinking and functionalization of electrospun fibers
Master of Science (M.S.), Drexel University
May 2014
DOI:
https://doi.org/10.17918/etd-4456
Abstract
One-step crosslinking of electrospun poly(allylamine) fibers was investigated for two new crosslinking agents: hexamethylene-1,6-diamino(carboxysulfonate) (HDACS) and genipin. Electrospun fibers have high surface area to volume ratios and high porosity, making them excellent candidates for water filtration membranes. Poly(allylamine) fibers were electrospun from acidic solvents to prevent crosslinking during the electrospinning process. As-spun poly(allylamine) fibers had an average diameter of 405±246 nm, while poly(allylamine) fibers containing HDACS and genipin had average fiber diameters of 879±272, and 538±269 nm, respectively. Activation of HDACS and genipin within the poly(allylamine) fibers initiated covalent crosslinking that allowed the crosslinked fibers, which was confirmed through FTIR spectroscopy and solubility testing in aqueous environments of pH 3, 7, and 13. The activated poly(allylamine) fibers crosslinked with HDACS and genipin remained stable in aqueous environments of pH 3, 7 and 13 up to 72 h, while the control fibers dissolved in pH 3 and 7 by 72 h. Additionally, a procedure for thiol-modification of one-step crosslinked electrospun chitosan fibers was developed. One-step electrospun chitosan fibers were crosslinked with glutaraldehyde in order to retain the stability of chitosan in aqueous environments. Glutaraldehyde also served as the reaction site for covalently attaching the thiol-containing molecule, L-cysteine, to the chitosan fibers. EDS confirmed the presence of sulfur and Ellman's reagent testing showed that sulfur exists in the form of thiol groups on the thiol-modified chitosan surface. Finally, FTIR confirmed the covalent attachment of L-cysteine to the crosslinked chitosan fibers. Since both poly(allylamine) and thiol-modified chitosan have intrinsic metal chelation properties, electrospun poly(allylamine) and thiol-modified chitosan fibers show great promise for removing heavy metal ions from contaminated water.
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Details
- Title
- One-step crosslinking and functionalization of electrospun fibers
- Creators
- Emily Christina Buck - DU
- Contributors
- Caroline L. Schauer (Advisor) - Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- Materials (Science and) Engineering (Metallurgical Engineering) (1970-2026); College of Engineering (1970-2026); Drexel University
- Other Identifier
- 4456; 991014632595904721