Nanofibers were produced using relatively new electrospinning technique. Single layer nanofibers were fabricated using nylon-6. Several parameters such as polymer molecular weight, concentration, surface tension, applied electric voltage, distance between tip to grounded electrode and feed rate were investigated to optimize fiber consistency and diameter. Scanning electron microscopy was employed to study fiber morphology and diameter. Understanding the effects of various parameters mentioned above, electrospinning strategy was further utilized to produce nanofibers with novel core-sheath structure using chitosan, a biopolymer and polyethylene oxide (PEO). Chitosan is very difficult to electrospin, to alleviate this problem PEO was used as sheath to support chitosan core. For this purpose, rheology of polymer solutions was evaluated for successful fabrication of core-sheath nanofibers. Only 3 wt % chitosan was found to produce coaxial structure with 4 wt % PEO, due to their proximity in rheological behavior. Coaxial morphology of nanofibers was verified by transmission electron microscopy having 250 nm and 100 nm as sheath and core diameters respectively. Fourier transform infrared spectroscopy was employed to investigate the effect of de-ionized water treatment of core-sheath mats where in PEO layer was removed off in order to get pure chitosan nanofibers. Coaxial nanofibers with one component were also fabricated using pure PEO as core and PEO doped with Multi-walled carbon nanotubes as sheath material. Results showed that as carbon nanotubes were subjected to relatively smaller volumes, predominantly on the surface culminated in appreciable increase in conductivity as well as mechanical properties. Coaxial nanofibers produced from electrospinning are of particular interest in tissue engineering and wound healing scaffolds.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-06082007-125208 |
| Date | 08 August 2007 |
| Creators | Ojha, Satyajeet Sooryakant |
| Contributors | Russell E. Gorga, Saad A. Khan, Wendy E. Krause |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-06082007-125208/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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