Post-processing of electrospun chitosan fibers

Marjorie Austero Kiechel

doi:10.17918/etd-7054

Electrospinning is a simple, inexpensive, scalable and flexible method of producing randomly oriented or aligned fiber mats. Electrostatic forces are employed to fabricate the mats, which intrinsically have larger surface area to volume ratio and smaller pores than commercial fibers. The prospects for market growth of fibrous mats are in the areas of biomedical engineering, food processing, bacterial control and treatment of waste or contaminated water. One application for porous, fibrous mats are in large industries as microfiltration devices. Effective separation using these filters depends on material structure and properties and thus, the advent of newer applications necessitates the need to find ways to improve mat reactivity, integrity and porosity. Chitosan, the N-deacetylated derivative of chitin, is environmentally friendly, biocompatible, renewable and biodegradable with excellent heavy metal ion chelating abilities. Chitosan possesses functional groups that can form bonds with other chemical species of interests, thereby increasing their reactivity and specificity, and can also be spun into fibers by electrospinning. Combining the porous structure of the randomly oriented, electrospun chitosan fiber mats and improved chemical reactivity by functional group modification promises reactive and porous microfiltration membranes. We have chemically and physically post-processed electrospun chitosan fibers for improved chemical and mechanical stability. Chemical crosslinking was performed using stimulus responsive crosslinkers such as genipin, hexamethylene-1,6-diaminocarboxysulfonate (HDACS), epichlorohydrin, glycerol phosphate, tripolyphosphate and tannic acid. Mat morphologies and chemistries were investigated under FESEM, EDS, FTIR and NMR. Mechanical properties, chemical stability, heavy metal chelating ability of the mats were determined using an Instron tensile tester, UV-Vis and ultrafiltration flow cell/EDS, respectively. The major impacts of the work include: (1) full chemical analysis of the aforementioned crosslinkers with electrospun chitosan fibers; (2) tensile property analysis of fibers spun with genipin, HDACS and epichlorohydrin; (3) introduction of the four methods of processing (one- or two-steps, activated one- or two-steps) of electrospun chitosan; (4) evaluation of the porosity and integrity of crosslinked and electrospun chitosan fibers; (5) hexavalent chromium ion filtration profile using HDACS-crosslinked chitosan membranes; and (6) applying knowledge of the system to design composite nanoparticle-chitosan electrospun fibers for bone tissue engineering and filtration applications. Future directions are aimed at optimizing and tailoring the structure and properties of biopolyelectrolyte and its composite fibers for tissue scaffolds engineering, controlled drug or particle delivery, active food packaging and filtration/separation applications.

Post-processing of electrospun chitosan fibers

Files and links (1)

Abstract

Metrics

Details

Post-processing of electrospun chitosan fibers

Files and links (1)

Abstract

Metrics

Details

Drexel University Social media