Electrospinning is an inexpensive and simple method of producing non-woven
fiber mats. Electrostatic forces are employed to produce the mats, which
intrinsically have larger specific surface to volume ratio and smaller pores
than traditional fibers. Fibrous mats are typically used in a wide variety
of industries such as filter media, tissue engineering, and sensors.
Chitosan, the N-deacetylated derivative of chitin, is
environmentally friendly, non-toxic, biodegradable, and anti-bacterial.
However, due to chitosan’s solubility in aqueous acids, it is electrospun
using trifluoroacetic acid (TFA). Modified chitosans, such as
carboxymethylchitosan, are currently under investigation as a means of
creating designed nanofibrous mats with specific chemistries. However,
typically an entirely new set of electrospinning conditions has to be
developed for each novel chemistry due to differences in solubility and
viscosity. In the present study, we have electrospun chitosan mats and
post-processed the fibers. Two different post-processing conditions were
employed. One post-production procedure, featuring vapor-phase
glutaraldehyde, effectively crosslinks the fiber mats utilizing a Schiff
base imine functionality. In another post-processing procedure, the as-spun
mats are solution-phase post-processed by chemically functionalizing the
mats with cyano, carboxylic acids and thiol groups. While both methods
maintained fiber shape and characteristics, there is a definite increase in
fiber diameters due to processing. FTIR, NMR, SEM and tensile testing have
been performed on the pre- or post-processed fiber mats. Investigations into
the percent modification are currently underway.