Electrospinning is an inexpensive and scalable process of fabricating non-woven fiber mats having small diameters with large specific volume-to-ratio. Fibrous mats are exploited in a wide range of applications including filter media, sensors and tissue engineering. Chitosan, the N-deacetylated derivative of chitin, is renewable, biodegradable, and contains reactive groups. Modified chitosans are currently investigated to create nanofibers with specific chemistries. However, entirely new set of electrospinning conditions has to be developed for each novel chemistry due to differences in solubility and viscosity. For this study, as-spun chitosan have been post-modified using two different conditions. The first features a vapor-phase glutaraldehyde crosslinking utilizing a Schiff base imine functionality, while the second involves solution-phase chemical functionalization by cyano, carboxylic acids and thiol groups. While both methods retained fiber characteristics, there was a definite increase in diameters. FTIR and SEM were performed on the spun mats. NMR and percent modification investigations are underway.