Electrospun biopolymer fibers are utilized in a wide variety of industries such as tissue engineering, sensors, drug delivery, membrane filtration, and protective membranes. The biopolymer chitosan, the partially N-deacetylated derivative of chitin, which has been the focus of many studies, contains amine or hydroxyl functionalities that may be substituted with a number of chemistries such as carboxylate, benzene, or cyano groups. Modified chitosan solutions are often challenging to electrospin, as an entirely new set of solution and operating conditions must be developed for each modification. In this study, a facile post-modification processing method for chitosan is introduced that circumvents the need to perform bulk modification prior to electrospinning, and therefore new spinning conditions. The chitosan mats were solution-phase post-processed by chemically functionalizing the mats with carboxylate, benzene and cyano groups. Scanning electron microscopy and Fourier-transform infrared have been performed to determine fiber morphology retention and chemical interactions, respectively. Post-modification retained the fibrous structure of the white-colored, round and smooth mats with spectral changes indicating changes in the chitosan mat. Mean fiber diameters were 131 ± 75 nm ($31% smaller), 210 ± 81 nm (46% larger), and 85 ± 29 nm ($11% smaller) for carboxymethylchitosan, benzylidenechitosan, and cyanochitosan, respectively.