Electrospinning and Characterization of Aligned Nanofibers from Chitosan/Polyvinyl Alcohol Mixtures: Comparison of Several Target Devices Newly Designed

Electrospinning of pure chitosan or chitosan/poly(vinyl alcohol) (PVA) (blend) was carried out with an optimization of the electrospinning conditions. The electrospinning of the pure chitosan was only possible at a relatively high electric field of 5 kV/cm into fibers with a diameter as thick as 30 gm, and its reproducibility was very poor. Blending of PVA into chitosan significantly improved the spinnability and the chitosan/PVA blend fiber was electrospun for further characterization. Several target devices were designed and examined to collect aligned nanofibers of chitosan/PVA. The most efficient was a rotating collector having grounded short wire bars arranged on a drum. Over 90 % of electrospun fibers were collected in parallel to the take-up direction with this collector. The fiber alignment was further improved with increasing the collector rotation speed up to a maximum speed of 4.7 m/s. The aligned chitosan/PVA fibers were subjected to drawing to 1.5 times and the crystallization of chitosan fractions was induced without indicating the clear crystal orientation.