Preparation Of Chitosan Composite Nanofibers Via Electrospinning

The nanosize, the larger specific surface area, the length-to-diameter ratio, andthe high degree of orientation are the obvious advantages of nanofibers, which made itthe hot spot of the materials field. Electrospining is the main method of preparingnanofibers at present for its virtues of efficiency, wide application, non-toxicity andnon-irritation. Additionally, it holds excellent hemostatic effects and biocompatibility,and can degrade automatically. Thus, it shows broad applications in the biomedicalmaterials fields. Owing to the promising future of chitosan composite nanofibers inbiomedical materials, the idea of mixing chitosan with other polymers and addingcross-linking agent was brought out in this study in order to improve the spinnabilityand morphology of this nanofibers.The chitosan composite nanofibers prepared by electrospinning was studied inthis paper based on the chitosan composite nanofibers system. The effects of severalfactors on the parameters in electrostatic spinning process were discussed in the paperincluding static voltage, flow rate and receiving distance. And the effects of ratio andproperties of raw solution (surface tension, viscosity, conductivity) on theperformance of spinning, morphology, phase, and group bonding property were alsodiscussed.The study results indicated that the optimum condition of preparing chitosancomposite nanofibers by electrospinning: a flow rate of0.2mL/h, a receiving distanceof15cm, and an electrostatic voltage of10-13kV according to the surface tension ofspinning solution. The spinability got a considerable improvement by addingpolyvinylalcohol (PVA) during the preparation of chitosan/PVA binary compositenanofibers. The morphology improved, the average diameter refined (the minimumvalue=110nm), and the distribution of the nanofibers centralized with the increasing of chitosan contents. And then, the spinability of the binary composite got furtherimproved when the water-soluble polymer, polyvinylpyrrolidone (PVP), was added.In this condition, the morphology of the nanofibers improved a lot apparently with theminimum average diameter of97nm. However, extra attention should be paid on thedosage of PVP. The results of prepraing the composite nanofibers mixed with thecrosslinking agent glutaraldehyde demonstrated that the morphology and the degreeof orientation both got improved. Beyond that the average diameter became moreuniform and decreased to65nm, which belonged to ultrafine nanofibers.The ultrafine chitosan composite nanofibers with fine morphology were obtainedby electrospinning, which laid a solid foundation on the following application.