Electrospinning of chitosan from its solutions in2% aqueous acetic acid was studied by adding poly(vinylalcohol) (PVA) as a “guest” polymer. Properties of thechitosan/PVA solutions including viscosity, conductivity, andsurface tension were measured, and effects of the polymerconcentration, chitosan/PVA mass ratio and processingparameters (applied voltage, flow rate, capillary-to-collectordistance) on the electrospinnability of chitosan/PVA wereinvestigated. Analyses of scanning electron micrographs andtransmission electron micrographs suggested that the chitosan/PVA ultrafine fibers were often obtained along withbeads, and chitosan was located in the elctrospun fibers aswell as in the beads. Uniform chitosan/PVA fibers with anaverage diameter of 99±21 nm could be prepared from a 7%chitosan/PVA solution in 40:60 mass ratio. Results ofFourier transform infrared spectroscopy and X-ray diffraction demonstrated that there were possible hydrogen bondsbetween chitosan and PVA molecules, which could weakenthe strong interaction in chitosan itself and facilitatechitosan/PVA electrospinnability. The electrospun chitosan/PVA membranes showed higher water uptake and wouldhave potential applications in wound dressings.
đang được dịch, vui lòng đợi..