Effect of polyvinyl alcohol/chitosan blend ratios on morphological, optical, and thermal properties of electrospun nanofibers

In this study, the electrospinning method was used to prepare polyvinyl alcohol (PVA)/chitosan (CS) blend nanofibers from their solutions. The effect of blend ratios (PVA/CS: 1%, 3%, 5%, and 7% (w/w)), applied voltage, and flow rate on the morphological, optical, and thermal properties of electrospun nanofibers were investigated by scanning electron microscopy (SEM), fluorescence and UV-Vis spectroscopies, and thermogravimetric analysis (TGA), respectively. Fourier transform infrared spectroscopy analysis indicated the existence of related functional groups of both PVA and CS in the electrospun fibers. During the electrospinning process, the maximum possible ratio of CS was 7% (w/w). SEM images indicated that more flat nanofibers were synthesized at lower flow rates, but the shape of the fibers was more circular at higher flow rates. On the other hand, an increase in CS ratio, flow rate, and applied voltage caused a decrease in the transmittance values of the fibers while samples including higher concentrations of CS showed lower emission intensities. Furthermore, the thermal properties of the electrospun fibers were developed by incorporation of a high amount of CS.