Electrospun pullulan/poly(vinyl alcohol)/silver hybrid nanofibers: Preparation and property characterization for antibacterial activity

Nanofibers composed of pullulan (PULL), poly(vinyl alcohol) (PVA) and silver (Ag) were prepared using an electrospinning method in aqueous solutions. Field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), antibacterial activity, and mechanical measurement were undertaken in order to characterize the PULL/PVA/Ag nanofiber morphology and properties. XRD and FTIR data demonstrated that there were good interactions between PULL and PVA possibly caused by hydrogen bonds. Moreover, XRD data and TEM images support the coexistence of a Ag and PULL/PVA blend matrix where Ag nanoparticles are well distributed. The study shows that the thermal stability in the mid-point temperature of the degradation and tensile strength of PULL could be increased with blending of PVA. It was also found that the Ag content could increase thermal stability and intensify antibacterial activity of the blend nanofibers. Since PULL and PVA are water-soluble and biocompatible polymers, the blended system can be considered one of the best materials for the preparation of excellent antibacterial nanofibers confirmed by a preservation test showing that the prepared material is suitable as a new preservative.