Morphological Modulation of Electrospun PVDF/PVP Nanofibers

Abstract

In electrohydrodynamics, the regulation of the morphology and structures of electrospun nanofibers is crucial for tuning the properties of the final product. In the electrospinning process, the uniform and smooth morphology of polyvinylidene fluoride (PVDF) nanofibers can be obtained by controlling experimental parameters, environmental parameter, and system parameters. However, there is inadequate research on the effect of polymer addition on the morphology enhancement of PVDF nanofibers and the underlying mechanisms. In this study, the effects of the polyvinylpyrrolidone (PVP) molecular weight and content on various process parameters (i.e., Taylor cone length, straight fluid jet length, and spray angle) are evaluated. The obtained electrospun PVDF/PVP nanofibers were further characterized by SEM, EDS, FTIR, and XRD. The results indicate that the solution viscosity, which was controlled by varying the molecular weight and content of PVP, was linearly correlated with the process parameters. As the PVP molecular weight and content increased, the nanofiber diameter increased and the nanofiber morphology became smoother. The EDS results revealed that the nanofibers consisted of PVDF encapsulated by PVP. The FTIR and XRD results indicated that hydrogen bonding between PVP and PVDF weakened the crystallization of PVDF, leading to the formation of smooth PVDF/PVP nanofibers.