Optimization of Electrospinning Parameters for Bead-free Morphology of Poly(vinyl alcohol) Nanofibers

Electrospinning is a relatively easy and perspective method for producing polymeric, ceramic, and composite fibers, which may vary from several nanometers to several micrometers. Poly(vinyl alcohol) (PVA) is a water-soluble, non-toxic, and biocompatible polymer with good mechanical properties, making it widely used for electrospinning. In this study, the influence of PVA solution concentration, applied voltage, tip-to-collector distance, and needle size on the morphology and diameter of the obtained fibers was investigated in order to optimize the conditions for the production of bead-free nanofibers. For this purpose, PVA solutions with different concentrations (5, 7.5, and 10 wt.%) were prepared and electrospun by altering the parameters of the process. Fiber morphology and diameter distribution as a function of the studied parameters were evaluated by Scanning electron microscopy (SEM). The results demonstrated a strong dependence of fiber morphology on solution viscosity. At low concentration (5 wt.%), fibers with numerous bead defects were obtained. Increasing the concentration to 7.5 wt.% led to a significant reduction in bead defect. Further increasing the concentration up to 10 wt.% led to the production of smooth and homogeneous fibers under the optimized conditions. A non-linear relationship between fiber diameter and tip-to-collector distance was observed, with an optimal distance of 140 mm yielding the thinnest and most uniform fibers. Additionally, needle diameter was found to influence both fiber size and process stability. Smaller needle diameters (G22) enabled the production of finer fibers (~180 nm), but with increased sensitivity to processing conditions, whereas larger diameters (G20–G21) provided more stable jet behavior and narrower diameter distributions. The statistical analysis ANOVA confirmed these findings. The study provides useful insights for optimizing electrospinning parameters to obtain high-quality, bead-free PVA nanofibers.