Effect of electrospinning parameters on nanofiber diameter made of poly (vinyl alcohol) as determined by Atomic Force Microscopy

A solution of poly (vinyl alcohol) (PVA) in water was electrospun into ultrafine nanofibers using a commercially available electrospinning set-up. Some major electrospinning parameters such as the concentration of polymer solution, flow rate, spinning voltage and distance between the needle tip and collection target were chosen to investigate its effect on the topological morphology as well as the average diameter of the electronspun PVA nanofibers using Atomic Force Microscopy (AFM). Diameters of the nanofibers obtained ranged from 150 nm to 900 nm. The diameters of electrospun nanofibers were most significantly affected by the concentration of polymer solution. While lower concentration always gave rise to the formation of discontinuous nanofibers with beads, an increasing concentration yielded smooth and uniform nanofibers with increasing diameters and beaded morphology was found disappearing. Keeping solution concentration constant at a higher value that yielded smooth nanofibers, an increase in the flow rate again changed the morphology from smooth to beaded morphology of nanofibers obtained. Spinning voltage did not show any specific trend of diameter change at a wider range (10 to 25 kV) selected in this study.