Influence of high voltage polarity in multi-pin upward electrospinning system on the Fiber morphology of poly (vinyl alcohol)

This study was carried out to evaluate the influence of high voltage polarity on a newly designed multi-pin upward electrospinning spinneret to produce poly (vinyl alcohol) nanofibers. Two different high voltage polarity configurations were applied to the spinneret and collector, namely collector charging configuration (configuration-1) and spinneret charging configuration (configuration-2). The outcomes demonstrated that the collector charging configuration is better in case of upward multi-pin electrospinning setup, to their conservative framework in terms of stable Taylor cone formation, smaller fiber diameter and less bead formation. Electrical field profile in the electrospinning zone was investigated using finite element modelling for both the configurations. No difference in electric field intensity norm (|E|) was observed near the tip of the pins for both the polarities (configurations). Although having the same magnitude, the dominant electrical field component, Ez for configuration -1 is found to be of opposite sign to that of configuration -2. The electrostatic simulations also suggested that all the pins were not at the same potential and that there was a minor difference in pin potentials. Also, optimizations of pin length to reduce the potential differences between the pins were theoretically estimated through COMSOL3D simulation software.