Multi-nozzle electrospinning optimization of carbon nanotube/epoxy submicron filaments – A numerical study

Abstract

Electrospinning is the process of spinning a polymer melt or solution through a nozzle in the presence of a high-voltage electric field, which causes it to coalesce into a continuous filament. Diameter of the filament is anywhere from tens of nanometers to a few microns, depending on the materials being spun, viscosity, electric field, and other experimental conditions. This process has gained attention because of its versatility, low cost, and ease of processing for many polymers. Thermosetting reinforced epoxy is particularly challenging because of the variability in viscosity caused by temperature changes and induced by the electrospinning process itself. Nevertheless, our research group previously developed the fabrication and characterization of submicron carbon nanotube (CNT)–epoxy nanocomposite filaments through an electrospinning process via a single nozzle, horizontal spray process. In this study, electric fields and other parameters were simulated using COMSOL Multiphysics® software to understand the induced surface charges that cause the Taylor cone of the CNT-epoxy solution.. Optimization of the simulation results coupled with those of experiments enabled us to achieve stability and fabricate smaller but more uniform diameter fibers with enhanced structural, electrical, and thermal properties. The main challenge addressed in this paper is the use of the COMSOL models to understand the effect of different geometries on the electric field in the presence of multi-nozzle systems.