Understanding fundamental challenges to broadly-applicable nanofiber formation from thermoplastics via melt electrospinning

Although electrospinning (a technique where the presence of a strong electric field results in formation of a fluid cone-jet which transitions into a fiber) is a reliable approach to form polymer nanofibers from a wide range of soluble polymers, its use with melts is more problematic. The high viscosity of thermoplastic melts is incompatible with the most common electrospinning configuration (a long thin needle placed at high voltage through which the fluid must be pumped), intrinsically low ionic conductivity in melts results in relatively large jet diameters [1,2], and additional thinning from jet to fiber due to solvent loss is absent. Resolving these experimental challenges (i.e., utilizing an open flat-plate configuration where pumping is unnecessary and enhancing conductivity with commercial additives) results in a simple system where interactions between the melt and electric field can be visualized and understood to push towards nanofiber formation. In this poster, we discuss controlling flow rate via melt film thickness, manipulating the number of jets to further choke flow, and tracking the transition from jet to fiber: strategies which enable ultimate formation of linear low density polyethylene nanofibers.