In electrospinning, applied electric field elongates a charged fluid jet to produce nanofibers. Recently, melt electrospinning has received much attention since the formation of nanofibers directly from polymer melts is more environmentally benign and economically attractive than polymer solution electrospinning.

We present a nonisothermal thin-filament model for the stable jet region of electrically-driven free-surface viscoelastic flow. Due to low inertia in highly viscous viscoelastic jets, the traditional asymptotic thinning boundary condition, previously used for Newtonian fluids and certain polymer solutions, is replaced with a new initial thinning rate expression. This modification resulted in the reduction of a boundary value problem to a simpler and numerically more stable initial value problem. Numerical solutions for various experimental conditions, such as temperature, flowrate, and applied electric field, agree with digitized images of electrospun polylactic acid melt jet near the spinneret and the final jet sizes from experiments where whipping motion has been suppressed by rapid cooling.

Some polymers such as nylon and polyolefins can crystallize in-flight, and thus crystallization during melt electrospinning has been incorporated into our nonisothermal thin-filament model.. Various approaches for modeling in-flight crystallization kinetics including flow induced crystallization in electrospinning will be presented and compared to experimental results. To account for coupling of the highly elongational flow with crystal morphology evolution, a mesoscale approach has been proposed and preliminary results will also be presented.