Modeling of polymer fiber evaporation

Solvent evaporation process from the surface of two-phase polymer solution axisymmetric fiber is analyzed. Fick's law of mass diffusion was employed under the condition that the solvent diffusion depends upon the solvent concentration according to the Vrentas–Duda free-volume theory. Numerical results are provided for the PAN/DMF fibers of different initial radii that are close to jet radii in electrospinning experiments. Significant non-uniformity of the solvent concentration distribution over the fiber cross-section was observed, that leads to the high inhomogeneity of physical properties inside the fiber. The given model can be used as a basis for more accurate modeling of electrospinning of nanofibers.