Effect of viscoelasticity in polymer nanofiber electrospinning: Simulation using FENE-CR model

Abstract

The uniaxial elongational flow of a polymer solution in the electrospinning process was investigated numerically and experimentally. The numerical model was constructed taking into account the viscoelasticity of the material. Therefore, governing equations were supported by a finite extensible non-linear elastic constitutive model and for the first time a FENE-CR model was used. This version of FENE model allows a good description of the rheology of extensional flows. For validation purposes, experimental studies were conducted using polymeric solutions of polyamide 6 (PA6). The main emphasis was made in determining the final fiber diameter and how initial polymer concentration acts on it. Further, the effect of the different concentration regimes on thinning dynamics was also examined. The comparative results of the numerical and experimental outcomes are sufficient to prove the predictive ability of the simulations. It can also be observed that the numerical approach adopted in this study captures not only the viscoelastic behavior of the material but also solidification of nanofibers due to solvent evaporation. As predictive quantitative models for electrospinning are lacking, this study gives good insights into the simulation of this process.