Shear-electrospinning: extending the electrospinnability range of polymer solutions

Electrospinning is recognised as an easily implementable method for the production of submicron-diameter polymer fibres. However, electrospinning is problematic for polymers such as biologically derived materials because of their higher viscosity. In this study, a new spinneret design applies shear forces to the polymer solution just prior to electrospinning. The efficacy of shear-electrospinning is proven using concentrated poly(vinyl alcohol) (PVOH) solutions as a model, with solutions designed around the various concentration regimes of PVOH, initially identified via rheological studies. Conventional electrospinning of solutions up to 16.8 wt% PVOH and viscosity in the order of 101 Pa s leads to the formation of ribbon-like fibres. In contrast, shear-electrospinning produces fibres finer in diameter, rounder in cross-section and smoother. Finally, fibre formation from solutions that are non-electrospinnable under conventional electrospinning is shown for the first time to be achievable via shear-electrospinning as demonstrated for a 30 wt% PVOH solution