Effect of improved electric field distribution on jet motion, fiber morphology, and properties of electrospun thermoplastic polyurethane fibrous membrane

Electric field plays a pivotal role in electrospinning to produce the desired micro and nanofibers, hence, a tricipital-needle spinneret was developed to improve electric field distribution and productivity in this work. The effects of electric field distribution induced by spinneret configuration on jet motion, fiber morphology, and properties of electrospun TPU fibrous membrane at different applied voltages were investigated by simulation and experiment. The simulation results show that the designed tricipital-needle spinneret weakens the electric field near the needle tip and strengthens the electric field in the whipping region in comparison to the single-needle spinneret, exhibiting a relatively uniform electric field distribution. The experimental results demonstrate that the fiber diameter prepared by the tricipital-needle spinneret at the corresponding voltage is smaller than that of the single-needle spinneret due to the improved electric field distribution. Moreover, the fibrous membrane prepared by the tricipital-needle spinneret shows excellent tensile properties (7 MPa tensile stress and 401% breaking elongation), air permeability (85.32 mm s-1) and water vapor permeability (6.7 kg m-2 d-1). Therefore, the electrospinning system with the tricipital-needle spinneret not only increases the fiber productivity, but also improves the electric field distribution and endows the fibrous membrane with better properties, which can widen the applications of electrospun TPU fibrous membrane and also provides a new approach for the performance design of other electrospun fibers.