The effect of nozzle spacing on the electric field and fiber size distribution in a multi-nozzle electrospinning system

Abstract

The present study investigates the characteristics of nanofiber uniformity in a multi-nozzle electrospinning system widely used to prepare nanofiber matrix. The effect of nozzle spacing on the electric field and nanofiber diameter uniformity is analyzed using a four-nozzle electrospinning system. The electric field distribution at the nozzle tip at different nozzle spacings is simulated numerically using COMSOL Multiphysics 5.6. Simulation results find that as nozzle spacings increase from 1 to 5 cm, the average electric field intensity at 1 mm from the tip of four nozzles increases from 32.46 to 40.08 kV/cm. Variations of electric field intensity at a given spacing decrease from 11% to 3.2% for spacings of 1 to 5 cm. Corresponding experiments are conducted with a gelatin solution. As the nozzle spacing increases, the four nozzles produce nanofibers with diameters of 88–508 nm, 112–498 nm, and 90–418 nm. Nanofiber diameter uniformity increases, and the average diameter decreases from 268 to 222 nm. In addition, the effect that changes in voltages and nozzle-to-collector distances have on fiber diameter is also studied. The experiments show that nanofiber diameter decreased as voltage increased and increased as nozzle-to-collector distance increased.