Effect of Magnetic Field on Stability of Jet Motion in Electrospinning

Electrospinning uses an electrical charge to draw fine polymer fibers from a liquid. Stable jet stage and whipping instability stage exist in the electrospinning process. It is difficult to control stability of jet motion. Electrospinning with NbFeB permanent magnets is proposed to enhance the stability of jet motion in this paper. This method is very simple and effective. The electrospinning process assisted by magnets was observed by a high-speed camera, and the magnetic field was numerically analyzed by finite element method. The experimental results showed that the stability of jet motion increased obviously. We have explained that the magnets restricted and focused the motion of charges as a magnetic lens and created a uniform electric field distribution as an auxiliary electrode at the end of spinneret. The stable jet length, whipping instability cone angle, and fiber diameter were measured by experiments. The stable jet length increased significantly, the whipping instability cone angle decreased, and the average diameter of fibers increased slightly and distributed more evenly as the magnets were fixed at the end of spinneret.