Electrospinning is a method of producing micro/nano fibers by injecting polymer solutions in electrostatic fields. In an electric field, the polymer droplets at the nozzle tip form a Taylor cone. When the electric field force to overcome the surface tension of the polymer solution is applied, a fine spinning flow is emitted from the tip of the Taylor cone, and during its flying towards the collector, solvent evaporation and cooling of the melt result in solid nanofibers deposited onto the collector.
Recently, highly productive electrospinning methods such as multi-nozzle electrospinning and needleless elecrospinning have been proposed. Multi-nozzle electrospinning is a method with many overlapped nozzles. It is difficult to realize stable and continuous spinning because corona discharge is created by strong electrical interaction between the nozzles, due to the nonuniform distribution of the electric field at the nozzle tip. Therefore, creating a uniform electric field between nozzles is very important for multi-nozzle electrospinning. Prediction of the diameter of electrospun fibers is also important in their applications.
Not only some methods of controlling the structure and diameter of electrospun fibers by changing the structure and arrangement of nozzles, but also a number of attempts to improve the structure and orientation degree of electrospun fiber by changing the setup of collectors have been proposed. However, few attempts have been made to obtain uniform electrospun fibers by changing the shape of collector geometry.
Pak Yong Ho, a researcher at the Nano Physics Engineering Institute, has determined a new type of curved profile for a collector to obtain uniform fibers in an arched multi-nozzle electrospinning device.
Applying the calculation model for polymer jet in an electrostatic field using Calculating Fluid Dynamics (CFD), he calculated the velocity field distribution in electrospun polymer jet fluid, and determined the uniform velocity profile. Taking a curved surface determined by the uniform velocity profile as a collector, he constructed an arched multi-nozzle electrospinning system. To obtain uniform electrospun nanofiber membranes suitable for preparation of nanofiber ion exchange membrane for electrodialysis applications, he proposed an equation of the curve for collector geometry. Curved collectors need no additional means for obtaining electrospun fibres in uniform diameter.
© 2021 KumChaek University of Technology