Modification of electrospinning solutions and yarn production for filtration application.

摘要

The electrospinning process has been known as a simple, feasible and effective technique to fabricate submicron fibers from polymeric solution. Many applications employ electrospun fibers such as biomedical application, filtration, composite application and clothing. Therefore a large amount of fibers is required to fulfill the needs of those applications. As we know the production rate of the single syringe electrospinning process is around 0.1 g/hr which is very low hence in this work the electrospinning process was redesigned to simultaneously create multiple of liquid jets during the operation. By increasing the numbers of liquid jet could improve the production rate of the electrospinning technique up to 4 g/hr. The new designs were simple and very economical compare to the industrial machine such as Nanospider(TM) having production rate of 4.5 g/hr.;The small diameter of the electrospun fiber without bead formation always prefers. The small diameter fiber will provide high surface area to mass/volume ratio which is useful for many applications such as drug delivery that allows more drugs to be adsorbed on the surface of the fibers. In this work the electrospinning solution was modified to reduce the average fiber diameter and reduce the bead formation by using mixed solvent system of ethanol and deionized water and incorporating additives such as ionic salts and surfactants. The average fiber diameter decreases with increasing amount of deionized water. By adding salts or surfactants into the electrospinning solution bead formation was reduced.;Nanospider(TM) parameters were studied to investigate the effect of rotational speed of the electrode and electrode types on average fiber diameter and morphology as well as the production rate. This work will provide the experimental result which could be benefit to other researchers to determine the type and speed of the electrode for their work.;In this work the electrospinning setup was modified in order to generate electrospun yarn. By using the grounded vortex water containing in a large funnel as a collector the electrospun fiber can be collected on the surface of the water and flow down out of the funnel and be drawn into yarn. The electrospun yarn then incorporated in a filter cartridge by wrapping as a yarn wound cartridge. The properties including permeability, porosity and capture efficiency of the cartridge were characterized. The yarn found out to improve the efficiency of the cartridge with high permeability and porosity.;Computational modeling was created to study the behavior of electrical field on the multiple electrospinning jet paths of the yarn setup. The model was modified to change the electrospinning jet paths by incorporating secondary electrodes to alter the electrical field. By comparing the model to experiment one could find that it could improve the production rate of fabrication of yarn.