Feasibility Study of a Novel Electrospinning System with Uniform & Non-uniform Electric Fields
Nanofibres are fibres that are 1000 times thinner than a human hair, they are a versatile form of material made from various polymers. They inherit the properties of the base material while also yielding the properties resulting from being a nanofibre and having a very high surface area to volume ratio.
Producing nanofibre yarn is a complex electro-chemical process that requires field manipulation to allow bundles of fibres to form and align in a manner to be gathered into a yarn. In order to achieve this, a setup is required to allow an investigation into the relationship between electric field shape and behavior of electrospinning solution is conducted. The feasibility of the setup testing the effects of changing polarity of the electrodes and electrode geometry is investigated as well.
This thesis investigates and explores experimental methodology, modeling electrostatic fields for electrospinning, design and build of an experimental setup which will be used to acquire electrospinning data to assess the feasibility of a novel method of electrospinning for future design optimization on existing methods of electrospinning.
Simulating electrostatic fields of different electrode geometries with ANSYS Maxwell is used to plot the fields for various of electrodes and the influence of non-conductive enclosures and nearby objects on the static electrospinning field. The plots are then gathered and processed to calculate the differences in electric field strength of two fields to evaluate the significance of changes in geometry.
Results from the simulations indicate the effect of having a non-conductive enclosure around the electrodes have an effect that is negligible. Nearby earthed objects require shielding by means of using high impedance film with an applied voltage gradient, to minise the effects of the earthed object.
Two experimental configurations were used to investigate the feasibility of electrospinning in uniform and non-uniform electric fields using needle and needle-less methods. No electrospinning was observed in a uniform field prior to the breakdown of air. However, solution convection was observed when the fluid container is placed near edge of the electrode. Non-uniform field electrospinning was tested with a needle-plate setup using two different diameter drill bits pointing through a petridish submerged in mineral oil. This test led to the conclusion that electrospinning with the designed modular setup was feasible.