Charge Transfer Mechanisms in Electrospinning

Type of content
Theses / Dissertations
Publisher's DOI/URI
Thesis discipline
Physics
Degree name
Master of Science
Publisher
University of Canterbury. Physics and Astronomy
Journal Title
Journal ISSN
Volume Title
Language
Date
2008
Authors
Stanger, Jonathan Jeffrey
Abstract

Electrospinning is a method of producing nano structured material from a polymer solution or melt using high strength electric fields. It is a process that has yet to find extensive industrial application yet shows promise if obstacles such as low rate of production overcome perhaps by more complete theoretical modelling. This work examines the effects of adding an ionic salt to a solution of poly(vinyl alcohol) in water. The direct effect was an increase the charge density and electric current. It was found that an increase in charge density decreases the mass deposition rate and forms a thinner initial jet. When the sign of the charge on the polymer solution was changed from positive to negative the charge density increased and the initial jet diameter and mass deposition rate also decreased. It was proposed that a smaller radius of curvature is formed by the Taylor cone at higher charge densities resulting in a smaller “virtual orifice”. The extent of the bending instability was explored and it was found that adding ionic salt results in a decrease in the bending instability resulting in thicker fibres. Changing the sign of the charge on the polymer solution from positive to negative resulted in an increase in the bending instability and resulted in thinner fibres. The charge transfer mechanisms used in different electrospinning models are explored and some assumptions not explicitly stated are discussed. From this discussion a generalized equation describing the charge transport mechanisms is proposed.

Description
Citation
Keywords
Electrospinning, Taylor cone, bending instability, charge transfer, ionic salt, poly(vinyl alcohol), deposition rate, charge density
Ngā upoko tukutuku/Māori subject headings
ANZSRC fields of research
Rights
Copyright Jonathan Jeffrey Stanger