Optimisation of Collagen Films Produced via Pulsed Current Electrophoretic Deposition
type: CreativeWork
description: Electrophoretic deposition (EPD) has been used for the deposition of insoluble collagen type I in aqueous suspensions. In this process, two electrodes are immersed in an aqueous collagen suspension and a voltage is applied. The charged particles in the suspension move towards the oppositely-charged electrode resulting in the deposition of a coating, which can be removed to create a free-standing collagen film. The aim of this project was to maximise processing efficiency and yield, and improve material properties of the collagen films produced using EPD. The behaviour of collagen I from two different suppliers was compared when processed using pulsed current electrophoretic deposition (PC-EPD). It was found that, at voltages required for adequate yield (at least 5 V), formation of bubbles or corrosion of the electrode occurred for suspensions in aqueous media. However, dialysis of collagen suspensions against deionised water for 30 hours was shown to remove residual charge-carrying ions, notably Na+, K+, Cl- and Ca2+, arising from the collagen extraction process. This allowed deposition to be carried out at higher voltages (up to 10 V), leading to higher yield and the production of consistent films, avoiding the processing problems. PC-EPD was mathematically modelled, in order to broaden understanding of the process and aid in future investigations. A pulsed current factor was developed and introduced to previously-described direct current EPD models, derived from the Hamaker equation. To validate this, collagen suspensions were characterised, and measured variables were implemented within the model. The model was compared with experimental data and was found to be accurate at applied potentials of 10 V and above. Deviations between the model and experimental values for voltages of 5 V or less were explained by factors within the pulse cycle that were not accounted for, such as molecule acceleration time. Collagen deposits, once dried, adhered strongly to the electr…
abstract: Electrophoretic deposition (EPD) has been used for the deposition of insoluble collagen type I in aqueous suspensions. In this process, two electrodes are immersed in an aqueous collagen suspension and a voltage is applied. The charged particles in the suspension move towards the oppositely-charged electrode resulting in the deposition of a coating, which can be removed to create a free-standing collagen film. The aim of this project was to maximise processing efficiency and yield, and improve material properties of the collagen films produced using EPD. The behaviour of collagen I from two different suppliers was compared when processed using pulsed current electrophoretic deposition (PC-EPD). It was found that, at voltages required for adequate yield (at least 5 V), formation of bubbles or corrosion of the electrode occurred for suspensions in aqueous media. However, dialysis of collagen suspensions against deionised water for 30 hours was shown to remove residual charge-carrying ions, notably Na+, K+, Cl- and Ca2+, arising from the collagen extraction process. This allowed deposition to be carried out at higher voltages (up to 10 V), leading to higher yield and the production of consistent films, avoiding the processing problems. PC-EPD was mathematically modelled, in order to broaden understanding of the process and aid in future investigations. A pulsed current factor was developed and introduced to previously-described direct current EPD models, derived from the Hamaker equation. To validate this, collagen suspensions were characterised, and measured variables were implemented within the model. The model was compared with experimental data and was found to be accurate at applied potentials of 10 V and above. Deviations between the model and experimental values for voltages of 5 V or less were explained by factors within the pulse cycle that were not accounted for, such as molecule acceleration time. Collagen deposits, once dried, adhered strongly to the electr…
author: Linley, Matthew
language: eng
keywords: Collagen, Films, Electrophoretic deposition, Pulsed Current
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/1ba363db-4274-4147-928c-cdbb3c926a3c/download
license: http://purl.org/NET/rdflicense/allrightsreserved
date published: 2020-11-01
date modified: 2026-07-22T22:23:57Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.71910