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Title: Synthesis and Structural Modification of Polymeric Vesicle Systems: An Investigation using Electron Microscopy.
Author: Parmenter, Christopher David James
ISNI:       0000 0001 3472 5884
Awarding Body: University of Warwick
Current Institution: University of Warwick
Date of Award: 2007
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This thesis aims to investigate the formation of vesicles by the use of synthetic molecules and then seeks to enhance their stability through the addition of hydrophobic monomer or a second polymeric species. Prior to this, Chapter 1 reviews vesicle forming molecules, methods for production, analytical techniques for vesicles and finally applications of vesicle technology. Chapter 2 uses Dioctadecyldimethylammonium Bromide (DODAB) to form vesicles and through the swelling and polymerisation of hydrophobic monomers, seeks to enhance the stability of the vesicles. Transmission electron microscopy reveals vesicles with polymer beads on the bilayer, due to phase separation between polymer and DODAB. Based on the observed phase separation in the DODAB system, a change to the use of block copolymers is made. Chapter 3. Three block copolymers are synthesised and characterised (NMR, GPC, (Cryo) TEM) with a view to forming a more compatible vesicle forming system. Analysis reveals that PEG4S-b-PMA164 forms polymer vesicles (polymersomes) upon dissolution in THF and slow addition of water. Cryo-TEM is used to create a morphology diagram of the block copolymer. Chapter 4 uses the polymersome forming block copolymer in a bid to enhance compatibility between vesicle and monomer. The polymersomes are swollen in place of the DODAB system. Despite an envisaged compatibility between monomer and polymersomes, the resultant polymersome structures adopt a 'tube walled' arrangement. Cryo and negative stain TEM are used to judge the effectiveness of this approach. Finally in Chapter 5 the effect of the addition of a Brij surfactant to the polymersomes in an attempt to form rafts in the bilayer is investigated. Additionally the effect of adding PMMA homopolymer to PEG4S-b-PMMA164 during polymersome formation is investigated as an alternative approach to monomer swelling.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available