This thesis presents numerical studies of phase behavior for both thermotropic and lyotropic liquid crystals. The nature of the orientational transition in the Lebwohl-Lasher model for the nematic-isotropic phase transition is found to be weak first-order with the stability limits of the nematic and isotropic phases being extremely close to the equilibrium transition temperature. It is also found that the director fluctuations in the nematic phase correspond to fractional Brownian motion whereas the fluctuations in the isotropic phase follow ordinary Brownian motion. The Pink model is extended to give an accurate description of the main phase transition in lipid bilayers by introducing hydrophobic mismatch interactions between acyl chains and also direct inter-monolayer attractive interactions. The lateral density fluctuations and the resulting dynamic bilayer heterogeneity are studied. Lipid-protein interactions are further included to describe the phase separation of lipid-protein mixtures, gramicidin channel formation and the effects of protein on the lipid bilayers. A model is also proposed for phase transitions involving hydrogen bonding between the polar heads in lipid bilayers.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41132 |
| Date | January 1993 |
| Creators | Zhang, Zhengping, 1957- |
| Contributors | Zuckermann, Martin J. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001337631, proquestno: NN87889, Theses scanned by UMI/ProQuest. |
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