Polystyrene-b-poly(acrylic acid) block copolymers can self-assemble in selective solvents to form aggregates of different morphologies, including spherical micelles and vesicles. The ability of spherical micelles to solubilize (incorporate) 2-nitrodiphenylamine, a model hydrophobic but polar dye molecule, is investigated. The solubilization capacity of the micelles is evaluated as a function of the dye concentration, and the results are explained by treating solubilization as an adsorption process. The location of the incorporated molecules within the micelle is also examined, and the interfacial region of the micelle is identified as the solubilization site. Vesicles prepared from polystyrene-b-poly(acrylic acid) in dioxane/water mixtures undergo fusion (and therefore increase in size) as the water content in the solvent mixture increases. The kinetics of this process is followed, and the evaluated relaxation times range between 10 and 700 s, depending on the solvent composition, the amount of water added, the polymer concentration, and the poly(acrylic acid) block length. In addition, the preparation of vesicles with tunable sizes is examined. Additives (such as NaCl, HCl, and NaOH), as well as the solvent composition (ternary mixtures of water/dioxane/THF) are used to vary the diameter of vesicles prepared from the same copolymer. The effect of poly(acrylic acid) block length on vesicles size is also determined. Finally, polystyrene- b-poly(acrylic acid) vesicles are used as model carriers for the anti-tumor drug, doxorubicin hydrochloride. A pH-induced, active loading method is applied to concentrate the drug into the aqueous cavity of the vesicles.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.84494 |
| Date | January 2004 |
| Creators | Choucair, Amira |
| Contributors | Eisenberg, Adi (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 Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002149651, proquestno: AAINQ98227, Theses scanned by UMI/ProQuest. |
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