Amphiphilic copolymers of hydrophobic Disperse Red 1 acrylate (DR1A) and hydrophilic acrylic acid (AA) were dissolved in THF and a H2O/THF co-solvent series. The thermal cis-trans isomerization behavior of the azo groups was measured by means of flash photolysis to investigate self-assembled structure in solution. The rate constants observed for the azo-containing polymers permit an estimation of how the thermal isomerization is influenced by both polymer and solution properties. In pure THF the relaxation can be analyzed by a monoexponential decay. In aqueous-organic solutions all poly(DRlA-co-AA) samples show a slow isomerization process due to inhibited mobility of the azo groups, preceded by a faster isomerization process for unaggregated azo groups. In such cases, the relaxation of the cz's-isomer was fit to a biexponential function which clearly demonstrates two distinct local chromophore environments. The spectroscopic results of this study suggest that weakly aggregated states of the amphiphilic polymers in an aqueous-organic solution can be readily studied through isomerization spectroscopy to estimate the fractions of aggregated groups involved and their local environment.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.19563 |
| Date | January 2003 |
| Creators | Norman, Lana Laurette |
| 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 | Master of Science (Department of Chemistry) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002022136, Theses scanned by McGill Library. |
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