Chain exchange kinetics of block copolymer micelles mediated by the air-water interface
| Author(s) | Heusele, Laurens | |
| Date Accessioned | 2017-10-20T11:17:38Z | |
| Date Available | 2017-10-20T11:17:38Z | |
| Publication Date | 2017 | |
| SWORD Update | 2017-09-07T16:26:12Z | |
| Abstract | The self-assembly of amphiphilic block copolymer micelles has been the center of extensive research due to their broad set of applications. Many of the applications, such as drug delivery vehicles, hinge on the stability of the micelles and how they interact with their environment. In expanding the knowledge of these nanostructures and their behavior, novel technologies can be further explored. However, despite their use in a wide range of fields, the fundamental growth mechanisms at work remain mostly unresolved. The work in this thesis focuses on the influence of the air-water interface on micellar growth. The system consists of poly(1,4-butadiene-b-ethylene oxide) in aqueous solvent. In order to examine the relaxation behavior, the system is perturbed from its equilibrium state by addition and removal of cosolvent (tetrahydrofuran). Dynamic light scattering is chosen as a primary characterization tool to monitor the micelle sizes over time as it offers a cheap and fast way to investigate trends before moving on to costlier techniques. A distinct difference in chain exchange was found for vortex mixed samples with varying interface turnover rate to bulk volume ratios, suggesting an interface mediated growth mechanism. Additionally, the same experiment was repeated on a rotator to obtain a more quantifiable result, however, yielding a less pronounced difference. Lastly, the concentration dependency of the micelle growth kinetics was investigated. The examined concentrations exhibited an equal growth, in agreement with the hypothesis of interfacial nucleation. Overall, the data gathered from the rotator experiments appeared noisy, making it hard to justify any conclusions. Nonetheless, the results presented in this thesis agree with the proposed role of the interface in the kinetic pathway. Understanding this process unlocks interesting new possibilities in utilizing block copolymers such as cargo exchange between drug delivery vehicles. | en_US |
| Advisor | Epps, Thomas H. | |
| Advisor | Sullivan, Millicent | |
| Degree | M.Ch.E. | |
| Department | University of Delaware, Department of Chemical and Biomolecular Engineering | |
| Unique Identifier | 1006874150 | |
| URL | http://udspace.udel.edu/handle/19716/21709 | |
| Language | en | |
| Publisher | University of Delaware | |
| URI | https://search.proquest.com/docview/1937538427?accountid=10457 | |
| Keywords | Applied sciences | en_US |
| Keywords | Air-water interface | en_US |
| Keywords | Block copolymers | en_US |
| Keywords | Kinetics | en_US |
| Keywords | Micelles | en_US |
| Title | Chain exchange kinetics of block copolymer micelles mediated by the air-water interface | en_US |
| Type | Thesis | en_US |