In this article, a multiple-responsive polymer micelles system was constructed by using ionic bond to link the hydrophobic tetraphenylthiophene (TP) fluorophores, which possess the property of aggregation-induced emission enhancement (AIEE), with the hydrophilic poly(N-isopropyl acrylamide) (PNIPAM). The susceptibility of the ionic ammonium-sulfonate (Am-Sul) bonds towards metal ions, acid and base triggered the AIEE-operative fluorescence (FL) response. To exercise the idea, PNIPAM with sulfonate terminal was primarily prepared to react with TP-derivatives functionalized with ammonium groups to generate polymer complex of TP-PNIPAM. When in water, the polymer complex TP-PNIPAM formed micelles with the aggregated TP core interconnecting the hydrophilic PNIPAM shell by the ionic Am-Sul bonds. With the operative AIEE effect, the aggregated TP core of the micelles fluoresced but upon the additions of metal ions, acid and base, the ionic bonds dissociated to result in the collapse of the micelles and the FL quenching. A novel fluorogenic sensor capable to respond to multi-stimuli was therefore constructed.
Amphiphilic micelle systems with the hydrophilic poly(N-isopropyl amide) (PNIPAM) shell and the hydrophobic tetraphenylthiophene (TP), which has the novel aggregation-induced emission enhancement (AIEE) feature, core inter-connected by ionic bonds were prepared in this study to explore the AIEE-operative emission response towards critical micelle concentration (CMC) and lower critical solution temperature (LCST). To exercise the idea, TP functionalized ammonium cations and PNIPAM with terminal sulfonate group were individually prepared and mixed together to yield three amphiphilic TP-PNIPAM complexes with different hydrophobic TP to the hydrophilic PNIPAM (x/y) ratios. When in aqueous solution, TP-PNIPAMs form micelles with the aggregated TP core, which emits strongly due to the operative AIEE effect, encompassed by the PNIPAM shell. The resultant CMC and LCST of the TP-PNIPAM micelles can be varied by changing the hydrophobic to the hydrophilic x/y ratio and can be monitored by the AIEE-dominant fluorescence responses towards concentration and temperature variables.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0713112-211913 |
| Date | 13 July 2012 |
| Creators | Lai, Yi-Wen |
| Contributors | Lie-Li Ling, Shao-Wei Guo, Jin-Long Hong, Ming Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0713112-211913 |
| Rights | user_define, Copyright information available at source archive |
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