Synthesis and Self-assembly Behavior of a Thermo-/photo-dual Responsive Triblock Copolymer
Received date: 2013-01-23
Online published: 2013-03-08
Supported by
Project supported by the National Natural Science Foundation of China (Nos. 21134003, 21273048, 51225304, 51203023), Specialized Research Fund for the Doctoral Program of Higher Education (20100071110014), Shanghai Rising-Star (follow-up-supported) Program (11QH1400400).
A novel triblock copolymer containing azobenzene (AZO) and N-isopropylacrylamide (NIPAM) was synthesized by atom transfer radical polymerization (ATRP) using a poly(ethylene oxide) bifunctional macroinitiator (Br-PEO-Br). The triblock copolymer was characterized by 1H NMR and gel permeation chromatography (GPC). Uniformly distributed polymeric micelles were obtained in aqueous solution by self-assembly method. Transmission electron microscope (TEM), fluorescence spectroscopy and dynamic light scattering (DLS) were used for the investigation of the self-assemblies and their stimuli-responsive behavior. Photoinduced release behavior was achieved with the as-prepared triblock copolymer micelles, which has not been observed in our previously-reported diblock copolymer micelles: the fluorescence intensity of Nile Red trapped in the triblock copolymer micelles dropped by approximately 40% after UV and Vis light alternative irradiation, indicating that a portion of the Nile Red was released to the aqueous media. Besides, the micelles shrank during the heating process.
Key words: ATRP; block copolymers; self assembly; photo-response; thermo-response
Pan Gaoxiang , Feng Ze , Wei Jia , Yu Yanlei . Synthesis and Self-assembly Behavior of a Thermo-/photo-dual Responsive Triblock Copolymer[J]. Acta Chimica Sinica, 2013 , 71(05) : 733 -738 . DOI: 10.6023/A13010117
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