Title: Synthesis and Self-assembly Behavior of a Thermo-/photo-dual Responsive Triblock Copolymer

Author: Gaoxiang Pan, Ze Feng, Jia Wei, Yanlei Yu*

Journal: Acta Chim. Sinica, 2013, 71(5), 733-738

Abstract:

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.

Fulltext Link: http://sioc-journal.cn/Jwk_hxxb/CN/10.6023/A13010117