UV‐Responsive Behavior of Azopyridine‐Containing Diblock Copolymeric Vesicles: Photoinduced Fusion, Disintegration and Rearrangement

• Published in: Macromolecular rapid communications. Vol. 30; no. 13; pp. 1089 - 1093
• Main Authors: Lin, Li, Yan, Zeng, Gu, Junsi, Zhang, Yuanyuan, Feng, Ze, Yu, Yanlei
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag 01-07-2009; Wiley
• Subjects: Applied sciences; azo polymers; diblock copolymers; Exact sciences and technology; Grafting and modifications; photochemistry; Physicochemistry of polymers; Polymers and radiations; self‐assembly; vesicles; Vesicle; Membrane fusion; Atom transfer polymerization; diblock copolymers; Photoinduced effect; Ethylene oxide copolymer; Experimental study; Lateral group; vesicles; Organic solution; Azo compound; self-assembly; photochemistry; Preparation; Diblock copolymer; Pyridine derivative copolymer; Light sensitive copolymer; Molecular aggregation; Methacrylate copolymer; Aqueous solution; azo polymers; Amphiphilic polymer
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.200900105

A novel amphiphilic diblock copolymer composed of a hydrophilic poly(ethylene oxide) and a hydrophobic polymethacrylate with photochromic azopyridine moieties in the side groups was synthesized by atom transfer radical polymerization. The copolymeric vesicles showed photoinduced circular process including fusion, damage and defect formation, disruption, disintegration and rearrangement in H2O/THF during the irradiation of UV light. The process of photoresponsive cycle can be inhibited at any moment by visible light.
Vesicles self‐assembled from an azopyridine‐containing amphiphilic diblock copolymer possess circular photoresponsive behavior including fusion, disintegration and rearrangement. The extent of photoinduced change can be determined by the irradiation of UV and visible light. It is possible to realize controlled release of the encapsulated substance only depending on light stimuli.