Light-triggered reversible solubility of α-cyclodextrin and azobenzene moiety complexes in PDMAA-co-PAPA via molecular recognition

Authors

  • Chunhua Luo,

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
    2. Graduate School of the Chinese Academy of Sciences, Beijing 100081, People's Republic of China
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  • Fang Zuo,

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
    2. Graduate School of the Chinese Academy of Sciences, Beijing 100081, People's Republic of China
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  • Xiaobin Ding,

    Corresponding author
    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
    • Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
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  • Zhaohui Zheng,

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
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  • Xu Cheng,

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
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  • Yuxing Peng

    1. Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, People's Republic of China
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Abstract

Photoresponsive polymer with azobenzene pendant group (PDMAA-co-PAPA) was synthesized by radical polymerization of N,N-dimethylacrylamide (DMAA) and N-4-phenylazophenyl acrylamide (PAPA), and the characterization of the inclusion complexes of the PDMAA-co-PAPA with α-cyclodextrin (α-CD) were performed by FTIR, GPC, 1H NMR, 2D NOESY, and UV–vis spectroscopy. It was found that the solubility of PDMAA-co-PAPA and α-CD inclusion complexes in aqueous solution showed tunable property, which could be triggered by alternating UV–vis light irradiation at a certain temperature due to the effect of molecular recognition of α-CD with azobenzene moiety in the polymer. After UV irradiation, the lower critical solution temperature (LCST) of the polymer aqueous solution increased slightly without α-CD while the LCST decreased sharply at presence of α-CD. Furthermore, UV spectroscopy showed that the photoisomerization of the polymer solution went on rapidly and reversibly, and 2D NOESY data suggested that the inclusion complexation of α-CD with trans azobenzene moiety and the decomplexation with cis azobenzene resulted in reversible solubility behavior when objected to UV and Vis light irradiation alternately. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

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