Temperature and light-induced self-assembly changes of a tetra-arm diblock copolymer in an ionic liquid

Xiaofeng Ma, Ryoji Usui, Yuzo Kitazawa, Hisashi Kokubo, Masayoshi Watanabe

    • 2 Citations

    Abstract

    A tetra-arm diblock copolymer ([PEG-b-P(AzoMA-r-NIPAm)] 4) was synthesized by reversible addition-fragmentation chain transfer copolymerization of N-isopropylacrylamide (NIPAm) and 4-phenylazophenyl methacrylate (AzoMA), initiating from the ends of functionalized tetra-arm polyethylene glycol (tetra-PEG). The resulting tetra-arm diblock copolymer consists of two segments: tetra-PEG (the center block; compatible with 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim]PF 6)) and P(AzoMA-r-NIPAm) (the end blocks; temperature- and photosensitive compatibility with [C 4 mim]PF 6 due to photoresponsive upper critical solution temperature phase behavior). We found that [PEG-b-P(AzoMA-r-NIPAm)] 4 underwent high-temperature unimer and low-temperature micelle (upper critical micellization temperature (UCMT)) transitions in [C 4 mim]PF 6. The UCMT of the tetra-arm diblock copolymer depended on photoisomerization states of the azobenzene groups within the copolymer. The UCMT of the trans-form polymer in dark conditions was higher than that of the cis-form polymer under UV-light irradiation. We demonstrated photoinduced self-assembly changes of the tetra-arm diblock copolymer in [C 4 mim]PF 6 at a 'bistable' temperature. Reversible photoinduced unimer/micelle transitions were also demonstrated.

    Original languageEnglish
    Pages (from-to)739-746
    Number of pages8
    JournalPolymer Journal
    Volume47
    Issue number11
    DOIs
    StatePublished - 2015 Nov 1

    Fingerprint

    Temperature
    Block copolymers
    Polyethylene glycols
    Micellization
    Micelles
    Self assembly
    Polymers
    Photoisomerization
    Azobenzene
    Phase behavior
    Ionic liquids
    Ultraviolet radiation
    Copolymerization
    Superconducting transition temperature
    Copolymers
    Irradiation

    ASJC Scopus subject areas

    • Polymers and Plastics
    • Materials Chemistry

    Cite this

    Temperature and light-induced self-assembly changes of a tetra-arm diblock copolymer in an ionic liquid. / Ma, Xiaofeng; Usui, Ryoji; Kitazawa, Yuzo; Kokubo, Hisashi; Watanabe, Masayoshi.

    In: Polymer Journal, Vol. 47, No. 11, 01.11.2015, p. 739-746.

    Research output: Contribution to journalArticle

    Ma, Xiaofeng; Usui, Ryoji; Kitazawa, Yuzo; Kokubo, Hisashi; Watanabe, Masayoshi / Temperature and light-induced self-assembly changes of a tetra-arm diblock copolymer in an ionic liquid.

    In: Polymer Journal, Vol. 47, No. 11, 01.11.2015, p. 739-746.

    Research output: Contribution to journalArticle

    @article{e1cbeb4e327a45708207db8763ab6b57,
    title = "Temperature and light-induced self-assembly changes of a tetra-arm diblock copolymer in an ionic liquid",
    author = "Xiaofeng Ma and Ryoji Usui and Yuzo Kitazawa and Hisashi Kokubo and Masayoshi Watanabe",
    year = "2015",
    month = "11",
    doi = "10.1038/pj.2015.55",
    volume = "47",
    pages = "739--746",
    journal = "Polymer Journal",
    issn = "0032-3896",
    publisher = "Nature Publishing Group",
    number = "11",

    }

    TY - JOUR

    T1 - Temperature and light-induced self-assembly changes of a tetra-arm diblock copolymer in an ionic liquid

    AU - Ma,Xiaofeng

    AU - Usui,Ryoji

    AU - Kitazawa,Yuzo

    AU - Kokubo,Hisashi

    AU - Watanabe,Masayoshi

    PY - 2015/11/1

    Y1 - 2015/11/1

    N2 - A tetra-arm diblock copolymer ([PEG-b-P(AzoMA-r-NIPAm)] 4) was synthesized by reversible addition-fragmentation chain transfer copolymerization of N-isopropylacrylamide (NIPAm) and 4-phenylazophenyl methacrylate (AzoMA), initiating from the ends of functionalized tetra-arm polyethylene glycol (tetra-PEG). The resulting tetra-arm diblock copolymer consists of two segments: tetra-PEG (the center block; compatible with 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim]PF 6)) and P(AzoMA-r-NIPAm) (the end blocks; temperature- and photosensitive compatibility with [C 4 mim]PF 6 due to photoresponsive upper critical solution temperature phase behavior). We found that [PEG-b-P(AzoMA-r-NIPAm)] 4 underwent high-temperature unimer and low-temperature micelle (upper critical micellization temperature (UCMT)) transitions in [C 4 mim]PF 6. The UCMT of the tetra-arm diblock copolymer depended on photoisomerization states of the azobenzene groups within the copolymer. The UCMT of the trans-form polymer in dark conditions was higher than that of the cis-form polymer under UV-light irradiation. We demonstrated photoinduced self-assembly changes of the tetra-arm diblock copolymer in [C 4 mim]PF 6 at a 'bistable' temperature. Reversible photoinduced unimer/micelle transitions were also demonstrated.

    AB - A tetra-arm diblock copolymer ([PEG-b-P(AzoMA-r-NIPAm)] 4) was synthesized by reversible addition-fragmentation chain transfer copolymerization of N-isopropylacrylamide (NIPAm) and 4-phenylazophenyl methacrylate (AzoMA), initiating from the ends of functionalized tetra-arm polyethylene glycol (tetra-PEG). The resulting tetra-arm diblock copolymer consists of two segments: tetra-PEG (the center block; compatible with 1-butyl-3-methylimidazolium hexafluorophosphate ([C 4 mim]PF 6)) and P(AzoMA-r-NIPAm) (the end blocks; temperature- and photosensitive compatibility with [C 4 mim]PF 6 due to photoresponsive upper critical solution temperature phase behavior). We found that [PEG-b-P(AzoMA-r-NIPAm)] 4 underwent high-temperature unimer and low-temperature micelle (upper critical micellization temperature (UCMT)) transitions in [C 4 mim]PF 6. The UCMT of the tetra-arm diblock copolymer depended on photoisomerization states of the azobenzene groups within the copolymer. The UCMT of the trans-form polymer in dark conditions was higher than that of the cis-form polymer under UV-light irradiation. We demonstrated photoinduced self-assembly changes of the tetra-arm diblock copolymer in [C 4 mim]PF 6 at a 'bistable' temperature. Reversible photoinduced unimer/micelle transitions were also demonstrated.

    UR - http://www.scopus.com/inward/record.url?scp=84947052523&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84947052523&partnerID=8YFLogxK

    U2 - 10.1038/pj.2015.55

    DO - 10.1038/pj.2015.55

    M3 - Article

    VL - 47

    SP - 739

    EP - 746

    JO - Polymer Journal

    T2 - Polymer Journal

    JF - Polymer Journal

    SN - 0032-3896

    IS - 11

    ER -