Hierarchical Sol-Gel Transition Induced by Thermosensitive Self-Assembly of an ABC Triblock Polymer in an Ionic Liquid

Journal Article · Fri Apr 29 04:00:00 EDT 2016 · Macromolecules

DOI:https://doi.org/10.1021/acs.macromol.5b02616· OSTI ID:1243117

Kitazawa, Yuzo ^[1]; Ueki, Takeshi ^[2]; McIntosh, Lucas D. ^[3]; Tamura, Saki ^[1]; Niitsuma, Kazuyuki ^[1]; Imaizumi, Satoru ^[1]; Lodge, Timothy P. ^[3]; Watanabe, Masayoshi ^[1]

---

1. Yokohama National Univ. (Japan)
2. Univ. of Tokyo (Japan)
3. Univ. of Minnesota, Minneapolis, MN (United States)

Here we investigate a hierarchical morphology change and accompanying sol–gel transition using a doubly thermosensitive ABC-triblock copolymer in an ionic liquid (IL). The triblock copolymer contains two different lower critical solution temperature (LCST) thermosensitive polymers, poly(benzyl methacrylate) (PBnMA) and poly(2-phenylethyl methacrylate) (PPhEtMA), as the end blocks and poly(methyl methacrylate) (PMMA) as the middle block (PBnMA-b-PMMA-b-PPhEtMA: BMP). BMP undergoes a hierarchical phase transition corresponding to the self-assembly of each of the thermosensitive blocks in the IL, and a sol–gel transition was observed in concentrated, above 10 wt %, polymer solutions. The gelation behavior was affected by polymer concentration, and at 20 wt %, the BMP/IL composite showed a phase transition, with increasing temperature, from solution through a jammed micelle suspension to a physically cross-linked gel. For each phase was formed reversibly and rapidly over the corresponding temperature range. Finally, the jammed micelle and cross-linked gel states were characterized using viscoelastic measurements and small-angle X-ray scattering (SAXS).

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: USDOE
• OSTI ID: 1243117
• Journal Information: Macromolecules, Journal Name: Macromolecules Journal Issue: (4) ; 02, 2016 Vol. 49; ISSN 0024-9297
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE