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Thermoresponsive core cross-linked star-shaped poly(N-isopropylacrylamide) for reversible and controlled aggregation of nanoscale molecular units

Polymer Journal volume 52, pages 359–363 (2020)Cite this article

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The controlled dispersion of nanodomains (spaces) in solution or in bulk material is key to producing unique reaction systems or developing higher performance and/or functional polymeric materials. For controlled and targeted dispersion, it is desirable for nanodomains to be designed in advance and to be maintained in the correct form under any conditions. To create such a designed nanospace, a simple method would be the use of a variety of sequence-controlled polymers prepared by living polymerization, in which a well-defined polymer forms a nanodomain by itself or in its aggregated state. An aggregate of linear polymers, such as micelles, however, may vary in shape and size under different conditions.

A molecule of a sequence-controlled multibranched polymer, including a graft, star-shaped, and hyperbranched polymer, can be regarded as a designed and fixed nanospace of up to several tens of nanometers in size. Among such branched polymers, a multiarmed star-shaped polymer, which is prepared by a simple polymer-linking method using a bifunctional vinyl compound [1,2,3,4], has a spherical and compact shape with unique properties that are different from those of the corresponding linear polymers [4, 5]. In addition, the polymer-linking method yields star-shaped molecules of relatively uniform size via a simple reaction [6]. Such spherical and uniform molecules may play a critical role in producing not only controlled dispersion but also controlled aggregation in solution or arrangements on the surface of another material.

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Scheme 1
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Acknowledgements

This work was partially supported by the Japan Society for the Promotion of Science through a Grant-in-aid for Young Scientists (B) (No. 16K17962) and a Grant for Scientific Research (C) (No. 19K05602), for which the authors are grateful. The authors thank Prof. Makoto Ouchi, Prof. Takaya Terashima and Mr Yoshihiko Kimura (Kyoto University) for performing the SEC-MALS analysis.

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  1. Department of Materials Science, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga, 522-8533, Japan

    Shohei Ida, Yuri Toyama, Sayuri Takeshima & Shokyoku Kanaoka

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  1. Shohei Ida
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Correspondence to Shokyoku Kanaoka.

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Ida, S., Toyama, Y., Takeshima, S. et al. Thermoresponsive core cross-linked star-shaped poly(N-isopropylacrylamide) for reversible and controlled aggregation of nanoscale molecular units. Polym J 52, 359–363 (2020). https://doi.org/10.1038/s41428-019-0285-1

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