Integrated Extrinsic and Intrinsic Self-Healing of Polysiloxane Materials by Cleavable Molecular Cages Encapsulating Fluoride Ions

Mai Suzuki; Taiki Hayashi; Takuya Hikino; Masafumi Kishi; Takamichi Matsuno; Hiroaki Wada; Kazuyuki Kuroda; Atsushi Shimojima

doi:10.1002/advs.202303655

Integrated Extrinsic and Intrinsic Self-Healing of Polysiloxane Materials by Cleavable Molecular Cages Encapsulating Fluoride Ions

Adv Sci (Weinh). 2023 Sep;10(27):e2303655. doi: 10.1002/advs.202303655. Epub 2023 Jul 28.

Authors

Mai Suzuki¹, Taiki Hayashi¹, Takuya Hikino², Masafumi Kishi¹, Takamichi Matsuno^{1

3}, Hiroaki Wada^{1

3}, Kazuyuki Kuroda^{1

3}, Atsushi Shimojima^{1

3}

Affiliations

¹ Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan.
² Department of Advanced Science and Engineering, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan.
³ Kagami Memorial Research Institute for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku-ku, Tokyo, 169-0051, Japan.

Abstract

Self-healing ability is crucial to increasing the lifetime and reliability of materials. In this study, spatiotemporal control of the healing of a polysiloxane material is achieved using a cleavable cage compound encapsulating a fluoride ion (F^- ), which triggeres the dynamic rearrangement of the siloxane (Si-O-Si) networks. A self-healing siloxane-based elastomer is prepared by cross-linking polydimethylsiloxane (PDMS) with a F^- -encapsulating cage-type germoxane (Ge-O-Ge) compound. This material can self-heal repeatedly under humid conditions. The F^- released by hydrolytic cleavage of the cage framework contributes to rejoining of the cut pieces by promoting the local rearrangement of the siloxane networks. The use of a molecular cage encapsulating a catalyst for dynamic bond rearrangement provides a new concept for designing self-healing polysiloxane materials based on integrated extrinsic and intrinsic mechanisms.

Keywords: cage compound; fluoride ion; germoxane; self-healing; silicone.

Abstract

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