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

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.