Ultrauniform Embedded Liquid Metal in Sulfur Polymers for Recyclable, Conductive, and Self-Healable Materials

Liquid metals (LMs) are receiving growing interest in modern technologies for their various advantages. This work reports using elemental sulfur to achieve nanodispersed liquid metals in bulk polymers for multifunctional LM-based materials. Ring-opening polymerization and inverse vulcanization of elemental sulfur provide many polysulfide loops and thiol groups as effective binding ligands that enable extraordinarily uniform dispersion of liquid metals (approximate to 1 mu m) in bulk matrix and improve the mechanical performance of the materials. Interestingly, the liquid-metal-embedded sulfur polymer (LM ESP) materials exhibit excellent thermal-/solventprocessability and recyclability. The uniform dispersion leads to phenomenal electrical conductivity of the LMESP at a low volume percentage of LM (30 vol%), overcoming the issue of nonconductivity typically seen in insulated LM-polymer blends. Additionally, the LM ESP shows resistive sensitivity toward external pressure. Furthermore, the LMESP materials exhibit an excellent self-healing ability under mild conditions via the dynamic bonds between polysulfide loops/thiol groups and liquid metals. This work clearly offers a new platform to design liquid metals and can push them for broad applications.