A universal strategy towards self-healing materials via dynamic interfacial liquid metal coordination

Self-healing polymer materials, capable of autonomously repairing physical damage, have been broadly applied in modern technologies. In various self-healing systems, metal–ligand coordination bonds have been extensively utilized for their advantages of rich metal–ligand species and functionalities. However, common metal-ligand coordination either has excessively stable bond strengths or is too weak to construct self-healing materials. This work introduces coordination metals into liquid metals (LMs) to form multi-component LMs (mLMs), which creatively leverage the inherent fluidity of mLMs to convert common metal-ligand coordination (e.g., silver-sulfur and zinc/copper-imidazole systems) into reversible interfacial coordination. Such dynamic coordination successfully offers the fantastic self-healing efficiency over 90% for general polymers. Considering the ultra-high thermal conductivity of mLMs, self-healable thermal interface materials (TIMs) are obtained, which successfully address the long-standing challenge of the irreversible damage in long-term used TIMs. The self-healable TIMs can lower the peak temperature of the central processing unit (CPU) by 20 oC under extreme conditions for long time (accumulated 16 hours thermal shock, −10 oC to 100 oC). This work provides a universal strategy for self-healing materials and greatly broadens the investigations of self-healing, coordination chemistry, liquid metal science, soft electronics, and thermal management materials. Self-healing polymer materials based on metal–ligand coordination bonds have been extensively utilized for their advantages of rich metal–ligand species and functionalities but the strength of the metal bonds is not easily tunable. Here, the authors introduce coordination metals into liquid metals leveraging the inherent fluidity of multi-component liquid metals to convert common metal-ligand coordination into reversible interfacial coordination.