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

Abstract

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.