An Effective Approach for the Preparation of High Performance Thermal Conductive Polymer Composites Containing Liquid Metal

Abstract

The preparation of high-performance thermal conductive composites containing liquid metals (LM) has attracted significant attention. However, the stable dispersion of LM within polymer solution and effective property contribution of liquid metals remains significant challenges that need to be overcome. Inspired by the properties of the dendritic structure of the tree root system in grasping the soil, “shear-induced precipitation-interfacial reset-reprotonation” processing strategy is proposed to prepare nanocomposites based on aramid micron fibers (AMFs) with hierarchical dendritic structure. Thanks to the combination of van der Waals force provided by hierarchical dendritic structure, electrostatic interaction between AMFs and LM, coordinative bonding of —NH to LM, together with interfacial re-setting and multi-step protonation, several features can be achieved through such strategy: conducive to the local filler network construction, improvement of interfacial interaction, improvement of the stability of filler dispersion in the solvent, and enhancement of mechanical and thermal properties of the films. The resulting AMFs-pH=4/LM films demonstrate a thermal conductivity of 10.98 W·m⁻¹·K⁻¹ at 70% filler content, improvement of 126.8% compared to ANFs/LM film; while maintaining a strength of ∼85.88 MPa, improvement of 77% compared to AMFs/LM film. They also possess insulation properties, enable heat dissipation for high power electronics. This work provides an effective strategy for the preparation of high performance polymer composites containing liquid metal.