Enhanced Thermal\nConductivity in Poly(ether imide)-Based\nComposites via Constructing Microscopic Segregated Networks with Ag-Bridged\nGraphite Nanoplatelets

In recent years, polymer-based composites\nwith high thermal\nconductivity\nhave become important for the effective removal of accumulated heat\nin thermal management devices, though enhancing the thermal conductivity\nof poly(ether imide) materials remains challenging. Herein, to prepare\nhigh-thermal-conductivity materials, silver nanoparticles are chemically\nreduced onto the surface of graphite nanoplates as hybrid fillers.\nConsequently, inspired by “cellular structures”, segregated\nthermally conductive networks in composites are designed by mixing\nhybrid fillers and poly(ether imide) microspheres, followed by a hot-pressing\nprocess. Benefiting from the three-dimensional heat-transfer network\nand the bridging effect of silver nanoparticles, thermal conduction\npathways are easily constructed, reducing interfacial heat resistance\nin the polymer matrix. At a hybrid filler loading of 40 wt %, the\nthrough-plane and in-plane thermal conductivities reach 4.7 and 11.3\nW/m K, respectively. Moreover, the finite-element simulation reveals\nthat the composites have high thermally conductive ability owing to\nthe hybrid fillers, which offer highly effective pathways for phonon\ntransmission. Besides, polymer composites exhibit a great electrical\nmagnetic shielding performance (30.5 dB). In summary, this study provides\na strategy for fabricating thermally conductive polymer-based composite\nmaterials for use in industrial heat dissipation devices.