Epoxy composites with satisfactory thermal conductivity and electromagnetic shielding yet electrical insulation enabled by Al2O3 platelet-isolated MXene porous microsphere networks

The development of highly integrated electronic devices has placed higher demands on the thermal conductivity, electromagnetic interference (EMI) shielding, and electrical insulation properties of electronic packaging materials. In this work, a facile strategy for the fabrication of epoxy composites with Al2O3 platelet-isolated MXene porous microsphere networks was proposed. The composites were prepared by a simple salt-template method under vortex conditions and showed effective electric insulation as well as satisfactory EMI shielding and thermal conductivity properties. Particularly, the EMI shielding performance is enhanced by MXene porous microspheres with multi-interfacial conductive networks. Moreover, Al2O3 platelets (Al2O3p) with shell-like arrangement enrich the thermal conductivity paths on one hand and synergistically interact with the epoxy matrix to intercept the electron transfer between the MXene porous microspheres on the other hand. As a result, the obtained MXene/Al2O3p/Epoxy composites exhibit excellent thermal conductivity (2.1 W/mK) and satisfactory EMI shielding performance (22.3 dB at 8.6 GHz), while maintaining high electrical insulation (1.2 × 109 Ωcm). This paper provided a new idea to synergistically improve the electrical insulation, thermal conductivity and EMI shielding properties of epoxy composites.