Hierarchically Porous MXene/Carbon Nanotube/Epoxy Composites for Effective Electromagnetic Interference Shielding and Flame Retardancy

Designing a functional filler in a polymer matrix for effective electromagnetic interference (EMI) shielding and flame retardancy is of great importance in electronic devices. Achieving optimized distribution of fillers in polymer to build a conductive network for EMI shielding and intact barrier for flame retardancy is still a great challenge since the reported fillers usually exist as a disorder or even aggregation state. Herein, a porous carbon nanotube (CNT) bridged MXene (MXene/CNT) skeleton with electrical continuity and barrier integrity was designed by using a facile freeze-drying method. Benefiting from the rich hierarchical pores and excellent conductivity of MXene/CNT, the obtained MXene/CNT supported epoxy (EP) composite exhibits an effective EM shielding value of 34.7 dB. Furthermore, the EP composite shows improved flame retardancy than pure EP. Specifically, compared to pure EP, the EP composite with a low content of MXene/CNT (1.7 wt %) shows a decreased heat release rate (19.17%), smoke production rate (22.73%), CO production rate (25.21%) and CO2 production rate (21.26%). This promising strategy provides a way to fabricate other advanced polymer composites.