Multifunctional MXene-based composite films with simultaneous terahertz/gigahertz wave shielding performance for future 6G communication

Wireless  communication technology has reshaped the entire society in the past 20  years. Recently, many countries have started planning for  sixth-generation (6G) communication, with an aim to provide services in  the 2030s. Compared with 5G, 6G signals will use higher and wider  frequency bands (both GHz and THz waves), and the application scenarios  will be extended to various harsh environments (oceans and outer space),  which poses great challenges for future 6G electromagnetic interference  (EMI) shielding materials. In this study, we fabricated a  multifunctional MXene/polyaramid composite film by  hydrogen-bonding-induced self-assembly. Compared with those currently  reported in the literature, this composite film exhibits three  noteworthy advantages, and could be applied as a potential 6G EMI  shielding material in the future. First, the composite film shows strong  EMI shielding efficiency in both THz (52.7 dB@0.2–1.6 THz) and GHz  (38.9 dB@8.2–12.4 GHz) bands with a low thickness of 20 μm. Second,  high-density hydrogen bonding interactions between MXenes and  polyaramids endow the composite film with excellent mechanical  performance (493 MPa) and superior heat resistance (T_g > 260 °C and T_d  > 520 °C). Third, the composite film displays outstanding durability  in various harsh environments including high/low temperatures (−193–250  °C), rapid thermal shock (500 °C for 30 s), large-angle bending and  acid/alkali/salt corrosion with its GHz/THz shielding performance and  mechanical properties nearly unchanged. Besides, it is integrated with  excellent Joule-heating performance with a remarkably high temperature  output of 225 °C. Altogether, the composite films could be considered as  promising 6G EMI shielding materials suitable for various harsh  environment scenarios in the future such as Mars exploration and ocean  mapping.