Janus-inspired flexible cellulose nanofiber-assisted MXene/Silver nanowire papers with fascinating mechanical properties for efficient electromagnetic interference shielding

MXene-based nanocomposites are highly desirable for electromagnetic interference (EMI) shielding applications. However, it is crucial but challenging to obtain an excellent trade-off between mechanical properties and EMI performances. Herein, inspired by Janus structure, flexible cellulose nanofiber-assisted MXene/silver nanowires (CNF-MXene/AgNWs) papers (CMAPs) are developed by a scalable sequential self-assembly plus a hot-pressing strategy. The ingenious introduction of highly conductive AgNWs into MXene forms a complementary leaf-like nanostructure, synergistically constructing highly effective conductive frameworks. Contributed by the designed Janus architecture, high-performance CNF substrate, and extensive hydrogen-bonding interactions, the resultant Janus CMAPs (J-CMAPs) with a low MXene/AgNWs addition of 30 wt% possess a high electrical conductivity (1066.85 S/cm), excellent mechanical strength (224.04 MPa) and modulus (9.98 GPa), exceptional EMI shielding effectiveness of 43.65 dB, and record-high EMI SE/t of 16788.51 dB cm−1 and SSE/t of 10543.18 dB cm2 g−1 with a reflection-dominant shielding mechanism, successfully achieving an outstanding balance between mechanical properties and EMI shielding performances. More importantly, high frequency structure simulator (HFSS) simulation in the frequency domain is further conducted to intuitively comprehend the attenuation process of electromagnetic waves and shield mechanism, verifying fascinating EMI shielding performances. Besides, the Janus paper also presents desirable Joule heating performances at low input voltage, short response time (<10 s), and superb heating stability and long-term steady reliability. We believe that the J-CMAPs demonstrate the great potential and advantage for advanced EMI shielding and portable thermal management applications.