Multifunctional, sandwich-structured ANF/PEDOT:PSS/MXene film with efficient electromagnetic interference shielding and thermal management

With the rapid development of intelligent, portable, and wearable electronic devices, flexible electromagnetic interference (EMI) shielding materials with integrated multifunctional performance have gained increasing attention. In this work, the flexible sandwich-structured aramid nanofiber (ANF)/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)-MXene-ANF/PEDOT:PSS composite film was successfully fabricated through alternating vacuum-assisted filtration and laminated hot pressing. Within this system, PEDOT:PSS played a dual role in enhancing interfacial bonding and regulating electrical conductivity. As an interfacial binder, PEDOT:PSS significantly strengthened the adhesion between the MXene layer and the ANF substrate through strong interfacial interactions. Meanwhile, as a conductive bridge, its conjugated π-π structure facilitated efficient electron transport and carrier migration, markedly improving the overall conductivity of the film. The synergistic interaction between PEDOT:PSS and MXene led to the formation of a continuous and stable conductive network, providing efficient pathways for charge transport and energy dissipation. As a result of this synergistic design, when the mass ratio of PEDOT:PSS to MXene was 1:6, the APM6 composite film exhibited optimal comprehensive performance, with an EMI shielding efficiency (SE) of 52.57 dB, a specific EMI SE of SSE/t of 7904.197 dB·cm²·g⁻¹, a Joule heating temperature of 110℃ at 2.5 V, a photothermal conversion temperature of 185℃ under 0.6 W/cm² laser irradiation, and a tensile strength of 42.75 MPa. These results demonstrated that the composite film possessed excellent EMI shielding and thermal management capabilities, making it a promising candidate for advanced electronic devices, military and aerospace applications.