Robust double-layered ANF/MXene-PEDOT:PSS Janus films with excellent multi-source driven heating and electromagnetic interference shielding properties

The strategy of incorporating polymers into MXene-based functional materials has been widely used to improve their mechanical properties, however with inevitable sacrifice of their electrical conductivity and electromagnetic interference (EMI) shielding performance. This study demonstrates a facile yet efficient layering structure design to prepare the highly robust and conductive double-layer Janus films comprised of independent aramid nanofiber (ANF) and Ti₃C₂T_x MXene/poly(3,4-ethylenedioxy- thiophene):poly(styrenesulfonate) (PEDOT:PSS) layers. The ANF layer serves to provide good mechanical stability, whilst the MXene/PEDOT:PSS layer ensures excellent electrical conductivity. Doping PEDOT:PSS into the MXene layer enhances the interfacial bonding strength between the MXene and ANF layers and improves the hydrophobicity and water/oxidation resistance of MXene layer. The resultant ANF/MXene-PEDOT:PSS Janus film with a conductive layer thickness of 4.4 μm was shown to display low sheet resistance (2.18 Ω/sq), good EMI shielding effectiveness (EMI SE of 48.1 dB), high mechanical strength (155.9 MPa), and overall toughness (19.4 MJ/m³). Moreover, the excellent electrical conductivity and light absorption capacity of the MXene-PEDOT:PSS conductive layer mean that these Janus films display multi-source driven heating functions, producing excellent Joule heating (382 °C at 4 V) and photothermal conversion (59.6 °C at 100 mW/m²) properties.