Ultrathin and flexible PDA modified MXene/bacterial cellulose composite film with a dense lamellar structure for enhanced electromagnetic interference shielding performance

The realization of high-performance EMI shielding materials with flexible, ultrathin and outstanding shielding efficiency is crucial in addressing the growing concern over electromagnetic radiation from electronic devices. In this research, flexible and ultrathin PDA modified Ti3C2Tx MXene/bacterial cellulose (PM/BC) composite films with densely stacked lamellar structures have been developed through a combination of experimental and theoretical investigations. The microstructure, interface interaction, mechanical properties and EMI shielding efficiency of the composite films have been comprehensively investigated. It is highlighted that the strong interfacial interaction between PDA and MXene nanosheets contributes to the enhanced tensile stress (178.1 ± 7.5 MPa) and fracture strain (6.9 ± 0.2%) of the flexible and ultrathin PM/BC composite film, demonstrating its excellent resistance to external forces. More interestingly, the composite film exhibits a remarkable electrical conductivity of up to 39 840 S m−1 and a superior EMI shielding performance of 53.9 dB, indicating its ability to attenuate electromagnetic waves effectively. These findings provide a feasible strategy to develop ultrathin and flexible MXene-based composite films with exceptional EMI shielding capability, which have great potential in protecting electronic devices, including wearable electronic products.