Preparation of layer-by-layer assembled MXene-lignin/polyacrylonitrile nanocomposite film and its electromagnetic interference shielding performance

With the growing prevalence of electromagnetic contamination, the development of advanced electromagnetic shielding materials has emerged as critical research topic. This study proposes a synergistic electrospinning-electrospraying technique to fabricate a sandwich layered-structured nanocomposite film. Specifically, the top and bottom layers are made of lignin/polyacrylonitrile (PAN) electrospun nanofibers, while the intermediate layer is engineered via the synergistic electrospinning-electrospraying process to uniformly deposit MXene onto the surface of nanofibers. Notably, due to the self-deposition of MXene, the intermediate layer exhibits a MXene-dominated conductive layered structure, facilitating multiple reflections and absorptions of electromagnetic waves. The results demonstrate that the film achieves an EMI shielding effectiveness of 44.1 dB at a low MXene loading of 15 wt.%, featuring with superior electromagnetic shielding efficiency under relatively low conductive filler dosage. Furthermore, the electromagnetic shielding effectiveness increases to 72.9 dB when 4 layers of the film is piled up. Furthermore, the sandwich structure effectively protects MXene, which significantly improved the stability and durability of the materials. This work provides a novel strategy to design high-performance, lightweight, and flexible electromagnetic shielding materials.