Millefeuille-inspired highly conducting polymer nanocomposites based on controllable layer-by-layer assembly strategy for durable and stable electromagnetic interference shielding

High-performance conductive polymer nanocomposites containing two-dimensional (2D) MXene are garnering substantial interest for electromagnetic shielding interference (EMI) in flexible electronics. However, owing to the non-sticky nature and undesirable mechanical performances of freestanding MXene film, it remains a formidable challenge to make the trade-off between outstanding EMI shielding capability and high stability. In this study, inspired by the structure and manufacturing process of millefeuille cakes, we propose a controllably layer-by-layer assembling strategy for fabricating flexible multi layered EMI shielding composite films based on MXene and an inherently conductive polymer (ICP). The multilayer films bearing alternating aramid nanofibers/polypyrrole nanowires (AFPy) and Ti3C2Tx reinforced by waterborne polyurethane (Ti3C2Tx@WPU) layers are orderly constructed by a facile alternating vacuum filtration method. Benefiting from the special architectures, the AFPy-70/Ti3C2Tx@WPU-4 film exhibits a high electrical conductivity of 1.74 S cm(-1) and superior EMI shielding effectiveness of 40.9 dB at lower Ti(3)C(2)T(x & nbsp;)loading content (32 wt%). Moreover, synergistic integration of hydrogen bonding and pi-pi stacks in multilayered films is achieved, especially in tandem with controlled crack generation within the whole film. Excellent EMI shielding performance remains well maintained even after being suffered to back-and-forth bending test (over 10,000 cycles), ultrasonication, and cryogenic temperature, validating great potential as high-performance EMI shielding film resisting extreme conditions. (C)& nbsp;& nbsp;2022 Elsevier Inc. All rights reserved.

Automated summary

In this study, a controllably layer-by-layer assembling strategy was proposed to fabricate flexible multi-layered EMI shielding composite films based on MXene and an inherently conductive polymer (ICP). The films exhibited high electrical conductivity, superior EMI shielding effectiveness, and remained stable under extreme conditions, showcasing great potential for applications.