“Mille-Feuille”-like Flexible MXene Hybrid Films with Tuned Silver Nanowires Framework for Asymmetric Electromagnetic Interference Shielding and Joule Heating Performance

Abstract

As wearable electronics and medical implants evolve, there is an increasing demand for protective devices that provide both electromagnetic interference (EMI) shielding and heating capabilities while operating at weaker voltages to accommodate various power sources. Herein, a simple, cost-friendly, step-by-step vacuum-assisted filtration method is utilized to prepare asymmetrical layered “MXene-MXene@Silver nanowires-MXene-Silver nanowires (AgNWs)” hybrid films, exhibiting a “Mille-Feuille” like structure. This composite structure exploits the excellent electrical and thermal conductivity of AgNWs together with the notable EMI shielding performance of MXene (SE/t = 112967 dB cm-1). By tuning the MXene layer and AgNWs framework, the multi-layer structured film achieves excellent EMI shielding effectiveness (SE/t = 68825 dB cm-1). Due to the introduction of the AgNWs layer, its interface reflection properties lead to differential electromagnetic waves (EMWs) consumption in the structure, resulting in asymmetric EMI shielding (56.66 dB from the AgNWs surface and 62.08 dB from the MXene surface with the film thickness of 9.02 μm). The enhanced EMI shielding is attributed to the AgNWs layer interface reflection, which significantly increases the effective consumption pathway of incident EMWs. Moreover, its Joule heating performance reaches 227.7 ℃ at 1.0 V, exhibiting superior ultra-low voltage drive characteristic. The flexible and self-supported composite film has significant potential applications in protecting human body implants, such as cardiac pacemakers from the influence of EMI pollution. Furthermore, it can be utilized in extreme weather conditions for de-icing, de-fogging, and anti-freezing purposes.