Asymmetric multilayer-porous structure of MXene nanocomposites with absorption-dominated high electromagnetic interference shielding performance

Abstract

There are limited reports on multilayer MXene-based electromagnetic interference shielding (EMI) nanocomposites featuring low-reflectivity characteristics with MXene nanocomposite films serving as electromagnetic wave reflection layers. In this study, the first combination of asymmetric porous structures with sequence-dependent gradient loss mechanisms, a MXene/cellulose nanofiber (MC) nanocomposite film was used as the electromagnetic wave reflecting layer, while Nickel-plated multi-walled carbon nanotube/iron tetroxide-loaded reduced graphene oxide/cellulose nanofiber/waterborne polyurethane (Ni@MCNT/Fe₃O₄@rGO/CNF/WPU(NFCW)) porous nanocomposites served as the absorbing layer. Four types of NFCW&MC asymmetric multilayer-porous nanocomposites were prepared with varying assembly orders through a layer-by-layer self-assembly method. Benefiting from the asymmetric multilayer-porous structure design, all four NFCW&MC asymmetric multilayer-porous nanocomposites exhibited absorption-dominated (A over R) EMI shielding mechanisms. The loss processes of electromagnetic waves in the nanocomposites were simulated using finite element analysis. Notably, different assembly orders resulted in distinct loss mechanisms, affecting the values of A and R for the nanocomposites. In particular, the asymmetric multilayer-porous nanocomposite with the optimal assembly order demonstrated an EMI shielding effectiveness of 57.4 dB and an A value of 0.807. Therefore, the findings of this study provide valuable insights for the development of absorption-dominated MXene nanocomposites.