Hollow Microsphere-Modified Asymmetric Multilayer Nanocomposites With Low Reflectivity and High Electromagnetic Shielding Performance

Electromagnetic interference (EMI) shielding materials with low reflectivity are ideal materials for addressing the pollution caused by electromagnetic radiation. Ti₃C₂T_x MXene is widely used for EMI shielding due to its excellent conductivity. However, the Ti₃C₂T_x MXene nanocomposites exhibiting low reflectivity and high EMI shielding performance simultaneously remain scarce. In this study, the MXene/cellulose nanofiber (MXene/CNF) nanocomposite films with tailored electrical conductivity were fabricated as reflective layers and then paired with aramid nanofiber/reduced graphene oxide/reduced graphene oxide loaded with iron tetroxide-T (ANF/rGO/rGO@Fe₃O₄-T) porous nanocomposite modified with varying hollow microsphere sizes as absorbing layers. Integrated into the ANF/rGO/rGO@Fe₃O₄-T&MXene/CNF (ArrF-T&MC) nanocomposites with a hollow microsphere-modified asymmetric gradient multilayer-porous structure, these components were assembled layer-by-layer using oily protoplasts as interfacial binders. By adjusting the assembly sequence of gradient absorbing or reflective layers, enabling precise control over the reflection (R) and absorption (A) values. Impressively, the ArrF-T-4.5-3-0.8&MC-30-10-0 nanocomposites exhibited an outstanding EMI shielding effectiveness (EMI SE) of 82.4 dB and an A value of 0.519, surpassing most reported values for multilayer MXene/polymer nanocomposites. The effective attenuation of electromagnetic waves by ArrF-T-4.5-3-0.8&MC-30-10-0 nanocomposites was verified through finite element simulations. These findings provide a robust framework for the design of multilayered MXene/polymer nanocomposites that deliver an exceptionally high EMI SE exceeding 80 dB and an absorption-dominated shielding mechanism, which are suitable for applications in precision electronics, military, and aerospace industries.