High Electrical Conductivity Induced by Surface Confinement Effect in Heterostructured Multifunctional Nanofiber Composite Films for Low-Reflection Electromagnetic Interference Shielding.

Electromagnetic interference (EMI) shielding films with low-reflection characteristics are ideal for blocking electromagnetic(EM) radiation and pollution. Poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibers, with high specific surface area and abundant active groups, can be compounded with various conductive materials to prepare EMI shielding materials with low-reflection features. However, the large-scale industrial application of such shielding materials with multifunctionality remains rarely explored. 1D silver nanowires (AgNW) and 2D MXene are tend to form 3D network structure, and their magnetoelectric synergistic effect can significantly enhance the energy loss of EM waves. In this study, heterostructured PVA-co-PE/AgNW/MXene (PAM) composite films are prepared via a two-step spray coating and solvent evaporation method. This method achieves the denseness of AgNW/MXene on the film surface through the surface confinement effect, significantly improving the utilization rate of conductive media. A 5.4 wt.% AgNW/MXene content, the EMI shielding efficiency (EMI SE), normalized SE (EMI SE/t), and absolute SE (SSE/t) are 60.2 dB, 5452.9 dB·cm and 36352.7 dB·cm·g in the ultra-wide frequency of 8-20 GHz, along with an extremely low reflection coefficient (R = 0.13). The straightforward preparation process makes it highly suitable for industrial-scale production, showing significant potential in aerospace, flexible wearables fields.