From 3D Forest to 2D Protection: Magnetic Wood with Reconfigurable Conductive Pathway for Versatile Electromagnetic Interference Shielding
Dandan Zou, Fei Pan, Xin Zhou, Xu Wang, Shaohua Jiang, Wei Lü, Qingfeng Sun, Xiaofan Ma
Abstract
Abstract Wood‐derived carbon has great potential in building sustainable, lightweight electromagnetic interference (EMI) shielding materials. However, developing a straightforward method for fabricating materials that exhibit both high EMI shielding effectiveness (SE) and multifunctionality remains a challenge. Herein, the carbonized wood/epoxy/iron composite (C/EP/Fe) with hierarchical porous architecture is synthesized by encapsulating magnetic nanoparticles inside the conduits of wood‐derived carbon materials through via a simple two‐step process. Hot pressing is used to convert the conductive pathways, the inherent 3D honeycomb structure into a 2D grid. This structural transition, synergized with the magnetic nanoparticles, markedly enhanced the EMI SE. At a density of 392.26 mg cm −3 and a thickness of 1.05 mm, the C/EP/Fe‐4 achieved an EMI SE of 95.3 dB in the X‐band and allowed for tunable EMI shielding performance through adjustments in rotation angles. Furthermore, the material demonstrated shielding efficiency exceeding 99.999999% across the C‐K bands, with excellent EMI SE values consistently above 89 dB. In addition to its superior EMI shielding performance, the C/EP/Fe exhibited a suite of multifunctional properties, including rapid Joule heating, excellent thermal stability, flame retardancy, hydrophobicity, and reliable mechanical strength.