VARTM Fabrication of High‐Performance EMI Shielding Composites From Prefabricated Bamboo Charcoal/Epoxy/Veneer With Synergistic Multilayer‐Porous Architecture

ABSTRACT The rapid expansion of 5G technology exacerbates electromagnetic interference (EMI) challenges, yet conventional metal‐based shields are limited by high density, cost, and environmental impact. This study presents a sustainable alternative by converting bamboo waste into conductive charcoal (BC) at 1600°C for use in multilayer composites with poplar veneer and E‐51 epoxy, fabricated via a combined spraying, vacuum‐assisted resin transfer molding (VARTM), and hot‐pressing process. This method ensures uniform BC dispersion and strong interfacial bonding, yielding a synergistic multilayer‐porous architecture. The influence of BC content on microstructure, mechanical properties, EMI shielding, water resistance, and thermal conductivity was systematically studied. Increasing BC loading markedly enhanced EMI shielding, with the highest‐loaded composite achieving 64.1 dB total shielding effectiveness while retaining substantial flexural strength (151.1 MPa), stable Shore D hardness (81.5 HD), improved water resistance, and elevated thermal conductivity (0.468 W m ⁻¹ K ⁻¹ ). The synergistic multilayer‐porous architecture facilitated continuous conductive networks and promoted absorption‐dominated attenuation through internal scattering and interfacial polarization. This work demonstrates a scalable, sustainable route to transform bamboo waste into lightweight, high‐performance, and eco‐friendly EMI shielding composites with promising potential for green electronics and modern construction applications.