Highly anisotropic MXene@Wood composites for tunable electromagnetic interference shielding

Smart electromagnetic interference (EMI) shielding material with a dynamically adjustable electromagnetic response based on real-time requirements is attractive for future electromagnetic devices. Herein, a highly anisotropic MXene@wood composite (M@wood) with convenient shielding effectiveness (SE) regulation is fabricated by coating MXene on the natural wood surface. Benefiting from the anisotropic pore structure and abundant free radicals, the M@wood displays a better impedance match in the tangential-section than in the cross-section. In the tangential-section, M@wood can respond to changes in the dihedral angle between the wood grain and the electromagnetic wave electric field, and achieve the off/on switch between electromagnetic wave transmission and shielding. The SE ranges from 27.4 to 57.6 dB as the dihedral angle alters from 90 degrees (perpen-dicular) to 0 degrees (parallel). The finite element analysis simulation further reveals the tunable electromagnetic response. This sustainable EMI shielding material based on natural wood offers a novel platform for exploiting intelligent electromagnetic devices.