Multilayer wood/Cu-Fe₃O₄@Graphene/Ni composites for absorption-dominated electromagnetic shielding

Abstract

A wood-based composite with excellent electromagnetic shielding performance was prepared by constructing a multilayer structure with positive conductance gradient and negative magnetic gradient, and the electromagnetic waves underwent a special absorption-reflection-reabsorption process and an interfacial polarization loss-induced absorption process. The results showed that with the increase of the content of Fe3O4@Graphene compound, the surface morphology of wood gradually becomes flat. When the content of Fe3O4@Graphene compound is 300 mg, the surface roughness of metal coatings on the wood surface of the composites was only 13.525 μm. The maximum thickness of the coatings on the wood surface section was 88 μm. XRD patterns showed that the crystalline structure of the coatings on the wood surface was further strengthened, which confirmed the existence of Cu, Ni and Fe3O4@Graphene nanoparticles on the wood surface. When the content of Fe3O4@Graphene compound was 400 mg, the hydrophobic property of the composite reached the best, and the contact angle was 85.4°. The electromagnetic shielding of the composite can be up to 94.73 dB ranging from 300 kHz to 3.0 GHz.