Thin carbon nanostructure mat with high electromagnetic interference shielding performance

The electromagnetic interference (EMI)pollution problem has led to an increasing interest in the development of lightweight materials for effective SE. This paper presents a facile approach for the fabrication of flexible, ultrathin, foldable, rollable, and highly conductive carbon nanostructures (CNS)-based mats. CNS epoxy, CNS-Fe₂O₃ nanoparticles (NPs)heterojunction mats and clean CNS mats of various thickness made of CNS flakes 300–350 μm long and of various width have been fabricated and tested for the SE application. Thinner CNS mats are found to have higher electrical and thermal conductivity. On the other hand, thicker CNS mats are found to have better SE performance, which reveals that thickness has a more profound impact on SE than electrical conductivity. Incorporation of the γ-Fe₂O₃ in the CNS mass provides magnetic properties and greatly improves the SE of the mats. Also, the uniform distribution of γ-Fe₂O₃ NPs increases the absorption of incident waves, which improves the overall shielding (SE_All). Thus, the SE_All performance improved from 47.1 dB for the clean CNS mat to 60.29 dB with the incorporation of γ-Fe₂O₃ NPs. Furthermore, the use of the epoxy to fabricate the CNS mats has significantly improved the mechanical properties of the CNS mats, but it reduced the SE performance by hindering the absorption of the electromagnetic waves.