High electromagnetic interference shielding effectiveness in MgO composites reinforced by aligned graphene platelets

Abstract

Graphene has been considered as an excellent filler to reinforce ceramics with enhanced properties. However, the uniform dispersion and controlled orientation of graphene sheets in a ceramic matrix have become major challenges toward higher performance. In this paper, we prepared MgO matrix composites with parallel graphene layers through the intercalation of the precursor into expandable graphite. We obtained a high electromagnetic interference (EMI) shielding effectiveness of ~30 dB, due to the multiple reflections and absorptance of electromagnetic waves between the parallel graphene layers. The hardness and strength of the MgO composite were also increased by introducing parallel graphene layers. All these properties suggest that the graphene/MgO composite represents a promising electromagnetic shielding material.

A study to determine electromagnetic interference‐shielding effectiveness on bio‐based polyurethane foam reinforced with PVDF/MgO/Ni for emerging applications

“…When EM radiation was passed through Fe nanoparticles in the MgO matrix, the shielding was excellent because of magnetic and dielectric properties and dispersion, with a maximum SE of −65.6 dB 28 . The average value of the EMI SET of pure MgO and 1, 3, 5 and 7 vol% graphene/ MgO are 5.78, 9.53, 21.88, 30.07 and 21.10 dB, respectively 29 …”

“…28 The average value of the EMI SET of pure MgO and 1, 3, 5 and 7 vol% graphene/ MgO are 5.78, 9.53, 21.88, 30.07 and 21.10 dB, respectively. 29 The Ni nanoparticles are more suitable for EMI shielding as it possesses good magnetic and electrical properties and thermal stability. 30 The electrical conductivity nature of Nickel significantly influences the EM-SE by reflection losses.…”

Ultra‐wideband electromagnetic interference shielding properties of parallel expanded graphite/Fe3O4 composites

“…The EG/Fe 3 O 4 composites were synthesized by a simple and convenient method we previously reported. 19,23 In a typical experiment, 11.4 g FeCl 3 and 7.0 g FeCl 2 ⋅4H 2 O at a molar ratio of 2:1 were dissolved in 80 mL deionized water, and 1 mL HCl was added to avoid the oxidation of Fe 2+ . Afterward, a 0.55 mL coupling agent dissolved in 20 mL ethanol was added to form the mixed solution of ceramic precursor.…”

Enhanced mechanical and tribological properties of oscillatory pressure sintered WC–GNPs composites

“…Meanwhile, it is spatially isolated and can maintain two‐dimensional state at high temperature 16 . It was reported that the mechanical properties of MgO‐GNPs composites can be enhanced by controlling the directional arrangement of GNPs 17,18 . Furthermore, the addition of GNPs can also lead to an enhancement of the tribological properties of the composites 19 .…”

“…16 It was reported that the mechanical properties of MgO-GNPs composites can be enhanced by controlling the directional arrangement of GNPs. 17,18 Furthermore, the addition of GNPs can also lead to an enhancement of the tribological properties of the composites. 19 Therefore, GNPs might simultaneously play the role in reinforcing WC ceramics and reducing their friction wear.…”