Hierarchical structured epoxy/reduced graphene oxide/Ni-chains microcellular composite foam for high-performance electromagnetic interference shielding

To simultaneously enhance the processability, electrical conductivity and mechanical properties of composite foam for high-performance electromagnetic interference (EMI) shielding application, in this work, the epoxy (EP)/reduced graphene oxide (rGO)/Ni-chains microcellular composite foam is prepared through strategy of combining the hierarchical structured aerogel skeleton and supercritical carbon dioxide (scCO2) foaming process. Benefiting from the construction of the rGO/Ni-chains bicontinuous conductive skeleton and introduction of microcellular structure, the EP/rGO/Ni-chains microcellular foam displays a brick-and-mortar structure and implements the multiple dissipation mechanism of electromagnetic (EM) wave to achieve outstanding EMI shielding efficiency (EMI SE) of 41.11 dB in X-band. Moreover, the selection of liquid epoxy as matrix avoids the use of large amounts of organic solvents, ensures the well processability of composite and realizes the excellent compressive strength (27.33 MPa) of the EP/rGO/Ni-chains microcellular foam with a density of 0.88 g/cm3, which shows great application value as a high-performance EMI shielding material.

Automated summary

In this study, a composite foam comprising epoxy (EP), reduced graphene oxide (rGO), and nickel chains (Ni) was prepared through a strategy that combined hierarchical structured aerogel skeleton and supercritical carbon dioxide (scCO2) foaming process. The foam exhibited a brick-and-mortar structure and achieved outstanding electromagnetic interference (EMI) shielding efficiency of 41.11 dB in X-band, thanks to the construction of a rGO/Ni bicontinuous conductive skeleton and microcellular structure. The use of liquid epoxy as matrix allowed for good processability and excellent compressive strength (27.33 MPa) of the foam with a density of 0.88 g/cm3, making it a valuable high-performance EMI shielding material.