Multi-interfaced graphene aerogel/polydimethylsiloxane metacomposites with tunable electrical conductivity for enhanced electromagnetic interference shielding

To satisfy the demand for multiple performances in the electromagnetic field, multi-interfaced graphene aerogel (GA)/polydimethylsiloxane (PDMS) composites with an integral three-dimensional (3-D) structure were constructed. In the microwave frequency range (1 MHz-1 GHz), the GA/PDMS composites exhibited negative permittivity corresponding to the plasmonic state at low frequencies which resulted from efficacious multiple interfaces in the GA/PDMS composites. Importantly, the negative permittivity could be adjusted by changing the testing pressure and GA amount. Multiple interfaces belonging to the GA were beneficial to achieve microwave absorption and electromagnetic interference (EMI) shielding. A much wider microwave absorption bandwidth,i.e., 9.15 GHz, was observed and was increased by more than 2-3 times compared with similar research, together with a total shielding effectiveness (SET) of over 60 dB from 2 to 18 GHz. The multi-functional GA/PDMS composites have the potential to be an effective electromagnetic protection material.