Microwave Irradiation of Graphene Aerogel and Its Use on the Electromagnetic Interference Shielding of BMI Nanocomposites

A facile approach to enhance the quality and conductivity of graphene aerogels (GAs) by microwave irradiation was reported. The obtained microwave reduced graphene aerogels (MRGAs) endowed the MRGA/bismaleimide (BMI) composites with high conductivity and electromagnetic interference (EMI) shielding performance. Moreover, the MRGA/BMI composites showed an EMI shielding mechanism dominated by absorption. In this work, graphene aerogels (GAs) with three-dimensional interconnected networks were prepared by chemical reduction and self-assembly of graphene oxide sheets. After microwave treatment, obtained microwave reduced graphene aerogels (MRGAs) were used in the preparation of bismaleimide (BMI) composites. The results show that the microwave treatment significantly enhanced the quality of GAs, and the three-dimensional networks in the GAs were well retained. Moreover, the MRGAs were highly efficient in endowing BMI with high electrical conductivity and excellent electromagnetic interference shielding effectiveness (EMI SE). The conductivity of MRGA/BMI composites was 42-68% higher than that of GA/BMI composites. When the filler content is 1.6 wt.%, the EMI SE of MRGA/BMI composite was 32.3% higher than that of GA/BMI composite in the X band.