Synergistic modification of glass beads/epoxy composites with multi-carbon nanomaterials

The surface-modified hollow glass beads with reduced graphene oxide (rGO@HGB) were prepared by electrostatic self-assembly method and then blended with conductive carbon black (CB), graphene nanoplates (GNPs) and epoxy resin (EP), and were further used to prepare CB-GNPs-rGO@HGB/EP composites. The microstructure, conductivity properties and dielectric properties of the CB-GNPs-rGO@HGB/EPcomposites were systematically studied. The results show that rGO@HGB can significantly improve the electrical conductivity and dielectric constant of rGO@HGB/EP composites. After further addition of CB and GNPs, a segregated conductive percolation network is formed by rGO@HGB. There are efficient synergistic effects of rGO, CB and GNPs on improving the properties of CB-GNPs-rGO@HGB/EP composites. With 0.2vol% CB-GNPs at the volume ratio of 10:1, the properties of CB-GNPs-rGO@HGB/EP composites are optimal with the volume resistivity of 1.88×10⁴ Ωcm and the dielectric constant of 454.5 at 1 kHz, which is 11.3% and 10.7% higher than that of CB-rGO@HGB/EP and GNPs-rGO@HGB/EP composites, respectively, while the dielectric loss is only 0.065.