Formation of unique three-dimensional interpenetrating network structure with a ternary composite

Ternary composite of reduced graphene oxide/multi-walled carbon nanotubes (RGO/MWCNT)/polyimide (PI) with high-performance mechanical and electrical properties was synthesized via in situ polymerization. The unique three-dimensional interpenetrating network structure conferred the conductive pathways for electrons, resulting from the strong interfacial covalent bonds between RGO/MWCNT and the PI matrix. The electrical conductivity of (RGO/MWCNT)/PI reached 4.4x10(-4) Sm-1 with the filler loading concentration at an extremely low value (0.2wt%), which was significantly higher than that of the neat PI. The (RGO/MWCNT)/PI composite films exhibited high tensile strength (up to 462MPa) and tensile modulus (260MPa). Furthermore, the introduction of RGO/MWCNT enhanced the thermal stability of the (RGO/MWCNT)/PI composites (from 579 to 623 degrees C). The composite film is expected to be extensively applied in the field of electronics, solar cells and biosensors.