Fabrication, optical and electrical properties of solvethermal reduced graphene oxide/polyimide composites by in situ polymerization

Solvothermal reduced graphene oxide (SRGO) suspensions in dimethylacetamide (DMAC) are facilely prepared by a solvothermal process. Then, SRGO/polyimide (PI) composites are efficiently prepared by in situ polymerization and finally cured at 300 °C for 2 h. Optical, dielectric and electrical properties are carefully evaluated by the optical transmission, dielectric constants (ε) and dielectric loss factors, conductivity, etc. The SRGO/PI composite film with 0.5 wt% SRGO sheets exhibits the obvious optical absorption in region of 0.5–2.4 μm and the higher emissivity in region of 6–24 μm. Moreover, the dielectric constants and resistivity of SRGO/PI composites display an obvious decrease from ε = 4.0 to ε = 3.0 and from 10¹⁴ to 10⁶ Ω cm, respectively. This approach would supply a potential revolution to improve optical and electrical properties of SRGO/PI composites.