▎ 摘　　要

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 degrees C for 2 h. Optical, dielectric and electrical properties are carefully evaluated by the optical transmission, dielectric constants (epsilon) 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 mu m and the higher emissivity in region of 6-24 mu m. Moreover, the dielectric constants and resistivity of SRGO/PI composites display an obvious decrease from epsilon=4.0 to epsilon=3.0 and from 10(14) to 10(6) Omega cm, respectively. This approach would supply a potential revolution to improve optical and electrical properties of SRGO/PI composites. (C) 2017 Elsevier B.V. All rights reserved.