▎ 摘　　要

Polyimide/reduced graphene oxide (PI/r-GO) core-shell structured microspheres were fabricated by in situ reduction of graphene oxide (GO), which was coated on the surface of PI microspheres via hydrogen bonding and pi-pi stacking interaction. The highly ordered 3D core-shell structure of PI/r-GO micro spheres with graphene shell thickness of 3 nm was well characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and Raman spectra. The glass transition temperature (T-g) of PI/r-GO microspheres was slightly increased because of the interaction of r-GO and PI matrix while the temperature at 5% weight loss (T-5%) of PI/r-GO microspheres was decreased due to the side effect of reductant hydrazine hydrate. The PI/r-GO nanocomposites exhibited highly electrical conductivity with percolation threshold of 0.15 vol% and ultimate conductivity of 1.4 x 10(-2) S/m. Besides, the thermal conductivity of PI/r-GO nanocomposites with 2% weight content of r-GO could reach up to 0.26 W/m K. (C) 2016 Elsevier Ltd. All rights reserved.