▎ 摘　　要

Graphene nanosheet/polymer composites were prepared using in situ reduction-extractive dispersion technology. The morphology and microstructure of the composites were examined by scanning electron and optical microscopy. The results indicate that graphene nanosheets from the reduction of graphite oxide are about 5 nm thick and 1-3 pm in diameter. Reduction-extractive dispersion technology can effectively promote the dispersion of graphene nanosheets and consequently an excellent conductive network is formed in the matrix. The percolation threshold of the composite is about 0.15 vol.%. When the graphene nanosheet content is lower than 1.5 vol.%, the conductivity of the composites is 3-5 orders of magnitude higher than that of composites filled with graphite nanosheets from expanded graphite. (C) 2009 Elsevier Ltd. All rights reserved.