▎ 摘　　要

The preparation of aqueous graphene dispersions by exfoliation of pristine graphite in the presence of a wide range of surfactants is reported. High graphene concentrations, up to about 1 mg mL(-1), were obtained with the use of some non-ionic surfactants. The dispersions consisted of single- and few-layer graphene platelets with their basal planes virtually free of even atomic-sized (point) defects. The potential utility of such highly concentrated dispersions toward the low-cost, large-scale manipulation and processing of graphene was demonstrated by processing them into electrically conductive, freestanding paper-like films. (C) 2010 Elsevier Ltd. All rights reserved.