▎ 摘　　要

Preparing highly homogeneous and stable aqueous graphene nanoplatelets (GNPs) suspension is significant for practical applications. In this study, non-covalent modified GNPs in aqueous solution were prepared using a non-ionic surfactant polyoxyethylene (40) nonylphenylether (Igepal, CO890) under probe-type sonication. The dispersing performance and mechanism of GNPs were concluded by various characterization methods. The UV-vis absorbance of GNP suspension suggested that the optimum concentration ratio of GNPs to CO890 is 1:5. The minimum sonication time and optimum sonication power were 20 minutes and 360 W for dispersing 0.1 g/L GNPs respectively. The maximum achievable dispersing status of GNPs in aqueous solution has been demonstrated by optical microscope and transmission electron microscopy (TEM) from both macro and micro aspects. The dispersing mechanism is conducted by two aspects: on the one hand, the GNP bundles are broken into small particles by cavitation effect of sonication. On the other hand, the CO890 molecules are adsorbed onto the surface or the edges of GNPs to prevent re-aggregation of GNPs by steric hindrance.