▎ 摘　　要

NOVELTY - Preparing graphene oxide dispersion comprises preparing a graphite intercalation of sulfate/sulfuric acid mixture by mixing graphite with concentrated sulfuric acid, where graphite is natural graphite powder having a particle size of 80-500 meshes, natural graphite flake, microcrystalline graphite or expanded graphite, adding potassium permanganate, ultrasonically processing, for oxidation reaction to obtain primary graphite oxide, centrifuging or filtering to obtain yellow-brown sludge or cake, adding deionized water, adding a solvent, ultrasonically processing and vacuum drying. USE - The method is useful for preparing graphene oxide dispersion (claimed). ADVANTAGE - The method: produces graphene oxide dispersion with good dispersibility and good stability; is simple and reduces the production cost and energy consumption; and does not generate toxic gases including release nitrogen dioxide/dinitrogen tetroxide into the environment. DETAILED DESCRIPTION - Preparing graphene oxide dispersion comprises: (a) mixing graphite with concentrated sulfuric acid in a ratio of 1 g:20 ml, ultrasonically processing at room temperature for 0.5-1.5 hours to obtain sulfate intercalated graphite/sulfuric acid mixture, where graphite is natural graphite powder having a particle size of 80-500 meshes, natural graphite flake, microcrystalline graphite or expanded graphite; (b) adding sulfate intercalated graphite/sulfuric acid mixture into potassium permanganate under ultrasonic conditions at room temperature for 5-10 seconds to produce sulfate intercalated graphite/sulfuric acid/potassium permanganate mixture, controlling the temperature at 25-40 degrees C for 1-3 hours for oxidation reaction to obtain a primary graphite oxide, where the mass ratio of potassium permanganate added to graphite/sulfuric acid mixture is 1:6-10, (c) adding deionized water (1-5 times the amount of primary graphite oxide) at a constant temperature of 90-100 degrees C for 10-20 minutes for hydrolysis reaction to obtain a solution of graphite oxide having hydrophilic group, adding 30% aqueous hydrogen peroxide solution formed by mixing deionized water (2-5 times) to the solution of graphite oxide having hydrophilic group to obtain bright yellow graphite oxide solution, centrifuging or filtering to obtain yellow-brown sludge or cake, adding the resulting sludge or cake to 2-10 times its volume of a mixture made by mixing hydrogen peroxide and concentrated sulfuric acid and centrifuging the resulting mixture, where the volume ratio of the hydrogen peroxide to concentrated sulfuric acid is 1:3-7, and (d) washing sludge graphite oxide containing hydrophilic group successively with 10 wt.% aqueous hydrochloric acid and with deionized water until the effluent is neutral, centrifuging or filtering to obtain a precipitate or filter cake at 60-80 degrees C, vacuum drying to obtain graphite oxide, adding to a solvent, ultrasonically processing at room temperature at an ultrasonic power of 100 W for 15-60 minutes to obtain graphene oxide dispersion, where the mass ratio of graphite oxide to solvent is 1:1, and the solvent is water, ethanol, acetone or tetrahydrofuran.