Study On Preparation And Conductivity Of Graphene

In carbon materials, graphene has special structures such as single-layer,two-dimensional and honeycomb, which make graphene have excellentchemical and physical properties, for example, ultrahigh specific surfacearea(2630m2/g), excellent conductivity(conductivity106S/m), mechanicalcapacity(Young modulus1TPa), it shows huge potential in high-technologyfield and attracts lots of researchers’ attention. But the Vander Waals’ forcebetween different layers makes them easy to reunite and results in problemssuch as weak dispersity, increasing electrical resistivity and layer thickness, allthe problems make it impossible to produce graphene with high quality and inlarge scale. As to above problems, the paper mainly focuses on preparation ofsingle layer graphene via oxidation-reduction method, the influences ofdifferent kinds of oxidizing agent and reducing agent on graphene are studiedsystematic and the preparation conditions of graphene and oxidized grapheneare also studied. By the modification of graphene, it is easy to be dispersed inwater.The preparation methods of graphene and oxidized graphene. Oxidizedgraphene is prepared by Hummers method and the influence of mixing speed,amount of potassium permanganate and reacting time in low temperature onthe properties of oxidized graphene are studied. In reduction of oxidizedgraphene, the impacts of reducing agent and reacting time on oxidizedgraphene. The characterization such as infrared spectroscopy, Ramanspectrum, transmission electron microscopy, atomic force microscope andthermo gravimetry of graphene and oxidized graphene are tested, thedispersibility of oxidized graphene and electrical conductivity of graphene aretested too.Prepare modified graphene by reaction between oxidized graphene, silane coupling agent KH-560and glucose and the characterization such asinfrared spectroscopy, Raman spectrum, transmission electron microscopy,atomic force microscope are made, the dispersibility and electrical conductivityof graphene are tested too.The results indicate that: the layer of oxidized graphene is opened andgraft lots of oxygen-containing groups on surface and oxidized graphene hasbetter dispersibility in water. The oxygen-containing groups on surface ofgraphene prepared by reduction with glucose is almost removed which hassmaller electrical resistivity and the electrical resistance value is32.6·m. Themodified graphene has better dispersibility in water and the patch that made upof3-4layers have different kinds of sizes with thickness of1.46nm. Theelectrical resistance value is48.7·m, a little higher than that of graphene, butthe modified graphene has better dispersibility in water.