Studies On Preparation And Application Of Nano-graphite By Magnetic Stirring Grinding Method

In this paper, the various mature methods of preparing nano-graphite and its advantages and disadvantages are compared. A new method of preparing nano-graphite, magnetic stirring grinding method, is first introduced. Magnetic stirring grinding method uses changing magnetic field to drive grinding media moving high frequently in the rigid grinding chamber which triggers high frequency elastic shear and collision between the grinding media and the rigid grinding chamber. These strong shear and collision forces arising therefore help to grind the powder finer.The factors affecting the preparation of nano-graphite, the material of grinding rigid, grinding time, grinding media, rotation speed, the ratio of material filling, the ratio of material and the dry and wet milling technology were studied. The samples were characterized by XRD, BET, EDS, TG, FTIR, SEM, HRTEM, laser particle size analyzer and laser Raman analysis techniques. The test results show that nano-graphite containing graphene whose number of layer is 5 can be prepared from the raw flake graphite within 16 h using the grinding media (size:φ0.3 mm×5 mm and φ1.0 mm×5 mm) in the dry grinding progress. After milled for 30 h, the nano-graphite still retains the hexagonal structure of graphite using the grinding media whose size isφ0.3 mm×5 mm. While, the graphite turns to amorphous carbon after milled for 16 h accompanying with the decrease of graphitic structure using the grinding media whose size isφ1.0 mm×5 mm. Nano-graphite is mainly composed of nano-graphite sheets with an average size of 60 nm and has a high BET specific surface area of 738m2/g, whose surface contains some oxygen-containing, hydrogen-containing functional groups. Graphite during the grinding process was partially oxidized leading to its surface contains more oxygen-containing, hydrogen-containing functional groups. The bigger graphite sheets instead of nano-graphite were obtained in the wet grinding technology.After the as-prepared graphite reduced KMnO4, its composite could be a super capacitor material, and its alcohol solution has a fluorescent effect.