Modification Of Graphene Oxide And Applications

In recent years, graphene oxide has attracted much attention due to their high surface area, unique two-dimensional（2D） structures, excellent thermodynamic and mechanical properties. These features lead to many potential applications of graphene oxide in various fields, such as electronic devices, advanced sensors and composites.However, the inevitable aggregation or restacking of GO in organic solvents because of Van der Waals’ force, which could significantly limit the practical use of graphene oxide. In this paper, graphene oxide was modified and analyzed using IR, TGA, XRD,XPS and TEM, then the modified graphene oxide was applied to the field of catalysis and dispersibility.In this thesis, diethylenetriamine was used to functionalize graphene oxide and as-obtained modified graphene oxide was applied it to catalyze Knoevenagel condensation and Michael addition reaction. The results suggested the obtained diethylenetriamine modified graphene oxide（GO-DETA） showed high catalytic activity for the reactions of aromatic aldehydes and heterocyclic aldehydes with malononitrile, while aliphatic aldehydes gave the products with low yields. The Michael addition of various kinds of chalcones with malononitrile afforded the corresponding products in excellent yields as well. The solvent of the reactions is water, which is green and nontoxic. As a solid catalyst, GO-DETA is easily available.It has good recyclability compared with graphene oxide.Graphene oxide was also modified by acetic anhydride via its reaction with the epoxy groups on the surface of graphene oxide. Similar to graphene oxide, the acetic anhydride modified graphene oxide could disperse in some polar solvents, such as H₂O, DMF, DMSO and NMP. In addition, it could be also well dispersed in various organic solvents, especially in dichloromethane, 1,2-dichloroethane, chlorobenzene and bis（2-methoxyethyl）ether, etc.