О проекте

Graphene and graphene oxide are found to be extremely promising materials for various applications due to their unique chemical, physical, and mechanical properties1-6. A significant number of applications require mass scale processing of graphene nanosheets, particularly their dispersion in the suitable media for the efficient and effectual utilization. As such graphene nanosheets are hydrophobic and readily agglomerate in most of solvents7. Hence, the processability and solubility of graphene nanosheets in large-scale without destructing their key characteristics still remains as great challenge for the breakthrough in various applications of Graphene nanosheets. The surface functionalities of non-stoichiometric graphene oxide provides a platform for rich chemistry to occur both within the intersheet gallery and along the sheet edges8-10. Recently, the dispersion of graphene nanosheets in water and various polar organic solvents have been addressed either by aid of surfactant or by mean of chemical functionalization11-13. The surface chemistry on graphene oxide is specific to the type of functionalities available. The carboxylic groups of graphene oxide participates in acylation reaction with alkylamine in the presence of coupling reagent14-20. In such approach the organic entities can be attached through amide bond formation on the edges of graphene nanosheets, because the most of carboxylic groups are located on the edges. The dispersion of graphene nanosheets in polar solvents have been addressed by many researchers21-24. However, their solubility in non-polar organic solvents particular in hydrocarbons still remains as an obstacle in order to broaden the scope of applications. Herein, we address the chemical functionalization of graphene oxide at their edges. Graphene oxide, rich in surface functionalities, carries ample of carboxylates groups at their edges. These groups were chemically activated using thionyl chloride and subsequently allowed to react with various alkylamines. During such chemical functionalization, most of the basal plan functionalities were reduced and ultimately restored the graphene characteristics. The chemical functionalization of graphene nanosheets were examined and monitored by FTIR, TGA, and UV-Visible characterizations. The length of alkyl amines covalently bounded on graphene nanosheets were found to plays significant role in order to monitor their dispersibility in various organic solvents.

P Chemically Modified Graphene Nanosheets and their Dispersion Characterstics

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