Diazonium Functionalization of Surfactant-Wrapped Chemically Converted Graphene Sheets

Abstract

Surfactant-wrapped chemically converted graphene sheets obtained from reduction of graphene oxide with hydrazine were functionalized by treatment with aryl diazonium salts. The nanosheets are characterized by X-ray photoelectron spectroscopy, attenuated total reflectance infrared spectroscopy, Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. The resulting functionalized nanosheets disperse readily in polar aprotic solvents, allowing alternative avenues for simple incorporation into different polymer matrices.

Janus graphene from asymmetric two-dimensional chemistry

“…3b and Supplementary Fig. S9) centred at 406.2 eV (labelled by * and assigned to nitro groups 23,24 ), confirming the presence of nitro phenyl groups on Janus graphene. The lower N1s peaks is associated with the presence of reduced nitrogen species introduced by the transferring procedure and may be due to transformation of the nitro groups by X-ray irradiation in the XPS spectrometer chamber 49 .…”

“…XPS survey, the evolution of Raman spectra, and surface wettability measurements confirm that the fluorine and oxygen Figs S6,S7). Here, we show another example by using diazotization of graphene in the second step of functionalisation, in view of its simplicity and versatility [23][24][25]27 . Peeled mediator embedding chlorinated graphene was submerged into B20 mM diazonium salt (4-nitrobenzene diazonium tetrafluoroborate) aqueous solution for 1-2 h at 40 o C without stirring, allowing only the exposed surface to react and undergo surface functionalisation to form covalently bonded aryl-substituents.…”

“…Physisorption of chemical species on graphene would provide a facile way to alter its electronic properties 12 , however, covalent chemical modification shows a great advantage in achieving permanent stabilisation for long-term usage 13 . Previous attempts towards fundamental research on covalent functionalisation of graphene mainly involved the development of new modification strategies (for example, hydrogenation [14][15][16][17] , fluorination [18][19][20] , chlorination 21,22 , diazotization [23][24][25][26][27] and other cycloaddition reactions [28][29][30][31] ), covalent addition of edge and defects 27,32 , fabrication of chemical superlattices 26,33 and quantum effects in graphene modification 17,34 . Of the various significant research activities on graphene chemistry that have been conducted, nearly no work to date has been focused on the asymmetric chemistry of this ideal 2D atomic crystal via covalently attaching different functional groups on its two faces simultaneously.…”

The Prospective Two-Dimensional Graphene Nanosheets: Preparation, Functionalization and Applications

“…Through chemical reduction of GO by reducing reagents or thermal treatment, the covalently functionalized graphene can be formed, resulting in a much better dispersity in water or organic solvents. In order to enhance the hydrophilicity or lipophilicity of graphene, some small molecules and polymers, can be introduced to the plane of graphene, through radical addition reaction [32], cycloaddition reaction [33], or diazonium salts reaction [34] during the in situ reduction of GO into graphene. As a result, this would lead to a much better dispersity of graphene in water or organic solvents.…”

Colorful Polymer Compositions with Dyed Graphene Oxide Nanosheets

“…The presence of these groups deteriorates the mechanical and conducting properties of GO nanosheets with respect to those of graphene. A hydrazine processing restores [14][15][16] the GONS π-system and results in properties similar to those of graphene. Generally, the GO nanosheets possess [17] sites with different reaction abilities; therefore, it is difficult to predict beforehand the results of interactions between a GONS and different molecules.…”