Functionalization of Reduced Graphite Oxide Sheets with a Zwitterionic Surfactant

Abstract

Films of a few layers in thickness of reduced graphite oxide (RGO) sheets functionalized by the zwitterionic surfactant N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DDPS) are obtained by using the Langmuir-Blodgett method. The quality of the RGO sheets is checked by analyzing the degrees of reduction and defect repair by means of X-ray photoelectron spectroscopy, atomic force microscopy (AFM), field-emission scanning electron microscopy (SEM), micro-Raman spectroscopy, and electrical conductivity measurements. A modified Hummers method is used to obtain highly oxidized graphite oxide (GO) together with a centrifugation-based method to improve the quality of GO. The GO samples are reduced by hydrazine or vitamin C. Functionalization of RGO with the zwitterionic surfactant improves the degrees of reduction and defect repair of the two reducing agents and significantly increases the electrical conductivity of paperlike films compared with those prepared from unfunctionalized RGO.

The Role of Oxidative Debris on Graphene Oxide Films

“…The clear advantage of this method is the possibility of tuning the interface assembly by adjusting the surface pressure of the Langmuir monolayer by compressing or expanding the film using barriers 22. 23 Consequently, it offers the possibility of preparing reproducible films of polymers,24 surfactants25 and nanoparticles26–28 with the control over interparticle distance necessary to exploit the materials in technological applications. In the case of GO sheets, the air–water interface forces them to lay flat, so that the assemblies can be transferred onto solids by the LB technique.…”

“…In the case of GO sheets, the air–water interface forces them to lay flat, so that the assemblies can be transferred onto solids by the LB technique. Therefore, it has been successfully used to deposit graphite oxide29–32 and surfactant‐functionalized and non‐functionalized RGO 33. Note that several conditions must be fulfilled to build self‐assembled particle monolayers.…”

“…We choose this material because the low number of stacked graphene layers in its structure could constitute an excellent starting material to obtain few‐layer graphene oxide. We use a modified Hummers method to synthesize highly oxidized materials because we have proved that the most oxidized GO renders the highest‐quality material 33. Prior to preparing Langmuir and LB films of these materials, we have determined their chemical structure by means of X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), zeta potential, and FT‐IR and UV/Vis spectroscopies.…”

Synthesis of Graphene-Based Sensors and Application on Detecting SF6 Decomposing Products: A Review

“…Shukla et al [31] reported a fast and inexpensive method to the synthesis of single- or few-layer graphene by cleaving off the bulk graphite on the substrate made of borosilicate glass or any insulating materials with ionic conductivity, which has promise for industrial level production for certain engineering applications. Martín-García et al [32] showed that reduced GO functionalized zwitterionic surfactant can significantly improve the electrical conductivity of graphene film, thereby enhancing its quality. Obraztsov et al [33] employed chemical vapor deposition (CVD) to synthesize graphene on a Ni substrate and found that a few graphene layers with thickness ranging from 1 to 2 nm grew successfully on the surface of the substrate, while the same approach failed to make the graphene adhere to a Si substrate, ascribed to the large lattice incompatibility between silicon and graphite.…”

Raman investigation on carbonization process of metal-organic frameworks

“…An empirical formula shows that L a is inversely proportional to I D / I G . Not only the I D /I G ratio, but also the D and G band positions and linewidths can provide the information on the size and structural evolution of carbon materials such as carbon fibers and graphene …”