Oxygen Functionalization of Multiwall Carbon Nanotubes by Microwave-Excited Surface-Wave Plasma Treatment

Abstract

In this work, oxygen-containing groups were introduced onto multiwall carbon nanotubes (MWCNTs) by using microwave-excited Ar/O 2 surface-wave plasma (SWP) treatment. The changes of the atomic contents and structure properties of MWCNTs as a function of gas flow rate, treatment time, and plasma power were analyzed using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. A mechanism of MWCNT oxidation was proposed, based on XPS analysis, which showed how oxygen-containing groups, such as C-O, CdO, and O-CdO, were generated on the surfaces of MWCNTs. The surface morphology of MWCNTs was observed by field emission scanning electron microscopy (FE-SEM). The results indicated that Ar/O 2 plasma treatment greatly enhanced the content of oxygen, modified structure properties, induced more surface defects, and improved the dispersion of MWCNTs in aqueous solution. The integrity of the nanotube patterns was not damaged.

Selective Grafting of Primary Amines onto Carbon Nanotubes via Free-Radical Treatment in Microwave Plasma Post-Discharge

“…The CNT powder was stirred during the treatment allowing a permanent renewal of carbon nanotube accessible to the reactive atomic nitrogen flow. The treated CNTs were analyzed using X-ray photoelectron spectroscopy (XPS), a technique frequently used to determine the changes in the atomic content of CNTs after functionalization reactions [29,43,44]. The aim of this experiment was to determine whether nitrogenated groups were grafted homogeneously on the whole surface of the carbon nanotubes.…”

Dry Oxidation and Vacuum Annealing Treatments for Tuning the Wetting Properties of Carbon Nanotube Arrays

“…[26][27][28][29][30][31] However, none of these published methods have been previously performed on CNT arrays. Although the oxidation method described herein is similar to these published methods, it is optimized for CNT arrays, not CNT powders.…”

Carbon Nanotubes Supported Metal Nanoparticles for the Applications in Proton Exchange Membrane Fuel Cells (PEMFCs)

“…The possible mechanisms associated with the plasma treatment of CNTs include the generation of the C-O, C=O, and O-C=O bonds, as shown in Fig. 9 (C. Chen et al, 2009). Since the π bonds in C=C are active and are the most susceptible to the plasma attacks, it is believed that the radicals are first generated on the dissociated π bonds in C=C, which further react with active oxygen atoms (Fig.…”