Single-walled Carbon Nanotube Chemical Functionalization Of The Dispersion

In this thesis, we explored the effective strategies for functionalizing the single-walled carbon nanotubes (SWNTs) with ammonium sulfamate in order to improve the dispersity and stability of the SWNTs.First, the SWNTs prepared by the arc discharge process were purified through three different routes by using nitric acid, hydrochloric acid and ammonium sulfate, respectively. The products were characterized by scanning electron microscopy(SEM), Raman spectroscopy(Raman), X-ray diffraction(XRD) and ultravioletvisible near-infrared specrophotometry(UV-vis-NIR). The results indicated that the SWNTs with high purity could be obtained through these routes, and the intrinsic structure of the SWNTs was retained after purification process at the same time. Among three routes, the SWNTs purified with ammonium sulfate are best in term of the purity.After the purification, three routes, including solid, solution and hydrothermal routes, were adopted to modify the purified SWNTs with ammonium sulfamate. It is showed that the ammonium sulfamate could anchor on the surface of the SWNTs via covalent bonds through the hydrothermal routes. The ammonium sulfamate modification improved greatly the dispersity and stability of the SWNTs in the water and N,N-dimethylcarboxamide (DMF) medium.In addition, the "microwave-assisted heating technique" was developed to purify and modify SWNTs, and the optimized experimental parameters were explored. The technique exhibited obvious advantages over those methods mentioned above, including simple handle, low energy consumption and quick rate. Experimental results indicated that the improved modification effect could be obtained through the microwave-assisted heating process compared to the convenient hydrothermal methods.