Preparation Of Carbon Nanoparticles By DC Arc Discharge And Characterization Of Properties

Carbon nanoparticles (CNPs) is one kind of the novel carbon nano-materials. CNPs is widely used in various fields, because of its unique structure, large surface area, high stability and excellent optical, electrical and mechanical properties. DC arc discharge as one of the most important methods for the preparation of CNPs has come to people's attention. The thorough study on preparation conditions in DC arc discharge method and CNPs properties has continued for many years to meet the requirements of CNPs material in various fields. So far, there are still many worthwhile problems needing to be solved.In this dissertation, CNPs were prepared by DC arc discharge. The effects of catalysts, discharge atmosphere and temperature of atmosphere on the yields of the products, morphology, microstructures and conductivity of CNPs suspension in distilled water were investigated.Firstly, the main factors affecting the yield of products in preparation of CNPs by DC arc discharge were analysed by the calculation of product's yield. The results show that the discharge atmosphere obviously affected the yield of CNPs, as well as the catalyst and temperature of atmosphere have a weak effect on the yield of CNPs.It was found that the yield of CNPs prepared by DC arc discharge in the nitrogen atmosphere is higher than that in the argon atmosphere. The morphology and microstructures of the CNPs prepared by DC arc discharge under different conditions were characterized by the high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX), surface and pore structure instrument and X-ray diffraction (XRD). From the results of characterization, the DC arc discharge conditions affecting CNPs morphology and microstructure were discussed.The suspensions of CNPs in distilled water, which was obtained by DC arc discharge under the different conditions, were prepared. And the conductivity of CNPs-suspensions at different temperatures and under different deposited time was measured. The change of the conductivity of CNPs-suspension with temperature and deposited time was observed. CNPs prepared by DC arc discharge in the nitrogen atmosphere was found to be well dispersed to water, and its suspension is stable in about one year. But, at beginning, CNPs prepared by DC arc discharge in the argon atmosphere was not easy to be dispersed to water, while its dispersibility in the distilled water was improved with increasing deposited time.