The Simulation Of Thermal Stability Of Multi-wall Carbon Nanotube And Oscillatingtube

We have used molecular dynamics (MD) simulation to investigate the structure change and thermal stability of Multi-wall carbon nanotube (MWCNTs) at high temperature. We have also studied the effect of different temperatures on the oscillation period of oscillatingtube which consist of single-wall carbon nanotube(SWCNTs)and platinum clusters.Using the environment dependent interatomic potential (EDIP) to describe the C-C interaction in carbon nanotube, we simulate that the evaporation of the surface wall of MWCNTs by the Stone-Wales defect on the surface wall of MWCNTs. The simulation results show that the Stone-Wales defect in the surface wall of a multi-walled carbon nanotube vibrates intensely, which causes C-C bond breaking and evaporation of atoms along the circumferential directions of the nanotube. The formation of Stone-Wales defect is attributed to the atomic thermal motion or tensile strain. Using the Lindemann index and average atom internal energy as a criterion, we found that the surface wall of a MWCNTs evaporates around 2290K. Our simulation results agree very well with the observation of the surface wall evaporation of the MWCNTs at 2000℃.We have also studied carbon nanotube oscillatingtube, and we found that with the temperature increase the oscillation period of oscillatingtube keep stable in the range of 400～800K, and the oscillation periods had considerable fluctuation after 800K. The research shows that the structure of platinum clusters on different temperature has great influence on the oscillation period of oscillatingtube. Through the research of the Lindemann index and Radial Distribution Function of platinum clusters, it has been found that the melting temperature of large platinum clusters was consistent with the temperature of the oscillation periods had considerable fluctuation. We found that the platinum structure turn into amorphous structure after 800K. So we can consider that the melting structure of platinum cluster has great influence on the oscillation periods of carbon nanotube.