模拟研究碳纳米管的热稳定性质

Study on the thermal stability of carbon nanotubes by simulation

运用分子动力学方法具体模拟研究单个碳纳米管(CNTs)在加热过程中的结构变化.选择多组不同结构的单壁碳纳米管(SWCNTs)和双壁碳纳米管(DWCNTs)作为研究对象,加热温度从室温开始到4000K,压强保持为1atm.结果表明单壁碳管中手性型结构热稳定性最好,其次是扶手椅型和锯齿型,当手性角相同时,直径大的热稳定性更高;对于双壁碳管,研究表明当双壁中至少之一为手性结构时其热稳定好,而内外壁均为锯齿结构的稳定性最差,该结果进一步支持了有关单壁碳管的结论;还从理论上探索了描述结构热稳定性的方式,并在键层次上分析造成碳管之间热稳定性差异的原因.

Tight-binding molecular dynamics was used to simulate the thermal behavior of carbon nanotubes （CNTs） in this paper. A few kinds of single wall CNTs （SWCNTs） and double wall CNTs （DWCNTs） were studied during the simulation experiment at temperatures of 300—4000 K and the pressure of 1 atm. The results showed that the chiral SWCNTs have higher thermally stability than the armchair and zigzag type, and that the bigger the nanotube diameter is, the more stable the nanotube stucture is for those with the same chiral angles. The DWCNTs with at least one chiral structured wall are more stable than the others, but that with two zigzag walls were damaged badly, which also gives support to the study about SWCNT thermo-stability. One factor to describe CNTs in connection with their thermo-stability was proposed, and some data were theoretically analyzed based on carbon bond structures.