碳纳米管Y形分子结的热导率与热整流现象

Thermal conductivity and thermal rectification of carbon nanotube Y junctions

基于碳纳米管Y形分子结的结构重构,通过非平衡分子动力学方法和量子修正,模拟分析了Y形分子结的热导率和热整流现象.研究表明:相对单根完整碳管,Y形分子结在不同温度下导致热导率大约12%—85%的下降;Y结主干向分支方向的导热能力强于分支向主干方向的导热能力;Y结降低热导率的作用随着温度的升高逐渐减小;Y结的热整流效果随着温度的上升先减弱后增强.

The thermal conductivity of carbon nanotube （CNT） Y junctions and the thermal rectification behavior in the Y junctions have been investigated by means of classical non-equilibrium molecular dynamics simulation with quantum effects considered. The results indicate that the thermal conductivity of a CNT Y junction is about 12%–85% lower than a （10,10） pristine CNT. The thermal conductivity of the Y junction in the positive direction, when the heat flux is directed from the stem to branches, is always higher than that of the reverse direction, i.e. from branches to the stem. The decline of the thermal conductivity due to the existence of Y junctions decreases with increasing temperature. The thermal rectification coefficient of the Y junction first decreases and then increases with the increase of temperature.