I nfluence of biphenyl chemisorption on the thermal properties of single-walled carbon nanotube

摘要

Non-equilibrium molecular dynamics simulations are performed to investigate the influences of chemisorption biphenyl rings under axial thermal loadings of 1.65 K/Å. This investigation determines carbon nanotube thermal conductivity at biphenyl rings sorption density ranging from 0%~30%, using a non-equilibrium molecular dynamics simulation with true carbon potentials. The thermal impact causes system fluctuation in the initial 3 ps leading to a transport region temperature as high as 400K. The thermal relaxation process reduces impact energy influence after 30 ps and leads to Maxwell''s distribution. Steady-state constant heat flux is observed after thermal equilibrium. Furthermore, the temperature curves show distinct high disturbance at initial time and linear distribution along the tube axial direction after steady-state. Simulations are performed on pristine CNTs and CNTs on which 0.25%, 1%, 5%, 10%, 15%, 20%, 25% and 30% of the carbon atoms have a bonded biphenyl group. The case where biphenyl groups are attached to 0.25% of the atoms on a nanotube is illustrated in the left panel of Figure 1. Results suggest that thermal conductivity value increases with increasing CNT subjected to thermal loading up to a temperature gradient of ~ 20 K/Å representing rapidly thermal conductivity drop at sorption density of 10%. The functionalized CNTs all show significantly smaller thermal conductivities. Simulation results yield precise understanding of nano-scale transient heat transfer characteristics in a single-wall carbon nanotube.