Molecular dynamics simulations of the thermal conductivity of cross-linked functionalized single- and double-walled carbon nanotubes with polyethylene chains

Variation in the thermal conductivity of a metal-coated tri-walled carbon nanotube (3WCNT), in the presence of vacancies, was studied using non-equilibrium molecular dynamics simulations. A Two-Temperature model was used to account for electronic contribution to heat transfer. For 3WCNT with 0.5% and 1% random vacancies, there was 76%, and 86% decrease in the thermal conductivity, respectively. In that order, an overall ~66% and ~140% increase in the thermal conductivity was recorded when 3 nm thick coating of metal (nickel) was deposited around the defective models. We have also explored the effects of tube specific and random vacancies on thermal conductivity of the 3WCNT. The changes in thermal conductivity have also been justified by the changes in vibrational density of states of the 3WCNT and the individual tubes. The results obtained can prove to be useful for countering the detrimental effects of vacancies in carbon nanotubes.

Download Full-text

Molecular dynamics simulations of electrowetting in double-walled carbon nanotubes

Current Applied Physics ◽

10.1016/j.cap.2008.07.010 ◽

2009 ◽

Vol 9 (4) ◽

pp. 750-754 ◽

Cited By ~ 7

Author(s):

H.W. Zhang ◽

Z.Q. Zhang ◽

L. Wang

Keyword(s):

Carbon Nanotubes ◽

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Dynamics Simulations ◽

Double Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Download Full-text

Molecular Dynamics Study on Thermal Conductivity of Single-Walled Carbon Nanotubes

ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer, Volume 3 ◽

10.1115/mnhmt2009-18205 ◽

2009 ◽

Cited By ~ 1

Author(s):

Bingyang Cao ◽

Quanwen Hou ◽

Zengyuan Guo ◽

Wusheng Zhang

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Molecular Dynamics ◽

Carbon Nanotube ◽

Molecular Dynamics Simulations ◽

Phonon Transport ◽

Tube Length ◽

Length Dependence ◽

Dynamics Simulations ◽

Walled Carbon Nanotubes

In this paper, we study the thermal conductivities of sing-walled carbon nanotubes (CNTs) and CNTs-based nanocomposites using molecular dynamics simulations. Length dependence of the thermal conductivity of (5, 5) carbon nanotube at 300 K and 1000 K is simulated. At room temperature the thermal conductivity shows linear length dependence with the tube length less than 40 nm, which indicates the completely ballistic transport. The thermal conductivity increases with the increase of the nanotube length, but the increase rate decreases as the length increases. It shows that the phonon transport transits from ballistic to diffusive. In the simulations, the power exponent of the thermal conductivity of carbon nanotube to the tube length decreases by decaying exponential function as the tube length increases. We also observe a decrease of the low-dimensional effects by the surrounding matters. A carbon-nanotube-atom-fixed and -activated scheme of non-equilibrium molecular dynamics simulations is put forward to extract the thermal conductivity of carbon nanotubes embedded in solid argon. Though a 6.5% volume fraction of CNTs increases the composite thermal conductivity by about twice larger than that of the pure basal material, the thermal conductivity of CNTs embedded in solids is found to be decreased by 1/8–1/5 with reference to that of pure ones. The decrease of the intrinsic thermal conductivity of the solid-embedded CNTs and the thermal interface resistance are demonstrated to be responsible for the results.

Download Full-text