scholarly journals Thermal Conductivity of Metal-Coated Tri-Walled Carbon Nanotubes in the Presence of Vacancies-Molecular Dynamics Simulations

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 809 ◽  
Author(s):  
Ravindra Sunil Dhumal ◽  
Dinesh Bommidi ◽  
Iman Salehinia
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Temperature Model ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Individual ◽  
Walled Carbon Nanotubes ◽  
Two Temperature

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.

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

2009 ◽  
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.

A Molecular Dynamics Study of Thermal Conductivity in Nanocomposites via the Phonon Wave Packet Method

2009 ◽  
Author(s):  
Zhiting Tian ◽  
Sang Kim ◽  
Ying Sun ◽  
Bruce White
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Wave Packet ◽  
Molecular Dynamics Simulations ◽  
Phonon Scattering ◽  
Flow Direction ◽  
Normal Incidence ◽  
Material Interfaces ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations

The phonon wave packet technique is used in conjunction with the molecular dynamics simulations to directly observe phonon scattering at material interfaces. The phonon transmission coefficient of nanocomposites is examined as a function of the defect size, thin film thickness, orientation of interface to the heat flow direction. To generalize the results based on phonons in a narrow frequency range and at normal incidence, the effective thermal conductivity of the same nanocomposite structure is calculated using non-equilibrium molecular dynamics simulations for model nanocomposites formed by two mass-mismatched Ar-like solids and heterogeneous Si-SiCO2 systems. The results are compared with the modified effective medium formulation for nanocomposites.

Thermal conductivity and interfacial Thermal Resistance Behavior for the Polyaniline (C3N)– boron carbide (BC3) Heterostructure

2021 ◽  
Author(s):  
Arian Mayelifartash ◽  
Mohammad Ali Abdol ◽  
Sadegh Sadeghzadeh
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Thermal Resistance ◽  
Boron Carbide ◽  
Molecular Dynamics Simulations ◽  
Thermal Conductance ◽  
Interfacial Thermal Resistance ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
Non Equilibrium

In this paper, by employing non-equilibrium molecular dynamics simulations (NEMD), the thermal conductance of hybrid formed by polyaniline (C3N) and boron carbide (BC3) in both armchair and zigzag configurations has...

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