The Effect of AIREBO on Thermal Conductivity of EPDM Networks

2013 ◽  
Vol 561 ◽  
pp. 164-168
Author(s):  
Lian Xiang Ma ◽  
Gang Yang ◽  
Yuan Zheng Tang ◽  
Yan He

In this article, thermal conductivity of EPDM networks has been discussed using molecular dynamics simulations. The simulations are performed on four systems using adaptive intermolecular reactive empirical bond order (AIREBO) potential. The effect of Lennard-Jones (L-J) potential and torsion potential on thermal conductivity is discussed. The contribution of L-J potential to thermal conductivity is negative. However, contribution of torsion potential is positive. The results suggest that the randomly entanglement of molecular chains in EPDM networks is responsible for its low thermal conductivity.

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1982
Author(s):  
Paul Desmarchelier ◽  
Alice Carré ◽  
Konstantinos Termentzidis ◽  
Anne Tanguy

In this article, the effect on the vibrational and thermal properties of gradually interconnected nanoinclusions embedded in an amorphous silicon matrix is studied using molecular dynamics simulations. The nanoinclusion arrangement ranges from an aligned sphere array to an interconnected mesh of nanowires. Wave-packet simulations scanning different polarizations and frequencies reveal that the interconnection of the nanoinclusions at constant volume fraction induces a strong increase of the mean free path of high frequency phonons, but does not affect the energy diffusivity. The mean free path and energy diffusivity are then used to estimate the thermal conductivity, showing an enhancement of the effective thermal conductivity due to the existence of crystalline structural interconnections. This enhancement is dominated by the ballistic transport of phonons. Equilibrium molecular dynamics simulations confirm the tendency, although less markedly. This leads to the observation that coherent energy propagation with a moderate increase of the thermal conductivity is possible. These findings could be useful for energy harvesting applications, thermal management or for mechanical information processing.


Author(s):  
Zhiting Tian ◽  
Sang Kim ◽  
Ying Sun ◽  
Bruce White

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.


2010 ◽  
Author(s):  
Xueming Yang ◽  
Albert C. To ◽  
Jane W. Z. Lu ◽  
Andrew Y. T. Leung ◽  
Vai Pan Iu ◽  
...  

Author(s):  
Bo Qiu ◽  
Hua Bao ◽  
Xiulin Ruan

In this paper, thermoelectric properties of bulk PbTe are calculated using first principles calculations and molecular dynamics simulations. The Full Potential Linearized Augmented Plane Wave (FP-LAPW) method is first employed to calculate the PbTe band structure. The transport coefficients (Seebeck coefficient, electrical conductivity, and electron thermal conductivity) are then computed using Boltzmann transport equation (BTE) under the constant relaxation time approximation. Interatomic pair potentials in the Buckingham form are also derived using ab initio effective charges and total energy data. The effective interatomic pair potentials give excellent results on equilibrium lattice parameters and elastic constants for PbTe. The lattice thermal conductivity of PbTe is then calculated using molecular dynamics simulations with the Green-Kubo method. In the end, the figure of merit of PbTe is computed revealing the thermoelectric capability of this material, and the multiscale simulation approach is shown to have the potential to identify novel thermoelectric materials.


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