scholarly journals Thermal Transport in One-Dimensional Van Der Waals Heterostructures: Effects of Coating Layers on the Thermal Conductivity of Carbon Nanotubes

2020 ◽  
Author(s):  
Penghua Ying ◽  
Jin Zhang ◽  
Yao Du ◽  
Zheng Zhong
Keyword(s):  
Heat Flux ◽  
Thermal Transport ◽  
Van Der Waals ◽  
Thermal Conductance ◽  
One Dimensional ◽  
Interfacial Thermal Conductance ◽  
Quantitative Understanding ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Individual

In this paper, we conduct a comprehensive investigation on the thermal transport in one-dimensional (1D) van der Waals (vdW) heterostructures by using non-equilibrium molecular dynamics simulations. It is found that the boron nitride nanotube (BNNT) coating can increase the thermal conductance of inner carbon nanotube (CNT) base by 36%, while the molybdenum disulfide nanotube (<a>MSNT</a>) coating can reduce the thermal conductance by 47%. The different effects of BNNT and MSNT coatings on the thermal transport behaviors of 1D vdW heterostructures are explained by the competition mechanism between improved heat flux and increased temperature gradient in 1D vdW heterostructures. By taking CNT@BNNT@MSNT as an example, thermal transport in 1D vdW heterostructures containing three layers is also investigated. It is found that the coaxial BNNT-MSNT coating can significantly reduce the thermal conductance of inner CNT base by 61%, which is even larger than that of an individual MSNT coating. This unexpected reduction in thermal conductance of CNT@BNNT@MSNT can be explained by the suppression of heat flux arising from the possible compression effect, since BNNT-MSNT coating in CNT@BNNT@MSNT can more significantly suppress the vibration of inner CNT when compared to the individual MSNT coating in CNT@MSNT. In addition to the in-plane thermal transport, the interfacial thermal conductance between inner and outer nanotubes in 1D vdW heterostructures is also examined to provide a quantitative understanding of the thermal transport behaviors of1D vdW heterostructures. This work is expected to provide molecular insights into tailoring the heat transport in carbon base 1D vdW heterostructures and thus facilitate their broader applications as thermal interface materials.

scholarly journals Thermal Transport in One-Dimensional Van Der Waals Heterostructures: Effects of Coating Layers on the Thermal Conductivity of Carbon Nanotubes

2020 ◽  
Author(s):  
Penghua Ying ◽  
Jin Zhang ◽  
Yao Du ◽  
Zheng Zhong
Keyword(s):  
Heat Flux ◽  
Thermal Transport ◽  
Van Der Waals ◽  
Thermal Conductance ◽  
One Dimensional ◽  
Interfacial Thermal Conductance ◽  
Quantitative Understanding ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Individual

In this paper, we conduct a comprehensive investigation on the thermal transport in one-dimensional (1D) van der Waals (vdW) heterostructures by using non-equilibrium molecular dynamics simulations. It is found that the boron nitride nanotube (BNNT) coating can increase the thermal conductance of inner carbon nanotube (CNT) base by 36%, while the molybdenum disulfide nanotube (<a>MSNT</a>) coating can reduce the thermal conductance by 47%. The different effects of BNNT and MSNT coatings on the thermal transport behaviors of 1D vdW heterostructures are explained by the competition mechanism between improved heat flux and increased temperature gradient in 1D vdW heterostructures. By taking CNT@BNNT@MSNT as an example, thermal transport in 1D vdW heterostructures containing three layers is also investigated. It is found that the coaxial BNNT-MSNT coating can significantly reduce the thermal conductance of inner CNT base by 61%, which is even larger than that of an individual MSNT coating. This unexpected reduction in thermal conductance of CNT@BNNT@MSNT can be explained by the suppression of heat flux arising from the possible compression effect, since BNNT-MSNT coating in CNT@BNNT@MSNT can more significantly suppress the vibration of inner CNT when compared to the individual MSNT coating in CNT@MSNT. In addition to the in-plane thermal transport, the interfacial thermal conductance between inner and outer nanotubes in 1D vdW heterostructures is also examined to provide a quantitative understanding of the thermal transport behaviors of1D vdW heterostructures. This work is expected to provide molecular insights into tailoring the heat transport in carbon base 1D vdW heterostructures and thus facilitate their broader applications as thermal interface materials.

scholarly journals Atomistic Nodal Approach: a General Molecular Dynamics Method For Computing Local Thermal Conductance at Atomistic Resolution

2021 ◽  
Author(s):  
Mingxuan Jiang ◽  
Juan D. Olarte-Plata ◽  
Fernando Bresme
Keyword(s):  
Molecular Dynamics ◽  
Thermal Transport ◽  
Temperature Drop ◽  
Thermal Conductance ◽  
Fundamental Property ◽  
Lower Surface ◽  
Coordination Numbers ◽  
Interfacial Thermal Conductance ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations

The Interfacial Thermal Conductance (ITC) is a fundamental property of mate- rials and has particular relevance at the nanoscale. The ITC quanti�es the thermal resistance between materials of dierent compositions or between uids in contact with materials. Furthermore, the ITC determines the rate of cooling/heating of the materi- als and the temperature drop across the interface. Here we propose a method to com- pute local ITCs and temperature drops of nanoparticle- uid interfaces. Our approach resolves the ITC at the atomic level using the atomic coordinates of the nanomaterial as nodes to compute local thermal transport properties. We obtain high-resolution descriptions of the interfacial thermal transport by combining the atomistic nodal ap- proach, computational geometry techniques and \computational farming" using Non- Equilibrium Molecular Dynamics simulations. We illustrate our method by analyzing various nanoparticles as a function of their size and geometry, targeting experimentally relevant structures like capped octagonal rods, cuboctahedrons, decahedrons, rhombic dodecahedrons, cubes, icosahedrons, truncated octahedrons, octahedrons and spheres. We show that the ITC of these very dierent geometries can be accurately described in terms of the local coordination number of the atoms in the nanoparticle surface. Nanoparticle geometries with lower surface coordination numbers feature higher ITCs, and the ITC generally increases with decreasing particle size.

The impact of thermostat on interfacial thermal conductance prediction from non-equilibrium molecular dynamics simulations

2021 ◽  
Author(s):  
Song Hu ◽  
C. Y. Zhao ◽  
Xiaokun Gu
Keyword(s):  
Molecular Dynamics ◽  
Heat Flux ◽  
Thermal Conductance ◽  
Low Frequency ◽  
Temperature Calculation ◽  
Interfacial Thermal Conductance ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Impact ◽  
Non Equilibrium

Abstract The knowledge of interfacial thermal conductance (ITC) is key to understand thermal transport in nanostructures. The non-equilibrium molecular dynamics (NEMD) simulation is a useful tool to calculate the ITC. In this study, we investigate the impact of thermostat on the prediction of the ITC. The Langevin thermostat is found to result in larger ITC than the Nose-Hoover thermostat. In addition, the results from NEMD simulations with the Nose-Hoover thermostat exhibit strong size effect of thermal reservoirs. Detailed spectral heat flux decomposition and modal temperature calculation reveal that the acoustic phonons in hot and cold thermal reservoirs are of smaller temperature difference than optical phonons when using the Nose-Hoover thermostat, but in the Langevin thermostat phonons are of identical temperatures. Such a non-equilibrium state of phonons in the case of the Nose-Hoover thermostat reduces the heat flux of low-to-middle-frequency phonons. We also discuss how enlarging the reservoirs or adding an epitaxial rough wall to the reservoirs affect the predicted ITC, and find these attempts could help to thermalize the phonons, but still underestimate the heat flux from low-frequency phonons.

scholarly journals Temperature and interlayer coupling induced thermal transport across graphene/2D-SiC van der Waals heterostructure

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Md. Sherajul Islam ◽  
Imon Mia ◽  
A. S. M. Jannatul Islam ◽  
Catherine Stampfl ◽  
Jeongwon Park
Keyword(s):  
High Temperatures ◽  
Thermal Transport ◽  
Van Der Waals ◽  
Thermal Conductance ◽  
Interlayer Coupling ◽  
Phonon Modes ◽  
Out Of Plane ◽  
System Temperature ◽  
Non Equilibrium Molecular Dynamics ◽  
Increasing Temperature

AbstractGraphene based two-dimensional (2D) van der Waals (vdW) materials have attracted enormous attention because of their extraordinary physical properties. In this study, we explore the temperature and interlayer coupling induced thermal transport across the graphene/2D-SiC vdW interface using non-equilibrium molecular dynamics and transient pump probe methods. We find that the in-plane thermal conductivity κ deviates slightly from the 1/T law at high temperatures. A tunable κ is found with the variation of the interlayer coupling strength χ. The interlayer thermal resistance R across graphene/2D-SiC interface reaches 2.71 $$\times$$ × 10–7$${\text{Km}}^{2} /{\text{W}}$$ Km 2 / W at room temperature and χ = 1, and it reduces steadily with the elevation of system temperature and χ, demonstrating around 41% and 56% reduction with increasing temperature to 700 K and a χ of 25, respectively. We also elucidate the heat transport mechanism by estimating the in-plane and out-of-plane phonon modes. Higher phonon propagation possibility and Umklapp scattering across the interface at high temperatures and increased χ lead to the significant reduction of R. This work unveils the mechanism of heat transfer and interface thermal conductance engineering across the graphene/2D-SiC vdW heterostructure.

Optimized Design of Composite Materials for Heat Transport Applications

2011 ◽  
Author(s):  
Babak Kouchmeshky ◽  
Peter Kroll ◽  
Ibukun Olubanjo
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Thermal Transport ◽  
Elevated Temperatures ◽  
Phonon Scattering ◽  
Optimized Design ◽  
Individual Contributions ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
The Individual

Careful design of composite materials offers a chance for engineering phonon band gaps and controlling phonon scattering. Taking advantage of this strategy, we study properties of SiC composite materials for engineering applications in which the control of thermal transport is important. In particular, knowledge of the individual contributions of phonons on thermal transport provides us the necessary information to focus on most significant phonon frequencies. In our study, we select a series of candidate model geometries and use a virtual testing method for elevated temperatures to support the design process. Integrating atomistic non-equilibrium molecular dynamics simulations to determine thermal conductivity we provide a proof-of-concept study and deliver best design scenarios of SiC composite materials with very low-thermal conductivity.

scholarly journals Energetic and thermal properties of tilt grain boundaries in graphene/hexagonal boron nitride heterostructures

2015 ◽  
Vol 08 (03) ◽  
pp. 1550038 ◽  
Author(s):  
Mingchao Wang ◽  
Guangping Zhang ◽  
Huisheng Peng ◽  
Cheng Yan
Keyword(s):  
Thermal Properties ◽  
Boron Nitride ◽  
Grain Boundaries ◽  
Hexagonal Boron Nitride ◽  
Electronic Devices ◽  
Thermal Conductance ◽  
Interfacial Thermal Conductance ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
Misorientation Angles

Graphene/hexagonal boron nitride (G/h-BN) heterostructure has attracted tremendous research efforts owing to its great potential for applications in nanoscale electronic devices. In such hybrid materials, tilt grain boundaries (GBs) between graphene and h-BN grains may have unique physical properties, which have not been well understood. Here we have conducted non-equilibrium molecular dynamics simulations to study the energetic and thermal properties of tilt GBs in G/h-BN heterostructures. The effect of misorientation angles of tilt GBs on both GB energy and interfacial thermal conductance are investigated.

scholarly journals Atomistic Nodal Approach: a General Molecular Dynamics Method For Computing Local Thermal Conductance at Atomistic Resolution

2021 ◽  
Author(s):  
Mingxuan Jiang ◽  
Juan D. Olarte-Plata ◽  
Fernando Bresme
Keyword(s):  
Molecular Dynamics ◽  
Thermal Transport ◽  
Temperature Drop ◽  
Thermal Conductance ◽  
Fundamental Property ◽  
Lower Surface ◽  
Fluid Interfaces ◽  
Coordination Numbers ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations

The Interfacial Thermal Conductance (ITC) is a fundamental property of materials and has particular relevance at the nanoscale. The ITC quantifies the thermal resistance between materials of different compositions or between fluids in contact with materials. Furthermore, the ITC determines the rate of cooling/heating of the materials and the temperature drop across the interface. Here we propose a method to compute local ITCs and temperature drops of nanoparticle-fluid interfaces. Our approach resolves the ITC at the atomic level using the atomic coordinates of the nanomaterial as nodes to compute local thermal transport properties. We obtain high-resolution descriptions of the interfacial thermal transport by combining the atomistic nodal approach, computational geometry techniques and "computational farming'' using Non-Equilibrium Molecular Dynamics simulations. We illustrate our method by analyzing various nanoparticles as a function of their size and geometry, targeting experimentally relevant structures like capped octagonal rods, cuboctahedrons, decahedrons, rhombic dodecahedrons, cubes, icosahedrons, truncated octahedrons, octahedrons and spheres. We show that the ITC of these very different geometries can be accurately described in terms of the local coordination number of the atoms in the nanoparticle surface. Nanoparticle geometries with lower surface coordination numbers feature higher ITCs, and the ITC generally increases with decreasing particle size.

Molecular Dynamics Simulations of Relaxation and Heat Conduction in One-Dimensional FPU β Lattice

2009 ◽  
Author(s):  
Quan-Wen Hou ◽  
Bing-Yang Cao ◽  
Zeng-Yuan Guo
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Heat Flux ◽  
Heat Conduction ◽  
Relaxation Rate ◽  
Molecular Dynamics Simulations ◽  
One Dimensional ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations ◽  
Non Equilibrium

The phonon relaxation and heat conduction of the Femi-Pasta-Ulam β lattice are studied via molecular dynamics simulations. The phonon relaxation rate is calculated from the energy autocorrelation function for different modes at various temperatures through equilibrium molecular dynamics simulations. The relaxation rate as a function of wave vector k is estimated to be proportional to k1.688, which leads to a N0.41 divergence of the thermal conductivity in the framework of Green-Kubo relation. This result is in agreement with that obtained by non-equilibrium molecular dynamics simulations which estimate the length dependence exponent of thermal conductivity as 0.415. Our results confirm the N2/5 divergence in one-dimensional FPU β lattice. The effect of the heat flux on the thermal conductivity is also studied by imposing large temperature differences on the two ends of the lattice in non-equilibrium molecular dynamics simulations. The results indicate that the thermal conductivity is insensitive to the heat flux under our simulation conditions, and the linear response theory is widely applicable.

Interfacial Thermal Conductance and Thermal Rectification Across In-Plane Graphene/h-BN Heterostructures With Different Bonding Types

2019 ◽  
Author(s):  
Ting Liang ◽  
Ping Zhang ◽  
Peng Yuan ◽  
Man Zhou ◽  
Siping Zhai
Keyword(s):  
Thermal Management ◽  
Thermal Transport ◽  
Strain Distribution ◽  
Hexagonal Boron Nitride ◽  
Thermal Conductance ◽  
Interfacial Stress ◽  
Thermal Rectification ◽  
Nanoelectronic Devices ◽  
Interfacial Thermal Conductance ◽  
Non Equilibrium Molecular Dynamics

Abstract The in-plane graphene/hexagonal boron nitride (Gr/h-BN) heterostructures have received extensive attention in recent years due to their excellent physical properties and the development potential of next-generation nanoelectronic devices. Generally, different bonding types between Gr and h-BN are considered in different non-equilibrium molecular dynamics (NEMD) simulations studies. However, which type of bonding is most conducive to interface thermal transport is still very confusing. In this work, we investigate the interfacial thermal conductance (ITC) and the thermal rectification (TR) in five different bonding types of in-plane Gr/h-BN heterostructures by using NEMD simulations. It is found that the ITC depends strongly on the bonding strength and arrangement of different atoms across the boundary. Among the five different bonding types of heterostructures, the C-N bonded heterojunction exhibits the highest ITC due to its stronger interfacial bonding. The analyses on the strain distribution indicated that a low interfacial stress level at the interface junction, may facilitate the heat conduction, thus leading to a higher ITC. In addition, we found that TR occurs in all five bonded heterostructures, and the C-B bonded heterojunction possesses the highest TR factor. The present study is of significance for understanding the thermal transport behavior of Gr/h-BN heterostructures and promoting their future applications in thermal management and thermoelectric devices.

Spatial control of heat flow at the nanoscale using Janus particles

2021 ◽  
Author(s):  
Juan D. Olarte-Plata ◽  
Jordan Gabriel ◽  
Pablo Albella ◽  
Fernando Bresme
Keyword(s):  
Thermal Conductance ◽  
Fluid Temperature ◽  
Material Interfaces ◽  
Thermal Fields ◽  
Interfacial Thermal Conductance ◽  
Janus Nanoparticles ◽  
Complex Models ◽  
Temperature Contrast ◽  
Non Equilibrium Molecular Dynamics ◽  
Dynamics Simulations

Janus Nanoparticles (JNP) feature heterogeneous compositions bringing opportunities in technological and medical applications. We investigate using non-equilibrium molecular dynamics simulations the temperature field generated around heated spherical Janus Nanoparticles to assess the performance of the particles in the generation of anisotropic heating. We demonstrate that the contrasting interfacial thermal conductances of the fluid-material interfaces arising from the heterogeneous composition of the JNP can be exploited to control the thermal fields around the nanoparticle leading to a temperature difference between both sides of the nanoparticle (temperature contrast) that is significant for particles comprising regions with disparate hydrophilicity. We illustrate this idea using simplified atomistic and complex models of gold nanoparticles passivated with hydrophobic and hydrophilic ligands in water. Furthermore, we introduce a continuum model to predict the temperature contrast as a function of the interfacial thermal conductance and nanoparticle size. We further show that, unlike homogeneous nanoparticles, the interfacial fluid temperature depends on the interfacial thermal conductance of Janus nanoparticles.

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