Thermal transport across nanoparticle–fluid interfaces: the interplay of interfacial curvature and nanoparticle–fluid interactions

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.

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

Scientific Reports ◽

10.1038/s41598-021-04740-4 ◽

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.

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Prediction and Measurement of Thermal Transport Across Interfaces Between Isotropic Solids and Graphitic Materials

ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels: Parts A and B ◽

10.1115/fedsm-icnmm2010-30171 ◽

2010 ◽

Author(s):

Pamela M. Norris ◽

Justin L. Smoyer ◽

John C. Duda ◽

Patrick E. Hopkins

Keyword(s):

Thermal Transport ◽

Substrate Surface ◽

Unit Length ◽

Thermal Conductance ◽

Thin Film Deposition ◽

Film Deposition ◽

Transport Models ◽

Composite Systems ◽

Graphene Flakes ◽

Isotropic Solids

Due to the high intrinsic thermal conductivity of carbon allotropes, there have been many attempts to incorporate such structures into existing thermal abatement technologies. In particular, carbon nanotubes (CNTs) and graphitic materials (i.e., graphite and graphene flakes or stacks) have garnered much interest due to the combination of both their thermal and mechanical properties. However, the introduction of these carbon-based nanostructures into thermal abatement technologies greatly increases the number of interfaces per unit length within the resulting composite systems. Consequently, thermal transport in these systems is governed as much by the interfaces between the constituent materials as it is by the materials themselves. This paper reports the behavior of phononic thermal transport across interfaces between isotropic thin films and graphite substrates. Elastic and inelastic diffusive transport models are formulated to aid in the prediction of conductance at a metal-graphite interface. The temperature dependence of the thermal conductance at Au-graphite interfaces is measured via transient thermoreflectance from 78 to 400 K. It is found that different substrate surface preparations prior to thin film deposition have a significant effect on the conductance of the interface between film and substrate.

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Thermal Transport Across Carbon Nanotube Connected by Molecular Linkers

Volume 10: Heat and Mass Transport Processes, Parts A and B ◽

10.1115/imece2011-64931 ◽

2011 ◽

Author(s):

Jun Liu ◽

Mohamed Alhashme ◽

Ronggui Yang

Keyword(s):

Thermal Transport ◽

Large Scale ◽

Normal Modes ◽

Thermal Conductance ◽

Nonequilibrium Molecular Dynamics ◽

Practical Application ◽

The Past ◽

Interfacial Thermal Conductance ◽

Macro Scale ◽

Different Types

Carbon nanotubes (CNTs) have been reported to have excellent thermal and mechanical properties over the past two decades. However, the practical application of CNT-based technologies has been limited, due to the inability to transform the excellent properties of single CNTs into macroscopic applications. CNT network structure connects CNTs and can be possibly scaled up to macro-scale CNT-based application. In this paper, nonequilibrium molecular dynamics is applied to investigate thermal transport across two CNTs connected longitudinally by molecular linkers. We show the effect of different types and lengths of molecular linkers on interfacial thermal conductance. We also analyze the density of vibrational normal modes to further understand the interfacial thermal conductance between different molecular linkers and CNTs. These results provide guidance for choosing molecular linkers to build up large-scale CNT-based network structures.

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Thermal Contact Resistance of a Silicon Nanowire on a Substrate

ASME 2007 InterPACK Conference, Volume 2 ◽

10.1115/ipack2007-33431 ◽

2007 ◽

Author(s):

Dhruv Singh ◽

Timothy S. Fisher ◽

Jayathi Y. Murthy

Keyword(s):

Contact Resistance ◽

Thermal Transport ◽

Thermal Contact Resistance ◽

Silicon Nanowire ◽

Thermal Contact ◽

Thermal Conductance ◽

Boltzmann Transport ◽

Constriction Resistance ◽

The Wire ◽

Volume Method

Increased interest in determining the thermal contact resistance encountered in various nanoscale devices derives from its role as a critical bottleneck to thermal transport at submicron scales. In the present work, the contact resistance of one such configuration — a silicon nanowire on a Si substrate — has been studied. A model based on the phonon Boltzmann transport equation (BTE) in the solid and Fourier conduction in the surrounding gas is used, in conjunction with a previously published finite volume method. This approach enables the accurate computation and examination of the relative magnitudes of constriction resistance, air thermal resistances, and the bulk resistance of the wire on transverse heat transport. The results confirm that the effective resistance is dominated by constriction resistance even for low and moderate wire acoustic thicknesses and that the constriction resistance is well represented by ballistic-limit models. In the mesoscale regime when the constriction is partially diffusive, a simple addition of diffusive and ballistic resistances is shown to work reasonably well, in agreement with previously published estimates. For higher wire acoustic thicknesses, the effects of bulk scattering in the wire cannot be ignored and a simple additive formula is inadequate. The fluid surrounding the wire can act as a complementary parallel pathway for thermal transport; however, in the high gas-phase Knudsen regime, the constriction resistance remains the controlling factor for overall thermal conductance.

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

10.33774/chemrxiv-2021-fz10d ◽

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.

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

10.26434/chemrxiv.13125752.v1 ◽

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.

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Factors influencing thermal transport across graphene/metal interfaces with van der Waals interactions

Nanoscale ◽

10.1039/c9nr03538a ◽

2019 ◽

Vol 11 (30) ◽

pp. 14155-14163 ◽

Cited By ~ 4

Author(s):

Haiying Yang ◽

Yunqing Tang ◽

Ping Yang

Keyword(s):

Green’S Function ◽

Green's Function ◽

Thermal Transport ◽

Van Der Waals ◽

Thermal Conductance ◽

Van Der Waals Interactions ◽

Factors Influencing ◽

Metal Interfaces ◽

Non Equilibrium Green’S Function ◽

Non Equilibrium

We implement non-equilibrium Green's function (NEGF) calculations to investigate thermal transport across graphene/metal interfaces with interlayer van der Waals interactions to understand the factors influencing thermal conductance across the interface.

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