Effect of Phase Transition on the Thermal Transport in Isoreticular DUT Materials

Abnormal Effect of Phase Transition on Thermal Transport in Soft Porous Crystals

10.26434/chemrxiv.14229134.v2 ◽

2021 ◽

Author(s):

Penghua Ying ◽

Jin Zhang ◽

Zheng Zhong

Keyword(s):

Phase Transition ◽

Thermal Conductivity ◽

Thermal Transport ◽

Structural Integrity ◽

Gas Adsorption ◽

Phonon Scattering ◽

Current Knowledge ◽

Parent Phase ◽

Mechanical Pressure ◽

Thermal Transport Property

Soft porous crystals (SPCs) can undergo large-amplitude phase transitions under external stimulus such as mechanical pressure, gas adsorption, and temperature while retaining their structural integrity. During the gas adsorption process, the generated latent heat is needed to be effectively removed. Thus, understanding the effect of phase transition on the thermal transport in SPCs becomes extremely important for their applications in storage and separation applications. In this paper, taking isorecticular DUT series as an example, the evolution of the thermal transport in SPCs during the phase transition from the large pore (lp) phase to the narrow pore (np) phase is comprehensively investigated by molecular dynamics (MD) simulations together with the Green-Kubo method. After the phase transition, an abnormal thermal transport property is found in the np phase of DUT materials. We find that although the transformed np phase of DUT-48 has a density much larger than its parent phase, the thermal conductivity of its np phase is smaller than its lp phase. This result is in contrast to the previous finding that SPCs with larger density possess a larger thermal conductivity. However, as for other DUT crystals including DUT-47, DUT-49, DUT-50, and DUT-151, the np phase is found to have a higher thermal conductivity than their lp phase counterpart, which is in accordance with the previous finding. This complicated effect of phase transition on thermal transport in SPCs can be explained by the porosity-dominated competition mechanism between the increased volumetric heat capacity and the aggravated phonon scattering during the phase transition process. Overall, the finding extracted from the present study can greatly expand current knowledge about the thermal conductivity of metal-organic frameworks that is previously found to grow usually with increasing porosity.

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Optimized Design of Composite Materials for Heat Transport Applications

Volume 8: Mechanics of Solids, Structures and Fluids; Vibration, Acoustics and Wave Propagation ◽

10.1115/imece2011-65299 ◽

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.

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Tuning the Thermal Transport Properties of Graphene via Nanoconstriction Network

Volume 1: Micro/Nanofluidics and Lab-on-a-Chip; Nanofluids; Micro/Nanoscale Interfacial Transport Phenomena; Micro/Nanoscale Boiling and Condensation Heat Transfer; Micro/Nanoscale Thermal Radiation; Micro/Nanoscale Energy Devices and Systems ◽

10.1115/mnhmt2016-6646 ◽

2016 ◽

Author(s):

Bing-Yang Cao ◽

Wen-Jun Yao

Keyword(s):

Thermal Transport ◽

Three Dimensional ◽

Series System ◽

Two Dimensional ◽

Thermal Transport Property ◽

Ballistic Resistance ◽

Potential Applications ◽

In Series ◽

Dynamics Simulations ◽

Superimposed Effect

With the molecular dynamics simulations, we found that the nanoconstriction resistance arising from the single-constriction is inversely proportional to the constriction width, which can be well described by the two-dimensional ballistic resistance model we proposed. More importantly, after the nanoconstrictions are networked, the results elucidate a parallel relationship between ballistic resistances in parallel system, weather the constrictions are of equal width or not, and especially, a complicated superimposed effect of arrangement mode on ballistic resistances in series system, which could cause a decrease or further increase in the ballistic resistance. Thus, with the networked nanoconstrictions method, the thermal transport property of graphene could be tuned over a wider range. And we believe this route will effectively expand potential applications of two-dimensional graphene and also pave the way for three-dimensional materials in the future.

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Abnormal Effect of Phase Transition on Thermal Transport in Soft Porous Crystals

10.26434/chemrxiv.14229134 ◽

2021 ◽

Author(s):

Penghua Ying ◽

Jin Zhang ◽

Zheng Zhong

Keyword(s):

Phase Transition ◽

Thermal Conductivity ◽

Thermal Transport ◽

Work Performance ◽

Structural Integrity ◽

Phonon Scattering ◽

Dynamic Features ◽

Mechanical Pressure ◽

Wide Range ◽

Abnormal Effect

Soft porous crystals (SPCs) have attracted a lot of attention recently due to their great potential for a wide range of gas storage and separation applications. They can undergo large-amplitude phase transitions under external stimulus such as mechanical pressure, gas adsorption, and temperature while retaining their structural integrity. However, the thermal conductivity of SPCs is usually very low, owing to the porous structure and weak coordination bond, which would heavily influence their work performance. Hence, understanding the thermal transport in SPCs especially considering their dynamic features becomes extremely crucial. In this paper, taking the isorecticular DUT series as an example, the effect of phase transition from the large pore (lp) phase to narrow pore phase (np) on thermal transport in SPCs is comprehensively investigated by molecular dynamics (MDs) simulation together with the Green-Kubo method. According to our calculations, all DUT structures exhibit an ultralow thermal conductivity (). Specifically, we demonstrate here that the np phase of DUT-48 crystal after phase transition has a larger density but owns a smaller thermal conductivity. This abnormal effect of phase transition is in contrast to the previous finding that the SPCs with larger density possess a larger thermal conductivity. For other DUT crystals including DUT-47, DUT-49, DUT-50, and DUT-151, the np phase is found to have a higher thermal conductivity than their lp phase counterpart, which are as expected. This complicated effect of phase transition on thermal transport in SPCs can be explained by a porosity-dominated competition mechanism between the increased volumetric heat capacity and the aggravated phonon scattering during the phase transition process. This finding is expected to fill the gap in understanding the complicated effect of phase transition on the thermal transport in SPCs.

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Abnormal Effect of Phase Transition on Thermal Transport in Soft Porous Crystals

10.26434/chemrxiv.14229134.v1 ◽

2021 ◽

Author(s):

Penghua Ying ◽

Jin Zhang ◽

Zheng Zhong

Keyword(s):

Phase Transition ◽

Thermal Conductivity ◽

Thermal Transport ◽

Work Performance ◽

Structural Integrity ◽

Phonon Scattering ◽

Dynamic Features ◽

Mechanical Pressure ◽

Wide Range ◽

Abnormal Effect

Soft porous crystals (SPCs) have attracted a lot of attention recently due to their great potential for a wide range of gas storage and separation applications. They can undergo large-amplitude phase transitions under external stimulus such as mechanical pressure, gas adsorption, and temperature while retaining their structural integrity. However, the thermal conductivity of SPCs is usually very low, owing to the porous structure and weak coordination bond, which would heavily influence their work performance. Hence, understanding the thermal transport in SPCs especially considering their dynamic features becomes extremely crucial. In this paper, taking the isorecticular DUT series as an example, the effect of phase transition from the large pore (lp) phase to narrow pore phase (np) on thermal transport in SPCs is comprehensively investigated by molecular dynamics (MDs) simulation together with the Green-Kubo method. According to our calculations, all DUT structures exhibit an ultralow thermal conductivity (). Specifically, we demonstrate here that the np phase of DUT-48 crystal after phase transition has a larger density but owns a smaller thermal conductivity. This abnormal effect of phase transition is in contrast to the previous finding that the SPCs with larger density possess a larger thermal conductivity. For other DUT crystals including DUT-47, DUT-49, DUT-50, and DUT-151, the np phase is found to have a higher thermal conductivity than their lp phase counterpart, which are as expected. This complicated effect of phase transition on thermal transport in SPCs can be explained by a porosity-dominated competition mechanism between the increased volumetric heat capacity and the aggravated phonon scattering during the phase transition process. This finding is expected to fill the gap in understanding the complicated effect of phase transition on the thermal transport in SPCs.

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Thermal Transport Property of Novel Two-dimensional Nitride Phosphorus: an ab initio Study

Applied Surface Science ◽

10.1016/j.apsusc.2021.149463 ◽

2021 ◽

pp. 149463

Author(s):

Bing Lv Calculation ◽

Xiaona Hu ◽

Ning Wang ◽

Jia Song ◽

Xuefei Liu ◽

...

Keyword(s):

Ab Initio ◽

Transport Property ◽

Thermal Transport ◽

Two Dimensional ◽

Ab Initio Study ◽

Thermal Transport Property

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

ASME 2009 InterPACK Conference, Volume 1 ◽

10.1115/interpack2009-89272 ◽

2009 ◽

Cited By ~ 4

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.

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