Thermal diffusion sensitivity to the molecular parameters of a binary equimolar mixture, a non-equilibrium molecular dynamics approach

Galliéro, Guillaume; Duguay, B.; Caltagirone, Jean‐Paul; Montel, François

doi:10.1016/s0378-3812(03)00030-x

Cited by 82 publications

(121 citation statements)

References 29 publications

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“…Our code has shown to yield consistent values for noble gases and for simple alkane mixtures compared to experimental ones found in literature [9,17].…”

Section: Models and Methods Usedsupporting

confidence: 78%

“…where (9) and function z is a characteristic function of the transport property [11], m i being the molecular mass of component i. Nevertheless, when applied on real fluids, this scheme is appropriate for simple species only (e.g.…”

Section: Models and Methods Usedmentioning

confidence: 99%

“…This is particularly true when dealing with experimentally inaccessible thermodynamics conditions or with weak phenomena such as thermal diffusion. In particular, molecular dynamics reveals itself to be a useful tool to improve our understanding of the physical processes that govern this transport phenomenon [2,[6][7][8][9] which is a compulsory step to build reliable correlations based on the law of the corresponding states [10] for simple mixtures.…”

Section: Introductionmentioning

confidence: 99%

“…Then, following previous works [9,13], we have defined the relevant variables that correlate the thermal diffusion factor to the various molecular parameters in equimolar mixture. It is shown that these various contributions can be combined into a single relation taking into account the couplings.…”

Section: Introductionmentioning

confidence: 99%

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Thermal diffusion in Lennard–Jones fluids in the frame of the law of the corresponding states

Galliéro¹

2004

Fluid Phase Equilibria

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This work is related to the definition of a reduced thermal diffusion coefficient thanks to numerical microscale molecular dynamics simulations. This cross transport process, also called Soret effect, couples mass flux and thermal gradient and is still largely misunderstood. For this study, we have applied a boundary driven non equilibrium molecular dynamics algorithm on Lennard-Jones spheres mixtures. Simulations have been performed at a constant reduced supercritical state, using a van der Waals one fluid approximation in order to fulfil the law of the corresponding states. In binary mixtures, we have studied the molecular parameters and the molar fraction influences on thermal diffusion separately and then combined. It is shown that, on pressure and on thermal conductivity, the corresponding states law is fulfilled for a wide range of molecular 2 parameters ratios. In this frame, we have then constructed simple correlations which relate thermal diffusion factor to the mixture parameters. Combining the relations obtained, a reduced thermal diffusion factor taking into account all the various contributions has been defined. Finally, it is shown that this relation enables us to estimate thermal diffusion in various binary and ternary mixtures of Lennard-Jones spheres representing alkanes with a maximum deviation of 15 %.

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“…Our code has shown to yield consistent values for noble gases and for simple alkane mixtures compared to experimental ones found in literature [9,17].…”

Section: Models and Methods Usedsupporting

confidence: 78%

Section: Models and Methods Usedmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Thermal diffusion in Lennard–Jones fluids in the frame of the law of the corresponding states

Galliéro¹

2004

Fluid Phase Equilibria

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“…In the first group of mixtures the component with the larger mass or higher density moves to the cold side, and this effect becomes stronger if the components are less miscible [18][19][20][21] . This empirical observations still hold for some mixtures from the second group 18 such as benzene/carbon tetrachloride 22 and cyclohexane/carbon tetrachloride 23 while for systems benzene/cyclohexane 24 and benzene/alkanes 25 this approach fails.…”

Section: Introductionmentioning

confidence: 99%

Systematic study of the thermal diffusion in associated mixtures

Polyakov

Wiegand

2008

The Journal of Chemical Physics

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We performed systematic temperature and concentration dependent measurements of the Soret coefficient in different associated binary mixtures of water, deuterated water, dimethyl sulfoxide (DMSO), methanol, ethanol, acetone, methanol, 1-propanol, 2-propanol, propionaldehyde using the so called thermal diffusion forced Rayleigh scattering method. For some of the associating binary mixtures such as ethanol/water, acetone/water and DMSO/water the concentration x ± w at which the Soret coefficient changes its sign does not depend on temperature and is equal to the concentration x × w where the Soret coefficient isotherms intersect. While for others such as 1-propanol/water, 2-propanol/water and ethanol/DMSO the sign change concentration is temperature dependent, which is the typical behavior observed for non-associating mixtures. For systems with x ± w = x × w we found that x ± w depends linearly on the ratio of the vaporization enthalpies of the pure components. Probably due to the similarity of methanol and DMSO we do not observe a sign change for this mixture. The obtained results are related to structural changes in the fluid observed by nuclear magnetic resonance, mass specrometric and X-ray experiments in the literature. Furthermore we discuss the influence of hydrophilic and hydrophobic interactions and the solubility on thermal diffusion behavior.

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Predicting and Rationalizing the Soret Coefficient of Binary Lennard‐Jones Mixtures in the Liquid State

Zimmermann

Guevara‐Carrion

Vrabec

et al. 2022

Advcd Theory and Sims

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The thermodiffusion behavior of binary Lennard‐Jones mixtures in the liquid state is investigated by combining the individual strengths of non‐equilibrium molecular dynamics (NEMD) and equilibrium molecular dynamics (EMD) simulations. On the one hand, boundary‐driven NEMD simulations are useful to quickly predict Soret coefficients because they are easy to set up and straightforward to analyze. However, careful interpolation is required because the mean temperature in the measurement region does not exactly reach the target temperature. On the other hand, EMD simulations attain the target temperature precisely and yield a multitude of properties that clarify the microscopic origins of Soret coefficient trends. An analysis of the Soret coefficient suggests a straightforward dependence on the thermodynamic properties, whereas its dependence on dynamic properties is far more complex. Furthermore, a limit of applicability of a popular theoretical model, which mainly relies on thermodynamic data, was identified by virtue of an uncertainty analysis in conjunction with efficient empirical Soret coefficient predictions, which rely on model parameters instead of simulation output. Finally, the present study underscores that a combination of predictive models and EMD and NEMD simulations is a powerful approach to shed light onto the thermodiffusion behavior of liquid mixtures.

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Thermal diffusion sensitivity to the molecular parameters of a binary equimolar mixture, a non-equilibrium molecular dynamics approach

Cited by 82 publications

References 29 publications

Thermal diffusion in Lennard–Jones fluids in the frame of the law of the corresponding states

Thermal diffusion in Lennard–Jones fluids in the frame of the law of the corresponding states

Systematic study of the thermal diffusion in associated mixtures

Predicting and Rationalizing the Soret Coefficient of Binary Lennard‐Jones Mixtures in the Liquid State

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