Zur thermodynamischph�nomenologischen Theorie der Thermodiffusion

Haase, Rolf

doi:10.1007/bf01338979

Cited by 46 publications

(22 citation statements)

References 12 publications

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“…Colloids in a suspension tend to move towards the colder or hotter region, and the direction and magnitude of the Soret response depend on molecular properties such as charge and size [3,4]. Similarly, mixtures of molecules separate in response to a thermal gradient, with molecules moving to the hotter or colder region depending on mass, moment of inertia and intermolecular interactions [5][6][7][8][9]. As such, the Soret effect allows efficient separation of mixtures of nanoscopic particles and biomolecules [10][11][12][13][14][15][16][17].…”

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confidence: 99%

Microscopic mechanism of thermomolecular orientation and polarization

Lee

2016

Soft Matter

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Recent molecular dynamics simulations show that thermal gradients can induce electric fields in water that are comparable in magnitude to electric fields seen in ionic thin films and biomembranes. This surprising non-equilibrium phenomenon of thermomolecular orientation is also observed more generally in simulations of polar and non-polar size-asymmetric dumbbell fluids. However, a microscopic theory linking thermomolecular orientation and polarization to molecular properties is yet unknown. Here, we formulate an analytically solvable microscopic model of size-asymmetric dumbbell molecules in a temperature gradient using a mean-field, local equilibrium approach. Our theory reveals the relationship between the extent of thermomolecular orientation and polarization, and molecular volume, size anisotropy and dipole moment. Predictions of the theory agree quantitatively with molecular dynamics simulations. Crucially, our framework shows how thermomolecular orientation can be controlled and maximized by tuning microscopic molecular properties.

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confidence: 99%

Microscopic mechanism of thermomolecular orientation and polarization

Lee

2016

Soft Matter

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“…3, with the difference that in the present case a miscibility gap exists. Systems of the latter type are discussed by Haase (8).…”

Section: Discussionmentioning

confidence: 99%

THE ISOBARIC BOILING POINTS OF THE SYSTEM: ACETIC ACID – CHLOROFORM – WATER AT A PRESSURE OF 760 mm Hg

Campbell¹,

Gieskes²

1964

Can. J. Chem.

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In previous papers where complete bibliographies are given, Campbejl, Kartzmark, and Gieskes (1) have studied the isothermal vapor pressures a t 25' C, and Campbell and Kartzmark (2) the critical phenomena of the system acetic acid -chloroforrn -water. I t seemed a desirable sequel to the above work to determine the isobaric boiling points under one atmosphere pressure. Little discussion is necessary since the boiling point diagram is largely a consequence of the vapor pressure diagram. Further work is proceeding on the dielectric constants and heats of mixing of this system. EXPERIMENTALPressure was controlled with an accuracy of f 0.02 mm, by means of a two-stage barostat of the type described by Campbell and Dulmage (3). For the study of the liquid-vapor equilibria of the acetic acidchloroform system, we used the equilibrium still of Scatchard, Raymond, and Gillman (4). This still, however, was found not to be satisfactory for the ternary mixtures, because in these mixtures the distillates usually separate into two layers so that no proper equilibrium can be established. For this purpose, therefore, we used the apparatus of Reinders and de Minjer (5); instead of their bell stirrer, we introduced a Scatchard pump. Nevertheless, the accuracy of this apparatus is not high and the boiling temperatures of the ternary system are not more accurate than f 0.5" C. The corresponding accuracy with the Scatchard still is ~0 . 1 " C. Analyses were carried out by the method described by Campbell, Kartzinarlr, and Gieskes (I). Temperatures were measured with a double junction copper-constantan therinocouple and a precision potentiometer with an accuracy of f 0.1" C. The materials Tvere purified by the methods described by Campb~ll, Kartzmark, and-Gieskes (1). When the above figures are plotted in the usual way, the simplest type of boiling point diagram is obtained, without ~naximum or ~ninirnum ; in other words, complete separation of chloroform and acetic acid is possible by fractional distillation. Acetic Acid -Chloroform RESULTS

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“…Their difference Q 1 −Q 2 = T S is related to Eastman's entropy of transfer S introduced above (2). Dissipative aspects have been discussed by identifying Q with Eyring's viscous activation energy E that is defined through the temperature dependence of the viscosity η = η 0 e E/k B T [49][50][51][52]; a similar picture arises when relating Q to partial enthalpies [53], partial volumes [54] or the self-diffusion activation energy [55]. A refined description for the mutual interactions of the molecular species is achieved by introducing thermodynamic or "activity" factors in the chemical potential or the partial pressure [56,57].…”

Section: A Thermostatic Approachmentioning

confidence: 99%

Is Soret equilibrium a non-equilibrium effect?

Würger

2013

Comptes Rendus. Mécanique

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Recent thermophoretic experiments on colloidal suspensions revived an old debate, namely whether the Soret effect is properly described by thermostatics, or necessarily requires nonequilibrium thermodynamics. Based on colloidal transport theory and the entropy production of the related viscous flow, our analysis leads to the conclusion that the equilibrium approach may work for small ions, yet fails for colloidal particles and polymers. Regarding binary molecular mixtures, our results shed some doubt on the validity of thermostatic approaches that derive the Soret coefficient from equilibrium potentials.

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Zur thermodynamischph�nomenologischen Theorie der Thermodiffusion

Cited by 46 publications

References 12 publications

Microscopic mechanism of thermomolecular orientation and polarization

Microscopic mechanism of thermomolecular orientation and polarization

THE ISOBARIC BOILING POINTS OF THE SYSTEM: ACETIC ACID – CHLOROFORM – WATER AT A PRESSURE OF 760 mm Hg

Is Soret equilibrium a non-equilibrium effect?

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