Thermal and structural properties of the liquid-vapor interface in dipolar fluids

Frodl, Peter; Dietrich, S.

doi:10.1103/physreve.48.3741

Cited by 60 publications

(61 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A fluid of dipoles actually lowers its grand potential ⍀͑V , T , ͒ by a nonisotropic orientational distribution in inhomogeneous systems. [69][70][71][72][73][74][75] This leads to a lower surface tension compared to a case where a uniform orientational distribution function is assumed. A further study will have to show whether a simple mean-field assumption to account for the orientational distribution of dipoles, as worked out by Refs.…”

Section: -7mentioning

confidence: 99%

A density functional theory for vapor-liquid interfaces using the PCP-SAFT equation of state

Groß

2009

The Journal of Chemical Physics

107

110

View full text Add to dashboard Cite

A Helmholtz energy functional for inhomogeneous fluid phases based on the perturbed-chain polar statistical associating fluid theory ͑PCP-SAFT͒ equation of state is proposed. The model is supplemented with a capillary wave contribution to the surface tension to account for long-wavelength fluctuations of a vapor-liquid interface. The functional for the dispersive attraction is based on a nonlocal perturbation theory for chain fluids and the difference of the perturbation theory to the dispersion term of the PCP-SAFT equation of state is treated with a local density approximation. This approach suggested by Gloor et al. ͓Fluid Phase Equilib. 194, 521 ͑2002͔͒ leads to full compatibility with the PCP-SAFT equation of state. Several levels of approximation are compared for the nonlocal functional of the dispersive attractions. A first-order non-mean-field description is found to be superior to a mean-field treatment, whereas the inclusion of a second-order perturbation term does not contribute significantly to the results. The proposed functional gives excellent results for the surface tension of nonpolar or only moderately polar fluids, such as alkanes, aromatic substances, ethers, and ethanoates. A local density approximation for the polar interactions is sufficient for carbon dioxide as a strongly quadrupolar compound. The surface tension of acetone, as an archetype dipolar fluid, is overestimated, suggesting that a nonisotropic orientational distribution function across an interface should for strong dipolar substances be accounted for.

show abstract

Section: -7mentioning

confidence: 99%

A density functional theory for vapor-liquid interfaces using the PCP-SAFT equation of state

Groß

2009

The Journal of Chemical Physics

107

110

View full text Add to dashboard Cite

show abstract

“…We approximate the excess free-energy functional in terms of the modified mean-field density functional theory [21][22][23]. Using equation (13) for the present slab-like geometry, one obtains the following expression:…”

Section: The Excess Free-energy Functionalmentioning

confidence: 99%

Phase transitions and ordering of confined dipolar fluids

Szalai

Dietrich

2009

Eur. Phys. J. E

Self Cite

View full text Add to dashboard Cite

Abstract. We apply a modified mean-field density functional theory to determine the phase behavior of Stockmayer fluids in slit-like pores formed by two walls with identical substrate potentials. Based on the Carnahan-Starling equation of state, a fundamental-measure theory is employed to incorporate the effects of short-ranged hard-sphere-like correlations while the long-ranged contributions to the fluid interaction potential are treated perturbatively. The liquid-vapor, ferromagnetic-liquid-vapor, and ferromagneticliquid-isotropic-liquid first-order phase separations are investigated. The local orientational structure of the anisotropic and inhomogeneous ferromagnetic liquid phase is also studied. We discuss how the phase diagrams are shifted and distorted upon varying the pore width.

show abstract

“…17 and 20 and consider only two terms in the expansion of ␣(z, ) with respect to Legendre polynomials. The two terms are needed at least because ␣ 1 is zero in the absence of the external field [17][18][19]21 and in that case ␣ 2 will provide the leading contribution to the angular dependence of the density distribution function. Using Eq.…”

Section: Density Functional Theory Of Dipolar Fluidmentioning

confidence: 99%

“…Using the MMF density-functional theory Talanquer and Oxtoby 19 studied the vapor-liquid nucleation of the Stockmayer fluid. To investigate the interfacial properties of strongly dipolar fluids, Frodl and Dietrich 20,21 developed a more sophisticated density-functional approach without using the expansion of the grand canonical potential. They showed that when the reduced dipole moment is less than 1 ͑weakly dipolar͒, the MMF theory 17 gives reasonably good results compared to their theory ͑e.g., the discrepancy in the critical temperature is less than 10%͒.…”

Section: Introductionmentioning

confidence: 99%

Effects of external electric field on the interfacial properties of weakly dipolar fluid

Warshavsky

Bykov

Zeng

2001

The Journal of Chemical Physics

View full text Add to dashboard Cite

In the framework of modified mean-field density-functional theory, effects of a uniform electric field on the interfacial properties of a model dipolar fluid ͓Teixeira and Telo da Gama, J. Phys.: Condens. Matter 3, 111 ͑1991͔͒ are studied. Both density and orientational order-parameter profiles of the planar vapor-liquid interface are obtained as a function of the field strength. For the dipolar fluids with reduced dipole moment 0 *р1, we find that the field ͑under the condition 0 *E*/T*Ӷ1͒ can shift the surface tension by few percent. We also find that the electric field actually reduces the thermodynamical surface tension but enhances the mechanical surface tension at the equimolar dividing surface. To detect these field effects on the surface tension we estimate the field strength which can be as high as 10 8 V/m.

show abstract

Thermal and structural properties of the liquid-vapor interface in dipolar fluids

Cited by 60 publications

References 30 publications

A density functional theory for vapor-liquid interfaces using the PCP-SAFT equation of state

A density functional theory for vapor-liquid interfaces using the PCP-SAFT equation of state

Phase transitions and ordering of confined dipolar fluids

Effects of external electric field on the interfacial properties of weakly dipolar fluid

Contact Info

Product

Resources

About