Thermodynamic stability of fluid-fluid phase separation in binary athermal mixtures: The role of nonadditivity

Details Thermodynamic stability of fluid-fluid phase separation in binary athermal mixtures: The role of nonadditivity Thermodynamic stability of fluid-fluid phase separation in binary athermal mixtures: The role of nonadditivity

2006-01-12

arxiv.org/abs/cond-mat/0601250v1

The Journal of Physical Chemistry B 110, 4359-4364 (2006)

Physics

Condensed Matter

Soft Condensed Matter

17 pages, 7 figures, to appear in J. Phys. Chem. B

Scientific paper

10.1021/jp056039d

We study the thermodynamic stability of fluid-fluid phase separation in binary nonadditive mixtures of hard-spheres for moderate size ratios. We are interested in elucidating the role played by small amounts of nonadditivity in determining the stability of fluid-fluid phase separation with respect to the fluid-solid phase transition. The demixing curves are built in the framework of the modified-hypernetted chain and of the Rogers-Young integral equation theories through the calculation of the Gibbs free energy. We also evaluate fluid-fluid phase equilibria within a first-order thermodynamic perturbation theory applied to an effective one-component potential obtained by integrating out the degrees of freedom of the small spheres. A qualitative agreement emerges between the two different approaches. We also address the determination of the freezing line by applying the first-order thermodynamic perturbation theory to the effective interaction between large spheres. Our results suggest that for intermediate size ratios a modest amount of nonadditivity, smaller than earlier thought, can be sufficient to drive the fluid-fluid critical point into the thermodinamically stable region of the phase diagram. These findings could be significant for rare-gas mixtures in extreme pressure and temperature conditions, where nonadditivity is expected to be rather small.

Affiliated with

Also associated with

No associations

Rating

Thermodynamic stability of fluid-fluid phase separation in binary athermal mixtures: The role of nonadditivity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Thermodynamic stability of fluid-fluid phase separation in binary athermal mixtures: The role of nonadditivity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermodynamic stability of fluid-fluid phase separation in binary athermal mixtures: The role of nonadditivity will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-495576