Rescaled density expansions and demixing in hard-sphere binary mixtures



Downloads per month over past year

López de Haro, M. and Fernández Tejero, Carlos (2004) Rescaled density expansions and demixing in hard-sphere binary mixtures. Journal of Chemical Physics, 121 (14). pp. 6918-6921. ISSN 0021-9606

[thumbnail of F-Tejero03libre.pdf]

Official URL:


The demixing transition of a binary fluid mixture of additive hard spheres is analyzed for different size asymmetries by starting from the exact low-density expansion of the pressure. Already within the second virial approximation the fluid separates into two phases of different composition with a lower consolute critical point. By successively incorporating the third, fourth, and fifth virial coefficients, the critical consolute point moves to higher values of the pressure and to lower values of the partial number fraction of the large spheres. When the exact low-density expansion of the pressure is rescaled to higher densities as in the Percus-Yevick theory, by adding more exact virial coefficients a different qualitative movement of the critical consolute point in the phase diagram is found. It is argued that the Percus-Yevick factor appearing in many empirical equations of state for the mixture has a deep influence on the location of the critical consolute point, so that the resulting phase diagram for a prescribed equation has to be taken with caution.

Item Type:Article
Additional Information:

© 2004 American Institute of Physics. The authors acknowledge financial support from DGAPA-UNAM (México) (M.L.H.) and from the Ministerio de Ciencia y Tecnología (Spain) Ref. BFM2001-1017- C03-03 (C.F.T.).

Uncontrolled Keywords:Pair correlation-functions; Equation-of-state; Virial-coefficients; Thermodynamic properties; Phase-separation; Convex-bodies; Fluids; Gases
Subjects:Sciences > Physics > Thermodynamics
ID Code:23735
Deposited On:02 Dec 2013 11:10
Last Modified:24 Feb 2015 12:01

Origin of downloads

Repository Staff Only: item control page