Condensed Matter Physics, 2014, vol. 17, No. 4, 43004
DOI:10.5488/CMP.17.43004
arXiv:1408.5755
Title:
Gasliquid phase equilibrium in ionic fluids: Coulomb versus nonCoulomb interactions
Author(s):

O. Patsahan
(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii St., 79011 Lviv, Ukraine)

Using the collective variables theory, we study the effect of competition between Coulomb and dispersion forces on the gasliquid phase behaviour of a model ionic fluid, i.e. a chargeasymmetric primitive model with additional shortrange attractive interactions. Both the critical parameters and the coexistence envelope are calculated in a oneloop approximation as a function of the parameter α measuring the relative strength of the Coulomb to shortrange interactions. We found the very narrow region of α bounded from the both sides by tricritical points which separates the models with "nonionic" and "Coulombic" phase behaviour. This is at variance with the result of available computer simulations where no tricritical point is found for the finelydiscretized lattice version of the model.
Key words:
ionic fluids, gasliquid phase diagram, tricritical point, Coulomb interactions, shortrange attraction
PACS:
05.70.Fh, 64.60.De, 64.60.Kw
