Vapour-liquid critical parameters of a 2:1 primitive model of ionic fluids confined in disordered porous media

Abstract

We study the vapour-liquid critical parameters of an ionic fluid confined in a disordered porous medium by using the theory which combines the collective variables approach with an extension of the scaled particle theory. The ionic fluid is described as a two-component charge-and sizeasymmetric primitive model, and a porous medium is modelled as a disordered matrix formed by hard-spheres obstacles. In the particular case of the fixed valencies 2:1, the coexistence curves and the corresponding critical parameters are calculated for different matrix porosities as well as for different diameters of matrix and fluid particles. The obtained results show that the general trends of the reduced critical temperature and the reduced critical density with the microscopic characteristics are similar to the trends obtained in the monovalent case. At the same time, it is noticed that an ion charge asymmetry significantly weakens the effect of the matrix presence.

Phase behavior of patchy colloids confined in patchy porous media

“…In particular, a fluid of hard spheres confined in the hard-sphere matrix was used as a reference system in the framework of the Barker–Henderson perturbation theory, 83,84 high-temperature approximation, 85 Wertheim's thermodynamic perturbation theory (TPT), 81,86–89 associative mean spherical approximation 90–93 and the collective variable method. 94–96…”

“…In particular, a fluid of hard spheres confined in the hard-sphere matrix was used as a reference system in the framework of the Barker-Henderson perturbation theory, 83,84 high-temperature approximation, 85 Wertheim's thermodynamic perturbation theory (TPT), 81,[86][87][88][89] associative mean spherical approximation [90][91][92][93] and the collective variable method. [94][95][96] In the current paper we propose a simple model for functionalized disordered porous media and study the effects of confinement on the clusterization, percolation and phase behavior of a fluid of patchy particles. The media are represented by the disordered matrix of the hard-sphere obstacles bearing a certain number of off-center square-well sites ( patches).…”

Clustering effects on the diffusion of patchy colloids in disordered porous media

“…The SPT2 approach was generalized for fluids of anisotropic particles [17,18], for a hard sphere mixture [19], for a mixture of hard spheres and anisotropic particles [20] in disordered porous media. The obtained results were also used as a reference system to take into account the attractive [21,22], the associative [2] and Coulomb [23][24][25][26][27] interactions. The SPT2 approach is useful not only for the description of thermodynamic properties, but it can be also applied for the description of the static structure of hard sphere fluids in disordered porous media.…”