Phase behavior and percolation properties of the primitive model of Laponite suspension. TPT of Wertheim with ISM reference system

Abstract

Computation of the properties of associative fluids with the particles highly anisotropic in shape, using multi-density perturbation theory of Wertheim, has long been a challenge. We propose a simple and efficient scheme that allow us to perform such computations. The scheme is based on a combination of thermodynamic perturbation theory and the interaction site model approach for molecular fluids due to Chandler and Andersen. Our method is illustrated by its application to calculation of the phase diagram and percolation properties of a primitive model of Laponite suspension proposed recently.

Figures (3)

• Figure 1: $\Delta V_{PY}$ (lines) and $\Delta V_{RISM-PY}$ (symbols) vs density $\rho^*$ at $d=0.5\sigma$ (black line and squares), $d=0.45\sigma$ (red line and circles) and $d=0.4\sigma$ (blue lines and triangles)
• Figure 2: Schematic representation of the primitive model of Laponite nanoparticles. Here square-well sites are denoted as $A$ (red) and $B$ (blue) and hard-sphere sites are denoted as $C,D,E,F$ (black).
• Figure 3: Phase diagram and percolation threshold line of the primitive model of Laponit suspension in the $T^*$ vs $\rho^*$ coordinate frame. Here, the black lines and filled black circles represent theoretical results, the red circles represent computer simulation results ruzicka2011observation and the filled black circles mark the critical point. The percolation threshold line is marked by black lines. The inset in the figure shows the phase diagram and percolation threshold line in $T^*$ vs $m_{av}$ coordinate frame.