MIXTURES OF SPHERICAL COLLOIDS AND RODLIKE POLYMERS

Fluid-fluid phase separation in a simple model for a colloid dispersed in a solution of stiff rodlike polymers is studied by means of Gibbs-Ensemble Monte Carlo simulations. The fluid-solid transition for this model is computed using first-order perturbation theory. The phase diagrams clearly show that a stable critical point is not possible for polymer lengths smaller than 30% of the colloidal particle diameter. For very large polymers, the phase diagram can be derived directly from the hard sphere equation of state.

• Introduction
• Simulations
  • Configurational Bias Monte Carlo in the Gibbs-Ensemble
  • Fluid-fluid coexistence
  • Solid-fluid transition
• Theory
  • Perturbation theory
  • The limit
  • Comparison with simulation results
• Discussion