Phase behaviour of short range triangle well fluids: A comparison with lysozyme suspensions

- The phase coexistence of colloidal suspensions is studied by REMC simulations.
- Liquid-vapor coexistences are found at temperatures close to critical one.
- For low temperatures a vapor-solid coexistence appears.
- Coexistence curves are compared with experimental data for protein suspensions.

The phase coexistence of colloidal suspensions is studied by Monte Carlo Replica Exchange (REMC) simulations using an attractive triangle potential model of short range (1.15σ ≤ λ ≤ 1.4) in a wide temperature range. Typical liquid-vapor coexistences are found at temperatures close to the critical one, while for lower temperatures the liquid-vapor metastability is broken in favor of the vapor-solid coexistence. Structural properties are accessed through the radial distribution function and the global order parameter. The formation of a solid phase with structure belonging to the close-packed family is shown. The coexistence curves are plotted in reduced coordinates and compared with those experimentally obtained for protein suspensions (lysozyme aqueous suspensions with additives). A good qualitative agreement between experimental data and simulation results is found.