Regensburg 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 6: Colloids and Complex Fluids II (joint session BP/CPP/DY, organized by CPP)

CPP 6.3: Vortrag

Montag, 7. März 2016, 10:15–10:30, H51

Free energies, liquid and crystal phases of the Asakura--Oosawa model: a density functional theory study — •Mostafa Mortazavifar and Martin Oettel — Institut für Angewandte Physik, Uni Tübingen, Tübingen, Germany

The Asakura--Oosawa(AO) model is a well known model for studying colloid--polymer mixtures in which the depletion interaction between colloidal particles results in a phase diagram similar to molecular liquids. More importantly, it is a generic model system for short range attractive colloidal particles. We have studied the model by means of density functional theory (DFT) by applying a linearization of a two--component fundamental measure hard sphere tensor functional with respect to the second (polymer) component. The linearized functional gives a unified description of gas, liquid, and crystal phases. We have calculated the free energies and phase diagrams for a variety of colloid--polymer size ratios. The results are in good agreement with available simulations. For small size ratios, the model can be mapped exactly to a one--component system with a short--range attractive potential between the colloids. Standard mean field approximations fail in describing the liquid and crystal phases; here our functional offers novel insights how to construct generically density functional descriptions of interparticle attractions.