Theory for systems with spontaneous inhomogeneities on a mesoscopic length scale

Expositor:  Alina Ciach – Institute of Physical Chemistry, Polish Academy of Sciences.

Fecha: Martes 07/05/2019 – 11:00 AM

In the talk, I’ll first present examples of different experimental systems with inhomogeneities on a mesoscopic length scale. Next, a generic shape of competing interactions between spherical particles leading to self-assembly will be discussed, and self-assembled structures obtained from simulation studies will be presented. The phase diagrams in the systems with competing short-range attraction and long-range repulsion, and in the amphiphilic systems show striking similarity. I’ll introduce a theory explaining the origin of this universal behavior. Within our theory, effects of fluctuations on the phase equilibria can be taken into account and the discrepancy between the mean-field (MF) and simulation results can be corrected. It should be noted that in simple fluids the MF approximation leads to predictions that are qualitatively correct, while in the case of spontaneous inhomogeneities, the topology of the phase diagram obtained in MF and in simulations is different at high T. It means that fluctuations in inhomogeneous systems play a more important role than in simple fluids. If time allows, striking low -T anomalies and effects of confinement predicted by simple model systems will be presented.