Soft Matter and Complex Systems Seminar

I will present theoretical and simulation results for a mixture of oppositely charged hydrophilic and hyrophobic particles immersed in a near-critical binary solvent. In such a mixture, the potential between like particles can have the form of short-range attraction long-range repulsion, and the cross-interaction is repulsive at short- and attractive at large distances. A theory combining the density functional and field-theoretical methods and the MD simulations show coexistence of a low-density disordered phase with a high-density phase with alternating layers rich in the first and second components. In these layers, crystalline structure is present in the solid, and absent in the liquid crystals. The density and the degree of order of the ordered phase decrease with increasing temperature, up to a temperature where the theory predicts a narrow two-phase region with increasing density of both disordered and ordered phases for increasing temperature. MD simulations show that monocrystals of the solid and liquid crystals have a prolate shape with the axis parallel to the direction of concentration oscillations, and the deviation from the spherical shape increases with increasing periodic order.