Liquid/liquid interface in periodic boundary condition

We study how surface phenomena can change the interface geometry in liquid–liquid two-phase systems with periodic boundary conditions. Without any curvature effect on surface tension, planar (slab), cylindrical, and spherical structures are successively obtained as a function of the total composition and elongation of the box, in accordance with molecular dynamics simulations for a water/heptane system.
The curvature effects described by Tolman relationship desymmetrize the phase diagram by stabilizing a concavity but it leads to inconsistencies with high curvature. Helfrich model partially resolves this and predicts the possible presence of shells reflecting a frustrated system.

For more information please read the article from Marin Vatin, Magali Duvail, Philippe Guilbaud and Jean-François Dufrêche in Phys.Chem.Chem.Phys., 2021, 23, 1178