Phase stability condition and liquid–liquid phase separation under mesoscale confinement

Here we establish the thermodynamic phase stability condition under mesoscale confinement, which is essential in elucidating how confinement of solutions inside a droplet, cell or liposome may influence separation. To clarify affected by external conditions, formal analogy between partially open ensemble and mesoscopic system will be exploited, through nonnegligible role boundary identified as crucial difference from macroscopic condition. The extended for shown to involve several different orders magnitude that are all considered O(1) at limit. Phase instability ensue when self-association (relative self-fluctuation particle number) mutual association number correlation species) reaches order magnitude, contrast divergence fluctuation (namely, reaching magnitude) required macroscale. Thus, enhance instability.