Figure 7. Non-equilibrium concentration profiles in a multi-drop system at steady state. The profiles of P (red curve) and S (blue curve) (Eq. (10)) are shown along an axis connecting the centres of two drops of radius R. The interfaces are at local thermal equilibrium so the coexistence solute concentrations (Pin,out(R)) are given by the Gibbs-Thomson relations (Eqs (1) and (2)). The concentration S is continuous at the interface (Sin(R) = Sout(R)). The non-equilibrium chemical reactions coupled with diffusion and phase separation create a circulating flux of molecules P and S between drops and cytoplasm. Drops are rich in P so the chemical conversion P →k S dominates, leading to accumulation of an S molecules inside drops (downward red/blue arrows). The excess of S is then transported by diffusion toward the cytoplasm (blue arrows). In the cytoplasm the reverse reaction dominates, leading to creation and accumulation of P molecules between drops (upward blue/red arrow), which diffuse toward the drops (red arrows).
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