Late stages of spinodal decomposition in binary mixtures

The influence of hydrodynamic interactions on the coarsening rate $r$ of a mist of droplets combining through diffusive coalescence is examined in detail. For a sufficiently rarified mist, the competing Lifshitz-Slyozov or evaporation-condensation mechanism is dominant, but the volume fraction of precipitate actually produced in most off-critical quench experiments probably favors direct coalescence. When the minority phase is continuous, as in a quench at the critical concentration, surface-tension effects lead to a crossover from $r\sim t^{\frac{1}{3}}$ to $r\sim t$, where $t$ is the time.