Late-stage phase separation and sedimentation in a binary liquid mixture.

Abstract

Visualization studies of the phase separation of the critical binary liquid mixture, aniline-cyclohexane, in the late stage of the gravity-dominated regime are reported. The sedimentation behavior, following the formation of the bulk interface, shows that the residual domains grow in size according to a(t)=${\mathit{At}}^{\mathrm{\ensuremath{\varphi}}}$, with \ensuremath{\varphi}=0.27\ifmmode\pm\else\textpm\fi{}0.06 and A=(7\ifmmode\pm\else\textpm\fi{}5)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}7}$ m ${\mathrm{s}}^{\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\varphi}}}$. Domain growth in the earlier stages of spinodal decomposition and nucleation mechanisms also yield similar growth exponents and prefactors. The differences are probably due to some hydrodynamic interactions during the sedimentation.