The hydrodynamic effects on the late stage kinetics of phase separation in liquid mixtures is studied using the model H. Mass and momentum transport are coupled via a nonequilibrium body force, which is proportional to the Peclet number, i.e., the ratio between convective and diffusive molar ﬂuxes. Numerical simulations based on this theoretical model show that phase separation in low viscosity, liquid binary mixtures is mostly driven by convection, thereby explaining the experimental ﬁndings that the process is fast, with the typical size of single-phase domains increasing linearly with time. However, as soon as sharp interfaces form, the linear growth regime reaches an end, and the process appears to be driven by diffusion, although the condition of local equilibrium is not reached. During this stage, the typical size of the nucleating drops increases like t^n, where 1/3<n<1/2, depending on the value of the Peclet number. As the Peclet number increases, the transition between convection- and diffusion-driven regimes occurs at larger times, and therefore for larger sizes of the nucleating drops.
|Autori:||VLADIMIROVA N; MALAGOLI A; MAURI R|
|Titolo:||Two-Dimensional Model of Phase Segregation in Liquid Binary Mixtures|
|Anno del prodotto:||1999|
|Digital Object Identifier (DOI):||10.1103/PhysRevE.60.6968|
|Appare nelle tipologie:||1.1 Articolo in rivista|