Numerical prediction of colloidal phase separation based on its scale-invariant nature
| When |
Mar 06, 2018
from 10:45 to 12:00 |
|---|---|
| Where | salle Conférence (1 place de l'Ecole) |
| Attendees |
Michio Tateno |
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Phase separation of colloidal suspensions and the resulting gelation are ubiquitous in our life and the physical understanding of the kinetic process toward the final state is important not only in basic science (e.g., soft and bio matter science) but also in many industries (e.g., foods, inks, cosmetics, and cements). Because of its intrinsically out-of equilibrium nature, there is no clear understanding on how the kinetic pathway is selected. The main difficulty comes from the momentum conservation imposed by the solvent, more specifically, many-body hydrodynamic interactions between colloids. Here we systematically study the phase-separation process of colloidal suspensions by combining time-resolved single-particle-level confocal microscopy observation, Brownian dynamic (BD) simulations without hydrodynamics, and fluid particle dynamics simulations (FPD) with hydrodynamics. We find that the coarsening dynamics of colloidal aggregates in the experiments can be well reproduced by the FPD simulations after proper scaling of the length, time, and energy, but
not by the BD simulations. This finding not only demonstrates the fundamental importance of many-body hydrodynamic interactions in the structural formation of colloidal suspensions, but also indicates the predictive power of FPD simulation, which is a consequence of the scale invariant nature of the phenomena.