Berlin 2015 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 57: Complex Fluids and Soft Matter - Part I (joint session DY, CPP, BP)
CPP 57.2: Vortrag
Mittwoch, 18. März 2015, 15:15–15:30, BH-N 333
Suppression of Ostwald Ripening by Chemical Reactions in Active Emulsions — •David Zwicker1,2, Anthony A. Hyman3, and Frank Jülicher2 — 1Harvard University, Cambridge MA, USA — 2Max Planck Institute for the Physics of Complex Systems, Dresden, Germany — 3Max Planck Institute of Cell Biology and Genetics, Dresden, Germany
Ostwald ripening is a coarsening process of droplets in an emulsions that is driven by the surface tension of the droplets. This coarsening must be suppressed to stabilize emulsions, e.g. to control the properties of pharmaceuticals, food, or cosmetics. Ostwald ripening must also be suppressed in biological cells, which contain liquid-like compartments, e.g. germ granules, Cajal-bodies, and centrosomes. Such systems are often driven away from equilibrium by chemical reactions and can thus be described as active emulsions.
Here, we show that non-equilibrium chemical reactions can suppress Ostwald Ripening, leading to stable, monodisperse emulsions. Using a coarse-grained description of the droplet dynamics, we derive analytical approximations of the typical droplet size, droplet count, and time scale of the dynamics. We also compare these results to numerical simulations of the continuous concentration fields. We thus show how chemical reactions can be used to stabilize emulsions and control their properties.