Berlin 2012 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 34: Colloids and Complex Liquids II
CPP 34.10: Vortrag
Donnerstag, 29. März 2012, 17:45–18:00, C 130
Particles as emulsion stabilizers: a simulation study — •Florian Günther1, Stefan Frijters1, and Jens Harting1,2 — 1Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands — 2Institute for Computational Physics, University of Stuttgart, Stuttgart, Germany
Emulsions stabilized by particles are ubiquitous in the food and cosmetics industry, but our understanding of the influence of microscopic fluid-particle and particle-particle interactions on the macroscopic rheology is still limited. Modern simulation algorithms based on a multicomponent lattice Boltzmann model to describe the solvents combined with a molecular dynamics solver for the description of the suspended particles allow to tune the particle size, shape, wettability and surface tensions between the fluids. Further, they are ideal candidates to harness the power of today's largest available supercomputers allowing to model small macroscopic systems with microscopic resolution.
We report on the adsorption of spherical or ellipsoidal particles to liquid interfaces and demonstrate the existence of stable and semi-stable equilibrium states. On larger scales, different phases of stabilized emulsions have been found. While Pickering emulsions are already known for more than a century, so-called bicontinuous interfacially jammed emulsion gels (Bijels) where only predicted recently. The particles can fully arrest domain growth and a transition between both phases can be found by tuning the concentration, contact angle, or fluid ratio. Further, by tuning the particle shape additional geometrical degrees of freedom add additional time scales to the arrest of domain growth.