Regensburg 2013 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 28: Crystallization, Nucleation and Self Assembly II
CPP 28.2: Talk
Wednesday, March 13, 2013, 15:30–15:45, H40
Self-Assembly of Janus-particles in critical fluids — •Marcel Labbé-Laurent1,2, Matthias Tröndle1,2, Ludger Harnau1,2, and Siegfried Dietrich1,2 — 1Max-Planck-Institut für Intelligente Systeme, Stuttgart, Germany — 2Universität Stuttgart, Germany
Critical fluctuations in simple fluids or binary liquid mixtures give rise to forces acting on immersed colloidal particles. These Casimir-like forces are attractive or repulsive depending on the chemical surface properties [1]. Spacial ordering of colloids opposite to chemically structured surfaces, induced by the critical Casimir effect, is observed experimentally for colloidal particles immersed in a critical water-2,6-lutidine mixture and is in agreement with theory [2]. Janus-particles immersed in a critical fluid are subject to orientation-dependent stabilizing and destabilizing forces. Within density functional theory we study the phase diagram of cylindrical and spherical Janus-particles. We find first and second order phase transitions between isotropic and structured colloidal phases. Janus-particles self-assemble into a doublelayer phase, which is tunable by temperature, density and external potentials.
[1] C. Hertlein, L. Helden, A. Gambassi, S. Dietrich, and C. Bechinger, Nature 451, 172 (2008).
[2] M. Tröndle, O. Zvyagolskaya, A. Gambassi, D. Vogt, L. Harnau, C. Bechinger, and S. Dietrich, Mol. Phys. 109, 1169 (2011)