Berlin 2015 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 58: Computational Physics of Soft Matter II

CPP 58.4: Talk

Wednesday, March 18, 2015, 16:45–17:00, PC 203

Self organization of asymmetric dipolar particles in external fields — •Arzu Bahar Yener and Sabine H. L. Klapp — Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany

A colloidal system of spherical particles with centred dipolar moments shows layer formation in the presence of an external rotating magnetic field [1]. This non-equilibrium phenomenon requires synchronization of the particles with the driving field [1]. Here, we investigate a model system of spherical particles with off-centred, i.e. laterally shifted dipole moments. The pair potential is modeled by a short-range repulsive potential and a point dipole potential. In a first step, we analytically and numerically determine the ground state structures of up to four particles. Then, we quantify the self assembly behaviour at non-zero temperature for several shifts by using Molecular Dynamics simulations and show that our model reproduces features observed for synthesized particles with magnetic caps [2] or Janus particles [3]. Finally, we apply an external rotating magnetic field and ask if layer formation emerges as in the centred system, and if synchronization is still a condition for layer formation.
[1] S. Jäger, and S. H. L. Klapp, Soft Matter 7, 6606 (2011)
[2] D. Zerrouki, J. Baudry, D. Pine, P. Chaikin, and J. Bibette, Nature 455, 380 (2008)
[3] J. Yan, M. Bloom, S. C. Bae, E. Luijten, and S. Granick, Nature 491, 578 (2012)