To what extent can the decoration of a colloidal surface directing pair wise interactions drive global emergent structure formation and dynamics? We address this question using a continuous potential representation of colloid interactions in which the colloid surface is represented by an underlying discretized grid of points. The interaction between points on different colloids is the sum of their point-charge electrostatics and a purely repulsive potential up to a cutoff radius. This in turn allows us to describe dipolar Janus colloids with differently charged hemispheres though Molecular Dynamics, and not just Monte Carlo sampling. More generally, we also treat striped charged colloids for which the dipolar Janus colloids is a limiting case. The equilibrium structure of the latter system has been characterized over a broad regime and, perhaps surprisingly, resulted in structures similar to those from a system of corresponding isotropically attractive colloids [J. Chem. Phys. 137 , 044505 (2012).] This corresponds to a coarse-graining of the rotations. We find that the existing methods to rescale the coarse-grained dynamics are insufficient in addressing the time scales of multiple observables simultaneously. Moreover, we will also report on the resulting structure and dynamics of the striped colloidal suspensions.

Coarse-grained dynamics in complex environments: Janus particles and striped colloids

246th National Meeting (2013)

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