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arXiv · 1403.5387

Strong Effect of Weak Charging in Suspensions of Anisotropic Colloids

Sven Dorosz·Nikhilesh Shegokar·Tanja Schilling·Martin Oettel
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Abstract

Suspensions of hard colloidal particles frequently serve as model systems in studies on fundamental aspects of phase transitions. But often colloidal particles that are considered as ``hard'' are in fact weakly charged. If the colloids are spherical, weak charging has a only a weak effect on the structural properties of the suspension, which can be easily corrected for. However, this does not hold for anisotropic particles. We introduce a model for the interaction potential between charged ellipsoids of revolution (spheroids) based on the Derjaguin approximation of Debye--Hückel Theory and present a computer simulation study on aspects of the system's structural properties and phase behaviour. In line with previous experimental observations, we find that even a weak surface charge has a strong impact on the correlation functions. A likewise strong impact is seen on the phase behaviour, in particular, we find stable cubatic order in suspensions of oblate ellipsoids.

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Sven Dorosz, Nikhilesh Shegokar, Tanja Schilling, Martin Oettel. 2014-03-21. Strong Effect of Weak Charging in Suspensions of Anisotropic Colloids. https://arxiv.org/abs/1403.5387

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