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arXiv · 1707.09015

Nematohydrodynamics for Colloidal Self-Assembly and Transport Phenomena

Sourav Mondal·Apala Majumdar·Ian M. Griffiths
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Abstract

We study colloidal particles in a nematic-liquid-crystal-filled microfluidic channel and show how elastic interactions between the particle and the channel wall lead to different particle dynamics compared with conventional microfluidics. For a static particle, in the absence of a flow field, the director orientation on the particle surface undergoes a rapid transition from uniform to homeotropic anchoring as a function of the anchoring strength and the particle size. In the presence of a flow field, in addition to fluid viscous stresses on the particle, nematic-induced elastic stresses are exerted as a result of the anchoring conditions. The resulting forces are shown to offer the possibility of size-based separation of individual particles. For multi-particle systems, the nematic forces induce inter-particle attraction induces particle attraction, following which the particles aggregate and reorientate. These results illustrate how coupled nematic-hydrodynamic effects can affect the mobility and spatial reorganization of colloidal particles in microfluidic applications.

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Sourav Mondal, Apala Majumdar, Ian M. Griffiths. 2017-07-18. Nematohydrodynamics for Colloidal Self-Assembly and Transport Phenomena. https://arxiv.org/abs/1707.09015

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