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arXiv · 1809.02831

Phase separation of stable colloidal clusters

Thomas Petersen·Martin Z. Bazant·Roland J. M. Pellenq·Franz-Josef Ulm
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Abstract

This Article presents a nonequilibrium thermodynamic theory for the mean-field precipitation, aggregation and pattern formation of colloidal clusters. A variable gradient energy coefficient and the arrest of particle diffusion upon "jamming" of cluster aggregates in the spinodal region predicts observable gel patterns that, at high inter-cluster attraction, form system-spanning, out-of-equilibrium networks with glass-like, quasi-static structural relaxation. For reactive systems, we incorporate the free energy landscape of stable pre-nucleation clusters into the Allen-Cahn-Reaction equation. We show that pattern formation is dominantly controlled by the Damk\"ohler number and the stability of the clusters, which modifies the auto-catalytic rate of precipitation. As clusters individually become more stable, bulk phase separation is suppressed.

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Thomas Petersen, Martin Z. Bazant, Roland J. M. Pellenq, Franz-Josef Ulm. 2018-09-08. Phase separation of stable colloidal clusters. https://doi.org/10.1103/physrevmaterials.2.095602

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