Clustering and gelation of hard spheres induced by the Pickering effect

Abstract

A mixture of hard-sphere particles and model emulsion droplets is studied with a Brownian dynamics simulation. We find that the addition of nonwetting emulsion droplets to a suspension of pure hard spheres can lead to both gas-liquid and fluid-solid phase separations. Furthermore, we find a stable fluid of hard-sphere clusters. The stability is due to the saturation of the attraction that occurs when the surface of the droplets is completely covered with colloidal particles. At larger emulsion droplet densities a percolation transition is observed. The resulting networks of colloidal particles show dynamical and mechanical properties typical of a colloidal gel. The results of the model are in good qualitative agreement with recent experimental findings [E. Koos and N. Willenbacher, Science 331, 897 (2011)] in a mixture of colloidal particles and two immiscible fluids.

5 figures, 5 pages

References in corpus (5)

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• From Bijels to Pickering emulsions: a lattice Boltzmann study
• Crystallization and gelation in colloidal systems with short-ranged attractive interactions
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Cited by in corpus (6)

• Capillary suspensions: Particle networks formed through the capillary force
• Restructuring and aging in a capillary suspension
• Connecting particle clustering and rheology in attractive particle networks
• Assembly of open clusters of colloidal dumbbells via droplet evaporation
• Microstructure and yielding of capillary force induced gel
• Minimal Model for Dynamic Bonding in Colloidal Transient Networks