1203.5216 (Andrea Fortini)

Clustering and gelation of hard spheres induced by the Pickering effect    [PDF]

Andrea Fortini

A mixture of hard-sphere particles and model emulsion droplets is studied with Brownian Dynamics simulation. We find that the addition of non-wetting 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 spheres 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 shows dynamical and mechanical properties typical of a colloidal gel. The results of the model are in good qualitative agreement with recent experimental findings [Koos, E. and Willenbacher, N. (2011). Science, 331, p.897] in a mixtures of colloidal particles and two immiscible fluids.

View original: http://arxiv.org/abs/1203.5216