Models of gel-forming colloids

We study the phenomenon of structral arrest in colloidal suspensions, with emphasis on the equilibrium and non-equilibrium routes to gel formation. We describe a number of model systems, treated with molecular dynamics simulations, which give rise to equilibrium gels in a wide region of volume fractions of the dispersed phase. These models have in common the anisotropy of the mutual interactions and show a set of characteristic features, i.e. the drastic reduction of the unstable two-phase region ('empty liquids'), the Arrhenius form decay for the diffusivity, the typical behavior of strong glasses, and the approach to an ideal gel state due to bonding among the particles. We also show that anisotropic interactions allow self-assembly in colloids to be treated using an equilibrium liquid-state approach. © 2008 American Institute of Physics