| Abstract
| - We have studied equilibrium phase behavior and nonequilibrium particle aggregation in a mixture ofcharged colloids and ionic wormlike micelles. At high enough concentration of micelles but below theoverlap concentration (c*), separation into coexisting colloidal gas and liquid phases occurred. Beyond c*,we observed rapid, nonequilibrium aggregation of the particles to form “transient gels”. These space-fillingstructures can show rapid gravitational collapse after an initial “latency period”, a behavior also foundin model colloid−polymer mixtures at high polymer concentrations. The depletion mechanism was foundto play an important role in phase separation. Diffusing wave spectroscopy (DWS) was used to study thedynamics of a transient gel. After about one-half of the latency period, the fluctuations in the scatteredintensity increased significantly. The particle dynamics slowed during the whole latency period, consistentwith the aging of the gel structure. After gravitational collapse, a very broad, logarithmic decay of thecorrelation function was detected for the sediment.
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