Microstructure and Dynamics of Colloidal Suspensions with Attractive and Repulsive Interactions

We study suspensions of colloidal particles (1nm to 1µm) that interact via short-range attractive and long-range repulsive interactions. The competition between these interactions results in a wide variety of equilibrium and nonequilibrium behavior. Thermodynamic perturbation theory is employed to determine equilibrium phase diagrams showing regions of stable fluid, stable crystal, and fluid-crystal coexistence. Depending on the strength and range of the interparticle interactions, the equilibrium fluid-crystal phase separation can be preempted by nonequilibrium transitions such as gelation or vitrification. Dynamic simulations with many-body hydrodynamics and stochastic Brownian motion are performed to observe the evolution of the microstructure and single particle dynamics during both equilibrium and nonequilibrium transitions.