(527a) Equilibrium Crystallization of Attractive Colloids on Energetically Patterned Surfaces

To intelligently design, control, and optimize equilibrium colloidal crystallization on energetically patterned substrates, it is necessary to understand how relative magnitudes of colloid-colloid and colloid-pattern attraction control interfacial crystallization from initially 2D fluid configurations. In this talk, we present experimental microscopy and simulation results that capture the dynamic assembly and equilibrium structure of depletion attraction mediated colloidal crystallization on attractive chemically and physically patterned surfaces. Digital video microscopy is used to directly monitor equilibrium crystallization of silica colloids on patterned gold features and lithographically patterned surface topographies in the presence of micellar, nanoparticle, and macromolecular depletants. Monte Carlo and Brownian Dynamic simulations are used to construct equilibrium micro-phase diagrams and to model self-diffusion processes important to assembly on microscale pattern features comparable to colloid dimensions. Our results demonstrate universal behavior that allow specification of design rules and control parameters for tuning colloidal and surface interactions to assemble various crystal morphologies on pattern features having a broad range of geometric and energetic characteristics.