Computer simulation of heterogeneous nucleation of colloidal crystals at planar walls

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The classical theory of heterogeneous nucleation at planar walls shall be tested by Monte Carlo simulations for simple models of colloidal suspensions exhibiting a fluid-solid transition. This theory (due to Turnbull) assumes spherecap shaped ”sessile” droplets at the substrate, and the nucleation barrier that appears in the classical theory of homogeneous nucleation is reduced by a factor depending on the Young contact angle. Using the Asakura-Oosawa (AO) model for colloid-polymer mixtures in the range of sizes where the polymers are much smaller than the colloids, and related models, the fluid-crystal interfacial stiffness and free energy for flat interfaces will be extracted from a capillary wave analysis, while free energy barriers of sessile droplets will be estimated by umbrella sampling and other free energy methods. We also address the problem of the line tension. A comparison with density functional calculations, experiments and simulations using complementary approaches or models will be performed, and the results will be useful as input to phase field methods. Later corrugated planar walls shall be considered too.