Monte Carlo Simulation of Colloid and Polymer Systems

Owen Hehmeyer, Princeton University

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Model systems consisting of asymmetric hard spheres are studied within 3D and quasi 2D geometries by grand canonical Monte Carlo simulation with histogram reweighting. Phase diagrams for ternary mixtures of polymer and asymmetric colloid species are compared to their constituent binary systems. Phase diagrams for binary hard sphere systems are compared to those for their constituent monocomponent systems. The simulations are implemented using the finite lattice discretization method [1], allowing more rapid convergence to equilibrium.

This study is a preparatory study for examination of a model system consisting of a heterogeneous charged surface, polymer chains, and electrolytes in solution. Some progress towards this goal is discussed. Such systems are relevant for understanding adsorption of proteins on patterned surfaces. The lattice discretization method [2] is only moderately useful for uncharged systems, such as this study, but is shown to significantly speed the Ewald summation of the Coulombic interactions for 2D systems, and is expected to enable simulation of the charged model system.


[1] A.Z. Panagiotopoulos and S.K. Kumar, “Large Lattice Discretization Effects on the Phase Coexistence of Ionic Fluids,” Phys. Rev. Letters, 83, 2981-2984 (1999).
[2] A.Z. Panagiotopoulos, “On the Equivalence of Continuum and Lattice Models for Fluids,” J. Chem. Phys., 112, 7132-7137 (2000).

Abstract Author(s): Owen J. Hehmeyer and Athanassios Z. Pangiotopoulos<br />Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544