We review a class of new computer simulation methods for polymeric fluids and other soft condensed matter systems that are based on an underlying field-theoretic description. These methods, while still in an early stage of development, show considerable promise for studying the equilibrium properties of many-component systems capable of intricate self-assembly, such as solutions and blends containing block and graft copolymers. Field-theoretic simulation methods also provide a great deal of flexibility in model building and coarse graining, and appear to be particularly well suited to treat systems with soft, long-range interactions, such as polyelectrolytes. We attempt to connect various related theoretical approaches, such as self-consistent field theory and dynamic density functional theory, within a common framework.

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Recent experiments by Ryu, Hermel, and co-workers have demonstrated a correlation between the presence of bridging A-blocks and practical toughness in themoplastic ABABA pentablock copolymers. Building on this observation, we develop a computational tool for evaluating average bridging fractions of internal blocks in complex block copolymers and apply the tool to the optimization of bridging fractions in mesophase structures computed with self-consistent-field theory. We identify optimal molecular designs for ABABA pentablock copolymers that could provide the useful combination of high modulus and high toughness. Further applications of the approach to property screening in complex mesophases formed by ABC and ABCA block copolymers are discussed.

A full phase field model of eutectic growth is proposed, which incorporates the generic features of a eutectic phase diagram and reduces to the sharp-interface model in the appropriate limit. Large scale two-dimensional simulations are presented for the isothermal solidification of a uniformly undercooled eutectic melt, in which the Avrami exponent is 3. The results of this study identify three possible growth mechanisms: diffusion limited growth, lamellar growth, and spinodal decomposition