Modeling Diblock Copolymer Melts with a Soft Quadrumer Model: Bulk Behavior and Directed Self-Assembly

摘要

We present results for a recently introduced soft-particle type model for diblock copolymers. Our focus will be the interaction of this model with confining walls and the possibility to direct the microphase morphologies by tailoring the interactions with these walls. We begin by presenting its bulk phase diagram and our method for determination of the different phases. We interpret the phase behavior in comparison to experimental data as well as other model results. By a systematic coarse-graining of chemically realistic simulations, one can obtain the effective potential acting between the walls and the repeat units of our soft quadrumer model. We employ this coarse-grained potential then for simulations of the confined case for several strengths of attraction to the walls and determine when extending the film thickness leads to nucleation of a new lamella in the center of the film and when it leads to reorientation transitions of the lamellar micro-phase.