摘要

We have studied the self-assembly of nano-particles (NPs) at the surface of microphase-separated AB diblock copolymer brushes in a selective solvent by means of dissipative particle dynamics (DPD) simulations. The structure of such nano-composites depends both on the morphology of the underlying brush which is basically determined by chain composition f(B) and solvent selectivity tau(B), and on specific parameters of the NPs added such as polymer compatibility a(BP), solvophobicity a(PS), and concentration phi, where a(ij) are the DPD interaction parameters. The immense parameter space is explored within a coarse-grained model that contains polymer A and B beads, solvent (S), nano-particle (P), and wall (W) beads. For composites with B-like nano-particles, i.e., NPs that are covered by polymer B ligands, we construct the phase diagram in the f(B) phi space. For B-unlike NPs, it is found that the solvophobicity of the particles set by aPS is crucial for the spreading of nano-droplets. We show that in principle microphase-separated diblock copolymer brushes can be used to create ordered nano-dots as well as nano-wires and deduce some rules which should facilitate the design of such novel polymer nano-composites. Finally we suggest a new mechanism to move nano-objects on the surface of diblock copolymer brushes.

  • 出版日期2012