Organization of nanoparticles at the polymer brush-solvent interface

Max Planck Institute of Colloids and Interfaces, Science Park Golm - D-14476 Potsdam, Germany, EU

Corresponding authors: olga.guskova@mpikg.mpg.de seidel@mpikg.mpg.de

Received: 28 July 2009
Accepted: 19 October 2009

Abstract

We investigate the organization of nanosized particles in a polymer brush by DPD simulations. The brush is composed of flexible chains grafted by one end to a solid substrate. The polymer-insoluble nanoparticles are treated as rather rigid aggregates of almost spherical form. Varying either the strength of interaction between polymer and nanoparticle beads or the concentration of nanoparticles (i.e., the load by nanoparticles) we observe particle cluster formation in the distal brush region. For low load, in agreement with theoretical predictions we demonstrate that the nanodroplet formed is vertically oriented and exhibits cylinder shape. With increasing concentration the aggregate at the rim of the brush becomes a flattened sphere. For high load, when the droplet-droplet interaction is significant, the cluster becomes highly anisotropic and the horizontally oriented nanodroplet adopts a cylinder (or baguette-like) shape.