Effective Interactions and Self-Assembly of Hybrid Polymer Grafted Nanoparticles in a Homopolymer Matrix

Abstract

We apply the microscopic polymer reference interaction site model integral equation theory to study the structure and phase behavior of spherical nanoparticles with six symmetrically grafted chains in a homopolymer matrix that is chemically identical to the grafted polymer. Calculations of the particle−particle potential of mean force (PMF), pair correlation functions, and collective structure factors under athermal conditions and in the presence interfiller attractions are presented. Polymer grafted nanoparticles disperse or aggregate in the homopolymer matrix depending on how much of the filler surface is effectively covered by the tethered chains which sterically shield direct intercore attractions. If the nanoparticle volume is less than its total tether analogue, the filler surface is well shielded and nanoparticles tend to disperse. For smaller filler cores (∼2 nm) the grafting density is more brush-like, and the PMF becomes more attractive at contact with increasing matrix chain length due to decre...