Expanded chain dimensions in polymer melts with nanoparticle fillers

We apply the self-consistent polymer reference interaction site model (SC/PRISM) to liquid state calculations of the chain dimensions in polymer melts with added nanoparticle fillers. The nanoparticles are assumed to be smaller than the polymer radius of gyration and are attracted to the polymer so that they are miscible. We find that the nanoparticles perturb the chain dimensions, causing an increase in the radius of gyration with increasing nanoparticle volume fractions, assuming reasonable interaction energies between the various components. The magnitude of the expansion is in qualitative agreement with recent neutron scattering results and suggests that the SC/PRISM approach is reasonable when dealing with these apparent nonlinear phenomena present in nanocomposites in the protein limit.