Nanoparticle Diffusion in Athermal And Attractive Entangled Polymer Melts

POSTER

Abstract

Understanding the mechanisms by which nanoparticles (NPs) diffuse in a polymer melt remains an experimental challenge. In this study, we combine Rutherford backscattering spectrometry (RBS) and X-ray photon correlation spectroscopy (XPCS) to probe the diffusion of (i) enthalpically attractive silica (SiO2) NPs in poly(2-vinyl pyridine) melts and (ii) athermal phenyl-capped SiO2 NPs in polystyrene melts. In both systems, RBS shows NP diffusion in reasonable agreement with recent theoretical predictions where the athermal NPs diffuse faster than the attractive NPs. XPCS show quantitative agreement with RBS in weakly entangled polymer melts but in well-entangled polymers, XPCS shows unexpected hyperdiffusive behavior that is not observed in RBS. Our direct comparison of these techniques probes NP diffusion between ~30 and 800 nm, isolates the effect of NP-polymer interaction, and highlights the different sensitivities and observations of these experimental methods.

Presenters

  • Eric Bailey

    University of Pennsylvania, Materials Science and Engineering, University of Pennsylvania

Authors

  • Eric Bailey

    University of Pennsylvania, Materials Science and Engineering, University of Pennsylvania

  • Russell John Composto

    University of Pennsylvania, Materials Science and Engineering, University of Pennsylvania

  • Karen Winey

    University of Pennsylvania, Department of Materials Science and Engineering, University of Pennsylvania, U.S., Materials Science and Engineering, University of Pennsylvania, Dept of Materials Science and Engineering, University of Pennsylvania