Nanoparticle Diffusion in Polymer Nanocomposites

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.112.108301· OSTI ID:1128987

Kalathi, Jagannathan ^[1]; Yamamoto, Umi ^[2]; Schweizer, Kenneth ^[3]; Grest, Gary S. ^[4]; Kumar, Sanat ^[1]

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1. Columbia University, New York
2. University of Illinois, Urbana-Champaign
3. University of Illinois
4. Sandia National Laboratories (SNL)

Large-scale molecular dynamics simulations show that nanoparticle (NP) diffusivity in weakly interacting mixtures of NPs and polymer melts has two very different classes of behavior depending on their size. NP relaxation times and their diffusivities are completely described by the local, Rouse dynamics of the polymer chains for NPs smaller than the polymer entanglement mesh size. The motion of larger NPs, which are comparable to the entanglement mesh size, is significantly slowed by chain entanglements, and is not describable by the Stokes-Einstein relationship. Our results are in essentially quantitative agreement with a force-level generalized Langevin equation theory for all the NP sizes and chain lengths explored, and imply that for these lightly entangled systems, activated NP hopping is not important.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1128987
• Journal Information: Physical Review Letters, Vol. 112, Issue 10; ISSN 0031--9007
• Country of Publication: United States
• Language: English