Nanorheology of Entangled Polymer Melts

Journal Article (Academic article)

We use molecular simulations to probe the local viscoelasticity of an entangled polymer melt by tracking the motion of embedded nonsticky nanoparticles (NPs). As in conventional microrheology, the generalized Stokes-Einstein relation is employed to extract an effective stress relaxation function GGSE(t) from the mean square displacement of NPs. GGSE(t) for different NP diameters d are compared with the stress relaxation function G(t) of a pure polymer melt. The deviation of GGSE(t) from G(t) reflects the incomplete coupling between NPs and the dynamic modes of the melt. For linear polymers, a plateau in GGSE(t) emerges as d exceeds the entanglement mesh size a and approaches the entanglement plateau in G(t) for a pure melt with increasing d. For ring polymers, as d increases towards the spanning size R of ring polymers, GGSE(t) approaches G(t) of the ring melt with no entanglement plateau.

Full Text

Duke Authors

Cited Authors

  • Ge, T; Grest, GS; Rubinstein, M

Published Date

  • 2018

Published In

PubMed ID

  • 29481209

Pubmed Central ID

  • PMC5896298

International Standard Serial Number (ISSN)

  • 1079-7114

Digital Object Identifier (DOI)

  • 10.1103/PhysRevLett.120.057801