title: Resolving Dynamic Properties of Polymers through Coarse-Grained Computational Studies.
abstract: Coupled length and time scales determine the dynamic behavior of polymers and underlie their unique viscoelastic properties. To resolve the long-time dynamics it is imperative to determine which time and length scales must be correctly modeled. Here we probe the degree of coarse graining required to simultaneously retain significant atomistic details and access large length and time scales. The degree of coarse graining in turn sets the minimum length scale instrumental in defining polymer properties and dynamics. Using linear polyethylene as a model system, we probe how the coarse-graining scale affects the measured dynamics. Iterative Boltzmann inversion is used to derive coarse-grained potentials with 2-6 methylene groups per coarse-grained bead from a fully atomistic melt simulation. We show that atomistic detail is critical to capturing large-scale dynamics. Using these models we simulate polyethylene melts for times over 500  μs to study the viscoelastic properties of well-entangled polymer melts.
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: K Michael
authors.initials: KM
authors.lastname: Salerno
authors.affiliation: Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, Missouri 63130, USA.|Department of Chemistry, Clemson University, Clemson, South Carolina 29634, USA.
authors.forename: Anupriya
authors.initials: A
authors.lastname: Agrawal
authors.affiliation: Department of Chemistry, Clemson University, Clemson, South Carolina 29634, USA.
authors.forename: Dvora
authors.initials: D
authors.lastname: Perahia
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Grest