Abstract
We present a quantitative approach to the self-dynamics of polymers under steady flow by employing a set of complementary reference frames and extending the spherical harmonic expansion technique to dynamic density correlations. Application of this method to nonequilibrium molecular dynamics simulations of polymer melts reveals a number of universal features. For both unentangled and entangled melts, the center-of-mass motions in the flow frame are described by superdiffusive, anisotropic Gaussian distributions, whereas the isotropic component of monomer self-dynamics in the center-of-mass frame is strongly suppressed. Spatial correlation analysis shows that the heterogeneity of monomer self-dynamics increases significantly under flow.
| Original language | English |
|---|---|
| Article number | 057801 |
| Journal | Physical Review Letters |
| Volume | 129 |
| Issue number | 5 |
| DOIs | |
| State | Published - Jul 29 2022 |
Funding
The research is supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Early Career Research Program Award No. KC0402010, under Contract No. DE-AC05-00OR22725. The computational work was carried out at Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. Our investigation used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. We thank L. Sanchez-Diaz and W.-R. Chen for their assistance with the simulations.