Abstract
Drawing an analogy to the paradigm of quasielastic neutron scattering, we present a general approach for quantitatively investigating the spatiotemporal dependence of structural anisotropy relaxation in deformed polymers by using small-angle neutron scattering. Experiments and nonequilibrium molecular dynamics simulations on polymer melts over a wide range of molecular weights reveal that their conformational relaxation at relatively high momentum transfer Q and short time can be described by a simple scaling law, with the relaxation rate proportional to Q. This peculiar scaling behavior, which cannot be derived from the classical Rouse and tube models, is indicative of a surprisingly weak direct influence of entanglement on the microscopic mechanism of single-chain anisotropy relaxation.
| Original language | English |
|---|---|
| Article number | 117801 |
| Journal | Physical Review Letters |
| Volume | 121 |
| Issue number | 11 |
| DOIs | |
| State | Published - Sep 11 2018 |
Funding
This research was sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy. W.-R. C. and Z. W. acknowledge the support by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. The material characterization and SANS experiments were performed at the Center for Nanophase Materials Sciences and the EQ-SANS beam line of the Spallation Neutron Source, respectively, which are DOE Office of Science User Facilities. This research 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 Award No. DE-AC05-00OR22725. Access to NGB 30m SANS was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology and the National Science Foundation under Agreement No. DMR-1508249.
| Funders | Funder number |
|---|---|
| National Science Foundation | DMR-1508249, 1508249 |
| U.S. Department of Energy | |
| National Institute of Standards and Technology | |
| Office of Science | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| Division of Materials Sciences and Engineering | DE-AC05-00OR22725 |
| UT-Battelle |