Abstract
Segmental dynamics of polymer chains in a model nanocomposite of poly(ethylene oxide) and silica nanoparticles (NPs) was investigated using quasielastic neutron scattering. The dynamics can be accurately described with the Rouse model. The bulklike polymer far from the NP surface behaves as the neat polymer. However, the slower polymer in the interface close to the NP surface is described either with a second Rouse population with different relaxation time or using the suppressed Rouse model. These simple two-population models accurately reproduce the experimental data, with the suppressed Rouse model describing topological constraints, on average, every 12 beads with an interfacial thickness up to 13.5 beads, and the effect of the interface extending to a layer of thickness comparable to the end-to-end distance of the polymer. This modeling provides an explanation for the observed reinforcement in PNC even at low loadings, consistent with current understanding of the relevance of the interphase.
| Original language | English |
|---|---|
| Article number | 015405 |
| Journal | Physical Review E |
| Volume | 113 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2026 |
Funding
Work at ORNL's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for U.S. DOE under Contract No. DEAC05-00OR22725. The beam time was allocated to BASIS (BL-2) on proposal IPTS-30449. The authors thank Ryan Murphy and Ted Egnaczyk for measurement of NPs with USAXS. We acknowledge the European Synchrotron Radiation Facility (ESRF) for provision of synchrotron radiation facilities under Proposal No. SC-5535 and we would like to thank William Chevremont for assistance and support in using beamline ID02. Support for J.R.R. was provided through the Midscale RI:1 program of the NSF, Award No. DMR-1935956. G.F. and E.F. are thankful for partial financial support from CSGI. This work benefited from the use of the SasView application, originally developed under NSF Award No. DMR-0520547. SasView contains code developed with funding from the European Union's Horizon 2020 research and innovation programme under the SINE2020 project, Grant Agreement No. 654000.