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DOE OSTI · 3013446

Two-population Rouse models for polymer segmental dynamics in nanocomposites

Rooks, Jack R. [Univ. of Delaware, Newark, DE (United States)] (ORCID:0000000253971340)·Ferraro, Giovanni [Univ. of Florence (Italy)] (ORCID:0000000283762486)·Fratini, Emiliano [Univ. of Florence (Italy)] (ORCID:0000000171046530)·Osti, Naresh C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000202132299)·Takahito, Osawa [Japan Atomic Energy Agency (JAEA), Tokai (Japan)] (ORCID:0000000176007020)·Faraone, Antonio [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)]·Wagner, Norman J. [Univ. of Delaware, Newark, DE (United States)] (ORCID:000000019565619X)
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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.

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Composite materialsPolymer behaviorPolymersQuasi elastic neutron scatteringRouse model

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Rooks, Jack R. [Univ. of Delaware, Newark, DE (United States)] (ORCID:0000000253971340), Ferraro, Giovanni [Univ. of Florence (Italy)] (ORCID:0000000283762486), Fratini, Emiliano [Univ. of Florence (Italy)] (ORCID:0000000171046530), Osti, Naresh C. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)] (ORCID:0000000202132299), Takahito, Osawa [Japan Atomic Energy Agency (JAEA), Tokai (Japan)] (ORCID:0000000176007020), Faraone, Antonio [National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)], Wagner, Norman J. [Univ. of Delaware, Newark, DE (United States)] (ORCID:000000019565619X). 2026-01-07. Two-population Rouse models for polymer segmental dynamics in nanocomposites. https://doi.org/10.1103/s8k6-cvfr

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