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Resolving Segmental Polymer Dynamics in Nanocomposites by Incoherent Neutron Spin-Echo Spectroscopy
Dafne Musino1, Julian Oberdisse1, Bela Farago2
1Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, F-34095 Montpellier, France.
ACS Macro Letters
|June 1, 2022
Summary
This study investigates silica nanoparticles in styrene-butadiene nanocomposites. Even industrial fillers slightly slow down polymer segmental motion, revealing insights into material dynamics.
Area of Science:
- Materials Science
- Polymer Science
- Nanotechnology
Background:
- Styrene-butadiene nanocomposites with silica nanoparticles (NPs) are crucial industrial materials.
- Understanding the impact of NPs on polymer segmental dynamics is key to material performance.
Purpose of the Study:
- To investigate the segmental dynamics of styrene-butadiene nanocomposites with embedded silica NPs.
- To compare dynamics in industrial nanocomposites with colloidal ones.
- To resolve subtle changes in polymer dynamics using advanced spectroscopy.
Main Methods:
- Broadband dielectric spectroscopy (BDS) to study relaxation times.
- Neutron spin-echo spectroscopy (NSE) to probe segmental dynamics at the nanoscale.
- Experiments utilizing fully hydrogenated polymers for self-dynamics analysis.
Main Results:
- BDS showed broad relaxation time distributions in industrial nanocomposites due to polydisperse NPs.
- Colloidal nanocomposites exhibited well-defined relaxation times, with slight widening and minimal slowing compared to neat polymers.
- Incoherent NSE resolved that industrial filler NPs systematically slow down segmental motion.
Conclusions:
- Industrial silica NPs, despite polydispersity, induce a measurable slowdown in polymer segmental dynamics.
- NSE is effective in detecting minor alterations in polymer dynamics caused by fillers.
- The findings contribute to a deeper understanding of filler-polymer interactions in nanocomposites.
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