Effect of SiO<sub>2</sub> on polymer dynamics in PEO / nanocomposites: A combined experimental and computational approach

ORAL

Abstract

The dynamics of polymers in PEO / SiO2 nanocomposites is investigated experimentally utilizing dielectric relaxation spectroscopy (DS) over a broad range of frequencies and for temperatures both below and above the glass transition temperature, Tg, of the neat polymer. Different compositions were chosen to cover the range from a dilute in nanoparticles (NP) system up to one where the chains are severely confined. The sub-Tg local and the segmental relaxations of the neat PEO are identified in the hybrids, as well. A very weak effect on polymer dynamics is observed in contrast to the effect on PEO conformations or crystallinity observed for these systems. In parallel, atomistic molecular dynamics (MD) simulations have been performed in equivalent systems to predict the polymer dynamic behavior and correlate it to the experimental findings. The segmental relaxation and the center of mass translational dynamics of PEO chains close to the SiO2 NP are slower compared to the bulk. Moreover, the orientational dynamics of PEO at the PEO/SiO2 interphase is found to be slower and more heterogeneous (broader distribution of relaxation times) when compared to the bulk one. Similarities and differences between the experimental and theoretical findings are discussed.

*This research has been co-financed by EU and Greek national funds (Action RESEARCH – CREATE - INNOVATE, project INGRECO, MIS: 5030174)

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Presenters

  • Spiros H Anastasiadis

    • Foundation for Research & Technology- Hellas and Univ. of Crete
    • Foundation for Research & Technology-Hellas and Univ. of Crete, Greece

Authors

  • Spiros H Anastasiadis

    • Foundation for Research & Technology- Hellas and Univ. of Crete
    • Foundation for Research & Technology-Hellas and Univ. of Crete, Greece

  • Kiriaki Chrissopoulou

    • Foundation for Research & Technology- Hellas and Univ. of Crete
    • Foundation for Research & Technology-Hellas and Univ. of Crete, Greece

  • Eleni Papananou

    • Foundation for Research & Technology-Hellas and Univ. of Crete, Greece

  • Albert J Power

    • University of Crete
    • Foundation for Research & Technology-Hellas and Univ. of Crete, Greece

  • Anastassia Rissanou

    • 1) Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas, (FORTH) Heraklion, Greece; 2) University of Crete
    • 1. Institute of Applied and Computational Mathematics (IACM), Foundation for Research and Technology Hellas, (FORTH), Heraklion, Greece; 2. University of Crete
    • Foundation for Research & Technology-Hellas and Univ. of Crete, Greece

  • Vagelis Harmandaris

    • 1) IACM/FORTH Heraklion, Greece; 2) University of Crete; 3)The Cyprus Institute, Nicosia, Cyprus
    • University of Crete & FORTH, Greece & The Cyprus Insitute
    • 1. Institute of Applied and Computational Mathematics, Foundation for Research and Technology Hellas (FORTH), Heraklion Greece. 2. University of Crete; 3. The Cyprus Institute
    • University of Crete & IACM/FORTH & the Cyprus Institute
    • The Cypus Institute, Nicosia, Cyprus; Foundation for Research and Technology-Hellas and Univ. of Crete, Heraklion Crete, Greece.
    • Foundation for Research & Technology-Hellas and Univ. of Crete, Greece

  • Massimiliano Labardi

    • CNR-IPCF, c/o Physics Department, University of Pisa, Italy
    • University of Pisa, Italy