Correlated heterogeneous dynamics in glass-forming polymers

H. Conrad, F. Lehmkühler, B. Fischer, F. Westermeier, M. A. Schroer, Y. Chushkin, C. Gutt, M. Sprung, and G. Grübel
Phys. Rev. E 91, 042309 – Published 15 April 2015

Abstract

We report x-ray photon correlation spectroscopy experiments on the dynamics of the glass-former polypropylene glycol covering a temperature range from room temperature to the glass transition at Tg=205 K using silica tracer particles. Three temperature regimes are identified: At high temperatures, Brownian motion of the tracer particles is observed. Near Tg, the dynamics is hyperdiffusive and ballistic. Around 1.12Tg, we observe an intermediate regime. Here the stretching exponent of the Kohlrausch-Williams-Watts function becomes q dependent. By analyzing higher-order correlations in the scattering data, we find that dynamical heterogeneities dramatically increase in this intermediate-temperature regime. This leads to two effects: increasing heterogeneous dynamics and correlated motion at temperatures close to and below 1.12Tg.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 14 January 2015

DOI:https://doi.org/10.1103/PhysRevE.91.042309

©2015 American Physical Society

Authors & Affiliations

H. Conrad1, F. Lehmkühler1,2,*, B. Fischer1,†, F. Westermeier1,‡, M. A. Schroer1,2, Y. Chushkin3, C. Gutt4, M. Sprung1, and G. Grübel1,2

  • 1Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
  • 2The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
  • 3European Synchrotron Radiation Facility, Avenue des Martyrs 71, 38000 Grenoble, France
  • 4University of Siegen, Walter-Flex Straße 3, 57072 Siegen, Germany

  • *Corresponding author:felix.lehmkuehler@desy.de
  • Current address: University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
  • Current address: Max Planck Institute for the Structure and Dynamics of Matter, CFEL, Luruper Chaussee 149, 22761 Hamburg, Germany.

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 91, Iss. 4 — April 2015

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review E

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×