The European Physical Journal E

, Volume 8, Issue 2, pp 167–173

Confinement-induced differences between dielectric normal modes and segmental modes of an ion-conducting polymer

  • K. Kojio
  • S. Jeon
  • S. Granick

DOI: 10.1140/epje/i2001-10090-x

Cite this article as:
Kojio, K., Jeon, S. & Granick, S. Eur. Phys. J. E (2002) 8: 167. doi:10.1140/epje/i2001-10090-x

Abstract:

Dielectric measurement in the range 0.1 Hz to 1 MHz were used to study the motions of polymers and ions in an ion-conducting polymer, polypropylene oxide containing small quantities (on the order of 1%) of lithium ions (LiClO4), confined as a sandwich of uniform thickness between parallel insulating mica surfaces. In the dielectric loss spectrum, we observed three peaks; they originated from the normal mode of the polymer, segmental mode of the polymer, and ion motions. With decreasing film thickness, the peak frequencies corresponding to the normal mode and ion motion shifted to lower frequencies, indicating retardation due to confinement above 30 nm. This was accompanied by diminished intensity of the dielectric normal-mode relaxation, suggesting that confinement diminished the fluctuations of the end-to-end vector of the chain dipole in the direction between the confining surfaces. On the contrary, the segmental mode was not affected at that thickness. Finally, significant retardation of the segmental mode was observed only for the thinnest film (14 nm). The different dynamical modes of the polymer (segmental and slowest normal modes) respond with different thickness and temperature dependence to confinement.

PACS. 82.35.Gh Polymers on surfaces; adhesion – 61.25.Hq Macromolecular and polymer solutions; polymer melts; swelling 

Copyright information

© EDP Sciences, Springer-Verlag, Società Italiana di Fisica 2002

Authors and Affiliations

  • K. Kojio
    • 1
  • S. Jeon
    • 1
  • S. Granick
    • 1
  1. 1.Department of Materials Science & Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USAUS

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