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2D-Deuteron NMR Studies of Ultraslow Motions in Solid Polymers Phenylflips in the Glassy State and Chain Motions at the Glass Transition

  • D. Schaefer
  • M. Hansen
  • B. Blümich
  • H. W. Spiess
Conference paper

Abstract

Ultraslow reorientation can be monitored by two-dimensional (2D) exchange NMR on the time scale of milliseconds to seconds /l/. Molecular reorientation during the mixing time results in 2D cross-signals, which correlate initial and final orientations. The singularities of these exchange signals form characteristic geometrical ridge patterns. Molecular reorientation by discrete jumps and by angular diffusion can be discriminated simply by inspection. The 2D absorption mode spectrum is identical to a two-time distribution function /2/, which describes the joint probability density of finding a frequency w 1 at the beginning of the experiment and a frequency w 2 at the end. Thus a 2D spectrum for a fixed mixing time is an image of the state of the dynamic process. It directly provides the distribution of reorientational angles in that state.

PACS numbers

76.60.Es 64.70.Pf 66.30.-h 

References

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    C. Schmidt, B. Blümich, H. W. Spiess, J. Magn. Res. 79, 269 (1988).ADSGoogle Scholar
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    S. Wefing, H. W. Spiess, J. Chem. Phys. 89, 1219 (1988).ADSCrossRefGoogle Scholar
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    S. Kaufmann, S. Wefing, D. Schaefer, H. W. Spiess, . 93, (1990), in press.Google Scholar
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    D. Schaefer, H. W. Spiess, U. W. Suter, W. W. Fleming, Macromolecules 23, (1990), in press.Google Scholar
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    S. Wefing, S. Kaufmann, H. W. Spiess, J. Chem. Phys. 89, 1234 (1988).ADSCrossRefGoogle Scholar
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    U. Pschorn, E. Rössler, H. Sillescu, S. Kaufmann, D. Schaefer, H. W. Spiess, submitted to Macromolecules.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1990

Authors and Affiliations

  • D. Schaefer
    • 1
  • M. Hansen
    • 1
  • B. Blümich
    • 1
  • H. W. Spiess
    • 1
  1. 1.MPI für PolymerforschungMainsGermany

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