Skip to main content

Ultraslow nonequilibrium dynamics in supercooled glycerol by stimulated Brillouin gain spectroscopy

Publication ,  Journal Article
Miller, RS; MacPhail, RA
Published in: Journal of Chemical Physics
February 22, 1997

We have used high resolution stimulated Brillouin gain spectroscopy to monitor the nonequilibrium relaxation dynamics of supercooled glycerol near its glass transition temperature. After a temperature quench from 192.4 to 179.8 K, the Brillouin frequency shift increased over a period of 17 d from 16.877±0.005 GHz to 17.195±0.005 GHz, the equilibrium value expected for the final temperature. The relaxation of the shift appears to proceed in three distinct stages. The first and most rapid stage tracks the time dependence of the temperature. This is followed by a slower relaxation process which is well characterized by a stretched exponential function exp[-(t/τ)β]. The values determined for τ (12±2 ks) and β (0.61±0.09) are consistent with values predicted from recent dielectric and enthalpy relaxation studies of glycerol in the same temperature range, as long as allowances are made for the nonlinear nature of the nonequilibrium experiment. The third and final stage in the relaxation is approximately exponential with a time constant of 430±40 ks. We speculate that this ultraslow process may have its origin in the relaxation of mechanical strain built up in the sample during the temperature quench, or that it could result from the nonlinear nature of the experiment and the heterogeneous nature of dynamics in supercooled liquids. A comparison with other methods (dilatometry, probe fluorescence) for studying nonequilibrium relaxation in supercooled liquids shows our technique to be comparable in sensitivity. Finally, the Brillouin linewidth showed no change after an initial rapid decrease to 18±2 MHz (half width at half maximum), indicating a lack of significant spatial heterogeneity in the physical properties and/or relaxation dynamics on length scales of the order of the acoustic wavelength (0.2 μm) or longer. © 1997 American Institute of Physics.

Duke Scholars

Published In

Journal of Chemical Physics

DOI

ISSN

0021-9606

Publication Date

February 22, 1997

Volume

106

Issue

8

Start / End Page

3393 / 3401

Related Subject Headings

  • Chemical Physics
  • 51 Physical sciences
  • 40 Engineering
  • 34 Chemical sciences
  • 09 Engineering
  • 03 Chemical Sciences
  • 02 Physical Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Miller, R. S., & MacPhail, R. A. (1997). Ultraslow nonequilibrium dynamics in supercooled glycerol by stimulated Brillouin gain spectroscopy. Journal of Chemical Physics, 106(8), 3393–3401. https://doi.org/10.1063/1.473068
Miller, R. S., and R. A. MacPhail. “Ultraslow nonequilibrium dynamics in supercooled glycerol by stimulated Brillouin gain spectroscopy.” Journal of Chemical Physics 106, no. 8 (February 22, 1997): 3393–3401. https://doi.org/10.1063/1.473068.
Miller RS, MacPhail RA. Ultraslow nonequilibrium dynamics in supercooled glycerol by stimulated Brillouin gain spectroscopy. Journal of Chemical Physics. 1997 Feb 22;106(8):3393–401.
Miller, R. S., and R. A. MacPhail. “Ultraslow nonequilibrium dynamics in supercooled glycerol by stimulated Brillouin gain spectroscopy.” Journal of Chemical Physics, vol. 106, no. 8, Feb. 1997, pp. 3393–401. Scopus, doi:10.1063/1.473068.
Miller RS, MacPhail RA. Ultraslow nonequilibrium dynamics in supercooled glycerol by stimulated Brillouin gain spectroscopy. Journal of Chemical Physics. 1997 Feb 22;106(8):3393–3401.

Published In

Journal of Chemical Physics

DOI

ISSN

0021-9606

Publication Date

February 22, 1997

Volume

106

Issue

8

Start / End Page

3393 / 3401

Related Subject Headings

  • Chemical Physics
  • 51 Physical sciences
  • 40 Engineering
  • 34 Chemical sciences
  • 09 Engineering
  • 03 Chemical Sciences
  • 02 Physical Sciences