Entropy and fragility in supercooling liquids

Research output: Contribution to journalArticle

321 Citations (Scopus)

Abstract

We review the Kauzmann paradox and what it implies about the configuration space energy hypersurface for "structural glassformers." With this background, we then show how the relaxation expression of Adam and Gibbs qualitatively accounts for most of the phenomenology of liquid and polymeric glassformers including the strong/fragile liquid pattern, and the behavior of nonergodic systems. Extended temperature range relaxation studies are consistent with a relaxation time pre-exponent on the quasilattice vibration time scale. When this boundary condition is imposed on Vogel-Fulcher-Tammann fittings, correspondence of To with 7k is found for liquids with Tg ranging over 1000 K. When it is imposed on the WLF equation C1 is obliged to become ∼16, and the corresponding force-fitted C2 provides a measure of the polymer fragility which is generally not available from thermodynamic studies. Systems which exhibit discontinuous changes in configurational entropy on temperature increase, which include unfolding proteins, are briefly reviewed.

Original languageEnglish (US)
Pages (from-to)171-181
Number of pages11
JournalJournal of Research of the National Institute of Standards and Technology
Volume102
Issue number2
StatePublished - Mar 1997

Fingerprint

Supercooling
Entropy
Liquids
Relaxation time
Boundary conditions
Thermodynamics
Proteins
Temperature
Polymers

Keywords

  • Energy landscapes
  • Fragility
  • Glass formers
  • Glass transition
  • Protein folding
  • Relaxation

ASJC Scopus subject areas

  • General
  • Engineering (miscellaneous)

Cite this

Entropy and fragility in supercooling liquids. / Angell, Charles.

In: Journal of Research of the National Institute of Standards and Technology, Vol. 102, No. 2, 03.1997, p. 171-181.

Research output: Contribution to journalArticle

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