Dynamics of glass-forming liquids. V. On the link between molecular dynamics and configurational entropy

We compare dielectric relaxation τ(T) data of several low molecular weight glass-forming liquids with the predictions of the Adam–Gibbs theory using experimental data for the configurational entropy Sc(T). Combination of Adam–Gibbs and Vogel–Fulcher equations yields an expression for Sc(T) which can be compared with experimental data. Good agreement is found for a range of temperatures near Tg<T<TB which depends on the fragility of the liquid and on the presence of a β relaxation. For fragile liquids, TB coincides with a qualitative change in the temperature dependence of the relaxation time scale or viscosity, with the temperature Tβ, where Johari–Goldstein-type β processes tend to merge into the α process, and with other crossover temperatures. For nonfragile liquids, TB/Tg increases, and the deviations from the Adam–Gibbs equation weaken or disappear altogether. The significance of TB, and of the Sc(T) temperature dependence implied by the Vogel–Fulcher theory fitting, are discussed in terms of the lan...

[1]  S. Brawer.  Relaxation in Viscous Liquids and Glasses , 1985 .

[2]  J. Jäckle,et al.  Models of the glass transition , 1986 .

[3]  C. Angell.  Entropy and Fragility in Supercooling Liquids , 1997, Journal of research of the National Institute of Standards and Technology.

[4]  O. Yamamuro,et al.  Heat capacities and glass transitions of 1-propanol and 3-methylpentane under pressure. New evidence for the entropy theory , 1994 .

[5]  J. Dyre,et al.  Energy master equation: A low-temperature approximation to Bässler's random-walk model. , 1995, Physical review. B, Condensed matter.

[6]  Martin Goldstein,et al.  Viscous liquids and the glass transition. V. Sources of the excess specific heat of the liquid , 1976 .

[7]  A. B. Bestul,et al.  Heat Capacity and Thermodynamic Properties of o‐Terphenyl Crystal, Glass, and Liquid , 1972 .

[8]  Baessler,et al.  Viscous flow in supercooled liquids analyzed in terms of transport theory for random media with energetic disorder. , 1987, Physical review letters.

[9]  C. Angell,et al.  Nonexponential relaxations in strong and fragile glass formers , 1993 .

[10]  M. Goldstein.  Viscous liquids and the glass transition. IV. Thermodynamic equations and the transition , 1973 .

[11]  R. Richert,et al.  DYNAMICS OF GLASS-FORMING LIQUIDS. I: TEMPERATURE-DERIVATIVE ANALYSIS OF DIELECTRIC RELAXATION DATA , 1995 .

[12]  J. H. Magill.  Physical Properties of Aromatic Hydrocarbons. III. A Test of the Adam—Gibbs Relaxation Model for Glass Formers Based on the Heat‐Capacity Data of 1,3,5‐tri‐α‐Naphthylbenzene , 1967 .

[13]  C. Angell,et al.  Thermodynamic aspects of the vitrification of toluene, and xylene isomers, and the fragility of liquid hydrocarbons , 1990 .

[14]  R. Richert,et al.  Dynamics of glass-forming liquids. III. Comparing the dielectric α- and β-relaxation of 1-propanol and o-terphenyl , 1997 .

[15]  S. Nagel,et al.  Supercooled Liquids and Glasses , 1996 .

[16]  O. Yamamuro,et al.  CALORIMETRIC STUDY OF 3-BROMOPENTANE : CORRELATION BETWEEN STRUCTURAL RELAXATION TIME AND CONFIGURATIONAL ENTROPY , 1995 .

[17]  G. P. Johari,et al.  Viscous Liquids and the Glass Transition. III. Secondary Relaxations in Aliphatic Alcohols and Other Nonrigid Molecules , 1971 .

[18]  H. Bässler,et al.  Dynamics of supercooled melts treated in terms of the random-walk concept , 1990 .

[19]  M. Maroncelli,et al.  Solvation dynamics and the dielectric response in a glass-forming solvent: from picoseconds to seconds , 1994 .

[20]  A. Sokolov,et al.  THE DYNAMICS OF STRONG AND FRAGILE GLASS FORMERS , 1996 .

[21]  F. Stillinger,et al.  Packing Structures and Transitions in Liquids and Solids , 1984, Science.

[22]  Gary S. Grest,et al.  Liquid-glass transition, a free-volume approach , 1979 .

[23]  P. Debenedetti,et al.  The distribution of tetravalent network glasses , 1996 .

[24]  R. Richert,et al.  Dynamics of glass-forming liquids. II. Detailed comparison of dielectric relaxation, dc-conductivity, and viscosity data , 1996 .

[25]  G. Adam,et al.  On the Temperature Dependence of Cooperative Relaxation Properties in Glass‐Forming Liquids , 1965 .

[26]  R. Davies,et al.  Thermodynamic and kinetic properties of glasses , 1953 .

[27]  O. Yamamuro,et al.  Structural relaxations of 3-methylpentane and 1-propanol under high-pressure: temperature- and pressure-jump methods , 1995 .

[28]  A. Blumen,et al.  Disorder Effects on Relaxational Processes , 1994 .

[29]  R. Cole,et al.  Approach to glassy behavior of dielectric relaxation in 3‐bromopentane from 298 to 107 K , 1986 .

[30]  B. Derrida.  Random-energy model: An exactly solvable model of disordered systems , 1981 .

[31]  E. W. Fischer.  Light scattering and dielectric studies on glass forming liquids , 1993 .

[32]  D. Turnbull,et al.  Test of Adam—Gibbs Liquid Viscosity Model with o-Terphenyl Specific-Heat Data , 1967 .

[33]  G. Tammann,et al.  Die Abhängigkeit der Viscosität von der Temperatur bie unterkühlten Flüssigkeiten , 1926 .

[34]  David Turnbull,et al.  Molecular Transport in Liquids and Glasses , 1959 .

[35]  Andersen,et al.  Testing mode-coupling theory for a supercooled binary Lennard-Jones mixture. II. Intermediate scattering function and dynamic susceptibility. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[36]  C. Angell.  Relaxation in liquids, polymers and plastic crystals — strong/fragile patterns and problems☆ , 1991 .

[37]  Martin Goldstein,et al.  Viscous Liquids and the Glass Transition: A Potential Energy Barrier Picture , 1969 .

[38]  W. Kauzmann.  The Nature of the Glassy State and the Behavior of Liquids at Low Temperatures. , 1948 .