Spatially heterogeneous dynamics in supercooled liquids.

Although it has long been recognized that dynamics in supercooled liquids might be spatially heterogeneous, only in the past few years has clear evidence emerged to support this view. As a liquid is cooled far below its melting point, dynamics in some regions of the sample can be orders of magnitude faster than dynamics in other regions only a few nanometers away. In this review, the experimental work that characterizes this heterogeneity is described. In particular, the following questions are addressed: How large are the heterogeneities? How long do they last? How much do dynamics vary between the fastest and slowest regions? Why do these heterogeneities arise? The answers to these questions influence practical applications of glass-forming materials, including polymers, metallic glasses, and pharmaceuticals.

[1]  M. Ferrer,et al.  Supercooled liquids and the glass transition: Temperature as the control variable , 1998 .

[2]  K. Fox.  Biopreservation. Putting proteins under glass. , 1995, Science.

[3]  P. Harrowell,et al.  Origin of the Difference in the Temperature Dependences of Diffusion and Structural Relaxation in a Supercooled Liquid , 1998 .

[4]  W. Gotze,et al.  Dynamics of supercooled liquids and the glass transition , 1984 .

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

[6]  A. Rizos,et al.  Experimental determination of the cooperative length scale of a glass-forming liquid near the glass transition temperature , 1999 .

[7]  E. Leutheusser.  Dynamical model of the liquid-glass transition , 1984 .

[8]  H. Nakatsuka,et al.  Triphenylmethane Dyes Revealing Heterogeneity of Their Nanoenvironment: Femtosecond, Picosecond, and Single-Molecule Studies , 1999 .

[9]  C. Angell,et al.  Formation of Glasses from Liquids and Biopolymers , 1995, Science.

[10]  G. Hinze,et al.  Four-time rotational correlation functions , 1998 .

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

[12]  R. Böhmer.  Nanoscale heterogeneity in glass-forming liquids , 1998 .

[13]  S. Nagel,et al.  Structural studies of an organic liquid through the glass transition. , 1996 .

[14]  A. Heuer,et al.  Combined reduced 4D 13C exchange and 1H spin diffusion experiment for determining the length scale of dynamic heterogeneities. , 1999, Journal of magnetic resonance.

[15]  A. Heuer,et al.  Rate-memory and dynamic heterogeneity of first-order reactions in a polymer matrix , 1997 .

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

[17]  M. Cicerone,et al.  TRANSLATIONAL DIFFUSION ON HETEROGENEOUS LATTICES : A MODEL FOR DYNAMICS IN GLASS FORMING MATERIALS , 1997 .

[18]  H. Sillescu.  Heterogeneity at the glass transition: a review , 1999 .

[19]  Robert M. Dickson,et al.  Imaging Three-Dimensional Single Molecule Orientations , 1999 .

[20]  G. Hinze,et al.  2H nuclear magnetic resonance study of supercooled toluene: Slow and fast processes above and below the glass transition , 1996 .

[21]  Chia-Ying Wang,et al.  How long do regions of different dynamics persist in supercooled o-terphenyl? , 1999 .

[22]  Tadashi Inoue,et al.  Molecular motion during physical aging in polystyrene: Investigation using probe reorientation , 2000 .

[23]  P. Pissis,et al.  Glass Transition in Liquids: Two versus Three-Dimensional Confinement , 1998 .

[24]  P. Harrowell,et al.  Relaxation dynamics and their spatial distribution in a two-dimensional glass-forming mixture , 1999 .

[25]  M. Cicerone,et al.  Photobleaching technique for measuring ultraslow reorientation near and below the glass transition : tetracene in o-terphenyl , 1993 .

[26]  R. Zwanzig.  Diffusion in a dynamically disordered continuum , 1989 .

[27]  Bruno C. Hancock,et al.  CHARACTERIZATION OF THE TIME SCALES OF MOLECULAR MOTION IN PHARMACEUTICALLY IMPORTANT GLASSES , 1999 .

[28]  R. Böhmer.  Nanoscale heterogeneity if glass-forming liquids: experimental advances , 1998 .

[29]  C. T. Moynihan,et al.  Fluctuation model for structural relaxation and the glass transition , 1996 .

[30]  M. Ediger,et al.  Enhanced Translational Diffusion of 9,10-Bis(phenylethynyl)anthracene (BPEA) in Polystyrene , 1997 .

[31]  B. Bagchi,et al.  Decoupling of tracer diffusion from viscosity in a supercooled liquid near the glass transition , 1997 .

[32]  M. Ediger,et al.  Translational and Rotational Motion of Probes in Supercooled 1,3,5-Tris(naphthyl)benzene , 1996 .

[33]  M. Cicerone,et al.  Enhanced translation of probe molecules in supercooled o‐terphenyl: Signature of spatially heterogeneous dynamics? , 1996 .

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

[35]  M. Ediger.  Can density or entropy fluctuations explain enhanced translational diffusion in glass-forming liquids? , 1998 .

[36]  Randl,et al.  Tagged-particle motion in viscous glycerol: Diffusion-relaxation crossover. , 1996, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[37]  H. Sillescu,et al.  Size Dependence of Tracer Diffusion in Supercooled Liquids , 1996 .

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

[39]  A. Heuer,et al.  Dynamic heterogeneities of translational and rotational motion of a molecular glass former from computer simulations , 1999 .

[40]  H. Davis.  The Effective Medium Theory of Diffusion in Composite Media , 1977 .

[41]  R. Richert.  DIELECTRIC ASPECTS OF DIPOLAR SOLVATION AT THE GLASS-TRANSITION , 1994 .

[42]  C. T. Moynihan,et al.  Non-exponential structural relaxation, anomalous light scattering and nanoscale inhomogeneities in glass-forming liquids , 1993 .

[43]  K. Ngai.  Alternative Explanation of the Difference between Translational Diffusion and Rotational Diffusion in Supercooled Liquids , 1999 .

[44]  R. Böhmer,et al.  Rotational correlation functions and apparently enhanced translational diffusion in a free-energy landscape model for the α relaxation in glass-forming liquids , 1998 .

[45]  H. Sillescu,et al.  Translational and rotational molecular motion in supercooled liquids studied by NMR and forced Rayleigh scattering , 1994 .

[46]  A. Heuer,et al.  Glass transition of polymers: Memory effects in structural relaxation of polystyrene , 1997 .

[47]  J. Torkelson,et al.  Translation-rotation paradox for diffusion in glass-forming polymers: The role of the temperature dependence of the relaxation time distribution , 1997 .

[48]  M. Cicerone,et al.  How do molecules move near Tg? Molecular rotation of six probes in o‐terphenyl across 14 decades in time , 1995 .

[49]  G. Fredrickson.  Recent Developments in Dynamical Theories of the Liquid-Glass Transition , 1988 .

[50]  Molecular-dynamics study of long-lived structures in a fragile glass-forming liquid , 1998, cond-mat/9801016.

[51]  Marcus T. Cicerone,et al.  Relaxation of spatially heterogeneous dynamic domains in supercooled ortho‐terphenyl , 1995 .

[52]  Heterogeneous Diffusion in Highly Supercooled Liquids , 1998, cond-mat/9807180.

[53]  R. Richert.  Molecular probing of dielectric relaxation in the glass-transition region , 1992 .

[54]  M. Ediger,et al.  Translational diffusion of rubrene and tetracene in polyisobutylene , 1997 .

[55]  Joseph L. Keddie,et al.  Size-Dependent Depression of the Glass Transition Temperature in Polymer Films , 1994 .

[56]  F. Sciortino,et al.  Inherent Structure Entropy of Supercooled Liquids , 1999, cond-mat/9906081.

[57]  Asymptotic laws for tagged-particle motion in glassy systems , 1998, cond-mat/9807013.

[58]  Stillinger,et al.  Translation-rotation paradox for diffusion in fragile glass-forming liquids. , 1994, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[59]  R. Böhmer,et al.  Dielectric hole burning spectroscopy of supercooled liquids , 1997 .

[60]  R. Richert.  Evidence for dynamic heterogeneity near T-g from the time-resolved inhomogeneous broadening of optical line shapes , 1997 .

[61]  G. Diezemann.  A free-energy landscape model for primary relaxation in glass-forming liquids: Rotations and dynamic heterogeneities , 1997 .

[62]  O. Yamamuro,et al.  Calorimetric Study of Glassy and Liquid Toluene and Ethylbenzene: Thermodynamic Approach to Spatial Heterogeneity in Glass-Forming Molecular Liquids† , 1998 .

[63]  H. Sillescu,et al.  Heterogeneity at the Glass Transition: Translational and Rotational Self-Diffusion , 1997 .

[64]  K. Schmidt-Rohr,et al.  Nature of nonexponential loss of correlation above the glass transition investigated by multidimensional NMR. , 1991, Physical review letters.

[65]  D. Plazek.  Temperature dependence of the viscoelastic behavior of polystyrene. , 1965 .

[66]  Pablo G. Debenedetti,et al.  Metastable Liquids: Concepts and Principles , 1996 .

[67]  C. Angell,et al.  Perspective on the glass transition , 1988 .

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

[69]  E. Donth.  The size of cooperatively rearranging regions at the glass transition , 1982 .

[70]  G. Hinze.  Geometry and time scale of the rotational dynamics in supercooled toluene , 1998 .

[71]  Heuer,et al.  Rate memory of structural relaxation in glasses and its detection by multidimensional NMR. , 1995, Physical review letters.

[72]  Marcus T. Cicerone,et al.  Anomalous Diffusion of Probe Molecules in Polystyrene: Evidence for Spatially Heterogeneous Segmental Dynamics , 1995 .

[73]  John T. Fourkas,et al.  Supercooled liquids : advances and novel applications , 1997 .

[74]  P. Harrowell,et al.  Kinetic structure of a two-dimensional liquid. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[75]  T. Laurence,et al.  Polarization Spectroscopy of Single Fluorescent Molecules , 1999 .

[76]  R. Böhmer,et al.  Nonresonant dielectric hole burning spectroscopy of supercooled liquids , 1997 .

[77]  K. Ngai.  Modification of the Adam−Gibbs Model of Glass Transition for Consistency with Experimental Data , 1999 .

[78]  G. Tarjus,et al.  BREAKDOWN OF THE STOKES-EINSTEIN RELATION IN SUPERCOOLED LIQUIDS , 1995 .

[79]  George A. Gellert,et al.  Hard sell for the Sun , 1998, Nature.

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

[81]  S. Glotzer,et al.  Spatial correlations of mobility and immobility in a glass-forming Lennard-Jones liquid. , 1998, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[82]  Andersen,et al.  Testing mode-coupling theory for a supercooled binary Lennard-Jones mixture I: The van Hove correlation function. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[83]  F. Kremer,et al.  Molecular Dynamics in Confining Space: From the Single Molecule to the Liquid State , 1999 .

[84]  Steven J. Plimpton,et al.  STRINGLIKE COOPERATIVE MOTION IN A SUPERCOOLED LIQUID , 1998 .

[85]  John Maynard Smith,et al.  Painting a picture of development , 1999, Nature.

[86]  B. Ilan,et al.  Local Vitrification Model for Melt Dynamics , 1999 .

[87]  H. Sillescu,et al.  Translational and rotational diffusion in supercooled orthoterphenyl close to the glass transition , 1992 .

[88]  Ranko Richert,et al.  Dynamics of glass-forming liquids. V. On the link between molecular dynamics and configurational entropy , 1998 .

[89]  Frustration-Limited Domain Theory of Supercooled Liquids and the Glass Transition , 1997 .

[90]  Zohar Nussinov,et al.  A thermodynamic theory of supercooled liquids , 1995 .

[91]  R. Böhmer,et al.  Dynamic heterogeneity in supercooled ortho-terphenyl studied by multidimensional deuteron NMR , 1996 .

[92]  A. Heuer,et al.  Nature of the Non-exponential Primary Relaxation in Structural Glass-formers Probed by Dynamically Selective Experiments , 1998 .

[93]  G. Blond,et al.  Translational Diffusion in Sucrose Solutions in the Vicinity of Their Glass Transition Temperature , 1997 .

[94]  Ginzburg-Landau-Gor’kov theory of magnetic oscillations in a type-II two-dimensional superconductor , 1996, supr-con/9608004.

[95]  F. Stillinger,et al.  A Topographic View of Supercooled Liquids and Glass Formation , 1995, Science.