Related Experiment Video
Updated: Dec 7, 2025
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
8.9K
Fragility and correlated dynamics in supercooled liquids
Atreyee Banerjee1, David J Wales1
1Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
The Journal of Chemical Physics
|October 2, 2020
Summary
Supercooled liquids exhibit super-Arrhenius behavior linked to correlated dynamics. Short-time dynamics reveal similar nonergodic behavior across different potentials, suggesting a strong connection between fragility and dynamical correlation.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Computational Chemistry
Background:
- Supercooled liquids exhibit complex dynamics deviating from simple Arrhenius behavior.
- Understanding the relationship between dynamical properties and correlated motion is crucial for glass transition theories.
Purpose of the Study:
- To investigate the connection between super-Arrhenius behavior and correlated dynamics in supercooled liquids.
- To analyze dynamical properties using both Lennard-Jones and Weeks-Chandler-Andersen potentials across various densities.
Main Methods:
- Examination of short-time nonergodic trajectory segments within longer ergodic trajectories.
- Analysis of apparent diffusivity and its behavior at low temperatures.
- Introduction of a correlation factor to rescale nonergodic diffusivity.
Main Results:
- Apparent diffusivity follows Arrhenius behavior at short times, independent of potentials and densities.
- Short-time nonergodic dynamics show similarity across different potentials, despite differing ergodic diffusivities.
- A rescaled nonergodic diffusivity, incorporating a correlation factor, reasonably estimates the true ergodic diffusivity.
Conclusions:
- Confirms a strong link between system fragility and dynamical correlation in supercooled liquids.
- Short-time nonergodic dynamics provide insights into the collective behavior of supercooled liquids.
- The developed rescaling method offers a way to estimate true ergodic diffusivity from nonergodic segments.
Related Concept Videos
02:39Phase Transitions: Melting and Freezing
14.3K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
14.3K
02:39Phase Transitions: Vaporization and Condensation
20.2K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
20.2K
01:09Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model
648
Various dissolution theories provide insight into the factors that influence the dissolution rate. Danckwerts' Model suggests that turbulence, rather than a stagnant layer, characterizes the dissolution medium at the solid-liquid interface. In this model, the agitated solvent contains macroscopic packets that move to the interface via eddy currents, facilitating the absorption and delivery of the drug to the bulk solution. The regular replenishment of solvent packets maintains the...
648
01:20Characteristics of Fluids
7.3K
When a force is applied parallel to the top surface of a solid, it resists the applied force due to the internal frictional forces between the layers of the solid known as shearing resistance. However, when the force is removed, the shearing forces restore the original shape of the solid. Other deformation forces also cause temporary changes in shape if the forces are not beyond a threshold magnitude. Solids tend to retain their shape, making the study of their rest and motion easier. Beyond...
7.3K
01:31Characteristics of Fluids
842
Fluids differ from solids primarily in their molecular structure and stress response. Solids have tightly packed molecules with strong intermolecular forces, maintaining their shape and resisting deformation. In contrast, fluids have molecules spaced farther apart with weaker forces, allowing them to flow and deform easily.
Fluids, which include both liquids and gases, are substances that deform continuously under shearing stress. For example, water and oil are liquids with molecules that can...
Fluids, which include both liquids and gases, are substances that deform continuously under shearing stress. For example, water and oil are liquids with molecules that can...
842
02:56Intermolecular Forces and Physical Properties
25.6K
25.6K