Related Experiment Video
Updated: Jun 27, 2026
06:26
Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Transient ordering in a quasi-two-dimensional binary liquid near freezing
Alice Shu-Yao Sheu1, Stuart A Rice
1Department of Chemistry and the James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA.
The Journal of Chemical Physics
|December 3, 2008
Summary
Locally ordered fluctuations in quasi-two-dimensional binary hard sphere mixtures were studied. Smaller spheres can suppress these fluctuations due to unfavorable entropy changes from demixing.
Area of Science:
- Physics
- Materials Science
- Statistical Mechanics
Background:
- Understanding liquid-state behavior is crucial for materials design.
- Locally ordered fluctuations influence phase transitions in hard sphere systems.
- Quasi-two-dimensional systems offer a unique platform to study these phenomena.
Purpose of the Study:
- To theoretically investigate locally ordered fluctuations in quasi-2D binary hard sphere mixtures.
- To analyze the impact of sphere size ratio, density, and concentration on fluctuation symmetry.
- To compare findings with one-component systems and identify differences.
Main Methods:
- Theoretical study using aperture cross-correlation function.
- Simulation of quasi-2D binary hard sphere mixtures with varying parameters.
- Analysis of structured fluctuations (hexagonal and square symmetries) in the liquid phase.
Main Results:
- Structured fluctuations with hexagonal and square symmetries exist in the liquid phase below freezing density.
- Fluctuation symmetry correlates with the symmetry of the resulting solid phase.
- The presence of smaller spheres can suppress structured fluctuations.
Conclusions:
- Binary hard sphere mixtures exhibit similarities and differences in structured fluctuations compared to one-component systems.
- Smaller spheres' impact on fluctuations is attributed to entropy changes from demixing.
- Findings provide insights into the fundamental behavior of dense liquid mixtures.
Related Concept Videos
02:39Phase Transitions: Melting and Freezing
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...
02:39Phase Transitions: Vaporization and Condensation
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...
02:33Phase Transitions: Sublimation and Deposition
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
01:27Two Components: Liquid–Liquid Systems
A pressure-composition phase diagram explicitly describes the behavior of an ideal solution of two volatile liquids under varying pressures and compositions. A pressure-composition diagram has two main curves. The bubble point curve represents the plot of pressure versus liquid mole fraction. It indicates the pressure at which the first bubble of vapor forms from the liquid phase as the system pressure decreases.The dew point curve is the pressure versus vapor mole fraction. It indicates the...
01:24Solid–Solid Solutions
The temperature-composition phase diagram of two solids, A and B, which are immiscible in the solid phase but form miscible liquids, shows that when the temperature is low, these two exist as separate, pure solids (A and B). As the temperature increases, they transition into a single-phase liquid solution where A and B coexist. Moving from point a1 to a2 in the phase diagram, the composition changes such that solid B begins to separate from the solution, enriching the remaining liquid with A.
02:31Phase Transitions
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...