Related Experiment Video
Updated: Oct 29, 2025
06:26
Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
7.3K
Structural and topological changes across the liquid-liquid transition in water
Riccardo Foffi1, John Russo1, Francesco Sciortino1
1Department of Physics, Sapienza Università di Roma, Piazzale Aldo Moro, 2, 00185 Rome, Italy.
The Journal of Chemical Physics
|July 9, 2021
Summary
Simulations reveal that the high-density liquid water structure arises from the folding of long hydrogen-bond rings, not just neighbor shell collapse. This provides new insights into water
Area of Science:
- Physical Chemistry
- Computational Chemistry
- Materials Science
Background:
- The TIP4P/Ice model of water allows numerical study in metastable equilibrium.
- Two distinct liquid states (high-density and low-density) exist at the same temperature and pressure below the critical point.
Purpose of the Study:
- To investigate the structural changes across the liquid-liquid transition in the TIP4P/Ice water model.
- To analyze the topological properties of the hydrogen-bond network during this transition.
Main Methods:
- Numerical simulations of the TIP4P/Ice model.
- Equilibration of two liquid states along a subcritical isotherm.
- Analysis of hydrogen-bond network topology.
Main Results:
- The high-density liquid structure is characterized by interstitial molecules.
- This structure originates from the folding back of long hydrogen-bond rings.
- Pairs of molecules become spatially proximate due to ring folding, rather than solely second neighbor shell collapse.
Conclusions:
- The folding of long hydrogen-bond rings is the primary driver of the high-density liquid structure.
- This topological rearrangement offers a new explanation for the observed structural changes in water.
- Understanding these transitions is crucial for various fields, including atmospheric and biological sciences.
More Related Videos
10:28Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
9.0K
11:38Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
8.2K
Related Concept Videos
01:23States of Water
54.6K
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
54.6K
02:31Phase Transitions
21.0K
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...
21.0K
02:39Phase Diagrams
45.7K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
45.7K
01:19Phase Diagram
6.3K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
6.3K
02:39Phase Transitions: Vaporization and Condensation
19.5K
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...
19.5K
02:44Heating and Cooling Curves
24.9K
When a substance—isolated from its environment—is subjected to heat changes, corresponding changes in temperature and phase of the substance is observed; this is graphically represented by heating and cooling curves.
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance, q, and its...
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance, q, and its...
24.9K