Water under inner pressure: a dielectric spectroscopy study.

Area of Science:

• Physical Chemistry
• Condensed Matter Physics
• Materials Science

Background:

• Water exhibits anomalous properties, particularly at low temperatures and high pressures, which are not fully understood.
• Understanding water's unique structural and dynamical behaviors is crucial across various scientific disciplines.

Purpose of the Study:

• To investigate the dielectric properties of cold water under macroscopically constrained, constant-volume conditions.
• To explore anomalous behaviors of water that prevent freezing below its normal melting point.

Main Methods:

• Dielectric spectroscopy measurements were performed on cold water confined in a large container at constant volume.
• Experiments were conducted at temperatures and pressures where water would typically freeze but remained liquid due to confinement.

Main Results:

• Constrained conditions induced an internal pressure, shifting the alpha relaxation peak to frequencies characteristic of ice Ih.
• A peculiar dielectric response was observed at 267 K, potentially related to the Grotthuss mechanism.
• At 251 K, the triple point, the formation of ice III was observed.

Conclusions:

• Macroscopically constrained conditions significantly alter water's dynamical properties, mimicking some aspects of ice.
• The observed phenomena provide new avenues for studying water's anomalous behavior and the Grotthuss mechanism.