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Reversible structural transformations in supercooled liquid water from 135 to 245 K
Loni Kringle1, Wyatt A Thornley1, Bruce D Kay2
1Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, USA.
Science (New York, N.Y.)
|September 18, 2020
Summary
Researchers studied supercooled water's structure using laser heating. Findings reveal reversible structural changes, supporting mixture models for water's unique properties.
Area of Science:
- Physical Chemistry
- Materials Science
Background:
- Understanding water's anomalous properties is crucial but limited by experimental data at extreme conditions.
- Competing theories exist regarding water's behavior under supercooling.
Purpose of the Study:
- To investigate the structural transformations of supercooled water films under transient heating.
- To gather data at temperatures and pressures relevant to resolving competing water theories.
Main Methods:
- Transient laser heating of supercooled water films.
- Fast heating and subsequent quenching to 70 K.
- Analysis of structural evolution over several nanoseconds.
Main Results:
- Water structure reached a steady state before significant crystallization.
- Observed structural changes were reversible and reproducible.
- A decrease in high-temperature structural motifs was noted between 245 K and 190 K.
Conclusions:
- The results align with two-state mixture models for supercooled water.
- Structural dynamics are consistent with predictions in the supercritical regime.
- This study provides key data for understanding water's fundamental properties.
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