Ice 0 is Ice Shape If it is possible to induce the formation of ice crystals in supercooled water, University of Tokyo.
Ice nucleation in water nanodroplets at 180 K (minus 93.15 degrees Celsius, minus 135.76 degrees Fahrenheit). Image courtesy of G. Sun & H. Tanaka, doi: 10.1038/s41467-024-50188-1.
“Ice crystallization, known as ice nucleation, usually occurs heterogeneously, in other words, on solid surfaces,” said University of Tokyo researchers Gan Song and Hajime Tanaka.
“This is typically expected to occur at the surface of a container of water, where the liquid and solid meet.”
“But our study shows that ice crystallization can also occur just below the water surface, in contact with the air.”
“Here, ice nucleates around a small precursor that has the same characteristic ring-like structure as ice-0.”
“Simulations show that under isothermal conditions, water droplets are likely to crystallize near the free surface,” Dr Sun added.
“This settles a long-standing debate about whether crystallization occurs more easily on the surface or in the interior.”
The precursor to ice-0 has a structure very similar to supercooled water, which allows water molecules to crystallize more easily without having to form directly into the structure of regular ice.
These form naturally as a result of the negative pressure effect caused by the surface tension of water.
When crystallization begins from these precursors, the ice-0-like structure rapidly rearranges into the more typical ice-I.
“Our discovery of the mechanism behind water surface crystallization is expected to make significant contributions to various fields, such as climate research and food science, where water crystallization plays an important role,” said Dr. Tanaka.
“Understanding ice in more detail and how it forms can provide valuable insights into many different fields of research.”
“This work may be particularly important in meteorology, because the formation of ice from precursors such as ice-0 may have a much more pronounced effect on tiny water droplets such as those found in clouds.”
“Understanding ice also has benefits in technology, from food science to air conditioning.”
Team paper Published online in the journal Nature Communications.
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G. Sun & H. Tanaka. 2024. Surface-induced water crystallization driven by precursors formed in a negative pressure region. Nat Community 15, 6083; doi: 10.1038/s41467-024-50188-1
This article is based on a press release from the University of Tokyo.
Source: www.sci.news
