Ice is more complex than most people realize, with over 20 different types known to science.
The ice we use in our drinks is called ice I, and it’s one of the few forms of ice naturally found on Earth.
But researchers from Japan have recently discovered a new type of ice, called ice 0, which can help us understand how ice crystals form in supercooled water.
In a study published in Nature Communications, scientists from the University of Tokyo found that ice 0 plays a unique role in the formation of ice.
They discovered that ice 0-like structures can cause water droplets to freeze near their surface, rather than at their core.
This finding helps solve a long-standing mystery about how ice forms and could change our understanding of ice formation.
Typically, ice forms through a process called ice nucleation, which usually happens on solid surfaces. For instance, we expect ice to start forming at the surface of a container where water meets the solid material.
However, this new research shows that ice can also form just below the water’s surface, where it meets the air. Here, tiny crystal precursors, with a structure similar to ice 0, help the ice to form.
Lead author Gang Sun explains that simulations have shown that water droplets are more likely to crystallize near the free surface under stable temperature conditions. This discovery answers the question of whether ice formation happens more easily on the surface or inside the water.
Ice 0 precursors have a structure similar to supercooled water, which allows water molecules to crystallize more easily. They don’t need to directly form into the structure of regular ice.
These tiny ice 0 precursors form spontaneously because of the negative pressure effects caused by the surface tension of water. Once crystallization starts from these precursors, they quickly rearrange themselves into the more familiar ice I.
Senior author Hajime Tanaka highlights the broad implications of this study, noting that understanding the mechanism of surface crystallization of water can significantly impact various fields, including climate studies and food sciences, where ice formation is crucial.
This research provides a more detailed understanding of ice and how it forms, offering valuable insights for many areas of study. For instance, in meteorology, the formation of ice via ice 0-like precursors might significantly affect small water droplets found in clouds. This understanding could also benefit technology, from food preservation to air conditioning.
Overall, this discovery of ice 0 and its role in ice formation opens up new possibilities for scientific research and practical applications, making our understanding of ice even more fascinating.
