For the first time, researchers from Kobe University led by ONISHI Hiroshi observed the precise shape of ice at the ice-liquid interface.
Due to the complexity of the task, researchers used creative solutions to observe this phenomenon, such as using antifreeze and cooling the microscope system in a cool box to make accurate measurements.
They also experimented with different types of liquids to understand how they affect the surface of ice. Since ice is surrounded by liquid most of the time, and is therefore slippery, the key to understanding this mysterious relationship between ice and liquid lies in zooming in on this liquid layer (also on ice).
The ‘cool’ study of ice
Researchers say they first came up with the idea of measuring ice in antifreeze at temperatures below 0°C. Since water appears to be present no matter what, these conditions ensured that the state of the ice remained stable, allowing them to study the phenomenon without the ice melting.
Still, according to the press release, the experiments required a lot of trial and error to ultimately arrive at an innovative solution.
“We found that we had to cool the entire microscope system in a cold box, and it took some ingenuity to ensure that the atomic force microscope, a precision measuring instrument, could operate stably at subzero temperatures,” researchers from Kobe University explain.
Ice without this layer of liquid has “frost pillars” about 20 nanometers high. In antifreeze conditions it is flat with occasional molecular layers high, the press release said.
“We believe that the flat surface is formed by … partial dissolution and recrystallization of the ice surface in the 1-octanol liquid (the antifreeze),” the researchers were quoted as saying.
They also experimented with liquids such as alcohol, which changed the surface of the ice and its hardness. It fundamentally communicates the importance of measuring this relationship between ice and liquid, although it seems superficial.
They hope the study will stimulate more research into the ice-liquid interface. For the Kobe researchers, however, their plan is clear.
“We expect to increase the resolution of the microscope to single water molecules and use measurement methods other than atomic force microscopy. In this way, we hope to expand the range of possible applications of molecular-level measurements of the ice-antifreeze interface,” they conclude in a press release.
The phenomenon of liquid on ice
The surface of ice is covered with liquid water, anyway, which turns out to be a phenomenon. Interestingly, scientists do not yet know why there is always a thin layer of water on the surface of ice.
They have proposed pressure: the weight of a skate on ice, which could cause it to melt. However, that does not fully explain why all ice has this smooth layer.
Because the transmutation between ice and water happens quickly, scientists have yet to observe the relationship between ice and water. With the adjustments they made to the tools and process, the Kobe researchers were able to observe the nature of ice like never before, which will hopefully solve the mystery of why there is water on the surface of ice.
The findings were published in the Journal of Chemical Physics.
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Maria Mocerino Maria Mocerino is originally from LA and her work has been published in Business Insider, The Irish Examiner, The Rogue Mag, Chacruna Institute for Psychedelic Plant Medicines, and now Interesting Engineering.