Using ultra-low temperatures and some steel balls, scientists have created an entirely new, strange form of ice that has the same density as liquid water. Known as medium-density amorphous ice, ice fits into a void in frozen water annuals that scientists are sure will never be filled. Unlike the naturally occurring crystalline ice on Earth, newly formed ice does not have an organized molecular structure.

Instead, its molecules are in a more glass-like chaotic discord – a state known as amorphous. Other forms of amorphous ice have been created before, but these were either much less dense or much denser than liquid water. In a new study published in the journal Goldilocks, this new version of amorphous ice is right in the middle and almost exactly matches the density of liquid water, the researchers explain. Science February 2nd.

“This is something completely new,” said the senior author of the study. Christoph SalzmannProfessor of Physical and Materials Chemistry at University College London.

ice grinding

When ice freezes normally Soil, its molecules form an organized crystal structure. This crystalline ice is one of the strangest properties of H2O because instead of sinking on liquid water, it floats as a solid. This is due to the relatively large voids in the crystal structure of fruity ice compared to other materials that form denser structures during crystallization.

However, when used properly, liquid water can also freeze in an uneven, amorphous state. The first of these states, low-density amorphous ice, was discovered in the 1930s. It is done by applying water vapor to very cold surfaces. Salzmann said this process occurs naturally in space, so low-density amorphous ice may be the most common form of ice in the universe.

In the 1980s, researchers discovered that they could make high-density amorphous ice by compressing normal ice at very low pressure. temperatures. But no one had made medium-density shapeless ice—until Salzman and his colleagues had a “crazy idea one Friday afternoon.” They decided to break the ice.

A ball mill is a device like a very advanced cocktail shaker. The material is put into the chamber containing the stainless steel balls and shaken or rotated until the material is crushed. Ball milling is used in many industries, but is particularly good for creating amorphous materials and pulverizing soft, frozen materials, Salzmann said.

“We said, ‘Why don’t we melt the ice in a ball mill and see what happens,'” Salzmann said.

Incredible features

The researchers expected the ball mill to simply break the ice crystals into smaller ice crystals. But it didn’t. Instead, the rolling steel balls cut and compressed the ice crystals, pushing them into a new state of disorder. Conclusion? Medium density amorphous ice.

Computer modeling showed that ice initially had a good crystalline state, with hydrogen bonds forming a hexagonal lattice. A random slip in the ball mill pushes these hydrogen bonds back and forth, orienting them up and down in a chaotic zigzag pattern.

The new form of ice forms at temperatures of 77 Kelvin, or minus 321 degrees Fahrenheit (minus 196 degrees Celsius). Besides its density of 1.06 grams per cubic centimeter (0.06 ounces per cubic inch), it has some strange properties. (The density of water is 1 gram per cubic centimeter, or 0.035 ounces per 0.06 cubic inch.) Among them, Salzmann said, was when researchers compressed medium-density ice and heated it to minus 185 F (minus 120 C). recrystallizes, releasing a large amount of heat.

“In other forms [аморфного] “If you squeeze the ice and release the pressure, it’s like nothing happened,” Salzmann said. [аморфний лід середньої щільності] Somehow it has the ability to store mechanical energy and release it through heat.”

Amorphous, medium-density ice can form naturally on the icy moons of giant planets, where the gravitational forces of massive worlds compress and slice the moons’ ice, Saltzman said. If so, the mechanical energy stored in this form of ice could affect the tectonics of these Hoth-like moons.

Understanding amorphous medium-density ice could help researchers better understand liquid water more generally, Salzmann said. Water is strange not only because its crystalline form floats, but also because it has other unique properties such as high surface tension and high melting and boiling points. Scientists are still debating about the nature of water at extremely low temperatures. Any discussion now needs to account for shapeless, medium-density ice, Salzmann said.