The Weird New Solid That’s Actually A Liquid

Usually, if you cool any substance down enough it will turn into a solid — the most stable state of matter that exists, according to traditional physics. But that could all be about to change, because researchers have discovered a weird new liquid state that’s more stable than a solid crystal.



A team of scientists from La Sapienza University in Rome have used computer simulations to create a weird liquid that could help scientists create strange new materials in the future. Starting with a model of a colloid — a liquid with tiny particles suspended in it, like the way milk contains tiny fat globules — they were able to virtually cool the fluid until it took on a stable form that seemed solid but had the molecular structure of a liquid. Frank Smallenburg, one of the researchers, explains:

“A colloid has particles small enough that thermal energy is important… When we make the bonds more flexible, the liquid phase remains stable even at extremely low temperatures… The particles will simply never order into a crystal, unless they are compressed to high densities.”

In fact, if the fluid is cooled just right, the flexible bonds allow the virtual material to be cooled to super-low temperatures and behave like glass does at room temperature — part liquid, part solid. The key to the result is the bonds which exist in colloids. Solid crystals usually form as liquids cool because they require less energy to assume that kind of ordered structure; instead, it turns out, colloids with flexible bonds have more ways to connect with their fellow molecules when they’re a liquid. The research is published in Nature Physics.

The next step, of course, is to turn theory into practice, and use the newfound knowledge to create real materials that benefit from the finding — that might just take a little while. [Nature Physics via Live Science]