Water behaves strangely at low temperatures. What comes from?

Recent research shows that water at lower temperatures breaks down into two different liquids. One behaves like a colloid, and the other is just the opposite. What comes from?

A new type of phase transition in water was first proposed 30 years ago by scientists at Boston University. This transition was expected to occur under supercooling conditions, but confirming this has been challenging. This is because, under low-temperature conditions, water “does not want” to be a liquid, and instead turns into ice.

Currently Researchers from the University of Birmingham She found evidence of a liquid-to-liquid phase transition, which was proposed by the professor in 1992. Francesco Scortino. Computer simulations were used to help elucidate what characterizes these fluids at the microscopic level. They found that water molecules in systems with a high-density liquid form are considered “topologically complex,” such as paddle knots (molecules arranged to resemble a pretzel) or a Hopf bond (two bonds in a steel chain).

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The particles in a high-density liquid are entangled, while the particles in a low-density liquid tend to form straight rings, so the particles in a low-density liquid are not entangled. Details are described in Nature Physics.

This study gives us a fresh perspective on what has now become a 30-year research problem – and we hope this is just the beginning.Andreas Neuveto of the University of Birmingham

double-sided water

The scientists used a colloidal water model as well as two common molecular water models in the simulation. Colloids are molecules that can be up to a thousand times the size of a single water molecule. Colloidal materials are used to observe and understand physical phenomena that also occur on much smaller atomic and molecular length scales.

In this work, we propose for the first time to take a look at the liquid-to-liquid phase transition based on the network entanglement idea. I am sure this work will inspire cutting edge theoretical modeling based on topological concepts.a. Francesco Scortino from the University of Birmingham

The scientists expect that their model will pave the way for new experiments that validate the theory and expand the concept of “entangled” fluids to other fluids.