Cool something to the required temperature, it turns into a solid crystal, read as classical theories of physics. Although possible, it is not always the case, and two researchers from the Institute of La Sapienza in Rome believe they have identified cases where the fluid-like state is more stable than solid crystal.
To achieve the desired result of the experiment, the details of which were published a few days ago in the journal «Nature Physics», scientists used computer simulations to create a water that is not classified liquid. Although the experiment was carried out in a virtual environment, it provides us with the main idea of forming crystals.
To get this unusual fluid, the researchers started with a colloid - liquids with suspended particles. A classic example of a colloid is milk - which is actually the water but appears white due to the large amount of suspended therein particles of fat and protein. Ice milk, it turns into a crystallized water, and all the white particles are separated from it and harden.
Colloid feature is that if the molecules are bound to each other in a certain way, the crystallization does not occur in it. Instead, stable colloid takes the form that appears solid, but has a molecular structure of the liquid.
The lead author of the study, physicist Frank Smollenburg, feigned a colloid on the computer and found out how it behaves at lower temperatures. Using a model with four molecular bonds, he found that if these bonds were tough, crystallization occurs quickly. However, if they were flexible, ties were disordered and formed lumpy agglomeration. On further cooling, they became like glass - disordered molecules that do not move, but form a kind of amorphous solid.
When we made these connections flexible enough, the liquid phase was stable even at extremely low temperatures, says Smollenburg. Particles simply refused to form a crystal, as long as they are not compressed to very high densities.
And the best part - this computer simulation also describes some of the real system. There polymers and large organic molecules such as DNA, which have similar characteristics. Likewise, even water can be simulated and quartz.
The next step will be the scientists experimenting with these materials for the study of polymers. Smollenburg reports that his group has teamed up with the French team, which investigates polymers that behave like quartz when heated. Having done some work, you can apply a new simulation and to these substances, said Smollenburg.
