- Tram Ho
Until now, it was mistakenly thought that glass was a liquid. But that’s not really true – glass is essentially an amorphous solid. Normally, when a matter changes from a liquid to a solid, the free-floating atoms that previously would “line up” into a cramped crystal structure. However, that doesn’t happen with glass: its atoms “freeze” in a state of chaos.
Or at least that’s a constant situation. In a new study, scientists have discovered a form of glass where the atoms exhibit a rather complex behavior, never before seen in bulk glass. These atoms can move, but cannot rotate.
The team discovered this in a sample system of colloidal suspensions. This mixture is made up of large solid particles suspended in a liquid, making it easy for scientists to observe the physical behavior of atoms or molecules. Usually, these particles are spherical, but in this experiment the team used elliptical particles to see which direction they were pointing.
Researchers have tested various concentrates of particles in the liquid, tracking how they move and rotate. Eventually, they found that at a high concentration the particles would prevent each other’s rotation, but they were still moving, creating a state called liquid glass.
” At certain particle densities, the directional motion is stopped, while the translational motion continues, leading to glass states in which the particles gather in clusters to form local structures. with similar directions “- says lead author of the study, Andreas Zumbusch.
The behavior they observe comes from the interaction of two types of glass motions, the team said. Liquid glass is something that has been predicted for decades, and the new results suggest similar processes may also play a role in other glass-based systems.
” This is particularly interesting from a theoretical point of view ” – says Matthias Fuchs, study author. ” Our trials have provided evidence of the interplay between the significant fluctuations and the cessation of glass that the scientific community has long sought .”
Source : Genk