Scientists discovered a new state of a water molecule. They've found that under extreme confinement, water molecules reach a new tunneling state.
The new findings were made possible with the help of experiments at Tennessee's Oak Ridge National Laboratory's (ORNL's) Spallation Neutron Source and the Rutherford Appleton Laboratory in the United Kingdom. This revealed new features of water under ultra confinement in rocks, soil and cell walls.
"At low temperatures, this tunneling water exhibits quantum motion through the separating potential walls, which is forbidden in the classical world," said Alexander Kolesnikov of ORNL's Chemical and Engineering Materials Division. "This means that the oxygen and hydrogen atoms of the water molecule are 'delocalized' and, therefore, simultaneously present in all six symmetrically equivalent positions in the channel at the same time. It's one of those phenomena that only occur in quantum mechanics and has no parallel in our everyday experience."
Previous studies have shown the tunneling of atomic hydrogen in other systems. In this latest study, though, researchers saw the tunneling behavior of atomic hydrogen. The neutron scattering and computational chemistry experiments revealed that water molecules are delocalized around a ring so that the molecule turns into a double top-like shape in this tunneling state.
The existence of this tunneling state of water should help scientists better describe the thermodynamic properties and behavior of water in highly confined environments such as water diffusion and transport in the channels of cell membranes, in carbon nanotubes and along grain boundaries.
"This discovery represents a new fundamental understanding of the behavior of water and the way water utilizes energy," said Lawrence Anovitz of ORNL, co-author of the new study. "It's also interesting to think that those water molecules in your aquamarine or emerald ring - blue and green varieties of beryl - are undergoing the same quantum tunneling we've seen in our experiments."
The findings reveal a bit more about this tunneling state. More specifically, it may tell researchers how water reacts in certain environments. This is important for feats of engineering and also for better understanding processes that occur in these more-extreme locations.
The findings were published in the April edition of the journal Physical Review Letters.
