Water is a universal liquid with numerous highly exceptional properties.
The manner in which it reacts to changes in pressure and temperature can be totally different in relation to different liquids, and these properties are essential to numerous useful practical applications and especially to life as we probably are aware. What causes these anomalies have for some time been a source of scientific investigation.
yet now, an international team of scientists that includes Nicolas Giovambattista, a professor at CUNY, has proved that water can exist in two different liquid states a finding that can clarify many of water’s anomalous properties.
Their research shows in a paper published in the November 20 issue of the journal Science.
Giovambattista said, “The possibility that water could exist in two different liquid states was proposed approximately 30 years ago, based on results obtained from computer simulations.”
“This counterintuitive hypothesis has been one of the most important questions in the chemistry and physics of water, and a controversial scenario since its beginnings. This is because experiments that can access the two liquid states in water have been very challenging due to the apparently unavoidable ice formation at the conditions where the two liquids should exist.”
The usual “liquid” state of water that we are all familiar with corresponds to liquid water at normal temperatures (approx. 25°C). but, the paper shows that water at low temperatures (approx. -63°C) exists in two different liquid states, a low-density liquid at low pressures and a high-density liquid at high pressures.
These two liquids have noticeably different properties and differ by 20 percent in density.
The outcomes suggest that at appropriate conditions, water should exist as two immiscible liquids separated by a thin interface similar to the coexistence of oil and water.
Because water is one of the most important substances on Earth the solvent of life as we know it.
It is phase behavior plays a fundamental role in different fields, including biochemistry, climate, cryopreservation, material science, cryobiology, and in many industrial processes where water acts as a product, solvent, reactant, or impurity.
It follows that unusual characteristics in the phase behavior of water, for example, the presence of two liquid states, can affect many scientific and engineering applications.
Giovambattista said, “It remains an open question how the presence of two liquids may affect the behavior of aqueous solutions in general, and in particular, how the two liquids may affect biomolecules in aqueous environments.”
“This motivates further studies in the search for potential applications.”