Water is a ubiquitous liquid with many extremely unique properties. The way it reacts to changes in pressure and temperature can be completely different from other liquids, and these properties are essential for many practical applications and especially for life as we know it. What causes these anomalies has long been a source of research, but now an international team of researchers, including Nicholas Giovambatista, a professor at CUNY, has proven that water can exist in two different liquid states ̵
“The possibility of water existing in two different liquid states was proposed about 30 years ago based on the results of computer simulations,” said Jovambatista. “This counter-intuitive hypothesis is one of the most important issues in water chemistry and physics and a controversial scenario from the outset. This is because the experiments that can gain access to the two liquid states in water are very challenging due to the obviously inevitable ice formation under the conditions under which both liquids must exist. “
The usual “liquid” state of water that we all know corresponds to liquid water at normal temperatures (approximately 25 degrees C). However, the paper shows that water at low temperatures (approximately -63 degrees C) exists in two different liquid states, a low-density liquid at low pressure and a high-density liquid at high pressure. These two liquids have noticeably different properties and differ by 20% density. The results suggest that, under appropriate conditions, water should exist as two immiscible liquids separated by a thin surface 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 – its phase behavior plays a major role in various fields, including biochemistry, climate, cryopreservation, cryobiology, materials science and in many industrial processes where water acts. as a solvent, product, reagent or impurity. It follows that unusual characteristics in the phase behavior of water, such as the presence of two liquid states, can affect many scientific and engineering applications.
“The question remains how the presence of two liquids can affect the behavior of aqueous solutions in general and in particular how both liquids can affect biomolecules in an aqueous medium,” said Jovambatista. “This motivates further research in search of potential applications.”
Jovambatista is a member of the doctoral degree in physics and chemistry. programs in CUNY.
An international team led by Anders Nilsson, a professor of chemical physics at Stockholm University, used sophisticated experiments and computer simulations to prove this theory. The experiments, described as “sci-fi” by Jovambatista, were performed by colleagues from Stockholm University in Sweden, POSTECH University in Korea, PAL-XFEL in Korea and the National SLAC Accelerator Laboratory in degrees California. The computer simulations were performed by Jovambatista and Peter H. Poole, a professor at St. Francis Xavier University in Canada. Computer simulations played an important role in the interpretation of the experiments, as these experiments are extremely complex and some observables are not available during the experiments.
Tetrahedra can explain the uniqueness of water
Experimental observation of the liquid-liquid transition in bulk supercooled water under pressure. Science (2020). science.sciencemag.org/lookup/… 1126 / science.abb9385
Provided by CUNY Advanced Science Research Center
Quote: Researchers prove that water has many liquid states (2020, November 19), extracted on November 19, 2020 from https://phys.org/news/2020-11-multiple-liquid-states.html
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