Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Exploring the mysteries of supercooled water

01.03.2017

Physicists at Roma Tre University in Italy have developed a computer-based simulation to shed light on a thermodynamic property of water that can affect many biological and chemical processes

There are few things more central to life on earth than water. It dominates the physical landscape, covering much of the planet as oceans. It's also a major component of the human body, comprising, for example, more than 70% of the mass of a newborn baby.


Top left panel: Snapshot of a slice of water confined in the silica pore. The blue circle contains the 'free water,' the water molecules that are not in contact with the substrate. Bottom left panel: Density profile of the water molecules along the pore radius. The regions occupied respectively by the free water and the "bound water," water attached to the substrate, are indicated. Top right panel: The curves represent how the oxygen atoms of the molecules are arranged in shells around a given oxygen atom in the origin at different temperatures. The peaks represent the positions where the different shells are located. The structure is shown for some of the supercooled temperatures investigated. Bottom right panel: The main result of our computer simulation is given by the behavior of the excess entropy, a fraction of the total entropy, obtained from the oxygen structure of free water. The deviation of the calculated black points from the theoretical (red) curve indicates that water undergoes a change of behavior before and upon approaching the glass transition.

Credit: Margherita De Marzio, Gaia Camisasca, Maria Martin Conde, Mauro Rovere and Paola Gallo

Yet despite its omnipresence, water has many physical properties that are still not completely understood by the scientific community. One of the most puzzling relates to the activity of water molecules after they undergo a process called "supercooling."

Now, new findings from Roma Tre University, in Rome, Italy, on the interactions of water molecules under these exotic conditions appear this week in the Journal of Chemical Physics, from AIP Publishing.

"Normally, when liquid water is cooled below its freezing point, the water molecules arrange themselves in the ordered, crystal structure that is ice," said Paola Gallo, an associate professor of physics at Roma Tre University. "With supercooling, special techniques are employed to cool water very quickly in such a way that it remains a liquid even though its temperature has been lowered well below its freezing point. There are a number of anomalies in water molecules' activity in these supercooled conditions that have not yet been fully explained."

Using a computer-based simulation, Gallo and her colleagues shed light on a thermodynamic property of water that helps explain how water molecules in a supercooled state interact with each other and with the molecules of other materials.

"While supercooling is an important phenomenon to study, the challenge is that it's very difficult to supercool water in a lab," said Gallo.

In the past, scientists have attempted to address this issue by supercooling water "in confinement," focusing efforts on studying water confined in manufactured pores having a radius of a few namometers (i.e. one or two orders of magnitude larger than the diameter of the molecule of water). This, however, has raised a question of whether the properties of this confined water differ from that of bulk water, where water molecules interact freely in larger volumes.

"This question has been a point of ongoing interest in our work," said Gallo. "In previous studies, we have shown that interactions with other chemicals affect only those water molecules that are very physically close to the molecules of another chemical, such as the molecules that make up the wall of the pore. The water molecules at the center of the pore, the free water, retain many of the properties of bulk water."

"With this study, we discovered that there are further parallels," Gallo also said. "Specifically, our simulation shows that a property of the structure of the network of water molecules, which can be measured and verified experimentally, can be used to determine the changes in water's entropy, the thermodynamic quantity that measures disorder in a system [...] that may offer insights on some of the more unusual thermodynamic facets of water's activity in this supercooled state."

These findings create a framework for other experimental physicists to recreate the simulation with physical samples in a lab. For Gallo and her colleagues, their work offers a foundation for further investigation of the relationships between the thermodynamic characteristics of confined and bulk water.

"Water is the most important liquid that we have on earth," explained Gallo. "Any insights that researchers can uncover about its properties can advance not only our collective understanding of physics, but also of biology and chemistry, and open up new possibilities for integrating this knowledge into different technological applications."

###

The article, "Structural properties and fragile to strong transition in confined water," is authored by Margherita De Marzio, Gaia Camisasca, Maria Martin Conde, Mauro Rovere and Paola Gallo. The article will appear in The Journal of Chemical Physics Feb. 28, 2017 [DOI:10.1063/1.4975624]. After that date, it can be accessed at http://aip.scitation.org/doi/full/10.1063/1.4975624.

ABOUT THE JOURNAL

The Journal of Chemical Physics publishes concise and definitive reports of significant research in the methods and applications of chemical physics. See http://jcp.aip.org.

Media Contact

AIP Media Line
media@aip.org
301-209-3090

 @jasonbardi

http://www.aip.org 

AIP Media Line | EurekAlert!

Further reports about: human body supercooled water thermodynamic water molecules

More articles from Physics and Astronomy:

nachricht Structured light and nanomaterials open new ways to tailor light at the nanoscale
23.04.2018 | Academy of Finland

nachricht On the shape of the 'petal' for the dissipation curve
23.04.2018 | Lobachevsky University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>