. Earth Science News .
WATER WORLD
The ultrafast dance of liquid water
by Staff Writers
Stockholm, Sweden (SPX) May 23, 2018

A schematic of the approach used to capture water dynamics on the ultrafast timescale. If one were able to photograph the molecules in real space with different exposure times, the image would become gradually blurry because of the motion of the molecules. This is done with x-ray scattering in the so-called reciprocal space, where the diffraction pattern is gradually smoother for longer pulse durations.

Typically we consider that water molecules in the liquid state move randomly on ultrafast timescales due to thermal fluctuations. Now, scientists at Stockholm University have discovered correlated motion in water dynamics on a sub-100 femtoseconds timescale.

This appears as "caging effects" due to buildup of tetrahedral structures upon supercooling. The results, reported in Nature Communications on the 15th of May 2018 are based on a combination of experimental studies using x-ray lasers and theoretical simulations.

Liquid water is part of our everyday lives and due to its lack of color, taste and smell, it is often assumed to be very simple. On a molecular level the water molecule is indeed very simple, However, when many molecules come together they form a highly complex network of hydrogen bonds. The dynamics of this network is not yet fully understood and it is believed to be responsible for many of the peculiar thermodynamic and structural properties of liquid water.

An international team of researchers at Stockholm University carried out experiments at SLAC's Linac Coherent Light Source (LCLS) and probed for the first time the dynamics of molecules in liquid water in the sub-100 femtosecond range. The technique that was used relies on "photographing" the water molecules as a diffractogram using the x-ray laser.

By varying the x-ray pulse duration one essentially varies the exposure time of the "photograph" and thereby any motion of the water molecules during the exposure will "blur the picture".

Analysis of the blurring for different exposure times allowed the scientists to extract information about the molecular motion. On this timescale, it was assumed that water molecules move randomly due to heat, behaving more like a gas than a liquid. However the experiments indicate that the network plays a role even on this ultrafast timescale, making water molecules coordinate in an intricate dance, which becomes even more pronounced in the so called supercooled state.

"It is a brand new capability to be able to use x-ray lasers to see the motion of molecules in real time", says Fivos Perakis, researcher at Stockholm University with a background in ultrafast infrared spectroscopy.

"This can open up a whole new field of investigations on this timescales, combined with the unique structural sensitivity of x-rays."

The experimental results were reproduced by computer simulations, which indicate that the coordinated dance of water molecules is due to the formation of tetrahedral structures.

"I have studied the dynamics of liquid and supercooled water for a long time using computer simulations and it is very exciting to finally be able to directly compare with experiments" says Gaia Camisasca, postdoc at Stockholm university, who performed the computer simulations of this study.

"I look forward to seeing the future results that can come out from this technique, which can help improve the current water computer models".

"It is amazing to discover something new about water using x-ray ultrafast science and I feel that there is so much more to learn" says Alexander Spah, PhD student in Chemical Physics at Stockholm University.

"I really enjoy having the opportunity to use state-of-the-art x-ray facilities to investigate fundamental questions that could change our views on water."

"Both the experiments and simulations were very challenging", says Lars G.M. Pettersson, professor in Theoretical Chemical Physics at Stockholm University.

"It is extremely gratifying that working together can reveal so much about how the molecules move together."

"They key to understanding water on a molecular level is watching the changes of the hydrogen-bond network, which can play a major role in biological activity and life as we know it", says Anders Nilsson, professor in Chemical Physics at Stockholm University.

Research Report: "Coherent X-rays reveal the influence of cage effects on ultrafast water dynamics"


Related Links
Stockholm University
Water News - Science, Technology and Politics


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


WATER WORLD
Peatland contributions to UK water security
Leeds UK (SPX) May 21, 2018
Peatlands are vital to UK water security and must be protected to preserve the UK's water supply, say scientists. Scientists from the University of Leeds have developed a new global index that identifies water supplied from peatlands as a significant source of drinking water for the UK and the Republic of Ireland. The scientists estimated that in the UK 72.5% of the storage capacity of water supply reservoirs is peat-fed water. In the Republic of Ireland they estimated that drinking water fed by p ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

WATER WORLD
An electronic rescue dog

Brazil rescues African, Guyanese migrants drifting at sea

Latest shooting revives US arms control debate

National Guard role expanding on border: US Homeland chief

WATER WORLD
Keep the light off: A material with improved mechanical performance in the dark

Your body is transparentized in a virtual environment

Researchers use LiDAR to locate invasive fish and preserve a national treasure

Frequency-stable laser systems for space

WATER WORLD
Peatland contributions to UK water security

Only 1 pct of Japan's biggest coral reef healthy: survey

Even low concentrations of silver can foil wastewater treatment

NASA Satellites Reveal Major Shifts in Global Freshwater

WATER WORLD
Traditional knowledge sheds light on changing East Greenland climate and polar bear hunt

Antarctic seals can help predict ice sheet melt

Antarctica tourism regulation urgent for environment: summit

Ice stream draining Greenland Ice Sheet sensitive to changes over past 45,000 years

WATER WORLD
UN, EU call for global action to protect bees

French farmers furious over plans to release bears

Throwing out food

Some calories more harmful than others

WATER WORLD
Vanuatu to permanently evacuate volcanic island

Monitoring lava lake levels in Congo volcano

Dangerous 'laze' forms as Hawaii volcano lava reaches ocean

Continental shelf shape leads to long-lasting tsunami edge waves during Mexican earthquake

WATER WORLD
12 civilians killed in Mali market attack

Pay-backs to Africa from the Paris Agreement's temperature targets

African nations vow to recover stolen assets

In Lagos, the 'Venice of Africa' fights for survival

WATER WORLD
Trait tied to autism may explain emergence of realistic art

What we inherited from our bug-eating ancestors

Where hominid brains are concerned, size doesn't matter

UN: 68 percent of world population will live in urban areas by 2050









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.