Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New details of atomic structure of water under extreme conditions found

15.03.2013
Scientist from Dortmund, Helsinki, Potsdam, and the ESRF have revealed details of the microscopic atomic structure of water under extreme conditions. The results have now been published in the Proceedings of the National Academy of Sciences of the USA.

Liquid water remains a mystery even after decades of dedicated scientific investigations and researchers still struggle to fully describe its unusual structure and dynamics. At high temperatures and high pressures, water is in the so called supercritical state and exhibits a number of peculiar characteristics that are very unlike from water at ambient conditions.

In this state water is a very aggressive solvent, enabling chemical reactions impossible otherwise, e.g. the oxidization of hazardous waste or the conversion of aqueous biomass streams into clean water and gases like hydrogen and carbon dioxide.

High temperature and high pressure conditions can also be found inside the Earth, in its lower crust and upper mantle. Here, the unique properties of supercritical water have been believed to play a key role in the transfer of mass and heat as well as in the formation of ore deposits and volcanoes. Supercritical water is even thought to have contributed to the origin of life.

Knowledge of the structural properties of water on an atomic scale under these extreme conditions of high temperature and high pressure may become very helpful in understanding these processes, says Christoph Sahle, from the Department of Physics at the University of Helsinki and a member of the research team behind the new results.

Spectroscopic investigations confirm previous theoretical model

Now, a research team of scientists from the Technische Universität Dortmund, Germany, the University of Helsinki, Finland, the Deutsches GeoForschungsZentrum in Potsdam, Germany, and the European Synchrotron Radiation Facility (ESRF), Grenoble, France, have used x-ray spectroscopy to study the structural properties of water in the supercritical state.

Conventional spectroscopic analyses can provide key insights into the atomic structure of a substance, however, these techniques are not well suited to studying water under supercritical conditions because of the complicated sample environments in which supercritical water has to be contained. Using the intense x-ray radiation from the ESRF for inelastic x-ray scattering spectroscopy and a new technique that makes it possible to look at the chemistry of water inside a complex environment together with a quantum mechanical modeling framework known as density functional theory, the group of scientists has made these spectroscopic investigations of water at high temperature and high pressure feasible.

The researchers found that the measured inelastic x-ray scattering spectra evolve systematically from liquid-like at ambient conditions to more gas-like at high temperatures and pressures. To learn more about the local atomic structure of water at the tested conditions, theoretical inelastic x-ray scattering spectra from computer simulations were calculated and compared to the experimental data. All features found in the experimental data and the systematic changes of these features as a function of temperature and pressure could be reproduced by the calculation.

Based on this close resemblance of the calculated and measured data, the authors extracted detailed information about the atomic structure and bonding. They could show that, according to the theoretical model, the microscopic structure of water remains homogeneous throughout the range of examined temperatures and pressures.

The presented findings also implicate means to study unknown disordered structures and samples under extreme conditions on an atomic scale in depth even when other structural probing techniques fail.

Read more: Microscopic Structure of Water at Conditions of the Earth's Crust and Mantle, http://www.pnas.org/content/early/2013/03/07/1220301110

Additional information:

Christoph Sahle
tel. 358-9-191-59641
Yours truly,
Minna Meriläinen-Tenhu
Press officer
University of Helsinki
minna.merilainen@helsinki.fi

Christoph Sahle | EurekAlert!
Further information:
http://www.helsinki.fi

More articles from Earth Sciences:

nachricht Better model of water under extreme conditions could aid understanding of Earth's mantle
21.06.2018 | University of Chicago

nachricht The Janus head of the South Asian monsoon
21.06.2018 | Max-Planck-Institut für Chemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Better model of water under extreme conditions could aid understanding of Earth's mantle

21.06.2018 | Earth Sciences

What are the effects of coral reef marine protected areas?

21.06.2018 | Life Sciences

The Janus head of the South Asian monsoon

21.06.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>