Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Warm water vibrates for longer


Dutch researcher Arjan Lock has investigated the behaviour of vibrating water molecules. Using ultra-short laser pulses, he found that hydrogen atoms in water molecules vibrate for longer at higher temperatures. This is abnormal because in the majority of substances a vibration lives shorter at higher temperatures.

Lock studied the OH-stretch vibration in water. He found that the lifetime of the OH-stretch vibration, a vibration of a hydrogen atom with respect to the oxygen atom, is extremely short in water, just 0.26 picoseconds (0.26 millionth, millionth of a second). The energy is then transferred from the OH-stretch vibration to a bend vibration in water.

At a higher temperature the lifetime of the vibration increases. This is completely contrary to the expected behaviour because in the majority of substances, the duration of the vibration is shorter at higher temperatures. In water however, higher temperatures weaken the hydrogen bonds and as a result of this the lifetime of the vibration increases.

After a certain period of time, the hydrogen atom will stop vibrating with respect to the oxygen atom and the vibrational energy will then be transferred to other movements. The time span in which that occurs is termed the lifetime of the vibration. If the molecule has a hydrogen bond, the frequency of the OH-stretch vibration decreases and the lifetime of the vibration changes.

The lifetime of the vibration is a measure of the strength of the hydrogen bonds. Hydrogen bonds are weak bonds between the hydrogen atom in one molecule and the oxygen atom in another molecule. These bonds bind the individual water molecules together.

Lock used a special ultrafast infrared laser for his experiments. This laser provides extremely short light pulses: 0.2 picoseconds. As these are slightly shorter than the duration of the vibrations, they can be used to carefully follow the behaviour of the vibrations.

In the experiments the researcher used two light pulses. The first energy-rich pulse causes the molecules to vibrate. With the second pulse Lock could examine how many molecules were still vibrating at a certain point in time after the first pulse. A water molecule that is still vibrating will not absorb the energy from the second light pulse. By measuring how much light passes through the water, the number of water molecules still vibrating can be determined.

The research was funded by the Netherlands Organisation for Scientific Research.

Sonja Jacobs | NWO
Further information:

More articles from Physics and Astronomy:

nachricht Sharpening the X-ray view of the nanocosm
23.03.2018 | Changchun Institute of Optics, Fine Mechanics and Physics

nachricht Drug or duplicate?
23.03.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

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: Space observation with radar to secure Germany's space infrastructure

Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.

The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

New solar solutions for sustainable buildings and cities

23.03.2018 | Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

Latest News

For graphite pellets, just add elbow grease

23.03.2018 | Materials Sciences

Unique communication strategy discovered in stem cell pathway controlling plant growth

23.03.2018 | Agricultural and Forestry Science

Sharpening the X-ray view of the nanocosm

23.03.2018 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>