Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Data effort improves flow toward ’greener’ chemistry

22.04.2005


Jeopardy answer: Death Valley and "ionic liquids." Correct question: Where does a little bit of water make a whole lot of difference?


Molecular "space filling" models demonstrate the difference in size for the positively charged "anion" (top image) and the negatively charged "cation" (bottom left) that combine to form a promising ionic liquid. It is still a mystery how the much smaller water molecule (right) can have such a large effect on the viscosity of such ionic liquids.



Scientists at the National Institute of Standards and Technology (NIST) report* that flow properties for a relatively new class of alternative solvents called ionic liquids are extremely sensitive to tiny amounts of water. For example, for one of these solvents, just a 0.01 percent increase in water dissolved into a sample, caused a 1 percent decrease in flow resistance--a 100-fold effect. The finding should be helpful in the design of new industrial processes such as chemical separations that are both more efficient and more environmentally friendly.

Ionic liquids are salts. Just like table salt, ionic liquids consist of two components, one positively and one negatively charged. Unlike most simple salts, however, most of these new solvents are liquid at room temperature.


"People in industry are very interested in using ionic liquids because unlike most organic solvents, they don’t evaporate and they are not flammable," explains NIST’s Jason Widegren, lead author on the paper.

However, before ionic fluids can be used widely in industrial processes, reliable property data on characteristics like flow resistance (viscosity), density and thermal conductivity must be collected.

The new data help explain why reproducible measurements of viscosity for ionic liquids have been very difficult to achieve and published results have differed by 30 percent or more. Even the slightest contamination of samples with water vapor absorbed from the air dramatically affects measurements. The NIST group avoided these problems by carefully drying their samples and measuring water content both before and after each viscosity measurement.

The NIST work is part of a larger effort, conducted in conjunction with the International Union of Pure and Applied Chemistry, to perform "round robin" thermophysical property testing on the most promising ionic fluids and make the resulting data available to the scientific community.

Gail Porter | EurekAlert!
Further information:
http://www.nist.gov

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>