Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Oil and water: an icy interaction when oil chains are short, but steamy when chains are long

04.12.2012
Water transforms into a previously unknown structure in between a liquid and a vapor when in contact with alcohol molecules containing long oily chains, according to Purdue University researchers. However, around short oily chains water is more icelike.
Water plays a huge role in biological processes, from protein folding to membrane formation, and it could be that this transformation is useful in a way not yet understood, said Dor Ben-Amotz, the professor of chemistry who led the research.

Ben-Amotz's research team found that as they examined alcohols with increasingly long carbon chains, the transformation occurred at lower and lower temperatures.
When in contact with a chain seven carbon atoms long, the water molecules became much looser and more vaporlike at a temperature of 140 degrees Fahrenheit, which is about halfway between the melting and boiling points.

"For oils with chains longer than four carbons, or about one nanometer in length, we saw the water transform into a completely new structure as the temperature rose," Ben-Amotz said. "If the trend we saw holds true, then this transformation could be happening at body temperature around important physiological molecules like proteins and phospholipids."

Water responds very sensitively in its structure to small changes, he said.

"Water's versatility is what makes it so special," he said. "For instance, the surfaces of proteins have both oily and charged regions; and water changes itself to accommodate these very different components and everything in between. We are learning more about exactly how it does this."

The researchers found that water molecules interacting with the oil always formed a more ordered, icelike structure at lower temperatures, while the bulk of the water remained liquid. This ice-like structure would melt away as the temperatures increased and in longer molecules a new structure would appear, he said.
A paper detailing the National Science Foundation-funded work is published in the current issue of Nature and is also highlighted in a news and views article in the same issue. In addition to Ben-Amotz, co-authors include Purdue graduate student Joel Davis and postdoctoral fellows Kamil Gierszal and Ping Wang.

The team's observations add to a more than 70-year debate over the interaction of oil and water, with some studies suggesting that water forms little icebergs around the oil molecules, while others point to a more disordered, vaporlike water structure.
"This question was really up for grabs until we introduced an experimental method that could see these subtle changes in water structure," Ben-Amotz said. "Surprisingly, we found that both sides are right, and it depends on the size of the oil."

The challenge of the experiment was that the team needed to see the very small number of water molecules that are in contact with the oil chains in the presence of a very large number of other water molecules.
The team combined Raman scattering and multivariate curve resolution to create an analysis method capable of managing an unprecedented signal-to-noise ratio of 10,000-to-1.

"Most people never take a spectrum with a signal-to-noise ratio greater than 100-to-1, but if we performed this experiment that way we wouldn't see anything," Ben-Amotz said. "We needed to have a higher signal-to-noise ratio because we were looking for a needle in a mountain-sized haystack."

Raman scattering involves shooting a beam of light containing photons into a sample. As the photons hit molecules within the sample, they lose or gain energy. Such measurements create a spectrum of peaks that reveal the vibrational motions of the molecules present in the sample. Shifts in the peaks' shapes can show changes in the strength of bonds between water molecules and whether the molecules are becoming more or less ordered.

"With Raman scattering the bulk of the water creates a mountainous peak in the spectrum that buries everything else," Ben-Amotz said. "Multivariate curve resolution lets us see small changes in water structure under that mountain. As is often the case in science, the key was combining two already established techniques in a new way."

Davis said the team next plans to explore the effects of changes in pH and ionic charges on this transformation with the goal of making the experiments more relevant to proteins and biological systems.

"We are trying to better understand the driving forces of the behavior of proteins and cell membranes that are critical to our health," he said. "The role of water is an important piece of the puzzle."

Writer: Elizabeth K. Gardner, 765-494-2081, ekgardner@purdue.edu

Sources: Dor Ben-Amotz, 765-494-5256, bendor@purdue.edu

Joel Davis, jgdavis@purdue.edu

Elizabeth K. Gardner | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>