The environment has often suffered from the catastrophic effects of an oil spill, the most recent example being the oil spill in the Gulf of Mexico. The search for ways to remove oil from polluted water is therefore urgent.
US scientists working with George John have now developed a novel gelator that solidifies the oil into a gel from which it can easily be later reclaimed. As the scientists from the City College of New York and the University of Maryland report in the journal Angewandte Chemie, their gel is based on compounds synthesized from natural sugars.
All previously developed substances meant to selectively remove spilled oil from water and contain it have various disadvantages. These substances include dispersants that emulsify the oil, solid powders that adsorb the oil, and gelators that solidify the oil into a gel. In the past, polymers were primarily used, though they were difficult to mix with viscous types of oil and the retrieval of the bound oil was a very complex process.
John and his colleagues propose a new class of gelators based on naturally occurring sugar alcohols. John lists the advantages, “They are inexpensive, easy to produce, nontoxic, and biodegradable.” Gelators are constructed so that their molecules aggregate through a self-organization process into a three-dimensional network of fibers. This network sucks up the oil molecules and swells into a gel with an enormous capacity.
The researchers mixed different types of oil—ranging from crude oil to diesel, gasoline, and organic solvents—with water and added a few drops of the new gelator. This immediately formed a gel that separated from the water phase. The gel became so solid that it closed off the reaction flask like a cork. The flask could be inverted without any spillage of liquid. “In case of an oil spill, it would be relatively easy to collect the gel from the surface of the water,” says John. Simple distillation under vacuum is all that is needed to fully release oil from the gel. After separation, both the oil and the gelator are ready to be used again.
“We are optimistic that our sugar-based gelators provide an approach for the development of new materials to combat oil slicks on water, says John.
Author: George John, City College of New York (USA), http://www.sci.ccny.cuny.edu/~john/index.html
Title: Sugar-Derived Phase-Selective Molecular Gelators as Model Solidifiers for Oil Spills
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201002095
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The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
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Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
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The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
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