Tag Archives: Newcastle University

Trapping gases left from nuclear fuels

A July 20, 2014 news item on ScienceDaily provides some insight into recycling nuclear fuel,

When nuclear fuel gets recycled, the process releases radioactive krypton and xenon gases. Naturally occurring uranium in rock contaminates basements with the related gas radon. A new porous material called CC3 effectively traps these gases, and research appearing July 20 in Nature Materials shows how: by breathing enough to let the gases in but not out.

The CC3 material could be helpful in removing unwanted or hazardous radioactive elements from nuclear fuel or air in buildings and also in recycling useful elements from the nuclear fuel cycle. CC3 is much more selective in trapping these gases compared to other experimental materials. Also, CC3 will likely use less energy to recover elements than conventional treatments, according to the authors.

A July 21, 2014 US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL) news release (also on EurekAlert), which originated the news item despite the difference in dates, provides more details (Note: A link has been removed),

The team made up of scientists at the University of Liverpool in the U.K., the Department of Energy’s Pacific Northwest National Laboratory, Newcastle University in the U.K., and Aix-Marseille Universite in France performed simulations and laboratory experiments to determine how — and how well — CC3 might separate these gases from exhaust or waste.

“Xenon, krypton and radon are noble gases, which are chemically inert. That makes it difficult to find materials that can trap them,” said coauthor Praveen Thallapally of PNNL. “So we were happily surprised at how easily CC3 removed them from the gas stream.”

Noble gases are rare in the atmosphere but some such as radon come in radioactive forms and can contribute to cancer. Others such as xenon are useful industrial gases in commercial lighting, medical imaging and anesthesia.

The conventional way to remove xenon from the air or recover it from nuclear fuel involves cooling the air far below where water freezes. Such cryogenic separations are energy intensive and expensive. Researchers have been exploring materials called metal-organic frameworks, also known as MOFs, that could potentially trap xenon and krypton without having to use cryogenics. Although a leading MOF could remove xenon at very low concentrations and at ambient temperatures admirably, researchers wanted to find a material that performed better.

Thallapally’s collaborator Andrew Cooper at the University of Liverpool and others had been researching materials called porous organic cages, whose molecular structures are made up of repeating units that form 3-D cages. Cages built from a molecule called CC3 are the right size to hold about three atoms of xenon, krypton or radon.

To test whether CC3 might be useful here, the team simulated on a computer CC3 interacting with atoms of xenon and other noble gases. The molecular structure of CC3 naturally expands and contracts. The researchers found this breathing created a hole in the cage that grew to 4.5 angstroms wide and shrunk to 3.6 angstroms. One atom of xenon is 4.1 angstroms wide, suggesting it could fit within the window if the cage opens long enough. (Krypton and radon are 3.69 angstroms and 4.17 angstroms wide, respectively, and it takes 10 million angstroms to span a millimeter.)

The computer simulations revealed that CC3 opens its windows big enough for xenon about 7 percent of the time, but that is enough for xenon to hop in. In addition, xenon has a higher likelihood of hopping in than hopping out, essentially trapping the noble gas inside.

The team then tested how well CC3 could pull low concentrations of xenon and krypton out of air, a mix of gases that included oxygen, argon, carbon dioxide and nitrogen. With xenon at 400 parts per million and krypton at 40 parts per million, the researchers sent the mix through a sample of CC3 and measured how long it took for the gases to come out the other side.

Oxygen, nitrogen, argon and carbon dioxide — abundant components of air — traveled through the CC3 and continued to be measured for the experiment’s full 45 minute span. Xenon however stayed within the CC3 for 15 minutes, showing that CC3 could separate xenon from air.

In addition, CC3 trapped twice as much xenon as the leading MOF material. It also caught xenon 20 times more often than it caught krypton, a characteristic known as selectivity. The leading MOF only preferred xenon 7 times as much. These experiments indicated improved performance in two important characteristics of such a material, capacity and selectivity.

“We know that CC3 does this but we’re not sure why. Once we understand why CC3 traps the noble gases so easily, we can improve on it,” said Thallapally.

To explore whether MOFs and porous organic cages offer economic advantages, the researchers estimated the cost compared to cryogenic separations and determined they would likely be less expensive.

“Because these materials function well at ambient or close to ambient temperatures, the processes based on them are less energy intensive to use,” said PNNL’s Denis Strachan.

The material might also find use in pharmaceuticals. Most molecules come in right- and left-handed forms and often only one form works in people. In additional experiments, Cooper and colleagues in the U.K. tested CC3′s ability to distinguish and separate left- and right-handed versions of an alcohol. After separating left- and right-handed forms of CC3, the team showed in biochemical experiments that each form selectively trapped only one form of the alcohol.

The researchers have provided an image illustrating a CC3 cage,

Breathing room: In this computer simulation, light and dark purple highlight the cavities within the 3D pore structure of CC3. Courtesy:  PNNL

Breathing room: In this computer simulation, light and dark purple highlight the cavities within the 3D pore structure of CC3. Courtesy: PNNL

Here’s a link to and a citation for the paper,

Separation of rare gases and chiral molecules by selective binding in porous organic cages by Linjiang Chen, Paul S. Reiss, Samantha Y. Chong, Daniel Holden, Kim E. Jelfs, Tom Hasell, Marc A. Little, Adam Kewley, Michael E. Briggs, Andrew Stephenson, K. Mark Thomas, Jayne A. Armstrong, Jon Bell, Jose Busto, Raymond Noel, Jian Liu, Denis M. Strachan, Praveen K. Thallapally, & Andrew I. Cooper. Nature Material (2014) doi:10.1038/nmat4035 Published online 20 July 2014

This paper is behind a paywall.

Darwin’s barnacles become unglued

The world’s strongest glue comes from barnacles and those creatures have something to teach us. From a July 18, 2014 news item on Nanowerk,

Over a 150 years since it was first described by Darwin, scientists are finally uncovering the secrets behind the super strength of barnacle glue.

Still far better than anything we have been able to develop synthetically, barnacle glue – or cement – sticks to any surface, under any conditions.

But exactly how this superglue of superglues works has remained a mystery – until now.

An international team of scientists led by Newcastle University, UK, and funded by the US Office of Naval Research, have shown for the first time that barnacle larvae release an oily droplet to clear the water from surfaces before sticking down using a phosphoprotein adhesive.

A July 18, 2014 Newcastle University (UK) press release, which originated the news item, provides some context and describes the research,

“It’s over 150 years since Darwin first described the cement glands of barnacle larvae and little work has been done since then,” says Dr Aldred, a research associate in the School of Marine Science and Technology at Newcastle University, one of the world’s leading institutions in this field of research.

“We’ve known for a while there are two components to the bioadhesive but until now, it was thought they behaved a bit like some of the synthetic glues – mixing before hardening.  But that still left the question, how does the glue contact the surface in the first place if it is already covered with water?  This is one of the key hurdles to developing glues for underwater applications.

“Advances in imaging techniques, such as 2-photon microscopy, have allowed us to observe the adhesion process and characterise the two components. We now know that these two substances play very different roles – one clearing water from the surface and the other cementing the barnacle down.

“The ocean is a complex mixture of dissolved ions, the pH varies significantly across geographical areas and, obviously, it’s wet.  Yet despite these hostile conditions, barnacle glue is able to withstand the test of time.

“It’s an incredibly clever natural solution to this problem of how to deal with a water barrier on a surface it will change the way we think about developing bio-inspired adhesives that are safe and already optimised to work in conditions similar to those in the human body, as well as marine paints that stop barnacles from sticking.”

Barnacles have two larval stages – the nauplius and the cyprid.  The nauplius, is common to most crustacea and it swims freely once it hatches out of the egg, feeding in the plankton.

The final larval stage, however, is the cyprid, which is unique to barnacles.  It investigates surfaces, selecting one that provides suitable conditions for growth. Once it has decided to attach permanently, the cyprid releases its glue and cements itself to the surface where it will live out the rest of its days.

“The key here is the technology.  With these new tools we are able to study processes in living tissues, as they happen. We can get compositional and molecular information by other methods, but they don’t explain the mechanism.  There’s no substitute for seeing things with your own eyes. ” explains Dr Aldred.

“In the past, the strong lasers used for optically sectioning biological samples have typically killed the samples, but now technology allows us to study life processes exactly as they would happen in nature.”

The press release also notes some possible applications for these research findings (Note: Links have been removed),

Publishing their findings this week in the prestigious academic journal Nature Communications, author Dr Nick Aldred says the findings could pave the way for the development of novel synthetic bioadhesives for use in medical implants and micro-electronics.  The research will also be important in the production of new anti-fouling coatings for ships.

Here’s a link to and a citation for the paper,

Synergistic roles for lipids and proteins in the permanent adhesive of barnacle larvae by Neeraj V. Gohad, Nick Aldred, Christopher M. Hartshorn, Young Jong Lee, Marcus T. Cicerone, Beatriz Orihuela, Anthony S. Clare, Dan Rittschof, & Andrew S. Mount. Nature Communications 5, Article number: 4414 doi:10.1038/ncomms5414 Published 11 July 2014

This paper is behind a paywall although a free preview is available via ReadCube Access.

Phytoremediation, clearing pollutants from industrial lands, could also be called phyto-mining

The University of Edinburgh (along with the Universities of Warwick and Birmingham, Newcastle University and Cranfield University) according to its Mar. 4, 2013 news release on EurekAlert is involved in a phytoremediation project,

Common garden plants are to be used to clean polluted land, with the extracted poisons being used to produce car parts and aid medical research.

Scientists will use plants such as alyssum, pteridaceae and a type of mustard called sinapi to soak up metals from land previously occupied by factories, mines and landfill sites.

Dangerous levels of metals such as arsenic and platinum, which can lurk in the ground and can cause harm to people and animals, will be extracted using a natural process known as phytoremediation.

A Mar. 4, 2013 news item on the BBC News Edinburgh, Fife and East Scotland site offers more details about the project and the technology,

A team of researchers from the Universities of Edinburgh, Warwick, Birmingham, Newcastle and Cranfield has developed a way of extracting the chemicals through a process called phytoremediation, and are testing its effectiveness.

Once the plants have drawn contaminated material out of the soil, they will be harvested and processed in a bio-refinery.

A specially designed bacteria will be added to the waste to transform the toxic metal ions into metallic nanoparticles.

The team said these tiny particles could then be used to develop cancer treatments, and could also be used to make catalytic converters for cars.

Dr Louise Horsfall, of Edinburgh’s University’s school of biological sciences, said: “Land is a finite resource. As the world’s population grows along with the associated demand for food and shelter, we believe that it is worth decontaminating land to unlock vast areas for better food security and housing.

“I hope to use synthetic biology to enable bacteria to produce high value nanoparticles and thereby help make land decontamination financially viable.”

The research team said the land where phytoremediation was used would also be cleared of chemicals, meaning it could be reused for new building projects.

In my Sept. 28, 2012 posting I featured an international collaboration between universities in the UK, US, Canada, and New Zealand in a ‘phyto-mining’ project bearing some resemblance to this newly announced project. In that project, announced in Fall 2012, scientists were studying how they might remove platinum for reuse from plants near the tailings of mines.

I do have one other posting about phytoremediation. I featured a previously published piece by Joe Martin in a two-part series on the topic plant (phyto) and nano soil remediation. The March 30, 2012 posting is part one, which focuses on the role of plants in soil remediation.

Sea urchins taste yummy and (might) hold key to carbon capture

A prized sushi food item, sea urchins use nickel particles to convert carbon dioxide according to a Feb. 5, 2013 news item on ScienceDaily,

The discovery that sea urchins use nickel particles to harness carbon dioxide from the sea could be the key to capturing tons of carbon dioxide (CO2) from the atmosphere.

Experts at Newcastle University, UK, have discovered that in the presence of a nickel catalyst, CO2 can be converted rapidly and cheaply into the harmless, solid mineral, calcium carbonate.

This discovery, which is published February 5 in the academic journal Catalysis Science & Technology, has the potential to revolutionize the way we capture and store carbon enabling us to significantly reduce CO2 emissions — the key greenhouse gas responsible for climate change.

The Newcastle University Feb. 5, 2013 news release, which originated the news item, details how this discovery came about,

Dr Lidija Šiller, a physicist and Reader in Nanoscale Technology at Newcastle University, says the discovery was made completely by chance.

“We had set out to understand in detail the carbonic acid reaction – which is what happens when CO2 reacts with water – and needed a catalyst to speed up the process,” she explains.

“At the same time, I was looking at how organisms absorb CO2 into their skeletons and in particular the sea urchin which converts the CO2 to calcium carbonate.

“When we analysed the surface of the urchin larvae we found a high concentration of Nickel on their exoskeleton.  Taking Nickel nanoparticles which have a large surface area, we added them to our carbonic acid test and the result was the complete removal of CO2.”

Before discussing the implications it’s useful to understand the current situation regarding carbon capture processes, from the news release,

At the moment, pilot studies for Carbon Capture and Storage (CCS) systems propose the removal of CO2 by pumping it into holes deep underground.  However, this is a costly and difficult process and carries with it a long term risk of the gas leaking back out – possibly many miles away from the original downward source.

An alternative solution is to convert the CO2 into calcium or magnesium carbonate.

“One way to do this is to use an enzyme called carbonic anhydrase,” explains Gaurav Bhaduri, lead author on the paper and a PhD student in the University’s School of Chemical Engineering and Advanced Materials.

“However, the enzyme is inactive in acid conditions and since one of the products of the reaction is carbonic acid, this means the enzyme is only effective for a very short time and also makes the process very expensive.

“The beauty of a Nickel catalyst is that it carries on working regardless of the pH and because of its magnetic properties it can be re-captured and re-used time and time again. It’s also very cheap – 1,000 times cheaper than the enzyme.  And the by-product – the carbonate – is useful and not damaging to the environment.

“What our discovery offers is a real opportunity for industries such as power stations and chemical processing plants to capture all their waste CO2 before it ever reaches the atmosphere and store it as a safe, stable and useful product.”

Each year, humans emit on average 33.4 billion metric tons of CO2 – around 45% of which remains in the atmosphere.  Typically, a petrol-driven car will produce a ton of CO2 every 4,000 miles.

Calcium carbonate, or chalk, makes up around 4% of the Earth’s crust and acts as a carbon reservoir, estimated to be equivalent to 1.5 million billion metric tons of carbon dioxide.

It is the main component of shells of marine organisms, snails, pearls, and eggshells and is a completely stable mineral, widely used in the building industry to make cement and other materials and also in hospitals to make plaster casts.

The process developed by the Newcastle team involves passing the waste gas directly from the chimney top, through a water column rich in Nickel nano-particles and recovering the solid calcium carbonate from the bottom.

Dr Šiller adds: “The capture and removal of CO2 from our atmosphere is one of the most pressing dilemmas of our time.

“Our process would not work in every situation – it couldn’t be fitted to the back of a car, for example – but it is an effective, cheap solution that could be available world-wide to some of our most polluting industries and have a significant impact on the reduction of atmospheric CO2.”

According the news release the researchers have patented the process and are looking for investors as they plan for future development.

Phyto-mining and environmental remediation flower in the United Kingdom

Researchers on a £3 million research programme called “Cleaning Land for Wealth” (CL4W) are confident they’ll be able to use flowers and plants to clean soil of poisonous materials (environmental remediation) and to recover platinum (phyto-mining). From the Nov. 21, 2012 news item on Nanowerk,

A consortium of researchers led by WMG (Warwick Manufacturing Group) at the University of Warwick are to embark on a £3 million research programme called “Cleaning Land for Wealth” (CL4W), that will use a common class of flower to restore poisoned soils while at the same time producing perfectly sized and shaped nano sized platinum and arsenic nanoparticles for use in catalytic convertors, cancer treatments and a range of other applications.

The Nov. 20, 2012 University of Warwick news release, which originated the news item, describes both how CL4W came together and how it produced an unintended project benefit,

A “Sandpit” exercise organised by the Engineering and Physical Sciences Research Council (EPSRC) allowed researchers from WMG (Warwick Manufacturing group) at the University of Warwick, Newcastle University, The University of Birmingham, Cranfield University and the University of Edinburgh to come together and share technologies and skills to come up with an innovative multidisciplinary research project that could help solve major technological and environmental challenges.

The researchers pooled their knowledge of how to use plants and bacteria to soak up particular elements and chemicals and how to subsequently harvest, process and collect that material. They have devised an approach to demonstrate the feasibility in which they are confident that they can use common classes of flower and plants (such as Alyssum), to remove poisonous chemicals such as arsenic and platinum from polluted land and water courses potentially allowing that land to be reclaimed and reused.

That in itself would be a significant achievement, but as the sandpit progressed the researchers found that jointly they had the knowledge to achieve much more than just cleaning up the land.

As lead researcher on the project Professor Kerry Kirwan from WMG at the University of Warwick explained:

“The processes we are developing will not only remove poisons such as arsenic and platinum from contaminated land and water courses, we are also confident that we can develop suitable biology and biorefining processes (or biofactories as we are calling them) that can tailor the shapes and sizes of the metallic nanoparticles they will make. This would give manufacturers of catalytic convertors, developers of cancer treatments and other applicable technologies exactly the right shape, size and functionality they need without subsequent refinement. We are also expecting to recover other high value materials such as fine chemicals, pharmaceuticals, anti-oxidants etc. from the crops during the same biorefining process.”

I last mentioned phyto-mining in my Sept. 26, 2012 post with regard to an international project being led by researchers at the University of York (UK).  The biorefining processes (biofactories) mentioned by Kirwan takes the idea of recovering platinum, etc. one step beyond phyto-mining recovery.

Here’s a picture of the flower (Alyssum) mentioned in the news release,

Alyssum montanum photographed by myself in 1988, Unterfranken, Germany [http://en.wikipedia.org/wiki/Alyssum]

From the Wikipedia essay (Note: I have removed links],

Alyssum is a genus of about 100–170 species of flowering plants in the family Brassicaceae, native to Europe, Asia, and northern Africa, with the highest species diversity in the Mediterranean region. The genus comprises annual and perennial herbaceous plants or (rarely) small shrubs, growing to 10–100 cm tall, with oblong-oval leaves and yellow or white flowers (pink to purple in a few species).