Tag Archives: France

Graphene and an artificial retina

A graphene-based artificial retina project has managed to intermingle the European Union’s two major FET (Future and Emerging Technologies) funding projects, 1B Euros each to be disbursed over 10 years, the Graphene Flagship and the Human Brain Project. From an Aug. 7, 2014 Technische Universitaet Muenchen (TUM) news release (also on EurekAlert),

Because of its unusual properties, graphene holds great potential for applications, especially in the field of medical technology. A team of researchers led by Dr. Jose A. Garrido at the Walter Schottky Institut of the TUM is taking advantage of these properties. In collaboration with partners from the Institut de la Vision of the Université Pierre et Marie Curie in Paris and the French company Pixium Vision, the physicists are developing key components of an artificial retina made of graphene.

Retina implants can serve as optical prostheses for blind people whose optical nerves are still intact. The implants convert incident light into electrical impulses that are transmitted to the brain via the optical nerve. There, the information is transformed into images. Although various approaches for implants exist today, the devices are often rejected by the body and the signals transmitted to the brain are generally not optimal.

Already funded by the Human Brain Project as part of the Neurobotics effort, Garrido and his colleagues will now also receive funding from the Graphene Flagship. As of July 2014, the Graphene Flagship has added 86 new partners including TUM according to the news release.

Here’s an image of an ‘invisible’ graphene sensor (a precursor to developing an artificial retina),

Graphene electronics can be prepared on flexible substrates. Only the gold metal leads are visible in the transparent graphene sensor. (Photo: Natalia Hutanu / TUM)

Graphene electronics can be prepared on flexible substrates. Only the gold metal leads are visible in the transparent graphene sensor. (Photo: Natalia Hutanu / TUM)

Artificial retinas were first featured on this blog in an Aug. 18, 2011 posting about video game Deus Ex: Human Revolution which features a human character with artificial sight. The post includes links to a video of a scientist describing an artificial retina trial with 30 people and an Israeli start-up company, ‘Nano Retina’, along with information about ‘Eyeborg’, a Canadian filmmaker who on losing an eye in an accident had a camera implanted in the previously occupied eye socket.

More recently, a Feb. 15, 2013 posting featured news about the US Food and Drug Administration’s decision to allow sale of the first commercial artificial retinas in the US in the context of news about a neuroprosthetic implant in a rat which allowed it to see in the infrared range, normally an impossible feat.

It’s an ‘Alice in Wonderland’ world where a particle can be separated from its properties

In a joint research project, French, Austrians, and American researchers have achieved a state described in Lewis Carroll’s well loved story, Alice in Wonderland. (Three of the four institutions involved have issued news releases, as this is the only one to feature a quote from Alice in Wonderland describing the state, it gets mentioned first.) From a July 29, 2014 Chapman University news release on EurekAlert,

… “Well! I’ve often seen a cat without a grin,” thought Alice in Wonderland, “but a grin without a cat! It’s the most curious thing I ever saw in my life!” Alice’s surprise stems from her experience that an object and its property cannot exist independently. It seems to be impossible to find a grin without a cat. However, the strange laws of quantum mechanics (the theory which governs the microscopic world of atoms; and the most successful theory in history) tell us that it is indeed possible to separate a particle from its properties—a phenomenon which is strikingly analogous to the Cheshire Cat story. The quantum Cheshire Cat is the latest example of how strange quantum mechanics becomes when viewed through the lens of one of Aharonov’s fundamental discoveries called the “weak measurement.”

Modesty does not favour contemporary research and educational institutions and, as is common in situations where there’s significant scientific excitement with a number of collaborators, the cooperating institutions are angling to establish the importance of their institutions and/or researchers’ contributions.

Here’s more from the Chapman  University news release where it establishes its claim to the theory,

The idea of the Quantum Cheshire Cat was first discovered by Chapman’s Prof. Yakir Aharonov and first published by Aharonov’s collaborator, Prof. Jeff Tollaksen (also at Chapman University), in 2001. Aharonov’s team, including Sandu Popescu (University of Bristol and Chapman’s Institute for Quantum Studies) and Daniel Rorhlich (Ben Gurion University), continued to develop the Cheshire Cat theory in more recent publications.

A July 29, 2014 Vienna University of Technology news release on EurekAlert provides this description and its claim to inventing the technique used in the latest experimental work,

According to the law of quantum physics, particles can be in different physical states at the same time. If, for example, a beam of neutrons is divided into two beams using a silicon crystal, it can be shown that the individual neutrons do not have to decide which of the two possible paths they choose. Instead, they can travel along both paths at the same time in a quantum superposition.

“This experimental technique is called neutron interferometry”, says Professor Yuji Hasegawa from the Vienna University of Technology. “It was invented here at our institute in the 1970s, and it has turned out to be the perfect tool to investigate fundamental quantum mechanics.”

A July 29, 2014 Institut Laue-Langevin (international research institute located in Grenoble, France) news release on EurekAlert establishes its claim as the location for the experimental work,

Researchers from the Vienna University of Technology have performed the first separation of a particle from one of its properties. The study, carried out at the Institute Laue-Langevin (ILL) and published in Nature Communications, showed that in an interferometer a neutron’s magnetic moment could be measured independently of the neutron itself, thereby marking the first experimental observation of a new quantum paradox known as the ‘Cheshire Cat’. The new technique, which can be applied to any property of any quantum object, could be used to remove disturbance and improve the resolution of high precision measurements.

The fourth collaborating institution (l’Université de Cergy-Pontoise) does not seem to have issued a news release in either French or English as per my August 8, 2014 searches.

The research itself is quite fascinating and it’s worth reading all three news releases for additional nuggets information hidden amongst the repetitive bits. Here’s a description you’ll find in both the Vienna University of Technology and Chapman University news releases,

Neutrons are not electrically charged, but they carry a magnetic moment. They have a magnetic direction, the neutron spin, which can be influenced by external magnetic fields.

First, a neutron beam is split into two parts in a neutron interferometer. Then the spins of the two beams are shifted into different directions: The upper neutron beam has a spin parallel to the neutrons’ trajectory, the spin of the lower beam points into the opposite direction. After the two beams have been recombined, only those neutrons are chosen, which have a spin parallel to their direction of motion. All the others are just ignored. “This is called postselection”, says Hermann Geppert. “The beam contains neutrons of both spin directions, but we only analyse part of the neutrons.”

These neutrons, which are found to have a spin parallel to its direction of motion, must clearly have travelled along the upper path – only there, the neutrons have this spin state. This can be shown in the experiment. If the lower beam is sent through a filter which absorbs some of the neutrons, then the number of the neutrons with spin parallel to their trajectory stays the same. If the upper beam is sent through a filter, than the number of these neutrons is reduced.

Things get tricky, when the system is used to measure where the neutron spin is located: the spin can be slightly changed using a magnetic field. When the two beams are recombined appropriately, they can amplify or cancel each other. This is exactly what can be seen in the measurement, if the magnetic field is applied at the lower beam – but that is the path which the neutrons considered in the experiment are actually never supposed to take. A magnetic field applied to the upper beam, on the other hand, does not have any effect.

“By preparing the neurons in a special initial state and then postselecting another state, we can achieve a situation in which both the possible paths in the interferometer are important for the experiment, but in very different ways”, says Tobias Denkmayr. “Along one of the paths, the particles themselves couple to our measurement device, but only the other path is sensitive to magnetic spin coupling. The system behaves as if the particles were spatially separated from their properties.”

Here’s an illustration the researchers have provided,

Caption: The basic idea of the Quantum Cheshire Cat: In an interferometer, an object is separated from one if its properties -- like a cat, moving on a different path than its own grin. Credit: TU Vienna / Leon Filter

Caption: The basic idea of the Quantum Cheshire Cat: In an interferometer, an object is separated from one if its properties — like a cat, moving on a different path than its own grin.
Credit: TU Vienna / Leon Filter

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

Observation of a quantum Cheshire Cat in a matter-wave interferometer experiment by Tobias Denkmayr, Hermann Geppert, Stephan Sponar, Hartmut Lemmel, Alexandre Matzkin, Jeff Tollaksen, & Yuji Hasegawa. Nature Communications 5 Article number: 4492 doi:10.1038/ncomms5492 Published 29 July 2014

This is an open access paper.

Perhaps in response to concerns about the importance of theoretical physics, Chapman University’s Jeff Tollaksen offers this about possible applications  (from the Chapman University news release),

Co-Director of the Institute for Quantum Studies, Prof. Jeff Tollaksen has said: “Theoretical physics has yielded the most significant benefits for our society at the lowest costs. Discoveries in fundamental physics often lead to new industries: from electricity to smartphones to satellites. Quantum physics resulted in technological advances that drive our economy, such as the entire computer revolution, electronics, and the nuclear power industry. In addition, it impacts many other disciplines such as genetics, medicine and mathematics. Experts therefore estimate that nearly half the wealth created in the 20th century arose from quantum physics. At the Institute, we’re committed to producing the next generation of breakthroughs which will lead to the technology of the 21st century. Similarly, I’m sure this breakthrough will lead to many new applications including revised intuitions which can then serve as a guide to finding novel quantum effects.” This “Quantum Cheshire Cat” could be used for practical applications. For example, it could be used to make high precision measurements less sensitive to external perturbations. The measurements which now have been published in Nature Communications are the first experimental proof of this phenomenon.

By contrast the Europeans offer this,

With their landmark observation suitably vindicated, questions turn to the potential impact of their fundamental discovery. One application might high precision measurements of quantum systems which are often affected by disturbance.  [from the Institut Laue-Langevin news release]

Or, there’s this,

This counter intuitive effect is very interesting for high precision measurements, which are very often based on the principle of quantum interference. “When the quantum system has a property you want to measure and another property which makes the system prone to perturbations, the two can be separated using a Quantum Cheshire Cat, and possibly the perturbation can be minimized”, says Stephan Sponar. [from the Vienna University of Technology news release]

The contrast is certainly interesting.

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.

Carbon nanotubes: OCSiAl’s deal in Korea and their effect on the body after one year

I have two news items related only by their focus on carbon nanotubes. First, there’s a July 3, 2014 news item on Azonano featuring OCSiAl’s deal with a Korean company announced at NANO KOREA 2014,

At NANO KOREA 2014 OCSiAl announced an unprecedentedly large-scale deal with Korean company Applied Carbon Nano Technology [ACN] Co., Ltd. – one of the key industry players.

OCSiAl, the dominating graphene tubes manufacturer, that successfully presented its products and technology in Europe and USA, now to enter Asian nanotech markets. At NANO KOREA 2014 the company introduced TUBALL, the universal nanomodifier of materials featuring >75% of single wall carbon nanotubes, and announced signing of supply agreement with Applied Carbon Nano Technology Co., Ltd. (hereinafter referred to as ACN), a recognized future-oriented innovative company.

A July 3, 2014 OCSiAl news release, which originated the news item, describes the memorandum of understanding (MOU) in greater detail,

Under this MoU ACN would buy 100 kg of TUBALL. The upcoming deal is the first of OCSiAl’s Korean contracts to be performed in 2015 and it turns up the largest throughout SWCNT market, which annual turnover recently hardly reached 500 kg. The agreement is exceptionally significant as it opens fundamental opportunities for manufacturing of new nanomaterial-based product with the unique properties that were not even possible before.

“OCSiAl’s entry to Korean market required thorough preparation. We invested time and efforts to prove that our company, our technology and our products worth credibility, – says Viktor Kim, OCSiAl Vice President, – we urged major playmakers to take TUBALL for testing to verify the quality and effectiveness. We believe that ACN is more than an appropriate partner to start – they are experts at the market and they understand its future perspectives very clearly. We believe that mutually beneficial partnership with ACN will path the way for future contracts, since it will become indicative to other companies in Asia and all over the world”.

“It comes as no surprise that OCSiAl’s products here in Korea will be in a great demand soon. The country strives to become world’s leader in advanced technology, and we do realize the benefits of nanomaterial’s exploitation. TUBALL is a truly versatile additive which may be used across many market sectors, where adoption of new materials with top-class performance is essential”, – says Mr. Dae-Yeol Lee, CEO of ACN.

OCSiAl’s entering to Korean market will undoubtedly have a high-reaching impact on the industry. The recent merger with American Zyvex Technologies made OCSiAl the not only the world’s largest nanomaterial producer but a first-rate developer of modifiers of different materials based on carbon nanotubes. To its Korean partners OCSiAl offers TUBALL, the raw ‘as produced’ SWCNT material and masterbatches, which can be either custom-made or ready-to-use mixtures for different applications, including li-ion batteries, car tires, transparent conductive coatings and many others. “Since Korea is increasingly dynamic, our success here will build on continuous development of our product, – adds Viktor Kim, – And we are constantly working on new applications of graphene tubes to meet sophisticated demands of nanotech-savvy Korean consumers”.

OCSiAl’s Zyvex acquisition was mentioned in a June 23, 2014 posting here.

My second tidbit concerns a July 4, 2014 news item on Nanowerk about carbon nanotubes and their effect on the body (Note: A link has been removed),

Having perfected an isotope labeling method allowing extremely sensitive detection of carbon nanotubes in living organisms, CEA and CNRS researchers have looked at what happens to nanotubes after one year inside an animal. Studies in mice revealed that a very small percentage (0.75%) of the initial quantity of nanotubes inhaled crossed the pulmonary epithelial barrier and translocated to the liver, spleen, and bone marrow. Although these results cannot be extrapolated to humans, this work highlights the importance of developing ultrasensitive methods for assessing the behavior of nanoparticles in animals. It has been published in the journal ACS Nano (“Carbon Nanotube Translocation to Distant Organs after Pulmonary Exposure: Insights from in Situ 14C-Radiolabeling and Tissue Radioimaging”).

A July 1, 2014 CNRS [France Centre national de la recherche scientifique] press release, which originated the news item, describes both applications for carbon nanotubes and the experiment in greater detail,

Carbon nanotubes are highly specific nanoparticles with outstanding mechanical and electronic properties that make them suitable for use in a wide range of applications, from structural materials to certain electronic components. Their many present and future uses explain why research teams around the world are now focusing on their impact on human health and the environment.

Researchers from CEA and the CNRS joined forces to study the distribution over time of these nanoparticles in mice, following contamination by inhalation. They combined radiolabeling with radio imaging tools for optimum detection sensitivity. When making the carbon nanotubes, stable carbon (12C) atoms were replaced directly by radioactive carbon (14C) atoms in the very structure of the tubes. This method allows the use of carbon nanotubes similar to those produced in industry, but labeled with 14C. Radio imaging tools make it possible to detect up to twenty or so carbon nanotubes on an animal tissue sample.

A single dose of 20 µg [micrograms] of labeled nanotubes was administered at the start of the protocol, then monitored for one year. The carbon nanotubes were observed to translocate from the lungs to other organs, especially the liver, spleen, and bone marrow. The study demonstrates that these nanoparticles are capable of crossing the pulmonary epithelial barrier, or air-blood barrier. It was also observed that the quantity of carbon nanotubes in these organs rose steadily over time, thus demonstrating that these particles are not eliminated on this timescale. Further studies will have to determine whether this observation remains true beyond a year.

The CEA [French Alternative Energies and Atomic Energy Commission {Commissariat à l'énergie atomique et aux énergies alternatives}] and CNRS teams have developed highly specific skills that enable them to study the health and environmental impact of nanoparticles from various angles. Nanotoxicology and nanoecotoxicology research such as this is both a priority for society and a scientific challenge, involving experimental approaches and still emerging concepts.

This work is conducted as part of CEA’s interdisciplinary Toxicology and Nanosciences programs. These are management, coordination and support structures set up to promote multidisciplinary approaches for studying the potential impact on living organisms of various components of industrial interest, including heavy metals, radionuclides, and new products.

At the CNRS, these concerns are reflected in particular in major initiatives such as the International Consortium for the Environmental Implications of Nano Technology (i-CEINT), a CNRS-led international initiative focusing on the ecotoxicology of nanoparticles. CNRS teams also have a long tradition of close involvement in matters relating to standards and regulations. Examples of this include the ANR NanoNORMA program, led by the CNRS, or ongoing work within the French C’Nano network.

For those who would either prefer or like to check out  the French language version of the July 1, 2014 CNRS press release (La biodistribution des nanotubes de carbone dans l’organisme), it can be found here.

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

Carbon Nanotube Translocation to Distant Organs after Pulmonary Exposure: Insights from in Situ 14C-Radiolabeling and Tissue Radioimaging by Bertrand Czarny, Dominique Georgin, Fannely Berthon, Gael Plastow, Mathieu Pinault, Gilles Patriarche, Aurélie Thuleau, Martine Mayne L’Hermite, Frédéric Taran, and Vincent Dive. ACS Nano, 2014, 8 (6), pp 5715–5724 DOI: 10.1021/nn500475u Publication Date (Web): May 22, 2014

Copyright © 2014 American Chemical Society

This paper is behind a paywall.

Martini with your salad? an update on Janus particles and emulsification

Close to a year since I first posted about this research (my July 8, 2013 posting about oil, electricity, and emulsification), scientists have published their latest work on using electricity to control nanoparticles. A June 26, 2014 Polish Academy of Sciences press release (also on EurekAlert) provides this summary,

Everything depends on how you look at them. Looking from one side you will see one face; and when looking from the opposite side – you will see a different one. So appear Janus capsules, miniature, hollow structures, in different fragments composed of different micro- and nanoparticles. Theoreticians were able to design models of such capsules, but a real challenge was to produce them. Now, Janus capsules can be produced easily and at low cost.

Before describing the process for producing Janus capsules, an explanation of Janus (a Roman god) and the problem the scientists were trying to solve (from the press release),

Janus, the old Roman god of beginnings and transitions, attracted believers’ attention with his two faces, each looking to different direction of the world. Janus capsules – ‘bubbles’ made up of two shells stuck one another, each composed of micro- or nanoparticles of different properties – have been for some time attracting the researchers’ attention. They see in the capsules an excellent tool for transporting drugs and a vehicle leading to innovative materials. To have, however, Janus capsules generally accessible, efficient methods for their mass production must be developed. An important step in this direction is the achievement of researchers from the Norwegian and French research institutions and the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) in Warsaw, reported recently in one of the most reputable scientific journals: “Nature Communications”.

At present, it is not a problem to produce Janus spheres – round, entirely filled micro- and nanoobjects with one part having different properties than the other. Such spheres can be, for instance, produced by sticking together two drops of different substances. After merging, the new drop requires a sufficiently fast fixation only, e.g., by cooling it down or initiating polymerisation of its materials. For instance, Janus spheres are particles with white and black halves, used for image generation in electrophoretic displays incorporated in e-book reading devices.

“Janus capsules differ from Janus spheres: the former are hollow structures, and their partially permeable shell is made of colloidal particles. How to make such a ‘two-faced bubble’ using micro- and nanoparticles? Many researchers reflect on the problem. We proposed a really not complicated solution”, says Dr Zbigniew Rozynek (IPC PAS [Institute of Physical Chemistry Polish Academy of Sciences]), who experimentally studied Janus capsules during his postdoctoral training at Norwegian University of Science and Technology in Trondheim.

Here’s an illustration the researchers have provided,

Caption: These are typical capsules (mainly Janus capsules) obtained with the method described in the press release of the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw. Credit: adopted from Nat. Commun. 5, 3945 (2014)

Caption: These are typical capsules (mainly Janus capsules) obtained with the method described in the press release of the Institute of Physical Chemistry of the Polish Academy of Sciences in Warsaw.
Credit: adopted from Nat. Commun. 5, 3945 (2014)

Here’s how the researchers solved their problem (from the press release),

In their experiments, an international team of researchers produced Janus capsules with drops of single millilitres in volume. The drops were coated, for instance, with polystyrene or glass nanoparticles with diameters of about 500 nm (billionth parts of a meter) or 1000 nm, respectively. Also differently coloured polyethylene particles were used.

The experiments were performed with oil drops suspended in another oil. To a so prepared environment micro- or nanoparticles of one type were placed and deposited on the surface of a selected drop. Then, particles of another type were brought to the surface of the second drop. Due to the action of capillary forces, the particles were durably kept on the surfaces of both drops, being approximately uniformly distributed.

When an external electric field was turned on, microflows were induced inside and outside the drops. The microflows transported the particles toward the electric ‘equator’. In this step, the packing of colloidal particles could be controlled by shaking the drops in a slowly alternating electric field. The way how the particles are packed is an important factor, as it determines the number and size of pores of the future capsule, and consequently the capsule permeability.

The microflows around the electric equators of the drops resulted in formation of a ring-shaped ribbon, composed of densely packed particles , whereas both electric ‘poles’ became particles-free regions. At the same time, the poles of each drop were acquiring opposite electric charges.

Opposite electric charges attract one another, so the drops with charged poles were heading to each other. In this step, the only thing to do was to convince both drops not only to adjoin with their poles, but actually to merge. For that purpose the long-known electrocoalescence was used: the drops were stimulated for faster merging by an electric field. Finally the drops electrocoalesced, resulting in the formation of a Janus capsule. Due to a dense packing of particles within the capsule the particles of different types virtually did not mix with each other.

It’s like the famous James Bond’s martini: it was always to be shaken, not stirred“, laughs Dr Rozynek. [emphasis mine]

The ultimate capsule appearance was determined by the number of particles deposited on the surfaces of initial drops. If the particles covered both drops with a uniform film, extending almost to the poles, the coalescence resulted in a non-spherical structure. When empty areas around the poles were suitably larger, the Janus capsules acquired a spherical shape. Finally, if the ribbons around the equators of the initial drops were narrow, the coalescence resulted in formation of a structure, which could be called a Janus ring.

The rings with two parts composed of two different types of particles provide interesting opportunities. They can be further stuck each other and produce more complex striped structures. The capsules could be then composed of alternately placed strips of particles, with each strip having different properties than its neighbours.

Janus capsules enable encapsulation of microobjects, nanoparticles or molecules, which must be protected against the environment because of their sensitivity or reactivity. Different properties of both capsule parts make it easier to control the movement of the capsules and the release of their contents. In view of these factors, Janus capsules may find numerous applications. The proposed method for producing the Janus capsules is potentially of great importance for pharmaceutical, dye or food industries, as well as for the development of materials engineering and medicine.

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

Electroformation of Janus and patchy capsules by Zbigniew Rozynek, Alexander Mikkelsen, Paul Dommersnes, & Jon Otto Fossum. Nature Communications 5, Article number: 3945 doi:10.1038/ncomms4945 Published 23 May 2014

This is an open access paper,

Aug. 5, 2014 deadline for European Union public consultation on measures to increase transparency on nanomaterials on the market

A May 14, 2014 news item on Nanowerk announces a new ‘nanomaterials’ consultation (Public Consultation  on Impact Assessment on Possible Measures to Increase Transparency on Nanomaterials on the Market) in Europe,

As part of the Communication on the Second Regulatory Review on Nanomaterials, the European Commission has announced to launch an impact assessment to identify and develop the most adequate means to increase transparency and ensure regulatory oversight on nanomaterials.

The text of the May 14, 2014 news item can be found on this announcement page, which explains the background leading up to this consultation and the role of the companies  engaged to hold the study and the consultation, on the Risk Policy Analysts website,

More information on the background, methodology and planned timing of this impact assessment can be found in the working document – CASG(Nano)/02/14 (an updated version including a final version of the problem definition, objectives and policy options will be published in the second half of May). This document also contains a draft problem definition, policy objectives and a more detailed description of the following policy options that are under consideration:

     0.  Baseline scenario

  1. Recommendation on how to implement a “best practice model” for Member States wishing to establish a national system (soft law approach)
  2. Structured approach to collect information (“Nanomaterials Observatory”)
  3. Regulation creating an EU nanomaterial registry with one annual registration per substance for each manufacturer/importer/downstream user/distributor
  4. Regulation creating an EU nanomaterial registry with one annual registration per use (including substances, mixtures and articles with intended release)

The European Commission (DG Enterprise and Industry) has commissioned Risk & Policy Analysts Ltd. (RPA) and BiPRO GmbH to undertake a study to support the Commission on the preparation of this impact assessment. The terms of reference and the resulting reports are available here.

The description of the terms for the public consultation follows,

This public consultation is an integral part of this study. The objective of the public consultation is to obtain stakeholder views on the currently available information on nanomaterials on the market (as defined here), the problem definition that forms the basis of the impact assessment, as well as the potential positive and/or negative impacts of the aforementioned policy options.

Please be aware that within the European Union, France has already established a mandatory reporting scheme for manufactured nanomaterials produced, imported or distributed in its territory.  The Interministerial decree No. 2012-232 entered into force in January 2013. Moreover, at European level, when cosmetic products containing nanomaterials are put on the EU market, Article 16 of Regulation (EC) No 1223/2009 requires the responsible persons to submit information on the nanomaterial(s) contained through the Cosmetic Products Notification Portal.   Further information on these and other proposed schemes is available here.

Complete the questionnaire for non-industry stakeholders

(preview in pdf or in Word)

Complete the questionnaire for industry stakeholders

(preview in pdf or in Word)

Please note that, if your company/organisation is registered in the Transparency Register, you will be requested to indicate your Register ID number.  Your contribution will then be considered as representing the views of your organisation.  If your organisation is not registered, you have the opportunity to learn more and/or register now.

Please note that if your company has to notify to the French Notification System and/or to the Cosmetic Products Notification Portal but did not participate in the consultation undertaken by RPA/BiPRO for the European Commission in early 2014, please take the time to fill in the questionnaire on the administrative burden of the notification schemes which is available here.

I wonder what it means when the Cosmetic Products Notification Portal does not participate. This nonparticipation adds a level of intrigue I hadn’t anticipated when I caught sight of this announcement. Are the ‘cosmetics portal’ people boycotting the consultation for some reason?

* Upper case ‘M” changed to lower case ‘m’ in head on May 16, 2014 at 9:47 am PDT.

Mopping up that oil spill with a nanocellulose sponge and a segue into Canadian oil and politics

Empa (Swiss Federal Laboratories for Materials Science and Technology or ,in German, Eidgenössische Materialprüfungs- und Forschungsanstalt) has announced the development of a nanocellulose sponge useful for cleaning up oil spills in a May 5, 2014 news item on Nanowerk (Note: A link has been removed),

A new, absorbable material from Empa wood research could be of assistance in future oil spill accidents: a chemically modified nanocellulose sponge. The light material absorbs the oil spill, remains floating on the surface and can then be recovered. The absorbent can be produced in an environmentally-friendly manner from recycled paper, wood or agricultural by-products (“Ultralightweight and Flexible Silylated Nanocellulose Sponges for the Selective Removal of Oil from Water”).

A May 2, 2014 Empa news release (also on EurekAlert*}, which originated the news item, includes a description of the potential for oil spills due to transport issues, Empa’s proposed clean-up technology, and a request for investment,

All industrial nations need large volumes of oil which is normally delivered by ocean-going tankers or via inland waterways to its destination. The most environmentally-friendly way of cleaning up nature after an oil spill accident is to absorb and recover the floating film of oil. The Empa researchers Tanja Zimmermann and Philippe Tingaut, in collaboration with Gilles Sèbe from the University of Bordeaux, have now succeeded in developing a highly absorbent material which separates the oil film from the water and can then be easily recovered, “silylated” nanocellulose sponge. In laboratory tests the sponges absorbed up to 50 times their own weight of mineral oil or engine oil. They kept their shape to such an extent that they could be removed with pincers from the water. The next step is to fine tune the sponges so that they can be used not only on a laboratory scale but also in real disasters. To this end, a partner from industry is currently seeked.

Here’s what the nanocellulose sponge looks like (oil was dyed red and the sponge has absorbed it from the water),

The sponge remains afloat and can be pulled out easily. The oil phase is selectively removed from the surface of water. Image: Empa

The sponge remains afloat and can be pulled out easily. The oil phase is selectively removed from the surface of water.
Image: Empa

The news release describes the substance, nanofibrillated cellulose (NFC), and its advantages,

Nanofibrillated Cellulose (NFC), the basic material for the sponges, is extracted from cellulose-containing materials like wood pulp, agricultural by products (such as straw) or waste materials (such as recycled paper) by adding water to them and pressing the aqueous pulp through several narrow nozzles at high pressure. This produces a suspension with gel-like properties containing long and interconnected cellulose nanofibres .

When the water from the gel is replaced with air by freeze-drying, a nanocellulose sponge is formed which absorbs both water and oil. This pristine material sinks in water and is thus not useful for the envisaged purpose. The Empa researchers have succeeded in modifying the chemical properties of the nanocellulose in just one process step by admixing a reactive alkoxysilane molecule in the gel before freeze-drying. The nanocellulose sponge loses its hydrophilic properties, is no longer suffused with water and only binds with oily substances.

In the laboratory the “silylated” nanocellulose sponge absorbed test substances like engine oil, silicone oil, ethanol, acetone or chloroform within seconds. Nanofibrillated cellulose sponge, therefore, reconciles several desirable properties: it is absorbent, floats reliably on water even when fully saturated and is biodegradable.

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

Ultralightweight and Flexible Silylated Nanocellulose Sponges for the Selective Removal of Oil from Water by Zheng Zhang, Gilles Sèbe, Daniel Rentsch, Tanja Zimmermann, and Philippe Tingaut. Chem. Mater., 2014, 26 (8), pp 2659–2668 DOI: 10.1021/cm5004164 Publication Date (Web): April 10, 2014

Copyright © 2014 American Chemical Society

This article is behind a paywall.

I featured ‘nanocellulose and oil spills’ research at the University Wisconsin-Madison in a Feb. 26, 2014 post titled, Cleaning up oil* spills with cellulose nanofibril aerogels (Note: I corrected a typo in my headline hence the asterisk). I also have a Dec. 31, 2013 piece about a nanotechnology-enabled oil spill recovery technology project (Naimor) searching for funds via crowdfunding. Some major oil projects being considered in Canada and the lack of research on remediation are also mentioned in the post.

Segue Alert! As for the latest on Canada and its oil export situation, there’s a rather interesting May 2, 2014 Bloomberg.com article Canada Finds China Option No Easy Answer to Keystone Snub‘ by Edward Greenspon, Andrew Mayeda, Jeremy van Loon and Rebecca Penty describing two Canadian oil projects and offering a US perspective,

It was February 2012, three months since President Barack Obama had phoned the Canadian prime minister to say the Keystone XL pipeline designed to carry vast volumes of Canadian crude to American markets would be delayed.

Now Harper [Canadian Prime Minister Stephen Harper] found himself thousands of miles from Canada on the banks of the Pearl River promoting Plan B: a pipeline from Alberta’s landlocked oil sands to the Pacific Coast where it could be shipped in tankers to a place that would certainly have it — China. It was a country to which he had never warmed yet that served his current purposes. [China's President at that time was Hu Jintao, 2002 - 2012; currently the President is Xi Jinping, 2013 - ]

The writers do a good job of describing a number of factors having an impact on one or both of the pipeline projects. However, no mention is made in the article that Harper is from the province of Alberta and represents that province’s Calgary Southwest riding. For those unfamiliar with Calgary, it is a city dominated by oil companies. I imagine Mr. Harper is under considerable pressure to resolve oil export and transport issues and I would expect they would prefer to resolve the US issues since many of those oil companies in Calgary have US headquarters.

Still, it seems simple, if the US is not interested as per the problems with the Keystone XL pipeline project, ship the oil to China via a pipeline through the province of British Columbia and onto a tanker. What the writers do not mention is yet another complicating factor, Trudeau, both Justin and, the deceased, Pierre.

As Prime Minister of Canada, Pierre Trudeau was unloved in Alberta, Harper’s home province, due to his energy policies and the formation of the National Energy Board. Harper appears, despite his denials, to have an antipathy towards Pierre Trudeau that goes beyond the political to the personal and it seems to extend beyond Pierre’s grave to his son, Justin. A March 21, 2014 article by Mark Kennedy for the National Post describes Harper’s response to Trudeau’s 2000 funeral this way,

Stephen Harper, then the 41-year-old president of the National Citizens Coalition (NCC), was a proud conservative who had spent three years as a Reform MP. He had entered politics in the mid-1980s, in part because of his disdain for how Pierre Trudeau’s “Just Society” had changed Canada.

So while others were celebrating Trudeau’s legacy, Harper hammered out a newspaper article eviscerating the former prime minister on everything from policy to personality.

Harper blasted Trudeau Sr. for creating “huge deficits, a mammoth national debt, high taxes, bloated bureaucracy, rising unemployment, record inflation, curtailed trade and declining competitiveness.”

On national unity, he wrote that Trudeau was a failure. “Only a bastardized version of his unity vision remains and his other policies have been rejected and repealed by even his own Liberal party.”

Trudeau had merely “embraced the fashionable causes of his time,” wrote Harper.

Getting personal, he took a jab at Trudeau over not joining the military during the Second World War: “He was also a member of the ‘greatest generation,’ the one that defeated the Nazis in war and resolutely stood down the Soviets in the decades that followed. In those battles however, the ones that truly defined his century, Mr. Trudeau took a pass.”

The article was published in the National Post Oct. 5, 2000 — two days after the funeral.

Kennedy’s article was occasioned by the campaign being led by Harper’;s Conservative party against the  leader (as of April 2013) of the Liberal Party, Justin Trudeau.

It’s hard to believe that Harper’s hesitation over China is solely due to human rights issues especially  since Harper has not been noted for consistent interest in those issues and, more particularly, since Prime Minister Pierre Trudeau was one of the first ‘Western’ leaders to visit communist China . Interestingly, Harper has been much more enthusiastic about the US than Pierre Trudeau who while addressing the Press Club in Washington, DC in March 1969, made this observation (from the Pierre Trudeau Wikiquote entry),

Living next to you [the US] is in some ways like sleeping with an elephant. No matter how friendly and even-tempered is the beast, if I can call it that, one is affected by every twitch and grunt.

On that note, I think Canada is always going to be sleeping with an elephant; the only question is, who’s the elephant now? In any event, perhaps Harper is more comfortable with the elephant he knows and that may explain why China’s offer to negotiate a free trade agreement has been left unanswered (this too was not noted in the Bloomberg article). The offer and lack of response were mentioned by Yuen Pau Woo, President and CEO of the Asia Pacific Foundation of Canada, who spoke at length about China, Canada, and their trade relations at a Jan. 31, 2014 MP breakfast (scroll down for video highlights of the Jan. 31, 2014 breakfast) held by Member of Parliament (MP) for Vancouver-Quadra, Joyce Murray.

Geopolitical tensions and Canadian sensitivities aside, I think Canadians in British Columbia (BC), at least, had best prepare for more oil being transported and the likelihood of spills. In fact, there are already more shipments according to a May 6, 2014 article by Larry Pynn for the Vancouver Sun,

B.C. municipalities work to prevent a disastrous accident as rail transport of oil skyrockets

The number of rail cars transporting crude oil and petroleum products through B.C. jumped almost 200 per cent last year, reinforcing the resolve of municipalities to prevent a disastrous accident similar to the derailment in Lac-Mégantic in Quebec last July [2013].

Transport Canada figures provided at The Vancouver Sun’s request show just under 3,400 oil and petroleum rail-car shipments in B.C. last year, compared with about 1,200 in 2012 and 50 in 2011.

The figures come a week after The Sun revealed that train derailments jumped 20 per cent to 110 incidents last year in B.C., the highest level in five years.

Between 2011 and 2012, there was an increase of 2400% (from 50 to 1200) of oil and petroleum rail-car shipments in BC. The almost 300% increase in shipments between 2012 and 2013 seems paltry in comparison.  Given the increase in shipments and the rise in the percentage of derailments, one assumes there’s an oil spill waiting to happen. Especially so, if the Canadian government manages to come to an agreement regarding the proposed pipeline for BC and frankly, I have concerns about the other pipeline too, since either will require more rail cars, trucks, and/or tankers for transport to major centres edging us all closer to a major oil spill.

All of this brings me back to Empa, its oil-absorbing nanocellulose sponges, and the researchers’ plea for investors and funds to further their research. I hope they and all the other researchers (e.g., Naimor) searching for ways to develop and bring their clean-up ideas to market find some support.

*EurekAlert link added May 7, 2014.

ETA May 8, 2014:  Some types of crude oil are more flammable than others according to a May 7, 2014 article by Lindsay Abrams for Salon.com (Note: Links have been removed),

Why oil-by-rail is an explosive disaster waiting to happen
A recent spate of fiery train accidents all have one thing in common: highly volatile cargo from North Dakota

In case the near continuous reports of fiery, deadly oil train accidents hasn’t been enough to convince you, Earth Island Journal is out with a startling investigative piece on North Dakota’s oil boom and the dire need for regulations governing that oil’s transport by rail.

The article is pegged to the train that derailed and exploded last summer in  [Lac-Mégantic] Quebec, killing 47 people, although it just as well could have been the story of the train that derailed and exploded in Alabama last November, the train that derailed and exploded in North Dakota last December, the train that derailed and exploded in Virginia last week or — let’s face it — any future accidents that many see as an inevitability.

The Bakken oil fields in North Dakota are producing over a million barrels of crude oil a day, more than 60 percent of which is shipped by rail. All that greenhouse gas-emitting fossil fuel is bad enough; that more oil spilled in rail accidents last year than the past 35 years combined is also no small thing. But the particular chemical composition of Bakken oil lends an extra weight to these concerns: according to the Pipeline and Hazardous Materials Safety Administration, it may be more flammable and explosive than traditional crude.

While Abrams’ piece is not focused on oil cleanups, it does raise some interesting questions about crude oil transport and whether or not the oil from Alberta might also be more than usually dangerous.

The glassy side of fractals

An April 24, 2014 news item on Nanowerk highlights a breakthrough in glass (wordplay intended),

Colorful church windows, beads on a necklace and many of our favorite plastics share something in common — they all belong to a state of matter known as glasses. School children learn the difference between liquids and gases, but centuries of scholarship have failed to produce consensus about how to categorize glass.

Now, combining theory and numerical simulations, researchers have resolved an enduring question in the theory of glasses by showing that their energy landscapes are far rougher than previously believed.

An April 23, 2014 Duke University news release by Erin Weeks (also on EurekAlert), which originated the news item, provides a diagram (am I the only one who thinks these resemble cow udders?) and more infotmation,

Glasses form when their molecules get jammed into fractal "wells," as shown on the right, rather than smooth or slightly rough wells (left). Photo credit: Patrick Charbonneau. Courtesy: Duke University

Glasses form when their molecules get jammed into fractal “wells,” as shown on the right, rather than smooth or slightly rough wells (left). Photo credit: Patrick Charbonneau. Courtesy: Duke University

“There have been beautiful mathematical models, but with sometimes tenuous connection to real, structural glasses. Now we have a model that’s much closer to real glasses,” said Patrick Charbonneau, one of the co-authors and assistant professor of chemistry and physics at Duke University.

One thing that sets glasses apart from other phase transitions is a lack of order among their constituent molecules. Their cooled particles become increasingly sluggish until, caged in by their neighbors, the molecules cease to move — but in no predictable arrangement. One way for researchers to visualize this is with an energy landscape, a map of all the possible configurations of the molecules in a system.

Charbonneau [Patrick Charbonneau, one of the co-authors and assistant professor of chemistry and physics at Duke University] said a simple energy landscape of glasses can be imagined as a series of ponds or wells. When the water is high (the temperature is warmer), the particles within float around as they please, crossing from pond to pond without problem. But as you begin to lower the water level (by lowering the temperature or increasing the density), the particles become trapped in one of the small ponds. Eventually, as the pond empties, the molecules become jammed into disordered and rigid configurations.

“Jamming is what happens when you take sand and squeeze it,” Charbonneau said. “First it’s easy to squeeze, and then after a while it gets very hard, and eventually it becomes impossible.”

Like the patterns of a lakebed revealed by drought, researchers have long wondered exactly what “shape” lies at the bottom of glass energy landscapes, where molecules jam. Previous theories have predicted the bottom of the basins might be smooth or a bit rough.

“At the bottom of these lakes or wells, what you find is variation in which particles have a force contact or bond,” Charbonneau said. “So even though you start from a single configuration, as you go to the bottom or compress them, you get different realizations of which pairs of particles are actually in contact.”

Charbonneau and his co-authors based in Paris and Rome showed, using computer simulations and numeric computations, that the glass molecules jam based on a fractal regime of wells within wells.

The new description makes sense of several behaviors seen in glasses, like the property known as avalanching, which describes a random rearrangement of molecules that leads to crystallization.

Understanding the structure of glasses is more than an intellectual exercise — materials scientists stand to advance from the knowledge, which could lead to better control of the aging of glasses.

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

Fractal free energy landscapes in structural glasses by Patrick Charbonneau, Jorge Kurchan,     Giorgio Parisi, Pierfrancesco Urbani & Francesco Zamponi. Nature Communications 5, Article number: 3725 doi:10.1038/ncomms4725 Published 24 April 2014

This paper is behind a paywall but there is a free preview available through ReadCube Access.