Tag Archives: UK

Concrete proof that materials at the nanoscale behave differently than materials at any other scale

I hadn’t realized this still needed to be proved but it’s always good to have your misconceptions adjusted. Here’s more about the work from the University of Cambridge in a Sept. 30, 2016 news item on phys.org,

Scientists have long suspected that the way materials behave on the nanoscale – that is when particles have dimensions of about 1–100 nanometres – is different from how they behave on any other scale. A new paper in the journal Chemical Science provides concrete proof that this is the case.

The laws of thermodynamics govern the behaviour of materials in the macro world, while quantum mechanics describes behaviour of particles at the other extreme, in the world of single atoms and electrons.

A Sept. 29, 2016 University of Cambridge press release, which originated the news item, hones in on the peculiarities of the nanoscale,

In the middle, on the order of around 10–100,000 molecules, something different is going on. Because it’s such a tiny scale, the particles have a really big surface-area-to-volume ratio. This means the energetics of what goes on at the surface become very important, much as they do on the atomic scale, where quantum mechanics is often applied.

Classical thermodynamics breaks down. But because there are so many particles, and there are many interactions between them, the quantum model doesn’t quite work either.

And because there are so many particles doing different things at the same time, it’s difficult to simulate all their interactions using a computer. It’s also hard to gather much experimental information, because we haven’t yet developed the capacity to measure behaviour on such a tiny scale.

This conundrum becomes particularly acute when we’re trying to understand crystallisation, the process by which particles, randomly distributed in a solution, can form highly ordered crystal structures, given the right conditions.

Chemists don’t really understand how this works. How do around 1018 molecules, moving around in solution at random, come together to form a micro- to millimetre size ordered crystal? Most remarkable perhaps is the fact that in most cases every crystal is ordered in the same way every time the crystal is formed.

However, it turns out that different conditions can sometimes yield different crystal structures. These are known as polymorphs, and they’re important in many branches of science including medicine – a drug can behave differently in the body depending on which polymorph it’s crystallised in.

What we do know so far about the process, at least according to one widely accepted model, is that particles in solution can come together to form a nucleus, and once a critical mass is reached we see crystal growth. The structure of the nucleus determines the structure of the final crystal, that is, which polymorph we get.

What we have not known until now is what determines the structure of the nucleus in the first place, and that happens on the nanoscale.

In this paper, the authors have used mechanochemistry – that is milling and grinding – to obtain nanosized particles, small enough that surface effects become significant. In other words, the chemistry of the nanoworld – which structures are the most stable at this scale, and what conditions affect their stability, has been studied for the first time with carefully controlled experiments.

And by changing the milling conditions, for example by adding a small amount of solvent, the authors have been able to control which polymorph is the most stable. Professor Jeremy Sanders of the University of Cambridge’s Department of Chemistry, who led the work, said “It is exciting that these simple experiments, when carried out with great care, can unexpectedly open a new door to understanding the fundamental question of how surface effects can control the stability of nanocrystals.”

Joel Bernstein, Global Distinguished Professor of Chemistry at NYU Abu Dhabi, and an expert in crystal growth and structure, explains: “The authors have elegantly shown how to experimentally measure and simulate situations where you have two possible nuclei, say A and B, and determine that A is more stable. And they can also show what conditions are necessary in order for these stabilities to invert, and for B to become more stable than A.”

“This is really news, because you can’t make those predictions using classical thermodynamics, and nor is this the quantum effect. But by doing these experiments, the authors have started to gain an understanding of how things do behave on this size regime, and how we can predict and thus control it. The elegant part of the experiment is that they have been able to nucleate A and B selectively and reversibly.”

One of the key words of chemical synthesis is ‘control’. Chemists are always trying to control the properties of materials, whether that’s to make a better dye or plastic, or a drug that’s more effective in the body. So if we can learn to control how molecules in a solution come together to form solids, we can gain a great deal. This work is a significant first step in gaining that control.

Nicely written!

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

Solvation and surface effects on polymorph stabilities at the nanoscale by A. M. Belenguer, G. I. Lampronti, A. J. Cruz-Cabeza, C. A. Hunter, and J. K. M. Sanders. Chem. Sci., 2016, Advance Article DOI: 10.1039/C6SC03457H First published online 02 Sep 2016

This paper is open access.

Given that the news release mentions crystals, this lovely image illustrates the press release,

 Snow Crystal Landscape Credit: Peter Gorges

Snow Crystal Landscape Credit: Peter Gorges

Graphene Malaysia 2016 gathering and Malaysia’s National Graphene Action Plan 2020

Malaysia is getting ready to host a graphene conference according to an Oct. 10, 2016 news item on Nanotechnology Now,

The Graphene Malaysia 2016 [Nov. 8 – 9, 2016] (www.graphenemalaysiaconf.com) is jointly organized by NanoMalaysia Berhad and Phantoms Foundation. The conference will be centered on graphene industry interaction and collaborative innovation. The event will be launched under the National Graphene Action Plan 2020 (NGAP 2020), which will generate about 9,000 jobs and RM20 (US$4.86) billion GNI impact by the year 2020.

First speakers announced:
Murni Ali (Nanomalaysia, Malaysia) | Francesco Bonaccorso (Istituto Italiano di Tecnologia, Italy) | Antonio Castro Neto (NUS, Singapore) | Antonio Correia (Phantoms Foundation, Spain)| Pedro Gomez-Romero (ICN2 (CSIC-BIST), Spain) | Shu-Jen Han (Nanoscale Science & Technology IBM T.J. Watson Research Center, USA) | Kuan-Tsae Huang (AzTrong, USA/Taiwan) | Krzysztof Koziol (FGV Cambridge Nanosystems, UK) | Taavi Madiberk (Skeleton Technologies, Estonia) | Richard Mckie (BAE Systems, UK) | Pontus Nordin (Saab AB, Saab Aeronautics, Sweden) | Elena Polyakova (Graphene Laboratories Inc., USA) | Ahmad Khairuddin Abdul Rahim (Malaysian Investment Development Authority (MIDA), Malaysia) | Adisorn Tuantranont (Thailand Organic and Printed Electronics Innovation Center, Thailand) |Archana Venugopal (Texas Instruments, USA) | Won Jong Yoo (Samsung-SKKU Graphene-2D Center (SSGC), South Korea) | Hongwei Zhu (Tsinghua University, China)

You can check for more information and deadlines in the Nanotechnology Now Oct. 10, 2016 news item.

The Graphene Malalysia 2016 conference website can be found here and Malaysia’s National Graphene Action Plan 2020, which is well written, can be found here (PDF).  This portion from the executive summary offers some insight into Malyasia’s plans to launch itself into the world of high income nations,

Malaysia’s aspiration to become a high-income nation by 2020 with improved jobs and better outputs is driving the country’s shift away from “business as usual,” and towards more innovative and high value add products. Within this context, and in accordance with National policies and guidelines, Graphene, an emerging, highly versatile carbon-based nanomaterial, presents a unique opportunity for Malaysia to develop a high value economic ecosystem within its industries.  Isolated only in 2004, Graphene’s superior physical properties such as electrical/ thermal conductivity, high strength and high optical transparency, combined with its manufacturability have raised tremendous possibilities for its application across several functions and make it highly interesting for several applications and industries.  Currently, Graphene is still early in its development cycle, affording Malaysian companies time to develop their own applications instead of relying on international intellectual property and licenses.

Considering the potential, several leading countries are investing heavily in associated R&D. Approaches to Graphene research range from an expansive R&D focus (e.g., U.S. and the EU) to more focused approaches aimed at enhancing specific downstream applications with Graphene (e.g., South Korea). Faced with the need to push forward a multitude of development priorities, Malaysia must be targeted in its efforts to capture Graphene’s potential, both in terms of “how to compete” and “where to compete”. This National Graphene Action Plan 2020 lays out a set of priority applications that will be beneficial to the country as a whole and what the government will do to support these efforts.

Globally, much of the Graphene-related commercial innovation to date has been upstream, with producers developing techniques to manufacture Graphene at scale. There has also been some development in downstream sectors, as companies like Samsung, Bayer MaterialScience, BASF and Siemens explore product enhancement with Graphene in lithium-ion battery anodes and flexible displays, and specialty plastic and rubber composites. However the speed of development has been uneven, offering Malaysian industries willing to invest in innovation an opportunity to capture the value at stake. Since any innovation action plan has to be tailored to the needs and ambitions of local industry, Malaysia will focus its Graphene action plan initially on larger domestic industries (e.g., rubber) and areas already being targeted by the government for innovation such as energy storage for electric vehicles and conductive inks.

In addition to benefiting from the physical properties of Graphene, Malaysian downstream application providers may also capture the benefits of a modest input cost advantage for the domestic production of Graphene.  One commonly used Graphene manufacturing technique, the chemical vapour deposition (CVD) production method, requires methane as an input, which can be sourced economically from local biomass. While Graphene is available commercially from various producers around the world, downstream players may be able to enjoy some cost advantage from local Graphene supply. In addition, co-locating with a local producer for joint product development has the added benefit of speeding up the R&D lifecycle.

That business about finding downstream applications could also to the Canadian situation where we typically offer our resources (upstream) but don’t have an active downstream business focus. For example, we have graphite mines in Ontario and Québec which supply graphite flakes for graphene production which is all upstream. Less well developed are any plans for Canadian downstream applications.

Finally, it was interesting to note that the Phantoms Foundation is organizing this Malaysian conference since the same organization is organizing the ‘2nd edition of Graphene & 2D Materials Canada 2016 International Conference & Exhibition’ (you can find out more about the Oct. 18 – 20, 2016 event in my Sept. 23, 2016 posting). I think the Malaysians have a better title for their conference, far less unwieldy.

Space cloth (Zephlinear): a new technique for producing textiles

A lightweight zephlinear scarf with LEDs Courtesy: Nottingham Trent University

A lightweight zephlinear [space cloth]  scarf with LEDs Courtesy: Nottingham Trent University

What makes the scarf in the preceding image unusual is that the yarn hasn’t been knitted or woven. A Sept. 21, 2016 news item on phys.org describes the work,

Sonia Reynolds invented ‘space cloth’ – the first non-woven material made from yarn. It has a strong potential for use as a smart textile due to its unique structure with space to encase copper wiring, light emitting diodes (LEDs) and more.

Ms Reynolds brought the idea to Nottingham Trent University’s Advanced Textile Research Group and is now undertaking a PhD in the subject to further develop the fabric’s novel manufacturing process under the direction of Professor Tilak Dias and Dr Amanda Briggs-Goode, of the School of Art and Design.

Scientifically named Zephlinear, unlike traditional woven or knitted materials which are made by the interloping or interlacing of yarns, it is made by a newly established technique known as yarn surface entanglement.

A Sept. 21, 2016 Nottingham Trent University press release, which originated the news item, provides more information,

Ms Reynolds said: “This is a real breakthrough for the textiles industry. It’s the first non-woven material made from yarn and promises major benefits for the future of clothing, and more.

“Because of the material’s linear channels of yarn, it has great potential to be used as a smart textile. In particular, we believe it lends itself well to being embedded with microcapsules containing medication or scent, to either help deliver drugs to specific parts of the body or to create antibacterial and aromatic clothing.

“As the material is visually different, it has potential to be used for other applications as well, such as wall coverings, in addition to clothing.

“And because it’s much less labour intensive to make than knit or weave fabrics, it’s a more environmentally friendly material to produce as well.”

The name, Zephlinear, derives from the merger of two words, zephyr and linear. It was given the nickname ‘space cloth’ due to its appearance and its e-textile capabilities.

The material – which is patent pending – was recently presented at the Wearable Technology Show, USA, by Ms Reynolds.

Research shows that it is strongest and most efficient when created from natural yarns such as one hundred per cent wool, hair and wool/silk mixtures, though it can also be made from synthetic yarns.

Professor Dias, who leads the university’s Advanced Textiles Research Group, said: “Zephlinear is a remarkable development in an industry which is advancing at an incredible pace.

“We believe it has huge potential for textiles, and we have already found that it combines well with e-textile technologies such as heated textiles or textiles with embedded LEDs.

“As a fabric it is very lightweight and flexible, and it retracts back to its original shape well after it has been stretched.

“We’re very much looking forward to developing the material further and feel certain that it will help provide people with smarter and more environmentally friendly clothing in the future”.

Here’s an image of Sonia Reynolds with another Zephlinear scarf,

Sonia Reynolds with a zephlinear scarf Courtesy Nottingham Trent University

Sonia Reynolds with a zephlinear scarf Courtesy Nottingham Trent University

This is the first time I’ve heard of a ‘smart’ or ‘e’ textile that works better when a natural fiber is used.

Replacing the indium tin oxide (ITO) electrodes in smartphones?

Physicists have developed silver nanowires that could be used to replace the indium tin oxide electrodes found in touchscreens for smartphones, tablets, and more. From a Sept. 14, 2016 news item on Nanowerk,

Physicists at the University of Sussex are at an advanced stage of developing alternative touchscreen technology to overcome the shortfall in the traditional display, phone and tablet material that relies on electrodes made from indium tin oxide (ITO).

They have now shown that not only is the material suitable for touchscreens, but that it is possible to produce extremely small patterns (pixels), small enough for high definition LCD displays, such as smartphones and the next generation of television and computer screens.

The study, led by Sussex Professor of Experimental Physics Alan Dalton, investigates some of the intricacies of patterning silver nanowire films to produce detailed electrode structures. …

A Sept. 13, 2016 University of Sussex press release, which originated the news item, describes why this research presents some exciting possibilities (Note: Links have been removed),

Previous research by Professor Dalton’s group has shown that silver nanowires not only match the transmittances and conductivities of ITO films but exceed them. This makes the material very attractive for touch screens. However, the group have now shown, for the first time, that this type of nanomaterial is compatible with more demanding applications such as LCD and OLED displays.

Professor Dalton said: “Display technologies such as LCD and OLED form images using pixels. Each pixel of these displays is further broken down into subpixels; typically, one each for red, green and blue colours. In the display in a smartphone, for example, these subpixels are less than a sixth of the width of a human hair – which is also similar in length to the silver nanowires used in our research.”

Dr Matthew Large, the lead author of the paper, expanded: “In this research we have applied a mathematical technique to work out the smallest subpixel size we can make without affecting the properties of our nanowire electrodes. This method was originally developed to describe how phase changes like freezing happen in very small spaces, The results tell us how to tune our nanowires to meet the requirements of any given application.”

In collaboration with their industrial partners, M-SOLV based in Oxford, the team – which is now looking to apply these research results to commercial projects – has also demonstrated that the incorporation of silver nanowires into a multi-touch sensor actually reduces the production cost and energy usage.

Professor Dalton said: “Silver nanowire and silver nanowire/graphene hybrids are probably the most viable alternatives to existing technologies. Others scientists have studied several alternative materials, but the main issue is that the majority of other materials do not effectively compete with ITO or they are too costly to produce, at least at the moment.”

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

Finite-size scaling in silver nanowire films: design considerations for practical devices by Matthew J. Large, Maria Cann, Sean P. Ogilvie, Alice A. K. King, Izabela Jurewicz, and Alan B. Dalton. Nanoscale, (issue 28) 2016,8, 13701-13707 DOI: 10.1039/C6NR03960J First published online 27 Jun 2016

This paper is behind a paywall.

Dexter Johnson’s Sept. 16, 2016 posting (on his Nanoclast blog on the IEEE [Institute of Electrical and Electronics Engineers] website) adds some new detail (Note: Links have been removed),

The field of nanomaterials vying to replace indium tin oxide (ITO) as the transparent conductor that controls display pixels in touch screen displays is getting crowded. We’ve seen materials including carbon nanotubes, silver nanowires, and graphene promoted as the heir apparent for this application.

Now, researchers at the University of Sussex in England have introduced a strong contender into the battle to replace indium tin oxide: a hybrid material consisting of silver nanowires that are linked together with graphene.

“The hybrid material is a lot cheaper due to the fact that we only need to use a fraction of the nanowires normally required to attain the properties of ITO,” …

Making the impossible possible: on demand and by design, atomic scale pipes

This research on pipes from the University of Manchester will probably never finds its way into plumbing practices but, apparently, is of great interest in fundamental research. From a Sept. 7, 2016 news item on phys.org,

Materials containing tiny capillaries and cavities are widely used in filtration, separation and many other technologies, without which our modern lifestyle would be impossible. Those materials are usually found by luck or accident rather than design. It has been impossible to create artificial capillaries with atomic-scale precision.

Now a Manchester group led by postdoctoral researcher Radha Boya and Nobel laureate Andre Geim show how to make the impossible possible, as reported in Nature.

A Sept. 7, 2016 University of Manchester press release (also on EurekAlert), which originated the news item,  provides a description of the technology,

The new technology is elegant, adaptable and strikingly simple. In fact, it is a kind of antipode of the famous material graphene. When making graphene, people often take a piece of graphite and use Scotch tape to extract a single atomic plane of carbon atoms, graphene. The remaining graphite is discarded.

In this new research, Manchester scientists similarly extracted a strip of graphene from graphite, but discarded the graphene and focused on what was left: an ultra-thin cavity within the graphite crystal.

Such atomic scale cavities can be made from various materials to achieve not only a desired size but also to choose properties of capillary walls. They can be atomically smooth or rough, hydrophilic or hydrophobic, insulating or conductive, electrically charged or neutral; the list goes on.

The voids can be made as cavities (to confine various substances) or open-ended tunnels (to transport different gases and liquids), which is of huge interest for fundamental research and many applications. It is limited only by imagination what such narrow tunnels with designer properties can potentially do for us.

Properties of materials at this truly atomic scale are expected to be quite different from those we are familiar with in our macroscopic world. To demonstrate that this is the case of their atomic-scale voids, the Manchester group tested how water runs through those ultra-narrow pipes.

To everyone’s surprise, they found water to flow with little friction and at high speed, as if the channels were many thousands times wider than they actually are.

Radha Boya commented ‘This is an entirely new type of nanoscale systems. Such capillaries were never imagined, even in theory. No one thought that this degree of accuracy in design could be possible. New filtration, desalination, gas separation technologies are kind of obvious directions but there are so many others to explore’.

Sir Andre added ‘Making something useful out of an empty space is certainly cute. Finding that this space offers so much of new science is flabbergasting. Even with hindsight, I did not expect the idea to work so well. There are myriads of possibilities for research and development, which now need to be looked at. We are stunned by the choice.’

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

Molecular transport through capillaries made with atomic-scale precision by B. Radha, A. Esfandiar, F. C. Wang, A. P. Rooney, K. Gopinadhan, A. Keerthi, A. Mishchenko, A. Janardanan, P. Blake, L. Fumagalli, M. Lozada-Hidalgo, S. Garaj, S. J. Haigh, I. V. Grigorieva, H. A. Wu, & A. K. Geim. Nature (2016)  doi:10.1038/nature19363 Published online 07 September 2016

This paper is behind a paywall.

Sniffing for art conservation

The American Chemical Society (ACS) has produced a video titled, “How that ‘old book smell’ could save priceless artifacts” according to their Sept. 6, 2016 news release on EurekAlert,

Odor-detecting devices like Breathalyzers have been used for years to determine blood-alcohol levels in drunk drivers. Now, researchers are using a similar method to sniff out the rate of decay in historic art and artifacts. By tracking the chemicals in “old book smell” and similar odors, conservators can react quickly to preserve priceless art and artifacts at the first signs of decay. In this Speaking of Chemistry, Sarah Everts explains how cultural-heritage science uses the chemistry of odors to save books, vintage jewelry and even early Legos. …

Here’s the video,

Heritage Smells, the UK project mentioned in the video, is now completed but it was hosted by the University of Strathclyde and more project information can be found here.

What’s a science historian doing in the field of synthetic biology?

Dominic Berry’s essay on why he, a science historian, is involved in a synthetic biology project takes some interesting twists and turns, from a Sept. 2, 2016 news item on phys.org,

What are synthetic biologists doing to plants, and what are plants doing to synthetic biology? This question frames a series of laboratory observations that I am pursuing across the UK as part of the Engineering Life project, which is dedicated to exploring what it might mean to engineer biology. I contribute to the project through a focus on plant scientists and my training in the history and philosophy of science. For plant scientists the engineering of biology can take many forms not all of which are captured by the category ‘synthetic biology’. Scientists that aim to create modified organisms are more inclined to refer to themselves as the latter, while other plant scientists will emphasise an integration of biological work with methods or techniques from engineering without adopting the identity of synthetic biologist. Accordingly, different legacies in the biosciences (from molecular biology to biomimetics) can be drawn upon depending on the features of the project at hand. These category and naming problems are all part of a larger set of questions that social and natural scientists continue to explore together. For the purposes of this post the distinctions between synthetic biology and the broader engineering of biology do not matter greatly, so I will simply refer to synthetic biology throughout.

Berry’s piece was originally posted Sept. 1, 2016 by Stephen Burgess on the PLOS (Public Library of Science) Synbio (Synthetic Biology blog). In this next bit Berry notes briefly why science historians and scientists might find interaction and collaboration fruitful (Note: Links have been removed),

It might seem strange that a historian is focused so closely on the present. However, I am not alone, and one recent author has picked out projects that suggest it is becoming a trend. This is only of interest for readers of the PLOS Synbio blog because it flags up that there are historians of science available for collaboration (hello!), and plenty of historical scholarship to draw upon to see your work in a new light, or rediscover forgotten research programs, or reconsider current practices, precisely as a recent Nature editorial emphasised for all sciences.

The May 17, 2016 Nature editorial ‘Second Thoughts’, mentioned in Berry’s piece, opens provocatively and continues in that vein (Note: A link has been removed),

The thought experiment has a noble place in research, but some thoughts are deemed more noble than others. Darwin and Einstein could let their minds wander and imagine the consequences of certain actions or natural laws. But scientists and historians who try to estimate what might have happened if, say, Darwin had fallen off the Beagle and drowned, are often accused of playing parlour games.

What if Darwin had toppled overboard before he joined the evolutionary dots? That discussion seems useful, because it raises interesting questions about the state of knowledge, then and now, and how it is communicated and portrayed. In his 2013 book Darwin Deleted — in which the young Charles is, indeed, lost in a storm — the historian Peter Bowler argued that the theory of evolution would have emerged just so, but with the pieces perhaps placed in a different order, and therefore less antagonistic to religious society.

In this week’s World View, another historian offers an alternative pathway for science: what if the ideas of Gregor Mendel on the inheritance of traits had been challenged more robustly and more successfully by a rival interpretation by the scientist W. F. R. Weldon? Gregory Radick argues that a twentieth-century genetics driven more by Weldon’s emphasis on environmental context would have weakened the dominance of the current misleading impression that nature always trumps nurture.

Here is Berry on the importance of questions,

The historian can ask: What traditions and legacies are these practitioners either building on or reacting against? How do these ideas cohere (or remain incoherent) for individuals and laboratories? Is a new way of understanding and investigating biology being created, and if so, where can we find evidence of it? Have biologists become increasingly concerned with controlling biological phenomena rather than understanding them? How does the desire to integrate engineering with biology sit within the long history of the establishment of biological science over the course of the 19th and 20th centuries?

Berry is an academic and his piece reflects an academic writing style with its complicated sentence structures and muted conclusions. If you have the patience, it is a good read on a topic that isn’t discussed all that often.

Creating quantum dots (artificial atoms) in graphene

An Aug. 22, 2016 news item on phys.org describes some recent work on artificial atoms and graphene from the Technical University of Vienna (Austria) and partners in Germany and the UK,

In a tiny quantum prison, electrons behave quite differently as compared to their counterparts in free space. They can only occupy discrete energy levels, much like the electrons in an atom – for this reason, such electron prisons are often called “artificial atoms”. Artificial atoms may also feature properties beyond those of conventional ones, with the potential for many applications for example in quantum computing. Such additional properties have now been shown for artificial atoms in the carbon material graphene. The results have been published in the journal Nano Letters, the project was a collaboration of scientists from TU Wien (Vienna, Austria), RWTH Aachen (Germany) and the University of Manchester (GB).

“Artificial atoms open up new, exciting possibilities, because we can directly tune their properties”, says Professor Joachim Burgdörfer (TU Wien, Vienna). In semiconductor materials such as gallium arsenide, trapping electrons in tiny confinements has already been shown to be possible. These structures are often referred to as “quantum dots”. Just like in an atom, where the electrons can only circle the nucleus on certain orbits, electrons in these quantum dots are forced into discrete quantum states.

Even more interesting possibilities are opened up by using graphene, a material consisting of a single layer of carbon atoms, which has attracted a lot of attention in the last few years. “In most materials, electrons may occupy two different quantum states at a given energy. The high symmetry of the graphene lattice allows for four different quantum states. This opens up new pathways for quantum information processing and storage” explains Florian Libisch from TU Wien. However, creating well-controlled artificial atoms in graphene turned out to be extremely challenging.

Florian Libisch, explaining the structure of graphene. Courtesy Technical University of Vienna

Florian Libisch, explaining the structure of graphene. Courtesy Technical University of Vienna

An Aug. 22, 2016 Technical University of Vienna press release (also on EurekAlert), which originated the news item, provides more detail,

There are different ways of creating artificial atoms: The simplest one is putting electrons into tiny flakes, cut out of a thin layer of the material. While this works for graphene, the symmetry of the material is broken by the edges of the flake which can never be perfectly smooth. Consequently, the special four-fold multiplicity of states in graphene is reduced to the conventional two-fold one.

Therefore, different ways had to be found: It is not necessary to use small graphene flakes to capture electrons. Using clever combinations of electrical and magnetic fields is a much better option. With the tip of a scanning tunnelling microscope, an electric field can be applied locally. That way, a tiny region is created within the graphene surface, in which low energy electrons can be trapped. At the same time, the electrons are forced into tiny circular orbits by applying a magnetic field. “If we would only use an electric field, quantum effects allow the electrons to quickly leave the trap” explains Libisch.

The artificial atoms were measured at the RWTH Aachen by Nils Freitag and Peter Nemes-Incze in the group of Professor Markus Morgenstern. Simulations and theoretical models were developed at TU Wien (Vienna) by Larisa Chizhova, Florian Libisch and Joachim Burgdörfer. The exceptionally clean graphene sample came from the team around Andre Geim and Kostya Novoselov from Manchester (GB) – these two researchers were awarded the Nobel Prize in 2010 for creating graphene sheets for the first time.

The new artificial atoms now open up new possibilities for many quantum technological experiments: “Four localized electron states with the same energy allow for switching between different quantum states to store information”, says Joachim Burgdörfer. The electrons can preserve arbitrary superpositions for a long time, ideal properties for quantum computers. In addition, the new method has the big advantage of scalability: it should be possible to fit many such artificial atoms on a small chip in order to use them for quantum information applications.

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

Electrostatically Confined Monolayer Graphene Quantum Dots with Orbital and Valley Splittings by Nils M. Freitag, Larisa A. Chizhova, Peter Nemes-Incze, Colin R. Woods, Roman V. Gorbachev, Yang Cao, Andre K. Geim, Kostya S. Novoselov, Joachim Burgdörfer, Florian Libisch, and Markus Morgenstern. Nano Lett., Article ASAP DOI: 10.1021/acs.nanolett.6b02548 Publication Date (Web): July 28, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Dexter Johnson in an Aug. 23, 2016 post on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website) provides some additional insight into the world of quantum dots,

Quantum dots made from semiconductor materials, like silicon, are beginning to transform the display market. While it is their optoelectronic properties that are being leveraged in displays, the peculiar property of quantum dots that allows their electrons to be forced into discrete quantum states has long held out the promise of enabling quantum computing.

If you have time to read it, Dexter’s post features an email interview with Florian Libisch where they further discuss quantum dots and quantum computing.

Canada’s Ingenuity Lab receives a $1.7M grant to develop oil recovery system for oil spills

A Sept. 15, 2016 news item on Benzinga.com describes the reasons for the $1.7M grant for Alberta’s (Canada) Ingenuity Lab to develop an oil spill recovery system,

Since 2010’s tragic events, which saw BP’s Deepwater Horizon disaster desecrate the Gulf of Mexico, oil safety has been on the forefront of the environmental debate and media outrage. In line with the mounting concerns continuing to pique public attention, at the end of this month [Sept. 2016], Hollywood will release its own biopic of the event. As can be expected, more questions will be raised about what exactly went wrong, in addition to fresh criticism aimed at the entire industry.

One question that is likely to emerge is how do we prevent such a calamity from ever happening again? Fortunately, some of the brightest minds in science have been preparing for such an answer.

One team that has been focusing on this dilemma is Alberta-based, multi-disciplinary research initiative Ingenuity Lab. The institution has just secured $1.7m in project funding for developing a highly advanced system for recovering oil from oil spills. This injection of capital will enable Ingenuity Lab to conduct new research and develop commercial production processes for recovering heavy oil spills in marine environments. The technology is centred on cutting edge nanowire-based stimuli-responsive membranes and devices that are capable for recovering oil.

A Sept. 15, 2016 Ingenuity Lab news release on MarketWired, which originated the news item, provides more insight into the oil spill situation,

Oil is a common pollutant in our oceans; more than three million metric tonnes contaminate the sea each year. When crude oil is accidentally released into a body of water by an oil tanker, refinery, storage facility, underwater pipeline or offshore oil-drilling rig, it is an environmental emergency of the most urgent kind.

Depending on the location, oil spills can be highly hazardous, as well as environmentally destructive. Consequently, a timely clean up is absolutely crucial in order to protect the integrity of the water, the shoreline and the numerous creatures that depend on these habitats.

Due to increased scrutiny of the oil industry with regard to its unseemly environmental track record, attention must be focused on the development of new materials and technologies for removing organic contaminants from waterways. Simply put, existing methods are not sufficiently robust.

Fortuitously, however, nanotechnology has opened the door for the development of sophisticated new tools that use specifically designed materials with properties that are ideally suited to enable complex separations, including the separation of crude oil from water.

Ingenuity Lab’s project focuses on the efficient recovery of oil through the development of this novel technology using a variety of stimuli-responsive nanomaterials. When the time comes for scale up production for this technology, Ingenuity Lab will work closely with industry trendsetters, Tortech Nanofibers.

This project forms a strong element of the Oil Spill Response Science (OSRS), which is part of Canada’s world-class tanker safety system for Responsible Resource Development. Through this programme, the Canadian Government ensures that the country’s resource wealth can be safely developed and transported to market, thus creating new jobs and economic growth for all Canadians.

From a communications standpoint, the news release is well written and well strategized to underline the seriousness of the situation and to take advantage of renewed interest in the devastating (people’s lives were lost and environmental damage is still being assessed) 2010 BP oil spill in the Gulf of Mexico due to the upcoming movie titled, Deepwater Horizon. A little more information about the team (how many people, who’s leading the research, are there international and/or interprovincial collaborators?), plans for the research (have they already started? what work, if any, are they building on? what challenges are they facing?) and some technical details would have been welcome.

Regardless, it’s good to hear about this initiative and I wish them great success with it.

You can find our more about Ingenuity Lab here and Tortech Nanofibers here. Interestingly, Tortech is a joint venture between Israel’s Plasan Sasa and the UK’s Q-Flo. (Q-Flo is a spinoff from Cambridge University.) One more thing, Tortech Nanofibers produces materials made of carbon nanotubes (CNTs). Presumably Ingenuity’s “nanowire-based stimuli-responsive membranes” include carbon nanotubes.

Attosecond science impacts femtochemistry

An Aug. 17, 2016 news item on Nanowerk reveals the latest about attoscience and femtochemistry (Note: A link has been removed),

Attosecond Science is a new exciting frontier in contemporary physics, aimed at time-resolving the motion of electrons in atoms, molecules and solids on their natural timescale. Electronic dynamics derives from the creation and evolution of coherence between different electronic states and proceeds on sub-femtosecond timescales. In contrast, chemical dynamics involves position changes of atomic centers and functional groups and typically proceeds on a slower, femtosecond timescale inherent to nuclear motion.

Nonetheless, there are exciting ways in which chemistry can hugely benefit from the technological developments pushed forward in the vibrant field of Attosecond Science. This was exploited in the work recently published by Lorenz Drescher and coworkers (“XUV transient absorption spectroscopy of iodomethane and iodobenzene photodissociation”).

An Aug. 17, 2016 (?) Forschungsverbund Berlin press release, which originated the news item, provides more detail about the work,

Attosecond pulses are generated in the process of High Harmonic Generation (HHG), in which infrared photons are upconverted to the extreme ultraviolet (XUV) frequency domain in a highly non-linear interaction of intense coherent light and matter. The short duration of attosecond pulses implies a frequency spectrum with photon energies spanning from a few electron volts (eV) to hundreds of eV. Such broad and continuous frequency spectra are ideally suited for core shell absorption measurements in molecules.

Core shell to valence shell transitions are a unique probe of molecular structure and dynamics. Core-to-valence transitions are element specific, due to the highly localized nature of core orbitals on specific atoms. On the other hand the intramolecular local environment of specific atomic sites is encoded, since an electron is lifted from a core orbital to a hole in the valence shell, affected by chemical bonding (…). Importantly, these transitions typically correspond to very short lifetimes of only a few femtoseconds. The use of ultrashort XUV pulses hence gives a new twist to the ultrafast studies of chemistry: It allows to probe chemical dynamics, initiated by a UV pump laser pulse, from the perspective of different reporter atoms within a molecule in an XUV transient absorption experiment. This is now beginning to be explored by a number of groups around the world.

In the experiment carried out by Drescher and coworkers at the MBI, photodissociation of iodomethane (CH3I) and iodobenzene (C6H5I) was studied with time-resolved XUV transient absorption spectroscopy at the iodine pre-N4,5 edge, using femtosecond UV pump pulses and XUV probe pulses from HHG (…). For both molecules the molecular core-to-valence absorption lines were found to fade immediately, within the pump-probe time-resolution. Absorption lines converging to the atomic iodine product however emerge promptly in CH3I but are time-delayed in C6H5I. In CH3I, we interpret this observation as the creation of an instantaneous new target state for XUV absorption by the UV pump pulse, which is then subject to relaxation of the excited valence shell as the molecule dissociates. This relaxation shows in a continuous shift in energy of the emerging atomic absorption lines in CH3I, which we measured in the experiment. In contrast, the delayed appearance of the absorption lines in C6H5I is indicative of a UV created vacancy, which within the molecule is initially spatially distant from the iodine reporter atom and has to first travel intramolecular before being observed. This behaviour is attributed to the dominant π → σ* UV excitation in iodobenzene, which involves the π orbital of the phenyl moiety.

While in the current work only a simplistic independent particle model was used to rationalize the observed experimental findings, MBI with its newly created theory department provides unique opportunities for joint experimental and theory studies on XUV transient absorption of photochemical processes. This will involve a new theoretical approach developed recently by researchers from MBI together with colleagues in Canada, the UK and Switzerland, which was recently submitted as a publication.

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

Communication: XUV transient absorption spectroscopy of iodomethane and iodobenzene photodissociation by L. Drescher, M. C. E. Galbraith, G. Reitsma, J. Dura, N. Zhavoronkov, S. Patchkovskii, M. J. J. Vrakking, and J. Mikosch. J. Chem. Phys. 145, 011101 (2016); http://dx.doi.org/10.1063/1.4955212

This paper appears to be open access.