Tag Archives: C60

Inhaling buckyballs (C60 fullerenes)

Carbon nanotubes (also known as buckytubes) have attracted most of the attention where carbon nanomaterials and health and safety are concerned. But, University of Michigan researchers opted for a change of pace and focused their health and safety research on buckyballs (also known as C60 or fullerenes) according to a Feb. 24, 2016 news item on Nanowerk,

Scientists at the University of Michigan have found evidence that some carbon nanomaterials can enter into immune cell membranes, seemingly going undetected by the cell’s built-in mechanisms for engulfing and disposing of foreign material, and then escape through some unidentified pathway. [emphasis mine]

The researchers from the School of Public Health and College of Engineering say their findings of a more passive entry of the materials into cells is the first research to show that the normal process of endocytosis-phagocytosis isn’t always activated when cells are confronted with tiny Carbon 60 (C60 ) molecules.

A Feb. 23, 2016 University of Michigan news release (also on EurekAlert but dated Feb. 24, 2016), which originated the news item, provides more detail about the research,

… This study examined nanomaterials known as carbon fullerenes, in this case C60, which has a distinct spherical shape.

Over the last decade, scientists have found these carbon-based materials useful in a number of commercial products, including drugs, medical devices, cosmetics, lubricants, antimicrobial agents and more. Fullerenes also are produced in nature through events like volcanic eruptions and wildfires.

The concern is that however exposed, commercially or naturally, little is known about how inhaling these materials impacts health.

“It’s entirely possible that even tiny amounts of some nanomaterials could cause altered cellular signaling,” said Martin Philbert, dean and professor of toxicology at the U-M School of Public Health.

Philbert said much of the previously published research bombarded cells with large amounts of particle clusters, unlike a normal environmental exposure.

The U-M researchers examined various mechanisms of cell entry through a combination of classical biological, biophysical and newer computational techniques, using models developed by a team led by Angela Violi to determine how C60 molecules find their way into living immune cells of mice.

They found that the C60 particles in low concentrations were entering the membrane individually, without perturbing the structure of the cell enough to trigger its normal response.

“Computational modeling of C60 interacting with lipid bilayers, representative of the cellular membrane, show that particles readily diffuse into biological membranes and find a thermodynamically stable equilibrium in an eccentric position within the bilayer,” said Violi, U-M professor of mechanical engineering, chemical engineering, biomedical engineering, and macromolecular science and engineering.

“The surprising contribution of passive modes of cellular entry provides new avenues for toxicological research, as we still don’t know exactly what are the mechanisms that cause this crossing.”

So, while the buckyballs enter cells, they also escape from them somehow. I wonder if the mechanisms that allow them to enter the cells are similar to the ones that allow them to escape. Regardless, here’s a link to and a citation for the paper,

C60 fullerene localization and membrane interactions in RAW 264.7 immortalized mouse macrophages by K. A. Russ, P. Elvati, T. L. Parsonage, A. Dews, J. A. Jarvis, M. Ray, B. Schneider, P. J. S. Smith, P. T. F. Williamson, A. Violi and M. A. Philbert. Nanoscale, 2016, 8, 4134-4144 DOI: 10.1039/C5NR07003A First published online 25 Jan 2016

This paper is behind a paywall.

Soccer balls with no resistance (superconductivity)

Known as a fullerene (also buckminsterfullerene, buckyballs, and/or C60), the soccer ball in question is helping scientists to better understand how to develop materials that are superconductive at room temperature. A Feb. 9, 2016 news item on Nanotechnology Now describes the latest in ‘soccer ball’ research,

Superconductors have long been confined to niche applications, due to the fact that the highest temperature at which even the best of these materials becomes resistance-free is minus 70 degrees Celsius. Nowadays they are mainly used in magnets for nuclear magnetic resonance tomographs, fusion devices and particle accelerators. Physicists from the Max Planck Institute for the Structure and Dynamics of Matter at the Center for Free-Electron Laser Science (CFEL) in Hamburg shone laser pulses at a material made up from potassium atoms and carbon atoms arranged in bucky ball structures. For a small fraction of a second, they found it to become superconducting at more than 100 degrees Kelvin – around minus 170 degrees Celsius. A similar effect was already discovered in 2013 by scientists of the same group in a different material, a ceramic oxide belonging to the family of so-called “cuprates”. As fullerenes have a relatively simple chemical structure, the researchers hope to be able to gain a better understanding of the phenomenon of light-induced superconductivity at high temperatures through their new experiments. Such insights could help in the development of a material which conducts electricity at room temperature without losses, and without optical excitation.

A Feb. 8, 2016 Max Planck Institute press release (also on EurekAlert but dated Feb. 9, 2016), which originated the news item, expands on the theme of superconductivity at room temperature,

Andrea Cavalleri, Director at the Max Planck Institute for the Structure and Dynamics of Matter, and his colleagues aim at paving the way for the development of materials that lose their electrical resistance at room temperature. Their observation that fullerenes, when excited with laser pulses, can become superconductive at minus 170 degrees Celsius, takes them a step closer to achieving this goal. This discovery could contribute to establishing a more comprehensive understanding of light-induced superconductivity, because it is easier to formulate a theoretical explanation for fullerenes than for cuprates. A complete explanation of this effect could, in turn, help the scientists to gain a better understanding of the phenomenon of high-temperature superconductivity and provide a recipe for an artificial superconductor that conducts electricity without resistance losses at room temperature.

In 2013, researchers from Cavalleri’s group demostrated that under certain conditions it may be possible for a material to conduct electricity at room temperature without resistance loss. A ceramic oxide belonging to the family of cuprates was shown to become superconductive without any cooling for a few trillionths of a second when the scientists excited it using an infrared laser pulse. One year later, the Hamburg-based scientists presented a possible explanation for this effect.

They observed that, following excitation with the flash of light, the atoms in the crystal lattice change position. This shift in position persists as does the superconducting state of the material. Broadly speaking, the light-induced change in the structure clears the way for the electrons so that they can move through the ceramic without losses. However, the explanation is very dependent on the highly specific crystalline structure of cuprates. As the process was understood at the time, it could have involved a phenomenon that only arises in this kind of materials.

The researchers have included in the press release an image illustrating the latest work being described in the press release excerpt which follows this,

Intense laser flashes remove the electrical resistance of a crystal layer of the alkali fulleride K3C60, a football-like molecule containing 60 carbon atoms. This is observed at temperatures at least as high as minus 170 degrees Celsius. © J.M. Harms/MPI for the Structure and Dynamics of Matter

Intense laser flashes remove the electrical resistance of a crystal layer of the alkali fulleride K3C60, a football-like molecule containing 60 carbon atoms. This is observed at temperatures at least as high as minus 170 degrees Celsius.
© J.M. Harms/MPI for the Structure and Dynamics of Matter

The press release goes on to provide some technical details about the most recent research,

The team headed by Cavalleri therefore asked themselves whether light could also break the electrical resistance of more traditional superconductors, the physics of which is better understood. The researchers from the Max Planck Institute for the Structure and Dynamics of Matter, among which Daniele Nicoletti and Matteo Mitrano, have now hit the jackpot using a substance that is very different to cuprates: the fulleride K3C60, a metal composed of so-called Buckminster fullerenes. These hollow molecules consist of 60 carbon atoms which bond in the shape of a football: a sphere comprising pentagons and hexagons. With the help of intercalated positively charged potassium ions, which work like a kind of cement, the negatively charged fullerenes stick to each other to form a solid. This so-called alkali fulleride is a metal which becomes superconductive below a critical temperature of around minus 250 degrees Celsius.

The researchers then irradiated the alkali fulleride with infrared light pulses of just a few billionths of a microsecond and repeated their experiment for a range of temperatures between the critical temperature and room temperature. They set the frequency of the light source so that it excited the fullerenes to produce vibrations. This causes the carbon atoms to oscillate in such a way that the pentagons in the football expand and contract. It was hoped that this change in the structure could generate transient superconductivity at high temperatures in a similar way to the process in cuprates.

To test this, the scientists irradiated the sample with a second light pulse at the same time as the infrared pulse, albeit at a frequency in the terahertz range. The strength at which this pulse is reflected indicates the conductivity of the material to the researchers, meaning how easily electrons move through the alkali fulleride. The result here was an extremely high conductivity. “We are pretty confident that we have induced superconductivity at temperatures at least as high as minus 170 degrees Celsius,” says Daniele Nicoletti. This means that the experiment in Hamburg presents one of the highest ever-observed critical temperatures outside of the material class of cuprates.

“We are now planning to carry out other experiments which should enable us to reach a more detailed understanding of the processes at work here,” says Nicoletti. What they would like to do next is analyze the crystal structure during excitation with the infrared light. As was previously the case with the cuprate, this should help to explain the phenomenon. The researchers would then like to irradiate the material with light pulses that last much longer. “Although this is technically very complicated, it could extend the lifetime of superconductivity, making it potentially relevant for applications,” concludes Nicoletti.

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

Possible light-induced superconductivity in K3C60 at high temperature by M. Mitrano, A. Cantaluppi, D. Nicoletti, S. Kaiser, A. Perucchi, S. Lupi, P. Di Pietro, D. Pontiroli, M. Riccò, S. R. Clark, D. Jaksch, & A. Cavalleri. Nature (2016) doi:10.1038/nature16522 Published online 08 February 2016

This paper is behind a paywall.

#BCTECH: being at the Summit (Jan. 18-19, 2016)

#BCTECH Summit 2016*, a joint event between the province of British Columbia (BC, Canada) and the BC Innovation Council (BCIC), a crown corporation formerly known as the Science Council of British Columbia, launched on Jan. 18, 2016. I have written a preview (Jan. 17, 2016 post) and a commentary on the new #BCTECH strategy (Jan. 19, 2016 posting) announced by British Columbia Premier, Christy Clark, on the opening day (Jan. 18, 2016) of the summit.

I was primarily interested in the trade show/research row/technology showcase aspect of the summit focusing (but not exclusively) on nanotechnology. Here’s what I found,

Nano at the Summit

  • Precision NanoSystems: fabricates equipment which allows researchers to create polymer nanoparticles for delivering medications.

One of the major problems with creating nanoparticles is ensuring a consistent size and rapid production. According to Shell Ip, a Precision NanoSystems field application scientist, their NanoAssemblr Platform has solved the consistency problem and a single microfluidic cartridge can produce 15 ml in two minutes. Cartridges can run in parallel for maximum efficiency when producing nanoparticles in greater quantity.

The NanoAssemblr Platform is in use in laboratories around the world (I think the number is 70) and you can find out more on the company’s About our technology webpage,

The NanoAssemblr™ Platform

The microfluidic approach to particle formulation is at the heart of the NanoAssemblr Platform. This well-controlled process mediates bottom-up self-assembly of nanoparticles with reproducible sizes and low polydispersity. Users can control size by process and composition, and adjust parameters such as mixing ratios, flow rate and lipid composition in order to fine-tune nanoparticle size, encapsulation efficiency and much more. The system technology enables manufacturing scale-up through microfluidic reactor parallelization similar to the arraying of transistors on an integrated chip. Superior design ensures that the platform is fast and easy to use with a software controlled manufacturing process. This usability allows for the simplified transfer of manufacturing protocols between sites, which accelerates development, reduces waste and ultimately saves money. Precision NanoSystems’ flagship product is the NanoAssemblr™ Benchtop Instrument, designed for rapid prototyping of novel nanoparticles. Preparation time on the system is streamlined to approximately one minute, with the ability to complete 30 formulations per day in the hands of any user.

The company is located on property known as the Endowment Lands or, more familiarly, the University of British Columbia (UBC).

A few comments before moving on, being able to standardize the production of medicine-bearing nanoparticles is a tremendous step forward which is going to help scientists dealing with other issues. Despite all the talk in the media about delivering nanoparticles with medication directly to diseased cells, there are transport issues: (1) getting the medicine to the right location/organ and (2) getting the medicine into the cell. My Jan. 12, 2016 posting featured a project with Malaysian scientists and a team at Harvard University who are tackling the transport and other nanomedicine) issues as they relate to the lung. As well, I have a Nov. 26, 2015 posting which explores a controversy about nanoparticles getting past the ‘cell walls’ into the nucleus of the cell.

The next ‘nano’ booths were,

  • 4D Labs located at Simon Fraser University (SFU) was initially hailed as a nanotechnology facility but these days they’re touting themselves as an ‘advanced materials’ facility. Same thing, different branding.

They advertise services including hands-on training for technology companies and academics. There is a nanoimaging facility and nanofabrication facility, amongst others.

I spoke with their operations manager, Nathaniel Sieb who mentioned a few of the local companies that use their facilities. (1) Nanotech Security (featured here most recently in a Dec. 29, 2015 post), an SFU spinoff company, does some of their anticounterfeiting research work at 4D Labs. (2) Switch Materials (a smart window company, electrochromic windows if memory serves) also uses the facilities. It is Neil Branda’s (4D Labs Executive Director) company and I have been waiting impatiently (my May 14, 2010 post was my first one about Switch) for either his or someone else’s electrochromic windows (they could eliminate or reduce the need for air conditioning during the hotter periods and reduce the need for heat in the colder periods) to come to market. Seib tells me, I’ll have to wait longer for Switch. (3) A graduate student was presenting his work at the booth, a handheld diagnostic device that can be attached to a smartphone to transmit data to the cloud. While the first application is for diabetics, there are many other possibilities. Unfortunately, glucose means you need to produce blood for the test when I suggested my preference for saliva the student explained some of the difficulties. Apparently, your saliva changes dynamically and frequently and something as simple as taking a sip of orange juice could result in a false reading. Our conversation (mine, Seib’s and the student’s) also drifted over into the difficulties of bringing products to market. Sadly, we were not able to solve that problem in our 10 minute conversation.

  • FPInnovations is a scientific research centre and network for the forestry sector. They had a display near their booth which was like walking into a peculiar forest (I was charmed). The contrast with the less imaginative approaches all around was striking.

FPInnovation helped to develop cellulose nanocrystals (CNC), then called nanocrystalline cellulose (NCC), and I was hoping to be updated about CNC and about the spinoff company Celluforce. The researcher I spoke to was from Sweden and his specialty was business development. He didn’t know much about CNC in Canada and when I commented on how active Sweden has been its pursuit of a CNC application, he noted Finland has been the most active. The researcher noted that making the new materials being derived from the forest, such as CNC, affordable and easily produced for use in applications that have yet to be developed are all necessities and challenges. He mentioned that cultural changes also need to take place. Canadians are accustomed to slicing away and discarding most of the tree instead of using as much of it as possible. We also need to move beyond the construction and pulp & paper sectors (my Feb. 15, 2012 posting featured nanocellulose research in Sweden where sludge was the base material).

Other interests at the Summit

I visited:

  • “The Wearable Lower Limb Anthropomorphic Exoskeleton (WLLAE) – a lightweight, battery-operated and ergonomic robotic system to help those with mobility issues improve their lives. The exoskeleton features joints and links that correspond to those of a human body and sync with motion. SFU has designed, manufactured and tested a proof-of-concept prototype and the current version can mimic all the motions of hip joints.” The researchers (Siamak Arzanpour and Edward Park) pointed out that the ability to mimic all the motions of the hip is a big difference between their system and others which only allow the leg to move forward or back. They rushed the last couple of months to get this system ready for the Summit. In fact, they received their patent for the system the night before (Jan. 17, 2016) the Summit opened.

It’s the least imposing of the exoskeletons I’ve seen (there’s a description of one of the first successful exoskeletons in a May 20, 2014 posting; if you scroll down to the end you’ll see an update about the device’s unveiling at the 2014 World Cup [soccer/football] in Brazil).

Unfortunately, there aren’t any pictures of WLLAE yet and the proof-of-concept version may differ significantly from the final version. This system could be used to help people regain movement (paralysis/frail seniors) and I believe there’s a possibility it could be used to enhance human performance (soldiers/athletes). The researchers still have some significant hoops to jump before getting to the human clinical trial stage. They need to refine their apparatus, ensure that it can be safely operated, and further develop the interface between human and machine. I believe WLLAE is considered a neuroprosthetic device. While it’s not a fake leg or arm, it enables movement (prosthetic) and it operates on brain waves (neuro). It’s a very exciting area of research, consequently, there’s a lot of international competition.

  • Delightfully, after losing contact for a while, I reestablished it with the folks (Sean Lee, Head External Relations and Jim Hanlon, Chief Administrative Officer) at TRIUMF (Canada’s national laboratory for particle and nuclear physics). It’s a consortium of 19 Canadian research institutions (12 full members and seven associate members).

It’s a little disappointing that TRIUMF wasn’t featured in the opening for the Summit since the institution houses theoretical, experimental, and applied science work. It’s a major BC (and Canada) science and technology success story. My latest post (July 16, 2015) about their work featured researchers from California (US) using the TRIUMF cyclotron for imaging nanoscale materials and, on the more practical side, there’s a Mar. 6, 2015 posting about their breakthrough for producing nuclear material-free medical isotopes. Plus, Maclean’s Magazine ran a Jan. 3, 2016 article by Kate Lunau profiling an ‘art/science’ project that took place at TRIUMF (Note: Links have been removed),

It’s not every day that most people get to peek inside a world-class particle physics lab, where scientists probe deep mysteries of the universe. In September [2015], Vancouver’s TRIUMF—home to the world’s biggest cyclotron, a type of particle accelerator—opened its doors to professional and amateur photographers, part of an event called Global Physics Photowalk 2015. (Eight labs around the world participated, including CERN [European particle physics laboratory], in Geneva, where the Higgs boson particle was famously discovered.)

Here’s the local (Vancouver) jury’s pick for the winning image (from the Nov. 4, 2015 posting [Winning Photographs Revealed] by Alexis Fong on the TRIUMF website),

Caption: DESCANT (at TRIUMF) neutron detector array composed of 70 hexagonal detectors Credit: Pamela Joe McFarlane

Caption: DESCANT (at TRIUMF) neutron detector array composed of 70 hexagonal detectors Credit: Pamela Joe McFarlane

With all those hexagons and a spherical shape, the DESCANT looks like a ‘buckyball’ or buckminsterfullerene or C60  to me.

I hope the next Summit features TRIUMF and/or some other endeavours which exemplify, Science, Technology, and Creativity in British Columbia and Canada.

Onto the last booth,

  • MITACS was originally one of the Canadian federal government’s Network Centres for Excellence projects. It was focused on mathematics, networking, and innovation but once the money ran out the organization took a turn. These days, it’s describing itself as (from their About page) “a national, not-for-profit organization that has designed and delivered research and training programs in Canada for 15 years. Working with 60 universities, thousands of companies, and both federal and provincial governments, we build partnerships that support industrial and social innovation in Canada.”Their Jan. 19, 2016 news release (coincidental with the #BCTECH Summit, Jan. 18 – 19, 2016?) features a new report about improving international investment in Canada,

    Opportunities to improve Canada’s attractiveness for R&D investment were identified:

    1.Canada needs to better incentivize R&D by rebalancing direct and indirect support measures

    2.Canada requires a coordinated, client-centric approach to incentivizing R&D

    3.Canada needs to invest in training programs that grow the knowledge economy”

    Oddly, entrepreneurial/corporate/business types never have a problem with government spending when the money is coming to them; it’s only a problem when it’s social services.

    Back to MITACS, one of their more interesting (to me) projects was announced at the 2015 Canadian Science Policy Conference. MITACS has inaugurated a Canadian Science Policy Fellowships programme which in its first year (pilot) will see up up to 10 academics applying their expertise to policy-making while embedded in various federal government agencies. I don’t believe anything similar has occurred here in Canada although, if memory serves, the Brits have a similar programme.

    Finally, I offer kudos to Sherry Zhao, MITACS Business Development Specialist, the only person to ask me how her organization might benefit my business. Admittedly I didn’t talk to a lot of people but it’s striking to me that at an ‘innovation and business’ tech summit, only one person approached me about doing business.  Of course, I’m not a male aged between 25 and 55. So, extra kudos to Sherry Zhao and MITACS.

Christy Clark (Premier of British Columbia), in her opening comments, stated 2800 (they were expecting about 1000) had signed up for the #BCTECH Summit. I haven’t been able to verify that number or get other additional information, e.g., business deals, research breakthroughs, etc. announced at the Summit. Regardless, it was exciting to attend and find out about the latest and greatest on the BC scene.

I wish all the participants great and good luck and look forward to next year’s where perhaps we’ll here about how the province plans to help with the ‘manufacturing middle’ issue. For new products you need to have facilities capable of reproducing your devices at a speed that satisfies your customers; see my Feb. 10, 2014 post featuring a report on this and other similar issues from the US General Accountability Office.

*’BCTECH Summit 2016′ link added Jan. 21, 2016.

University of New Brunswick (Canada), ‘sun in a can’, and buckyballs

Cutting the cost for making solar cells could be a step in the right direction for more widespread adoption. At any rate, that seems to be the motivation for Dr. Felipe Chibante of the University of New Brunswick  and his team as they’ve worked for the past three years or so on cutting production costs for fullerenes (also known as, buckminsterfullerenes, C60, and buckyballs). From a Dec. 23, 2015 article by Michael Tutton for Canadian Press,

A heating system so powerful it gave its creator a sunburn from three metres away is being developed by a New Brunswick engineering professor as a method to sharply reduce the costs of making the carbon used in some solar cells.

Felipe Chibante says his “sun in a can” method of warming carbon at more than 5,000 degrees Celsius helps create the stable carbon 60 needed in more flexible forms of photovoltaic panels.

Tutton includes some technical explanations in his article,

Chibante and senior students at the University of New Brunswick created the system to heat baseball-sized lumps of plasma — a form of matter composed of positively charged gas particles and free-floating negatively charged electrons — at his home and later in a campus lab.

According to a May 22, 2012 University of New Brunswick news release received funding of almost $1.5M from the Atlantic Canada Opportunities Agency for his work with fullerenes,

Dr. Felipe Chibante, associate professor in UNB’s department of chemical engineering, and his team at the Applied Nanotechnology Lab received nearly $1.5 million to lower the cost of fullerenes, which is the molecular form of pure carbon and is a critical ingredient for the plastic solar cell market.

Dr. Chibante and the collaborators on the project have developed fundamental synthesis methods that will be integrated in a unique plasma reactor to result in a price reduction of 50-75 per cent.

Dr. Chibante and his work were also featured in a June 10, 2013 news item on CBC (Canadian Broadcasting Corporation) news online,

Judges with the New Brunswick Innovation Fund like the idea and recently awarded Chibante $460,000 to continue his research at the university’s Fredericton campus.

Chibante has a long history of working with fullerenes — carbon molecules that can store the sun’s energy. He was part of the research team that discovered fullerenes in 1985 [the three main researchers at Rice University, Texas, received Nobel Prizes for the work].

He says they can be added to liquid, spread over plastic and shingles and marketed as a cheaper way to convert sunlight into electricity.

“What we’re trying to do in New Brunswick with the science research and innovation is we’re really trying to get the maximum bang for the buck,” said Chibante.

As it stands, fullerenes cost about $15,000 per kilogram. Chibante hopes to lower the cost by a factor of 10.

The foundation investment brings Chibante’s research funding to about $6.2 million.

Not everyone is entirely sold on this approach to encouraging solar energy adoption (from the CBC news item),

The owner of Urban Pioneer, a Fredericton [New Brunswick] company that sells alternative energy products, likes the concept, but doubts there’s much of a market in New Brunswick.

“We have conventional solar panels right now and they’re not that popular,” said Tony Craft.

“So I can’t imagine, like, when you throw something completely brand new into it, I don’t know how people are going to respond to that even, so it may be a very tough sell,” he said.

Getting back to Chibante’s breakthrough (from Tutton’s Dec. 23, 2015 article),

The 52-year-old researcher says he first set up the system to operate in his garage.

He installed optical filters to watch the melting process but said the light from the plasma was so intense that he later noticed a sunburn on his neck.

The plasma is placed inside a container that can contain and cool the extremely hot material without exposing it to the air.

The conversion technology has the advantage of not using solvents and doesn’t produce the carbon dioxide that other baking systems use, says Chibante.

He says the next stage is finding commercial partners who can help his team further develop the system, which was originally designed and patented by French researcher Laurent Fulcheri.

Chibante said he doesn’t believe the carbon-based, thin-film solar cells will displace the silicon-based cells because they capture less energy.

But he nonetheless sees a future for the more flexible sheets of solar cells.

“You can make fibres, you can make photovoltaic threads and you get into wearable, portable forms of power that makes it more ubiquitous rather than having to carry a big, rigid structure,” he said.

The researcher says the agreement earlier this month [Nov. 30 – Dec. 12, 2015] in Paris among 200 countries to begin reducing the use of fossil fuels and slow global warming may help his work.

By the way,  Chibante estimates production costs for fullerenes, when using his system, would be less that $50/kilogram for what is now the highest priced component of carbon-based solar cells.

There is another researcher in Canada who works in the field of solar energy, Dr. Ted Sargent at the University of Toronto (Ontario). He largely focuses on harvesting solar energy by using quantum dots. I last featured Sargent’s quantum dot work in a Dec. 9, 2014 posting.

A trio of nano news items from Japan (Irago Conference 2015, novel tuneable metallofullerenes, and nanoislands and skeletal skin for fuel cells)

Getting onto a list for news releases from Japan has been a boon. I don’t know how it happened but now I can better keep up with the nanotechnology effort in the country where the term was first coined (Norio Taniguchi) and which is a research leader in this field.

Irago Conference

This is a very intriguing conference, from a joint Oct. 18, 2015 Toyohashi University of Technology and University of Electro-Communications press release,

Organized by the Toyohashi University of Technology and University of Electro-Communications, Tokyo, the Irago Conference aims to enhance mutual understanding between scientists, engineers, policy makers, and experts from a wide spectrum of pure and applied sciences in order to resolve major global issues.

The Irago Conference 2015 is a unique conference combining thought provoking insights into global issues including disaster mitigation, neuroscience, public health monitoring, and nanotechnology [emphasis mine] by internationally renowned invited speakers with selected talks, posters, and demonstrations from academics, industrialists, and think tanks. The conference is truly a ‘360 degree outlook on critical scientific and technological challenges’ facing mankind.

Recent changes in global economics and industrial priorities, environmental and energy policies, food production and population movements have produced formidable challenges that must be addressed for sustaining life on earth.

The Irago Conference will highlight the major issues by bringing together experts from across the world who will give their views on key areas such as energy and natural resources, medicine and public health, disaster prevention and management, as well as other advances in science, technology and life sciences.

Observation, measurement, and monitoring are the keywords of the core topics covered at Irago 2015 with invited speakers Professor Masashi Hayakawa (University of Electro-Communications, Japan) presenting his pioneering research on “Earthquake prediction with electromagnetic phenomena, and Nobuhiko Okabe  (Kawasaki City Institute for Public Health, Japan) discussing “The role and contribution of Kawasaki City Institute for Public Health (Local Public Health Laboratory), locally and globally” with first hand examples of monitoring food safety and the spread of possible diseases carried by insects.

The Irago Conference will be streamed live. Visit the conference website for the links to the streaming site.

http://iragoconference.jp/

When: Thursday, 22 October 2015 to Friday 23  October 2015.

Where: Irago Sea-Park & Spa Hotel, Tahara, Aichi, Japan

They don’t appear to have set up the streaming link yet.

Tuneable metallofullerenes

Originally issued as a Sept. 21, 2015 press release, the University of Electro-Communications has issued an Oct. 19, 2015 version,

Tiny nanoscale molecules in the form of spherical carbon cages, or ‘fullerenes’, have received considerable attention in recent years. Individual or small groups of atoms can be trapped inside fullerenes, creating stable molecules with unique electronic structures and unusual properties that can be exploited in the field of nanomaterials and biomedical science.

Endohedral metallofullerenes (EMFs) are one such class of molecules, in which one or more metal atoms are encapsulated inside many kinds of carbon cages. Crucially, the metal atom(s) are not chemically bonded with the carbon surrounds, but they do donate electrons to the carbon cage. Scientists have recently begun to understand how to control the movement, behavior and positioning of the enclosed atoms by adding other atoms, such as silicon or germanium (in their silyl or germyl groups), to the fullerene surface. This allows for the manipulation and fine-tuning of the EMF’s properties.

Now, Masahiro Kako and co-workers at the University of Electro-Communications in Tokyo, together with scientists across Japan and the USA, have created and analyzed the effects of silylation and germylation on an EMF called Lu3N@Ih-C80 (three lutetium atoms bonded to a nitrogen atom encased inside a carbon 80 cage).

Using X-ray crystallography, electrochemical analyses and theoretical calculations, the team discovered that adding silyl groups or germyl groups to the fullerene structure was a versatile way of controlling the EMF’s electronic properties. The exact positioning of the silyl or germyl groups in bonding to the carbon structure determined the energy gaps present in the EMF, and determined the orientation of the bonded metal atoms inside the cage.

The germyl groups donated more electrons and the process worked slightly more efficiently than the silyl groups, but Kako and his team believe that both provide an effective way of fine-tuning EMF electronic characteristics.

Background

A brief history of fullerenes

Fullerenes are carbon molecules that take the shape of spheres. The most famous and abundant fullerene is the buckminsterfullerene, or ‘buckyball’, C60, which resembles a soccer ball in shape with a bonded carbon atom at each point of every polygon.

Endohedral metallofullerenes, or EMFs, are created by trapping a metal atom or atoms inside a fullerene cage, rather like a hamster in a ball. The trapped atom(s) are not chemically-bonded to the carbon, but they do interact with it by donating electrons, thus creating unique and very useful molecules for nanomaterial science and biomedicine.

Silylation and germylation

The addition of other atoms to fullerene surfaces can affect EMF properties, by regulating the behavior of the metal atoms inside the fullerene cage. In one EMF, the movement of lanthanum atoms is restricted to two dimensions by the addition of silyl groups to the carbon cage. This alters the electrostatic potentials inside the cage and restricts the lanthanum atoms’ mobility, and thus changes the overall properties of the whole molecule.

This study by Masahiro Kako and co-workers further enhances understanding of the effects of silylation and germalytion (the addition of silicon-based and germanium-based groups) on lutetium-based EMFs. The team have shown that the exact positioning of the additional atoms in the carbon structure can influence the energy gaps across the molecule, thereby allowing them to tune the electronic properties of the EMF. This ability to ‘fine-tune’ EMFs could have some applications for functional materials in molecular electronics, such as acceptors in organic photovoltaic devices.

Further work

Kako and his team hope to carry out further investigations into the addition of alternative groups of atoms to fullerenes, to add to the tuning properties of silicon- and germanium-based groups. This could expand on the versatility of EMFs and their potential applications in future.

Fullerenes don’t get that much attention these days when compared to graphene and carbon nanotubes although there seems to be increasing interest in their potential as cages.

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

Preparation, Structural Determination, and Characterization of Electronic Properties of Bis-Silylated and Bis-Germylated Lu3N@Ih-C80 by Prof. Dr. Masahiro Kako, Kyosuke Miyabe, Dr. Kumiko Sato, Dr. Mitsuaki Suzuki, Dr. Naomi Mizorogi, Dr. Wei-Wei Wang, Prof. Dr. Michio Yamada, Prof. Dr. Yutaka Maeda, Prof. Dr. Marilyn M. Olmstead, Prof. Dr. Alan L. Balch, Prof. Dr. Shigeru Nagase, and Prof. Dr. Takeshi Akasaka. Chemistry – A European Journal DOI: 10.1002/chem.201503579 Article first published online: 21 SEP 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Nanoislands and skeletal skin for fuel cells

This final item concerns a platinum ‘skin’. From an Oct. 21, 2015 University of Electro-Communications press release,

Polymer electrolyte fuel cells (PEFC) could provide an alternative to traditional fossil fuel power, but higher performance and durability under harsh conditions are needed before PEFC vehicles can be considered commercially viable. Now researchers at the University of Electro-Communications, the University of Tokushima and Japan Synchrotron Radiation Research Institute in Japan have synthesised catalysts from platinum cobalt (PtCo3) nanoparticles on carbon (C) with tin oxide (SnO2) nanoislands and shown that they perform better than any previously reported.

Fuel cell research has focused on platinum alloys and transition metal oxides to improve on the durability and catalytic performance of platinum on carbon. Previous work with SnO2 islands grown on platinum tin alloy with carbon had already shown some improvement in the oxygen reduction reactions that occur in fuel cells. However growing islands of only SnO2 on other alloys posed a challenge.

Now Yasuhiro Iwasawa at the University of Electro-Communications and his colleagues have grown SnO2 islands on Pt3Co nanoparticles on carbon (Pt3Co/C) by selective electrochemical deposition of tin metal, which is then oxidized. The addition of the SnO2 nanoislands doubled the catalytic performance of the Pt3Co/C catalysts. In addition they were undamaged after undergoing 5000 cycles of voltage changes to test their durability.

The structure the Pt3Co nanoparticles form has a Pt3Co core surrounded by a platinum skin that has a rough – “skeleton” – morphology. The researchers attribute the high catalytic performance in part to efficient electronic modification specifically at the platinum skin surface, and in particular to the unique property of the SnO2 nanoislands at the compressive platinum skeleton-skin surface.

“In general, adhesion of transition metal oxides on carbon induces depression of the electrical conductivity of the carbon,” explain the researchers in their report. “Hence, the selective nano-SnO2 decoration on the Pt-enriched-surface nanoparticles provides a significant advantage as a cathode catalyst.”

Background

Polymer electrolyte fuel cells

Polymer electrolyte fuel cells consist of two porous polymer membranes. On one side hydrogen gas molecules give up electrons and on the other oxygen gas molecules accept electrons completing a current circuit.  The ions can then penetrate the membrane and combine to form water.

Polymer electrolyte fuel cells have several advantages over conventional fuel as they do not deplete the limited supplies of fossil fuels, and the waste products are water and heat, and therefore relatively non-polluting. The efficiency of fuel cells has already highlighted their potential for powering small vehicles.

Redox

The formation of hydrogen and oxygen ions from the gas molecules are referred to as redox reactions from the term ‘reduction’ and ‘oxidation’. In fuel cells neutral oxygen molecules are reduced to negatively charge oxygen ions with a charge of -2. The oxidation number is thus ‘reduced’ from 0 to -2. In contrast, ionisation of hydrogen molecules to positively charge hydrogen ions (that is single protons) increases the oxygen number by one – ‘oxidation’.

Catalysts are used to increase the efficiency of the redox reactions in fuel cells to improve the power and current density. The efficiency of the catalysts is measured in terms of the oxygen reduction reaction (ORR) activity.

Improving ORR

The researchers measured the potential difference required for other reactions in the presence of their catalyst to determine how the additional SnO2 islands improved the ORR. Their observations suggest that strain at the nanoislands on the Pt3Co nanoparticles modifies the electronic structure so that the centre of the electron d band is decreased. This decreases oxygen adsorption and improves the performance of the catalyst. In addition there is an increase in the proton affinity of the platinum near the nanoislands, which significantly enhances the ORR further still.

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

Surface-Regulated Nano-SnO2/Pt3Co/C Cathode Catalysts for Polymer Electrolyte Fuel Cells Fabricated by a Selective Electrochemical Sn Deposition Method by Kensaku Nagasawa, Shinobu Takao, Shin-ichi Nagamatsu, Gabor Samjeské, Oki Sekizawa, Takuma Kaneko, Kotaro Higashi, Takashi Yamamoto, Tomoya Uruga†, and Yasuhiro Iwasawa. J. Am. Chem. Soc., 2015, 137 (40), pp 12856–12864 DOI: 10.1021/jacs.5b04256 Publication Date (Web): September 27, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

A use for fullerenes—inside insulation plastic for high-voltage cables

A Jan. 27, 2015 news item on Nanowerk, describes research which suggests that there may a new use for buckminsterfullerenes (or what they’re calling ‘carbon nanoballs’),

Researchers at Chalmers University of Technology [Sweden] have discovered that the insulation plastic used in high-voltage cables can withstand a 26 per cent higher voltage if nanometer-sized carbon balls are added. This could result in enormous efficiency gains in the power grids of the future, which are needed to achieve a sustainable energy system.

The renewable energy sources of tomorrow will often be found far away from the end user. Wind turbines, for example, are most effective when placed out at sea. Solar energy will have the greatest impact on the European energy system if focus is on transport of solar power from North Africa and Southern Europe to Northern Europe.

“Reducing energy losses during electric power transmission is one of the most important factors for the energy systems of the future,” says Chalmers researcher Christian Müller. “The other two are development of renewable energy sources and technologies for energy storage.”

The Jan. 27, 2015 Chalmers University of Technology press release (also on EurekAlert) by Johanna Wilde, which originated the news item, provides more information about the research,

Together with colleagues from Chalmers and the company Borealis in Stenungsund, he [Müller] has found a powerful method for reducing energy losses in alternating current cables.  The results were recently published in Advanced Materials, a highly ranked scientific journal.

The researchers have shown that different variants of the C60 carbon ball, a nanomaterial in the fullerene molecular group, provide strong protection against breakdown of the insulation plastic used in high-voltage cables. Today the voltage in the cables has to be limited to prevent the insulation layer from getting damaged. The higher the voltage the more electrons can leak out into the insulation material, a process which leads to breakdown.

It is sufficient to add very small amounts of fullerene to the insulation plastic for it to withstand a voltage that is 26 per cent higher, without the material breaking down, than the voltage that plastic without the additive can withstand.

“Being able to increase the voltage to this extent would result in enormous efficiency gains in power transmission all over the world,” says Christian Müller. “A major issue in the industry is how transmission efficiency can be improved without making the power cables thicker, since they are already very heavy and difficult to handle.”

Using additives to protect the insulation plastic has been a known concept since the 1970s, but until now it has been unknown exactly what and how much to add. Consequently, additives are currently not used at all for the purpose, and the insulation material is manufactured with the highest possible degree of chemical purity.

In recent years, other researchers have experimented with fullerenes in the electrically conductive parts of high-voltage cables. Until now, though, it has been unknown that the substance can be beneficial for the insulation material.

The Chalmers researchers have now demonstrated that fullerenes are the best voltage stabilizers identified for insulation plastic thus far. This means they have a hitherto unsurpassed ability to capture electrons and thus protect other molecules from being destroyed by the electrons.

To arrive at these findings, the researchers tested a number of molecules that are also used within organic solar cell research at Chalmers. The molecules were tested using several different methods, and were added to pieces of insulation plastic used for high-voltage cables. The pieces of plastic were then subjected to an increasing electric field until they crackled. Fullerenes turned out to be the type of additive that most effectively protects the insulation plastic.

The press release includes some facts about buckyballs or buckminsterfullerenes or fullerenes or C60 or carbon nanoballs, depending on what you want to call them,

 Facts: Carbon ball C60

  • The C60 carbon ball is also called buckminsterfullerene. It consists of 60 carbon atoms that are placed so that the molecule resembles a nanometer-sized football. C60 is included in the fullerene molecular class.
  • Fullerenes were discovered in 1985, which resulted in the Nobel Prize in Chemistry in 1996. They have unique electronic qualities and have been regarded as very promising material for several applications. Thus far, however, there have been few industrial usage areas.
  • Fullerenes are one of the five forms of pure carbon that exist. The other four are graphite, graphene/carbon nanotubes, diamond and amorphous carbon, for example soot.

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

A New Application Area for Fullerenes: Voltage Stabilizers for Power Cable Insulation by Markus Jarvid, Anette Johansson, Renee Kroon, Jonas M. Bjuggren, Harald Wutzel, Villgot Englund, Stanislaw Gubanski, Mats R. Andersson, and Christian Müller. Advanced Materials DOI: 10.1002/adma.201404306 Article first published online: 12 DEC 2014

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Here’s an image of wind turbines, an example of equipment which could benefit greatly from better insulation.,

Images: Lina Bertling, Jan-Olof Yxell, Carolina Eek Jaworski, Anette Johansson, Markus Jarvid, Christian Müller

Images: Lina Bertling, Jan-Olof Yxell, Carolina Eek Jaworski, Anette Johansson, Markus Jarvid, Christian Müller

You can find this image and others by clicking on the Chalmers University press release link (assuming the page hasn’t been moved). You can find more information about Borealis (the company Müller is working with) here.

Water cages made of buckyballs could affect nuclear magnetic resonance and magnetic resonance imaging (MRI)

I wasn’t expecting to find this May 20, 2014 news item on Nanowerk to be* quite so fascinating, especially as It gets off to a slow start (a link has been removed),

In a new paper in The Journal of Chemical Physics (“Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance”), produced by AIP Publishing, a research team in the United Kingdom and the United States describes how water molecules “caged” in fullerene spheres (“buckyballs”) are providing a deeper insight into spin isomers — varieties of a molecule that differ in their nuclear spin. The results of this work may one day help enhance the analytical and diagnostic power of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI).

A May 20, 2014 American Institute of Physics (AIP) news release on EurekAlert, which originated the news item, provides some information about water molecules prior to describing the research in more detail,

Water molecules can exist as one of two isomers depending on how the spins of their two hydrogen atoms are oriented: ortho, where the spins are parallel and have a spin number of 1, and para, where the spins are antiparallel and have a spin number of 0. Scientists believe that any given molecule can transform from ortho- into para- spin states and vice versa, a process known as nuclear spin conversion.

“Currently, mechanisms for this conversion are not completely understood, nor how long it takes the molecules to transform from one spin isomer to the other,” said Salvatore Mamone, a post-doctoral physicist at the University of Southampton and lead author on the JCP paper. “To study this, we had to figure out how to reduce the strong intermolecular interactions that are responsible for aggregation and lower the rotational mobility of the water molecules.”

Next, there’s a brief summarized version of the research (from the news release),

The answer was to use chemical reactions to open a hole in fullerene (C60, also known as a buckyball) spheres, inject water molecules and then close the “cages” to form a complex referred to as H2O@C60. “At the end of this synthetic preparation nicknamed ‘molecular surgery,’ we find that 70 to 90 percent of the cages are filled, giving us a significant quantity of water molecules to examine,” Mamone said. “Because the [water] molecules are kept separated by the cages, there is a large rotational freedom that makes observation of the ortho and para isomers possible.”

This is followed by more technical details,

In their experiment, the researchers quickly cooled the individual H2O@C60 samples from 50 Kelvin (minus 223 degrees Celsius) to 5 K (minus 268 degrees Celsius) and then monitored their NMR signal every few minutes over several days.

“As the observed NMR signal is proportional to the amount of ortho-water in the sample [para-water with its spin number of 0 is “NMR silent”], we can track the percentages of ortho and para isomers at any time and any temperature,” Mamone explained. “At 50 K, we find that 75 percent of the water molecules are ortho, while at 5 K, they become almost 100 percent para. Therefore, we know that after the quick temperature jump, equilibrium is restored by conversion from ortho to para—and we see that conversion in real time.”

A surprising outcome of the experiment was that the researchers observed a second-order rate law in the kinetics of the spin conversion which proves that pairs of molecules have to interact for conversion to occur. “Previous studies have speculated that other nuclear spins can cause conversion but we found this not to be the case for H2O@C60,” Mamone said.

Next up, the research team plans to study the roles of isomer concentrations and temperature in the conversion process, the conversion of para-water to ortho (“back conversion”), how to detect single ortho- and para-water molecules on surfaces, and spin isomers in other fullerene-caged molecules.

Bravo to the news release writer for a very nice explanation of the science!

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

Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance by Salvatore Mamone, Maria Concistré, Elisa Carignani, Benno Meier, Andrea Krachmalnicoff, Ole G. Johannessen, Xuegong Lei, Yongjun Li, Mark Denning, Marina Carravetta, Kelvin Goh, Anthony J. Horsewill, Richard J. Whitby and Malcolm H. Levitt.  J. Chem. Phys. 140, 194306 (2014) DOI: 10.1063/1.4873343

This is an open access paper.

* ‘to be’ added on July 16, 2014.

Rice University (Texas) researchers ‘soften’ a buckyball (buckminster fullerene)

A Jan. 16, 2014 Rice University news release landed in my mailbox this morning and revealed that researchers have ‘detuned’ or softened the atomic bonks in a molecule known as a buckminster fullenere (aka, buckyball),

Rice University scientists have found they can control the bonds between atoms in a molecule.

The molecule in question is carbon-60, also known as the buckminsterfullerene and the buckyball, discovered at Rice in 1985. The scientists led by Rice physicists Yajing Li and Douglas Natelson found that it’s possible to soften the bonds between atoms by applying a voltage and running an electric current through a single buckyball.

“This doesn’t mean we’re going to be able to arbitrarily dial around the strength of materials or anything like that,” Natelson said. “This is a very specific case, and even here it was something of a surprise to see this going on.

“But in general, if we can manipulate the charge distribution on molecules, we can affect their vibrations. We can start thinking, in the future, about controlling things in a better way.”

The effect appears when a buckyball attaches to a gold surface in the optical nano antenna used to measure the effects of an electric current on intermolecular bonds through a technique called Raman spectroscopy.

Natelson’s group built the nano antenna a few years ago to trap small numbers of molecules in a nanoscale gap between gold electrodes. Once the molecules are in place, the researchers can chill them, heat them, blast them with energy from a laser or electric current and measure the effect through spectroscopy, which gathers information from the frequencies of light emitted by the object of interest.

With continuing refinement, the researchers found they could analyze molecular vibrations and the bonds between the atoms in the molecule. That ability led to this experiment, Natelson said.

Natelson compared the characteristic vibrational frequencies exhibited by the bonds to the way a guitar string vibrates at a specific frequency based on how tightly it’s wound. Loosen the string and the vibration diminishes and the tone drops.

The nano antenna is able to detect the “tone” of detuned vibrations between atoms through surface-enhanced Raman spectroscopy (SERS), a technique that improves the readings from molecules when they’re attached to a metal surface. Isolating a buckyball in the gap between the gold electrodes lets the researchers track vibrations through the optical response seen via SERS.

When a buckyball attaches to a gold surface, its internal bonds undergo a subtle shift as electrons at the junction rearrange themselves to find their lowest energetic states. The Rice experiment found the vibrations in all the bonds dropped ever so slightly in frequency to compensate.

“Think of these molecules as balls and springs,” Natelson said. “The atoms are the balls and the bonds that hold them together are the springs. If I have a collection of balls and springs and I smack it, it would show certain vibrational modes.

“When we push current through the molecule, we see these vibrations turn on and start to shake,” Natelson said. “But we found, surprisingly, that the vibrations in buckyballs get softer, and by a significant amount. It’s as if the springs get floppier at high voltages in this particular system.” The effect is reversible; turn off the juice and the buckyball goes back to normal, he said.

The researchers used a combination of experimentation and sophisticated theoretical calculations to disprove an early suspicion that the well-known vibrational Stark effect was responsible for the shift. The Stark effect is seen when molecules’ spectral responses shift under the influence of an electric field. The Molecular Foundry, a Department of Energy User Facility at Lawrence Berkeley National Laboratory, collaborated on the calculations component.

Natelson’s group had spied similar effects on oligophenylene vinylene molecules used in previous experiments, also prompting the buckyball experiments. “A few years ago we saw hints of vibrational energies moving around, but nothing this clean or this systematic. It does seem like C-60 is kind of special in terms of where it sits energetically,” he said.

The discovery of buckyballs, which earned a Nobel Prize for two Rice professors, kick-started the nanotechnology revolution. “They’ve been studied very well and they’re very chemically stable,” Natelson said of the soccer-ball-shaped molecules. “We know how to put them on surfaces, what you can do to them and have them still be intact. This is all well understood.” He noted other researchers are looking at similar effects through the molecular manipulation of graphene, the single-atomic-layer form of carbon.

“I don’t want to make some grand claim that we’ve got a general method for tuning the molecular bonding in everything,” Natelson said. “But if you want chemistry to happen in one spot, maybe you want to make that bond really weak, or at least make it weaker than it was.

“There’s a long-sought goal by some in the chemistry community to gain precise control over where and when bonds break. They would like to specifically drive certain bonds, make sure certain bonds get excited, make sure certain ones break. We’re offering ways to think about doing that.”

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

Voltage tuning of vibrational mode energies in single-molecule junctions by Yajing Li, Peter Doak, Leeor Kronik, Jeffrey B. Neatonc, and Douglas Natelsona. PNAS.  doi: 10.1073/pnas.1320210111

This paper is behind a paywall so you need either a subscription to the journal or access to a research library with a subscription or, alternatively, there are two short-term rental options (which for reasons that escape me were difficult to access) here.

As business models go, I don’t believe that aspect of the PNAS model is going to prove successful. Why not make all the options available from the page containing the abstract as do other academic publishers?

Getting back to the buckyball, the researchers have provided an image to illustrate their work,

Rice University scientists discovered the bonds in a carbon-60 molecule – a buckyball – can be "detuned" when exposed to an electric current in an optical antenna. (Credit: Natelson Group/Rice University)

Rice University scientists discovered the bonds in a carbon-60 molecule – a buckyball – can be “detuned” when exposed to an electric current in an optical antenna. (Credit: Natelson Group/Rice University)

Where do buckyballs come from?

I’ve always wondered where buckyballs come from (as have scientists for the last 25 years) and now there’s an answer of sorts  (from the July 31, 2012 Florida State University news release Note: I have removed some links),

“We started with a paste of pre-existing fullerene molecules mixed with carbon and helium, shot it with a laser, and instead of destroying the fullerenes we were surprised to find they’d actually grown,” they wrote. The fullerenes were able to absorb and incorporate carbon from the surrounding gas.

By using fullenes  that contained heavy metal atoms in their centers, the scientists showed that the carbon cages remained closed throughout the process.

“If the cages grew by splitting open, we would have lost the metal atoms, but they always stayed locked inside,” Dunk [Paul Dunk, a doctoral student in chemistry and biochemistry at Florida State and lead author of the study published in Nature Communications] noted.

The researchers worked with a team of MagLab chemists using the lab’s 9.4-tesla Fourier transform ion cyclotron resonance mass spectrometer to analyze the dozens of molecular species produced when they shot the fullerene paste with the laser. The instrument works by separating molecules according to their masses, allowing the researchers to identify the types and numbers of atoms in each molecule. The process is used for applications as diverse as identifying oil spills, biomarkers and protein structures.

Dexter Johnson in his Aug. 6, 2012 posting on the Nanoclast blog on the IEEE (Institute of Electrical and Electronics Engineers) provides some context and commentary (Note: I have removed a link),

When Richard Smalley, Robert Curl, James Heath, Sean O’Brien, and Harold Kroto prepared the first buckminsterfullerene (C60) (or buckyball), they kicked off the next 25 years of nanomaterial science.

Here’s an artist’s illustration of  what these scientists have achieved, fullerene cage growth,

An artist’s representation of fullerene cage growth via carbon absorption from surrounding hot gases. Some of the cages contain lanthanum metal atoms. (Image courtesy National Science Foundation) [downloaded from Florida State University website]

 As I noted earlier I’m not alone in my fascination (from the news release),

Many people know the buckyball, also known by scientists as buckminsterfullerene, carbon 60 or C60, from the covers of their school chemistry textbooks. Indeed, the molecule represents the iconic image of “chemistry.” But how these often highly symmetrical, beautiful molecules with  fascinating properties form in the first place has been a mystery for a quarter-century. Despite worldwide investigation since the 1985 discovery of C60, buckminsterfullerene and other, non-spherical C60 molecules — known collectively as fullerenes — have kept their secrets. How? They’re born under highly energetic conditions and grow ultra-fast, making them difficult to analyze.

“The difficulty with fullerene formation is that the process is literally over in a flash — it’s next to impossible to see how the magic trick of their growth was performed,” said Paul Dunk, a doctoral student in chemistry and biochemistry at Florida State and lead author of the work.

There’s more than just idle curiosity at work (from the news release),

The buckyball research results will be important for understanding fullerene formation in extraterrestrial environments. Recent reports by NASA showed that crystals of C60 are in orbit around distant suns. This suggests that fullerenes may be more common in the universe than previously thought.

“The results of our study will surely be extremely valuable in deciphering fullerene formation in extraterrestrial environments,” said Florida State’s Harry Kroto, a Nobel Prize winner for the discovery of C60 and co-author of the current study.

The results also provide fundamental insight into self-assembly of other technologically important carbon nanomaterials such as nanotubes and the new wunderkind of the carbon family, graphene.

H/T to Nanowerk’s July 31, 2012 news item titled, Decades-old mystery how buckyballs form has been solved. In addition to Florida State University, National High Magnetic Field Laboratory (or MagLab), the CNRS  (Centre National de la Recherche Scientifique)Institute of Materials in France and Nagoya University in Japan were also involved in the research.

Graphene, IBM’s first graphene-based integrated circuit, and the European Union’s pathfinder programme in information technologies

A flat layer of carbon atoms packed into a two-dimensional honeycomb arrangement, graphene is being touted as a miracle (it seems)  material which will enable new kinds of electronic products. Recently, there have been a number of news items and articles featuring graphene research.

Here’s my roundup of the latest and greatest graphene news. I’m starting with an application that is the closest to commercialization: IBM recently announced the creation of the first graphene-based integrated circuit. From the Bob Yirka article dated June 10, 2011 on physorg.com,

Taking a giant step forward in the creation and production of graphene based integrated circuits, IBM has announced in Science, the fabrication of a graphene based integrated circuit [IC] on a single chip. The demonstration chip, known as a radio frequency “mixer” is capable of producing frequencies up to 10 GHz, and demonstrates that it is possible to overcome the adhesion problems that have stymied researchers efforts in creating graphene based IC’s that can be used in analog applications such as cell phones or more likely military communications.

The graphene circuits were started by growing a two or three layer graphene film on a silicon surface which was then heated to 1400°C. The graphene IC was then fabricated by employing top gated, dual fingered graphene FET’s (field-effect transistors) which were then integrated with inductors. The active channels were made by spin-coating the wafer with a thin polymer and then applying a layer of hydrogen silsequioxane. The channels were then carved by e-beam lithography. Next, the excess graphene was removed with an oxygen plasma laser, and then the whole works was cleaned with acetone. The result is an integrated circuit that is less than 1mm2 in total size.

Meanwhile, there’s a graphene research project in contention for a major research prize in Europe. Worth 1B Euros, the European Union’s 2011 pathfinder programme (Future and Emerging Technologies [Fet11]) in information technology) will select two from six pilot actions currently under way to be awarded a Flagship Initiative prize.  From the Fet11 flagships project page,

FET Flagships are large-scale, science-driven and mission oriented initiatives that aim to achieve a visionary technological goal. The scale of ambition is over 10 years of coordinated effort, and a budget of up to one billion Euro for each Flagship. They initiatives are coordinated between national and EU programmes and present global dimensions to foster European leadership and excellence in frontier research.

To prepare the launch of the FET Flagships, 6 Pilot Actions are funded for a 12-month period starting in May 2011. In the second half of 2012 two of the Pilots will be selected and launched as full FET Flagship Initiatives in 2013.

Here’s the description of the Graphene Science and technology for ICT and beyond pilot action,

Graphene, a new substance from the world of atomic and molecular scale manipulation of matter, could be the wonder material of the 21st century. Discovering just how important this material will be for Information and Communication Technologies is the long term focus of the Flagship Initiative, simply called, GRAPHENE. This aims to explore revolutionary potentials, in terms of both conventional as well as radically new fields of Information and Communication Technologies applications.

Bringing together multiple disciplines and addressing research across a whole range of issues, from fundamental understandings of material properties to Graphene production, the Flagship will provide the platform for establishing European scientific and technological leadership in the application of Graphene to Information and Communication Technologies. The proposed research includes coverage of electronics, spintronics, photonics, plasmonics and mechanics, all based on Graphene.

[Project Team:]

Andrea Ferrari, Cambridge University, UK
Jari Kinaret, Chalmers University, Sweden
Vladimir Falko, Lancaster University, UK
Jani Kivioja, NOKIA, Finland [emphases mine]

Not so coincidentally (given one member of the team is associated with Nokia and another is associated with Cambridge University), the Nokia Research Centre jointly with Cambridge University issued a May 4, 2011 news release (I highlighted it in my May 6, 2011 posting [scroll down past the theatre project information]) about the Morph concept (a rigid, flexible, and stretchable phone/blood pressure cuff/calculator/and  other electronic devices in one product) which they have been publicizing for years now. The news release concerned itself with how graphene would enable the researchers to take the Morph from idea to actuality. The webpage for the Graphene Pilot Action is here.

There’s something breathtaking when there is no guarantee of success about the willingness to invest up to 1B Euros in a project that spans 10 years. We’ll have to wait until 2013 before learning whether the graphene project will be one of the two selected as Flagship Initiatives.

I must say the timing for the 2010 Nobel Prize for Physics which went to two scientists (Andre Geim and Konstantin Novoselov) for their groundbreaking work with graphene sems interesting (featured in my Oct. 7, 2010 posting) in light of this graphene activity.

The rest of these graphene items are about research that could lay the groundwork for future commercialization.

Friday, June 13, 2011 there was a news item about foaming graphene on Nanowerk (from the news item),

Hui-Ming Cheng and co-workers from the Chinese Academy of Sciences’ Institute of Metal Research at Shenyang have now devised a chemical vapor deposition (CVD) method for turning graphene sheets into porous three-dimensional ‘foams’ with extremely high conductivity (“Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapour deposition” [published in Nature Materials 10, 424–428 (2011) doi:10.1038/nmat3001 Published online 10 April 2011]). By permeating this foam with a siloxane-based polymer, the researchers have produced a composite that can be twisted, stretched and bent without harming its electrical or mechanical properties.

Here’s an image from the Nature Publishing Group (NPG) of both the vapour and the bendable, twistable, stretchable composite (downloaded from the news item on Nanowerk where you can find a larger version of the image),

A scanning electron microscopy image of the net-like structure of graphene foam (left), and a photograph of a highly conductive elastic conductor produced from the foam. (© 2011 NPG)

The ‘elastic’ conductor (image to the right) reminds me of the ‘paper’ phone which I wrote about May 8, 2011 and May 12, 2011. (It’s a project where teams from Queen’s University [in Ontario] and Arizona State University are working to create flexible screens that give you telephony, music playing and other capabilities  much like the Morph concept.)

Researchers in Singapore have developed a graphene quantum dot using a C60 (a buckminster fullerene). From the June 13, 2011 news item (Graphene: from spheres to perfect dots) on Nanowerk,

An electron trapped in a space of just a few nanometers across behaves very differently to one that is free. Structures that confine electrons in all three dimensions can produce some useful optical and electronic effects. Known as quantum dots, such structures are being widely investigated for use in new types of optical and electronics technologies, but because they are so small it is difficult to fabricate quantum dots reproducibly in terms of shape and size. Researchers from the National University of Singapore (NUS) and A*STAR have now developed a technique that enables graphene quantum dots of a known size to be created repeatedly and quickly (“Transforming C60 molecules into graphene quantum dots” [published in Nature Nanotechnology 6, 247–252 (2011) doi:10.1038/nnano.2011.30 Published online 20 March 2011]).

This final bit is about a nano PacMan that allows for more precise patterning from a June 13, 2011 article written by Michael Berger,

A widely discussed method for the patterning of graphene is the channelling of graphite by metal nanoparticles in oxidizing or reducing environments (see for instance: “Nanotechnology PacMan cuts straight graphene edges”).

“All previous studies of channelling behavior have been limited by the need to perform the experiment ex situ, i.e. comparing single ‘before’ and ‘after’ images,” Peter Bøggild, an associate professor at DTU [Danish Technical University] Nanotech, explains to Nanowerk. “In these and other ex situ experiments the dynamic behavior must be inferred from the length of channels and heating time after completion of the experiment, with the rate of formation of the channel assumed to be consistent over the course of the experiment.”

In new work, reported in the June 9, 2011 advance online edition of Nano Letters (“Discrete dynamics of nanoparticle channelling in suspended graphene” [published in Nano Letters, Article ASAP, DOI: 10.1021/nl200928k, Publication Date (Web): June 9, 2011]), Bøggild and his team report the nanoscale observation of this channelling process by silver nanoparticles in an oxygen atmosphere in-situ on suspended mono- and bilayer graphene in an environmental transmission electron microscope, enabling direct concurrent observation of the process, impossible in ex-situ experiments.

Personally, I love the youtube video I’ve included here largely because it features blobs (as many of these videos do) where they’ve added music and titles (many of these videos do not) so you can better appreciate the excitement,

From the article by Michael Berger,

As a result of watching this process occur live in a transmission electron microscope, the researchers say they have seen many details that were hidden before, and video really brings the “nano pacman” behavior to life …

There’s a reason why they’re so interested in cutting graphene,

“With a deeper understanding of the fine details we hope to one day use this nanoscale channelling behavior to directly cut desired patterns out of suspended graphene sheets, with a resolution and accuracy that isn’t achievable with any other technique,” says Bøggild. “A critical advantage here is that the graphene crystal structure guides the patterning, and in our case all of the cut edges of the graphene are ‘zigzag’ edges.”

So there you have it. IBM creates the first integrated graphene-based circuit, there’s the prospect of a huge cash prize for a 10-year project on graphene so they could produce the long awaited Morph concept and other graphene-based electronics products while a number of research teams around the world continue teasing out its secrets with graphene ‘foam’ projects, graphene quantum dots, and nano PacMen who cut graphene’s zigzag edges with precision.

ETA June 16, 2011: For those interested in the business end of things, i.e. market value of graphene-based products, Cameron Chai features a report, Graphene: Technologies, Applications, and Markets, in his June 16, 2011 news item on Azonano.