Tag Archives: C60

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

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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

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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)

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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)

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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?

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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

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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.