Tag Archives: fullerenes

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.


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.


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.”


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.


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.

The evolution of molecules as observed with femtosecond stimulated Raman spectroscopy

A July 3, 2014 news item on Azonano features some recent research from the Université de Montréal (amongst other institutions),

Scientists don’t fully understand how ‘plastic’ solar panels work, which complicates the improvement of their cost efficiency, thereby blocking the wider use of the technology. However, researchers at the University of Montreal, the Science and Technology Facilities Council, Imperial College London and the University of Cyprus have determined how light beams excite the chemicals in solar panels, enabling them to produce charge.

A July 2, 2014 University of Montreal news release, which originated the news item, provides a fascinating description of the ultrafast laser process used to make the observations,

 “We used femtosecond stimulated Raman spectroscopy,” explained Tony Parker of the Science and Technology Facilities Council’s Central Laser Facility. “Femtosecond stimulated Raman spectroscopy is an advanced ultrafast laser technique that provides details on how chemical bonds change during extremely fast chemical reactions. The laser provides information on the vibration of the molecules as they interact with the pulses of laser light.” Extremely complicated calculations on these vibrations enabled the scientists to ascertain how the molecules were evolving. Firstly, they found that after the electron moves away from the positive centre, the rapid molecular rearrangement must be prompt and resemble the final products within around 300 femtoseconds (0.0000000000003 s). A femtosecond is a quadrillionth of a second – a femtosecond is to a second as a second is to 3.7 million years. This promptness and speed enhances and helps maintain charge separation.  Secondly, the researchers noted that any ongoing relaxation and molecular reorganisation processes following this initial charge separation, as visualised using the FSRS method, should be extremely small.

As for why the researchers’ curiosity was stimulated (from the news release),

The researchers have been investigating the fundamental beginnings of the reactions that take place that underpin solar energy conversion devices, studying the new brand of photovoltaic diodes that are based on blends of polymeric semiconductors and fullerene derivatives. Polymers are large molecules made up of many smaller molecules of the same kind – consisting of so-called ‘organic’ building blocks because they are composed of atoms that also compose molecules for life (carbon, nitrogen, sulphur). A fullerene is a molecule in the shape of a football, made of carbon. “In these and other devices, the absorption of light fuels the formation of an electron and a positive charged species. To ultimately provide electricity, these two attractive species must separate and the electron must move away. If the electron is not able to move away fast enough then the positive and negative charges simple recombine and effectively nothing changes. The overall efficiency of solar devices compares how much recombines and how much separates,” explained Sophia Hayes of the University of Cyprus, last author of the study.

… “Our findings open avenues for future research into understanding the differences between material systems that actually produce efficient solar cells and systems that should as efficient but in fact do not perform as well. A greater understanding of what works and what doesn’t will obviously enable better solar panels to be designed in the future,” said the University of Montreal’s Carlos Silva, who was senior author of the study.

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

Direct observation of ultrafast long-range charge separation at polymer–fullerene heterojunctions by Françoise Provencher, Nicolas Bérubé, Anthony W. Parker, Gregory M. Greetham, Michael Towrie, Christoph Hellmann, Michel Côté, Natalie Stingelin, Carlos Silva & Sophia C. Hayes. Nature Communications 5, Article number: 4288 doi:10.1038/ncomms5288 Published 01 July 2014

This article is behind a paywall but there is a free preview available vie ReadCube Access.

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.

Université de Montréal (Canada) collaborates with University of Houston (US) for a new theory and better solar cells

Solar cell efficiency is not good as researchers from  l’Université de Montréal (UdeM, located in Quebec, Canada) and the University of Houston (UH, located Texas, US) note in a Jan. 29, 2014 joint UH/UdeM news release written by Lisa Merkl (UH) on EurekAlert,

“Scientists don’t fully understand what is going on inside the materials that make up solar cells. We were trying to get at the fundamental photochemistry or photophysics that describes how these cells work,” Bittner said [Eric Bittner, a John and Rebecca Moores Professor of Chemistry and Physics in UH’s College of Natural Sciences and Mathematics,].

Solar cells are made out of organic semiconductors – typically blends of materials. However, solar cells made of these materials have about 3 percent efficiency. Bittner added that the newer materials, the fullerene/polymer blends, only reach about 10 percent efficiency.

“There is a theoretical limit for the efficiency of the ideal solar cell – the Shockley-Queisser limit. The theory we published describes how we might be able to get above this theoretical limit by taking advantage of quantum mechanical effects,” Bittner said. “By understanding these effects and making use of them in the design of a solar cell, we believe you can improve efficiency.”

Silva [Carlos Silva, an associate professor at the Université de Montréal and Canada Research Chair in Organic Semiconductor Materials] added, “In polymeric semiconductors, where plastics form the active layer of solar cells, the electronic structure of the material is intimately correlated with the vibrational motion within the polymer chain. Quantum-mechanical effects due to such vibrational-electron coupling give rise to a plethora of interesting physical processes that can be controlled to optimize solar cell efficiencies by designing materials that best exploit them.”

Unfortunately, there’s no more information about this model other than this (from the news release),

“Our theoretical model accomplishes things that you can’t get from a molecular model,” he [Bittner] said. “It is mostly a mathematical model that allows us to look at a much larger system with thousands of molecules. You can’t do ordinary quantum chemistry calculations on a system of that size.”

The calculations have prompted a series of new experiments by Silva’s group to probe the outcomes predicted by their model.

Bittner and Silva’s next steps involve collaborations with researchers who are experts in making the polymers and fabricating solar cells.

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

Noise-induced quantum coherence drives photo-carrier generation dynamics at polymeric semiconductor heterojunctions by Eric R. Bittner & Carlos Silva. Nature Communications 5, Article number: 3119 doi:10.1038/ncomms4119 Published 29 January 2014

This article is behind a paywall although you can get a free preview via ReadCube Access.

Grossly warped ‘nanographene’, a brand new type of carbon

A new of form carbon sounds exciting although the naming convention escapes me. Why call it ‘nanographene’ (albeit grossly warped) when graphene is already nanoscale? (For anyone who can explain this to me, please do let me know.) A July 15, 2013 news release on EurekAlert (it’s also available as a July 15, 2013 news item on ScienceDaily) describes the new form of carbon,

Bucking planarity, contorted sheets of graphene alter physical, optical and electronic properties of new material

Chemists at Boston College and Nagoya University in Japan have synthesized the first example of a new form of carbon, the team reports in the most recent online edition of the journal Nature Chemistry.

The new material consists of multiple identical pieces of grossly warped graphene, each containing exactly 80 carbon atoms joined together in a network of 26 rings, with 30 hydrogen atoms decorating the rim. Because they measure slightly more than a nanometer across, these individual molecules are referred to generically as “nanocarbons,” or more specifically in this case as “grossly warped nanographenes.”

There’s an explanation of why this discovery is special and how it was made (from,the news release),

Until recently, scientists had identified only two forms of pure carbon: diamond and graphite. Then in 1985, chemists were stunned by the discovery that carbon atoms could also join together to form hollow balls, known as fullerenes. Since then, scientists have also learned how to make long, ultra-thin, hollow tubes of carbon atoms, known as carbon nanotubes, and large flat single sheets of carbon atoms, known as graphene. The discovery of fullerenes was awarded the Nobel Prize in Chemistry in 1996, and the preparation of graphene was awarded the Nobel Prize in Physics in 2010.

Graphene sheets prefer planar, 2-dimensional geometries as a consequence of the hexagonal, chicken wire-like, arrangements of trigonal carbon atoms comprising their two-dimensional networks. The new form of carbon just reported in Nature Chemistry, however, is wildly distorted from planarity as a consequence of the presence of five 7-membered rings and one 5-membered ring embedded in the hexagonal lattice of carbon atoms.

Odd-membered-ring defects such as these not only distort the sheets of atoms away from planarity, they also alter the physical, optical, and electronic properties of the material, according to one of the principle authors, Lawrence T. Scott, the Jim and Louise Vanderslice and Family Professor of Chemistry at Boston College.

“Our new grossly warped nanographene is dramatically more soluble than a planar nanographene of comparable size,” said Scott, “and the two differ significantly in color, as well. Electrochemical measurements revealed that the planar and the warped nanographenes are equally easily oxidized, but the warped nanographene is more difficult to reduce.”

… By introducing multiple odd-membered ring defects into the graphene lattice, Scott and his collaborators have experimentally demonstrated that the electronic properties of graphene can be modified in a predictable manner through precisely controlled chemical synthesis.

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

A grossly warped nanographene and the consequences of multiple odd-membered-ring defects by Katsuaki Kawasumi, Qianyan Zhang, Yasutomo Segawa, Lawrence T. Scott, & Kenichiro Itami. Nature Chemistry (2013) doi:10.1038/nchem.1704  Published online 14 July 2013

This paper is behind a paywall. For those who would like more information but can’t get access to the paper at this time, there’s a brief July 15, 2015 news piece by Caryl Richards on the Chemistry World website.

Crowdfunding Qii, a foldable, soft keyboard made of a carbon nanotube/fullerene hybrid

Canatu Ltd. is a Finnish company that’s trying to crowdfund its foldable, soft keyboard, Qii, on indiegogo. Here’s more about Canatu’s keyboard project from the Nov. 24, 2012 news item on Nanowerk,

Canatu Ltd., a developer of a new class of versatile carbon nanomaterial based custom films and sensors for flexible and formable touch devices, is launching Qii – the world’s first, truly mobile, rollable touch accessory.

The company appears to be creating a new class of product under the Qii brand name. From the indiegogo campaign description,

With Qii, your smartphone and your imagination, any surface can be effectively turned into a touch surface and any “dumb” object can be turned into a “smart” object. Nanotechnology and organic electronics make it possible. The idea is simple, but the applications are endless.

As our first Qii product, we’re offering a full QWERTY computer keyboard, including a number pad and function keys, wirelessly connected to your smartphone. Because its ultra thin and flexible, Qii is both full sized and pocket sized, so you’ll be able to effortlessly type and surf anywhere you go, be it in a café, the woods, or a car, train, bus or plane. It has an anti fingerprint coating to keep it clean and a textured surface for easy touch typing. It’s dirt and water resistant, so you don’t have to worry about spilling and it’s easily washable with soap and water. And, since Qii’s rollable electronics are printed, it’s tough.

Qii’s case is also a touchpad, allowing you to point, tap and scroll for easy surfing and graphical editing. You can use Qii on most any surface, so you can check your email on your friend’s belly, update your Facebook on your pet, or write your next novel on your pillow.

Some keyboards claim to be rollable, but you can’t roll them up and fit them in your pocket. We use a new kind of flexible transparent electronic film together with a new kind of touch sensing technology that can sense both position and force to create a compact and portable and programmable touch surface.

Qii will work with iPhone, iPod, iPad, Android, iPhone, Blackberry, Windows Phone, and Palm phones according to each platform’s available QWERTY keyboard and pointer standards.

Intriguing, non? You might want to watch this video for a demonstration,

There is a very brief description of the technology in the campaign material,

Our team has been working for years with our partners to bring Qii to life. Together we have developed new carbon based nanomaterials, new dry printing manufacturing techniques and now new, ultra-high transparency, flexible, bendable, stretchable, rollable and foldable touch technologies and unique touch algorithms to make Qii possible. It starts with our flexible, transparent, electrically conductive film made with a new carbon nanomaterial connected to state-of-the art sensing electronics to make a flexible, transparent touch sensing surface that determines both your finger’s position and force.

We’ll introduce the Qii in pliable hard coated plastic, but, in the future, the sensor can be printed on most anything, even paper, rubber or fabric.

I took a look at the Canatu website and found this information about a material they’ve developed and named, NanoBuds® and which I believe forms the basis for the company’s proposed Qii keyboard,

Canatu has developed a new material, the Carbon NanoBud®, which is a hybrid of Carbon Nanotubes and fullerenes. The hybridization is achieved directly in the material synthesis process and the resulting material combines the best features of both fullerenes and nanotubes.

Canatu’s first products focus on taking advantage of the high conductivity, high aspect ratio, low work function, chemical stability and mechanical flexibility of NanoBuds® to make the world’s highest performance carbon based transparent conductive film for transparent conductors in touch, haptics, displays and photovoltaics. These films, consisting of randomly oriented deposits of NanoBuds on polymer or glass substrates, are flexible, bendable, stretchable and have excellent transparency conductivity performance as shown below. [emphasis mine]

David Brown, the company’s Chief Technical Officer (CTO) originally announced the crowdfunding Qii campaign would take place on Kickstarter in Dan Rogers’s Oct. 10, 2012 article for Plastic Electronics,

An accessory using a novel nanomaterial touchscreen will be launched via the Kickstarter project in the coming weeks, according to nanotechnology developer Canatu.

Based in Finland, Canatu supplies carbon NanoBuds that can be used as a conductive layer alternative to indium tin oxide, which is considered too brittle for flexible electronics.

I’m not sure what happened with the ‘Kickstarter’ plans but the indiegogo campaign has 41 days left as Canatu tries to raise $1,850,000 by Jan. 6, 2013. The company must raise the entire amount requested or it receives nothing.

Good luck to the folks at Canatu. Qii looks like a product which would make moving around much easier. Imagine not having to lug your laptop or tablet around while enjoying the benefits of a full size keyboard.

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.