Tag Archives: Rice University

Nanoscale antioxidants

A Feb. 10, 2015 news item on Azonano features injectable nanoparticles that act as antioxidants useful in case of injury, in particular, brain injury,

Injectable nanoparticles that could protect an injured person from further damage due to oxidative stress have proven to be astoundingly effective in tests to study their mechanism.

Scientists at Rice University, Baylor College of Medicine and the University of Texas Health Science Center at Houston (UTHealth) Medical School designed methods to validate their 2012 discovery that combined polyethylene glycol-hydrophilic carbon clusters — known as PEG-HCCs — could quickly stem the process of overoxidation that can cause damage in the minutes and hours after an injury.

A Feb. 9, 2015 Rice University news release (also on EurekAlert), which originated the news item, describe the benefits in more detail,

The tests revealed a single nanoparticle can quickly catalyze the neutralization of thousands of damaging reactive oxygen species molecules that are overexpressed by the body’s cells in response to an injury and turn the molecules into oxygen. These reactive species can damage cells and cause mutations, but PEG-HCCs appear to have an enormous capacity to turn them into less-reactive substances.

The researchers hope an injection of PEG-HCCs as soon as possible after an injury, such as traumatic brain injury or stroke, can mitigate further brain damage by restoring normal oxygen levels to the brain’s sensitive circulatory system.

“Effectively, they bring the level of reactive oxygen species back to normal almost instantly,” said Rice chemist James Tour. “This could be a useful tool for emergency responders who need to quickly stabilize an accident or heart attack victim or to treat soldiers in the field of battle.” Tour led the new study with neurologist Thomas Kent of Baylor College of Medicine and biochemist Ah-Lim Tsai of UTHealth.

The news release goes on to describe the antioxidant particles and previous research,

PEG-HCCs are about 3 nanometers wide and 30 to 40 nanometers long and contain from 2,000 to 5,000 carbon atoms. In tests, an individual PEG-HCC nanoparticle can catalyze the conversion of 20,000 to a million reactive oxygen species molecules per second into molecular oxygen, which damaged tissues need, and hydrogen peroxide while quenching reactive intermediates.

Tour and Kent led the earlier research that determined an infusion of nontoxic PEG-HCCs may quickly stabilize blood flow in the brain and protect against reactive oxygen species molecules overexpressed by cells during a medical trauma, especially when accompanied by massive blood loss.

Their research targeted traumatic brain injuries, after which cells release an excessive amount of the reactive oxygen species known as a superoxide into the blood. These toxic free radicals are molecules with one unpaired electron that the immune system uses to kill invading microorganisms. In small concentrations, they contribute to a cell’s normal energy regulation. Generally, they are kept in check by superoxide dismutase, an enzyme that neutralizes superoxides.

But even mild traumas can release enough superoxides to overwhelm the brain’s natural defenses. In turn, superoxides can form such other reactive oxygen species as peroxynitrite that cause further damage.

“The current research shows PEG-HCCs work catalytically, extremely rapidly and with an enormous capacity to neutralize thousands upon thousands of the deleterious molecules, particularly superoxide and hydroxyl radicals that destroy normal tissue when left unregulated,” Tour said.

“This will be important not only in traumatic brain injury and stroke treatment, but for many acute injuries of any organ or tissue and in medical procedures such as organ transplantation,” he said. “Anytime tissue is stressed and thereby oxygen-starved, superoxide can form to further attack the surrounding good tissue.”

These details about the research are also noted in the news release,

The researchers used an electron paramagnetic resonance spectroscopy technique that gets direct structure and rate information for superoxide radicals by counting unpaired electrons in the presence or absence of PEG-HCC antioxidants. Another test with an oxygen-sensing electrode, peroxidase and a red dye confirmed the particles’ ability to catalyze superoxide conversion.

“In sharp contrast to the well-known superoxide dismutase, PEG-HCC is not a protein and does not have metal to serve the catalytic role,” Tsai said. “The efficient catalytic turnover could be due to its more ‘planar,’ highly conjugated carbon core.”

The tests showed the number of superoxides consumed far surpassed the number of possible PEG-HCC bonding sites. The researchers found the particles have no effect on important nitric oxides that keep blood vessels dilated and aid neurotransmission and cell protection, nor was the efficiency sensitive to pH changes.

“PEG-HCCs have enormous capacity to convert superoxide to oxygen and the ability to quench reactive intermediates while not affecting nitric oxide molecules that are beneficial in normal amounts,” Kent said. “So they hold a unique place in our potential armamentarium against a range of diseases that involve loss of oxygen and damaging levels of free radicals.”

The study also determined PEG-HCCs remain stable, as batches up to 3 months old performed as good as new.

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

Highly efficient conversion of superoxide to oxygen using hydrophilic carbon clusters by Errol L. G. Samuel, Daniela C. Marcano, Vladimir Berka, Brittany R. Bitner, Gang Wu, Austin Potter, Roderic H. Fabian, Robia G. Pautler, Thomas A. Kent, Ah-Lim Tsai, and James M. Tour. Published online before print February 9, 2015, doi: 10.1073/pnas.1417047112 PNAS February 9, 2015

This paper is behind a paywall.

Rice University collaborates with Shandong University on a Joint Center for Carbon Nanomaterials

They’re not billing this as a joint US-China project but with Rice University being in Texas, US and Shandong University being in Shandong (province) in China, I think it’s reasonable to describe it that way. Here’s more about the project from a Feb. 4, 2015 news item on Azonano,

Scientists from Rice University and Shandong University, China, celebrated the opening of the Joint Center for Carbon Nanomaterials, a collaborative facility to study nanotechnology, on Feb. 1 [2015].

Rice faculty members Pulickel Ajayan and Jun Lou, the chair and associate chair, respectively, of the university’s Department of Materials Science and NanoEngineering, took part in the ceremony along with Rice alumnus Lijie Ci, director of the new center and a professor of materials science and engineering at Shandong. The center’s dedication was part of the first International Workshop on Engineering and Applications of Nanocarbon, held Jan. 31-Feb. 2 [2015].

Determining where this new center is located proved to be a challenge. From a Feb. 2, 2015 Rice University news release, which originated the news item,

“We at Rice University are excited and honored to collaborate with Shandong University on this important endeavor,” Rice President David Leebron said in a message recorded for the ceremony. [emphasis mine] “The center represents and combines two very important initiatives for Rice: research excellence and applications in nanosciences and long-term partnerships with the best institutions worldwide.”

“A lot of people are working on carbon nanoscience on both campuses, and we expect they will be interested in taking part,” Ajayan said. “Nanotubes and graphene are essentially the building blocks for the center, but Lijie wants to build ecologically relevant, applied research that can be commercialized. That’s the long-term goal. All of the experience we have had in the area will be beneficial.”

Ajayan expects students from both universities will travel. “People from Rice will be engaged in some of the activities of this joint center, including advising students there. And we hope Shandong students will have the opportunity to come to Rice for a short time,” he said. “The center also contributes to Rice’s goal to build closer connections with China.” [emphases mine]

Ajayan and Ci came to Rice together in 2007 from Rensselaer Polytechnic Institute; Ajayan was a faculty member and Ci was a postdoctoral researcher. At Rice, they introduced the darkest material ever measured at the time of its invention in 2008, an accomplishment that landed them in the Guinness Book of World Records.

They also collaborated on the first two-dimensional material to incorporate graphene and hexagonal boron nitride in a seamless lattice. Such 2-D materials have since become the focus of worldwide research for their potential as electronic components. And Ci, Lou and Ajayan worked together to study the nanoscale friction properties of carbon nanotubes.

I’m inferring from the portions I’ve highlighted that this center is located at Shandong University.

Cute, adorable roundworms help measure nanoparticle toxicity

Caption: Low-cost experiments to test the toxicity of nanomaterials focused on populations of roundworms. Rice University scientists were able to test 20 nanomaterials in a short time, and see their method as a way to determine which nanomaterials should undergo more extensive testing. Credit: Zhong Lab/Rice University

Caption: Low-cost experiments to test the toxicity of nanomaterials focused on populations of roundworms. Rice University scientists were able to test 20 nanomaterials in a short time, and see their method as a way to determine which nanomaterials should undergo more extensive testing.
Credit: Zhong Lab/Rice University

Until now, ‘cute’ and ‘adorable’ are not words I would have associated with worms of any kind or with Rice University, for that matter. It’s amazing what a single image can do, eh?

A Feb. 3, 2015 news item on Azonano describes how roundworms have been used in research investigating the toxicity of various kinds of nanoparticles,

The lowly roundworm is the star of an ambitious Rice University project to measure the toxicity of nanoparticles.

The low-cost, high-throughput study by Rice scientists Weiwei Zhong and Qilin Li measures the effects of many types of nanoparticles not only on individual organisms but also on entire populations.

A Feb. 2, 2015 Rice University news release (also on EurekAlert), which originated the news item, provides more details about the research,

The Rice researchers tested 20 types of nanoparticles and determined that five, including the carbon-60 molecules (“buckyballs”) discovered at Rice in 1985, showed little to no toxicity.

Others were moderately or highly toxic to Caenorhabditis elegans, several generations of which the researchers observed to see the particles’ effects on their health.

The results were published by the American Chemical Society journal Environmental Sciences and Technology. They are also available on the researchers’ open-source website.

“Nanoparticles are basically new materials, and we don’t know much about what they will do to human health and the health of the ecosystem,” said Li, an associate professor of civil and environmental engineering and of materials science and nanoengineering. “There have been a lot of publications showing certain nanomaterials are more toxic than others. So before we make more products that incorporate these nanomaterials, it’s important that we understand we’re not putting anything toxic into the environment or into consumer products.

“The question is, How much cost can we bear?” she said. “It’s a long and expensive process to do a thorough toxicological study of any chemical, not just nanomaterials.” She said that due to the large variety of nanomaterials being produced at high speed and at such a large scale, there is “an urgent need for high-throughput screening techniques to prioritize which to study more extensively.”

Rice’s pilot study proves it is possible to gather a lot of toxicity data at low cost, said Zhong, an assistant professor of biosciences, who has performed extensive studies on C. elegans, particularly on their gene networks. Materials alone for each assay, including the worms and the bacteria they consumed and the culture media, cost about 50 cents, she said.

The researchers used four assays to see how worms react to nanoparticles: fitness, movement, growth and lifespan. The most sensitive assay of toxicity was fitness. In this test, the researchers mixed the nanoparticles in solutions with the bacteria that worms consume. Measuring how much bacteria they ate over time served as a measure of the worms’ “fitness.”

“If the worms’ health is affected by the nanoparticles, they reproduce less and eat less,” Zhong said. “In the fitness assay, we monitor the worms for a week. That is long enough for us to monitor toxicity effects accumulated through three generations of worms.” C. elegans has a life cycle of about three days, and since each can produce many offspring, a population that started at 50 would number more than 10,000 after a week. Such a large number of tested animals also enabled the fitness assay to be highly sensitive.

The researchers’ “QuantWorm” system allowed fast monitoring of worm fitness, movement, growth and lifespan. In fact, monitoring the worms was probably the least time-intensive part of the project. Each nanomaterial required specific preparation to make sure it was soluble and could be delivered to the worms along with the bacteria. The chemical properties of each nanomaterial also needed to be characterized in detail.

The researchers studied a representative sampling of three classes of nanoparticles: metal, metal oxides and carbon-based. “We did not do polymeric nanoparticles because the type of polymers you can possibly have is endless,” Li explained.

They examined the toxicity of each nanoparticle at four concentrations. Their results showed C-60 fullerenes, fullerol (a fullerene derivative), titanium dioxide, titanium dioxide-decorated nanotubes and cerium dioxide were the least damaging to worm populations.

Their “fitness” assay confirmed dose-dependent toxicity for carbon black, single- and multiwalled carbon nanotubes, graphene, graphene oxide, gold nanoparticles and fumed silicon dioxide.

They also determined the degree to which surface chemistry affected the toxicity of some particles. While amine-functionalized multiwalled nanotubes proved highly toxic, hydroxylated nanotubes had the least toxicity, with significant differences in fitness, body length and lifespan.

A complete and interactive toxicity chart for all of the tested materials is available online.

Zhong said the method could prove its worth as a rapid way for drug or other companies to narrow the range of nanoparticles they wish to put through more expensive, dedicated toxicology testing.

“Next, we hope to add environmental variables to the assays, for example, to mimic ultraviolet exposure or river water conditions in the solution to see how they affect toxicity,” she said. “We also want to study the biological mechanism by which some particles are toxic to worms.”

Here’s a citation for the paper and links to the paper and to the researchers’ website,

A multi-endpoint, high-throughput study of nanomaterial toxicity in Caenorhabditis elegans by Sang-Kyu Jung, Xiaolei Qu, Boanerges Aleman-Meza, Tianxiao Wang, Celeste Riepe, Zheng Liu, Qilin Li, and Weiwei Zhong. Environ. Sci. Technol., Just Accepted Manuscript DOI: 10.1021/es5056462 Publication Date (Web): January 22, 2015
Copyright © 2015 American Chemical Society

Nanomaterial effects on C. elegans

Home | Download | Tutorial | About

This heat map indicates whether a measurement for the nanomaterial-exposed worms is higher (yellow), or lower (blue) than the control worms. Black indicates no effects from nanomaterial exposure.

Clicking on colored blocks to see detailed experimental data.

The published paper is open access but you need an American Chemical Society site registration to access it. The researchers’ site is open access.

Quantum dots cycling through the food chain

Rice University (Texas, US) researchers have published a study which follows quantum dot nanoparticles as they enter the water supply and are taken up by plant roots and leaves and eaten by caterpillars. From a Dec. 16, 2014 news item on ScienceDaily,

In one of the most comprehensive laboratory studies of its kind, Rice University scientists traced the uptake and accumulation of quantum dot nanoparticles from water to plant roots, plant leaves and leaf-eating caterpillars.

The study, one of the first to examine how nanoparticles move through human-relevant food chains, found that nanoparticle accumulation in both plants and animals varied significantly depending upon the type of surface coating applied to the particles. The research is available online in the American Chemical Society’s journal Environmental Science & Technology.

A Dec. 16, 2014 Rice University news release (also on EurekAlert), which originated the news item, provides insight into some of the issues being addressed with this research (Note: Links have been removed),

“With industrial use of nanoparticles on the rise, there are increasing questions about how they move through the environment and whether they may accumulate in high levels in plants and animals that people eat,” said study co-author Janet Braam, professor and chair of the Department of BioSciences at Rice.

Braam and colleagues studied the uptake of fluorescent quantum dots by Arabidopsis thaliana, an oft-studied plant species that is a relative of mustard, broccoli and kale. In particular, the team looked at how various surface coatings affected how quantum dots moved from roots to leaves as well as how the particles accumulated in leaves. The team also studied how quantum dots behaved when caterpillars called cabbage loopers (Trichoplusia ni) fed upon plant leaves containing quantum dots.

“The impact of nanoparticle uptake on plants themselves and on the herbivores that feed upon them is an open question,” said study first author Yeonjong Koo, a postdoctoral research associate in Braam’s lab. “Very little work has been done in this area, especially in terrestrial plants, which are the cornerstone of human food webs.”

Some toxins, like mercury and DDT, tend to accumulate in higher concentrations as they move up the food chain from plants to animals. It is unknown whether nanoparticles may also be subject to this process, known as biomagnification.

While there are hundreds of types of nanoparticles in use, Koo chose to study quantum dots, submicroscopic bits of semiconductors that glow brightly under ultraviolet light. The fluorescent particles — which contained cadmium, selenium, zinc and sulfur — could easily be measured and imaged in the tests. In addition, the team treated the surface of the quantum dots with three different polymer coatings — one positively charged, one negatively charged and one neutral.

“In industrial applications, nanoparticles are often coated with a polymer to increase solubility, improve stability, enhance properties and for other reasons,” said study co-author Pedro Alvarez, professor and chair of Rice’s Department of Civil and Environmental Engineering. “We expect surface coatings to play a significant role in whether and how nanomaterials may accumulate in food webs.”

Previous lab studies had suggested that the neutral coatings might cause the nanoparticles to aggregate and form clumps that were so large that they would not readily move from a plant’s roots to its leaves. The experiments bore this out. Of the three particle types, only those with charged coatings moved readily through the plants, and only the negatively charged particles avoided clumping altogether. The study also found that the type of coating impacted the plants’ ability to biodegrade, or break down, the quantum dots.

Koo and colleagues found caterpillars that fed on plants containing quantum dots gained less weight and grew more slowly than caterpillars that fed on untainted leaves. By examining the caterpillar’s excrement, the scientists were also able to estimate whether cadmium, selenium and intact quantum dots might be accumulating in the animals. Again, the coating played an important role.

“Our tests were not specifically designed to measure bioaccumulation in caterpillars, but the data we collected suggest that particles with positively charged coatings may accumulate in cells and pose a risk of bioaccumulation,” Koo said. “Based on our findings, more tests should be conducted to determine the extent of this risk under a broader set of ecological conditions.”

The researchers have a couple of images illustrating their work,

The buildup of fluorescent quantum dots in the leaves of Arabidopsis plants is apparent in this photograph of the plants under ultraviolet light. Credit: Y. Koo/Rice University

The buildup of fluorescent quantum dots in the leaves of Arabidopsis plants is apparent in this photograph of the plants under ultraviolet light. Credit: Y. Koo/Rice University

And, there’s a caterpillar,

Cabbage looper

Cabbage looper

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

Fluorescence Reports Intact Quantum Dot Uptake into Roots and Translocation to Leaves of Arabidopsis thaliana and Subsequent Ingestion by Insect Herbivores by Yeonjong Koo, Jing Wang, Qingbo Zhang, Huiguang Zhu, E. Wassim Chehab, Vicki L. Colvin, Pedro J. J. Alvarez, and Janet Braam. Environ. Sci. Technol., Just Accepted Manuscript DOI: 10.1021/es5050562 Publication Date (Web): December 1, 2014

Copyright © 2014 American Chemical Society

This paper is open access but you must be registered on the website.

One final thought about the research, it did take place in a laboratory environment and there doesn’t seem to have been any soil involved so the uptake can not be directly compared (as I understand matters) to the uptake characteristics where plant cultivation requires soil. This seems to have been a study involving hydroponic framing practices.

Super-capacitors on automobiles

Queensland University of Technology* (QUT; Australia) researchers are hopeful they can adapt supercapacitors in the form of a fine film tor use in electric vehicles making them more energy-efficient. From a Nov. 6, 2014 news item on ScienceDaily,

A car powered by its own body panels could soon be driving on our roads after a breakthrough in nanotechnology research by a QUT team.

Researchers have developed lightweight “supercapacitors” that can be combined with regular batteries to dramatically boost the power of an electric car.

The discovery was made by Postdoctoral Research Fellow Dr Jinzhang Liu, Professor Nunzio Motta and PhD researcher Marco Notarianni, from QUT’s Science and Engineering Faculty — Institute for Future Environments, and PhD researcher Francesca Mirri and Professor Matteo Pasquali, from Rice University in Houston, in the United States.

A Nov. 6, 2014 QUT news release, which originated the news item, describes supercapacitors, the research, and the need for this research in more detail,

The supercapacitors – a “sandwich” of electrolyte between two all-carbon electrodes – were made into a thin and extremely strong film with a high power density.

The film could be embedded in a car’s body panels, roof, doors, bonnet and floor – storing enough energy to turbocharge an electric car’s battery in just a few minutes.

“Vehicles need an extra energy spurt for acceleration, and this is where supercapacitors come in. They hold a limited amount of charge, but they are able to deliver it very quickly, making them the perfect complement to mass-storage batteries,” he said.

“Supercapacitors offer a high power output in a short time, meaning a faster acceleration rate of the car and a charging time of just a few minutes, compared to several hours for a standard electric car battery.”

Dr Liu said currently the “energy density” of a supercapacitor is lower than a standard lithium ion (Li-Ion) battery, but its “high power density”, or ability to release power in a short time, is “far beyond” a conventional battery.

“Supercapacitors are presently combined with standard Li-Ion batteries to power electric cars, with a substantial weight reduction and increase in performance,” he said.

“In the future, it is hoped the supercapacitor will be developed to store more energy than a Li-Ion battery while retaining the ability to release its energy up to 10 times faster – meaning the car could be entirely powered by the supercapacitors in its body panels.

“After one full charge this car should be able to run up to 500km – similar to a petrol-powered car and more than double the current limit of an electric car.”

Dr Liu said the technology would also potentially be used for rapid charges of other battery-powered devices.

“For example, by putting the film on the back of a smart phone to charge it extremely quickly,” he said.

The discovery may be a game-changer for the automotive industry, with significant impacts on financial, as well as environmental, factors.

“We are using cheap carbon materials to make supercapacitors and the price of industry scale production will be low,” Professor Motta said.

“The price of Li-Ion batteries cannot decrease a lot because the price of Lithium remains high. This technique does not rely on metals and other toxic materials either, so it is environmentally friendly if it needs to be disposed of.”

A Nov. 10, 2014 news item on Azonano describes the Rice University (Texas, US) contribution to this work,

Rice University scientist Matteo Pasquali and his team contributed to two new papers that suggest the nano-infused body of a car may someday power the car itself.

Rice supplied high-performance carbon nanotube films and input on the device design to scientists at the Queensland University of Technology in Australia for the creation of lightweight films containing supercapacitors that charge quickly and store energy. The inventors hope to use the films as part of composite car doors, fenders, roofs and other body panels to significantly boost the power of electric vehicles.

A Nov. 7, 2014 Rice University news release, which originated the news item, offers a few technical details about the film being proposed for use as a supercapacitor on car panels,

Researchers in the Queensland lab of scientist Nunzio Motta combined exfoliated graphene and entangled multiwalled carbon nanotubes combined with plastic, paper and a gelled electrolyte to produce the flexible, solid-state supercapacitors.

“Nunzio’s team is making important advances in the energy-storage area, and we were glad to see that our carbon nanotube film technology was able to provide breakthrough current collection capability to further improve their devices,” said Pasquali, a Rice professor of chemical and biomolecular engineering and chemistry. “This nice collaboration is definitely bottom-up, as one of Nunzio’s Ph.D. students, Marco Notarianni, spent a year in our lab during his Master of Science research period a few years ago.”

“We built on our earlier work on CNT films published in ACS Nano, where we developed a solution-based technique to produce carbon nanotube films for transparent electrodes in displays,” said Francesca Mirri, a graduate student in Pasquali’s research group and co-author of the papers. “Now we see that carbon nanotube films produced by the solution-processing method can be applied in several areas.”

As currently designed, the supercapacitors can be charged through regenerative braking and are intended to work alongside the lithium-ion batteries in electric vehicles, said co-author Notarianni, a Queensland graduate student.

“Vehicles need an extra energy spurt for acceleration, and this is where supercapacitors come in. They hold a limited amount of charge, but with their high power density, deliver it very quickly, making them the perfect complement to mass-storage batteries,” he said.

Because hundreds of film supercapacitors are used in the panel, the electric energy required to power the car’s battery can be stored in the car body. “Supercapacitors offer a high power output in a short time, meaning a faster acceleration rate of the car and a charging time of just a few minutes, compared with several hours for a standard electric car battery,” Notarianni said.

The researchers foresee such panels will eventually replace standard lithium-ion batteries. “In the future, it is hoped the supercapacitor will be developed to store more energy than an ionic battery while retaining the ability to release its energy up to 10 times faster – meaning the car would be powered by the supercapacitors in its body panels,” said Queensland postdoctoral researcher Jinzhang Liu.

Here’s an image of graphene infused with carbon nantoubes used in the supercapacitor film,

A scanning electron microscope image shows freestanding graphene film with carbon nanotubes attached. The material is part of a project to create lightweight films containing super capacitors that charge quickly and store energy. Courtesy of Nunzio Motta/Queensland University of Technology - See more at: http://news.rice.edu/2014/11/07/supercharged-panels-may-power-cars/#sthash.0RPsIbMY.dpuf

A scanning electron microscope image shows freestanding graphene film with carbon nanotubes attached. The material is part of a project to create lightweight films containing super capacitors that charge quickly and store energy. Courtesy of Nunzio Motta/Queensland University of Technology

Here are links to and citations for the two papers published by the researchers,

Graphene-based supercapacitor with carbon nanotube film as highly efficient current collector by Marco Notarianni, Jinzhang Liu, Francesca Mirri, Matteo Pasquali, and Nunzio Motta. Nanotechnology Volume 25 Number 43 doi:10.1088/0957-4484/25/43/435405

High performance all-carbon thin film supercapacitors by Jinzhang Liu, Francesca Mirri, Marco Notarianni, Matteo Pasquali, and Nunzio Motta. Journal of Power Sources Volume 274, 15 January 2015, Pages 823–830 DOI: 10.1016/j.jpowsour.2014.10.104

Both articles are behind paywalls.

One final note, Dexter Johnson provides some insight into issues with graphene-based supercapacitors and what makes this proposed application attractive in his Nov. 7, 2014 post on the Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website; Note: Links have been removed),

The hope has been that someone could make graphene electrodes for supercapacitors that would boost their energy density into the range of chemical-based batteries. The supercapacitors currently on the market have on average an energy density around 28 Wh/kg, whereas a Li-ion battery holds about 200Wh/kg. That’s a big gap to fill.

The research in the field thus far has indicated that graphene’s achievable surface area in real devices—the factor that determines how many ions a supercapacitor electrode can store, and therefore its energy density—is not any better than traditional activated carbon. In fact, it may not be much better than a used cigarette butt.

Though graphene may not help increase supercapacitors’ energy density, its usefulness in this application may lie in the fact that its natural high conductivity will allow superconductors to operate at higher frequencies than those that are currently on the market. Another likely benefit that graphene will yield comes from the fact that it can be structured and scaled down, unlike other supercapacitor materials.

I recommend reading Dexter’s commentary in its entirety.

*’University of Queensland’ corrected to “Queensland University of Technology’ on Nov. 10, 2014 at 1335 PST.

Replacing copper wire in motors?

Finnish researchers at Lappeenranta University of Technology (LUT) believe it may be possible to replace copper wire used in motors with spun carbon nanotubes. From an Oct. 15, 2014 news item on Azonano,

Lappeenranta University of Technology (LUT) introduces the first electrical motor applying carbon nanotube yarn. The material replaces copper wires in windings. The motor is a step towards lightweight, efficient electric drives. Its output power is 40 W and rotation speed 15000 rpm.

Aiming at upgrading the performance and energy efficiency of electrical machines, higher-conductivity wires are searched for windings. Here, the new technology may revolutionize the industry. The best carbon nanotubes (CNTs) demonstrate conductivities far beyond the best metals; CNT windings may have double the conductivity of copper windings.

”If we keep the design parameters unchanged only replacing copper with carbon nanotube yarns, the Joule losses in windings can be reduced to half of present machine losses. By lighter and more ecological CNT yarn, we can reduce machine dimensions and CO2 emissions in manufacturing and operation. Machines could also be run in higher temperatures,” says Professor Pyrhönen [Juha Pyrhönen], leading the prototype design at LUT.

An Oct. ??, 2014 (?) LUT press release, which originated the news item, further describes the work,

Traditionally, the windings in electrical machines are made of copper, which has the second best conductivity of metals at room temperature. Despite the high conductivity of copper, a large proportion of the electrical machine losses occur in the copper windings. For this reason, the Joule losses are often referred to as copper losses. The carbon nanotube yarn does not have a definite upper limit for conductivity (e.g. values of 100 MS/m have already been measured).

According to Pyrhönen, the electrical machines are so ubiquitous in everyday life that we often forget about their presence. In a single-family house alone there can be tens of electrical machines in various household appliances such as refrigerators, washing machines, hair dryers, and ventilators.

“In the industry, the number of electrical motors is enormous: there can be up to tens of thousands of motors in a single process industry unit. All these use copper in the windings. Consequently, finding a more efficient material to replace the copper conductors would lead to major changes in the industry,” tells Professor Pyrhönen.

There are big plans for this work according to the press release,

The prototype motor uses carbon nanotube yarns spun and converted into an isolated tape by a Japanese-Dutch company Teijin Aramid, which has developed the spinning technology in collaboration with Rice University, the USA. The industrial applications of the new material are still in their infancy; scaling up the production capacity together with improving the yarn performance will facilitate major steps in the future, believes Business Development Manager Dr. Marcin Otto from Teijin Aramid, agreeing with Professor Pyrhönen.

“There is a significant improvement potential in the electrical machines, but we are now facing the limits of material physics set by traditional winding materials. Superconductivity appears not to develop to such a level that it could, in general, be applied to electrical machines. Carbonic materials, however, seem to have a pole position: We expect that in the future, the conductivity of carbon nanotube yarns could be even three times the practical conductivity of copper in electrical machines. In addition, carbon is abundant while copper needs to be mined or recycled by heavy industrial processes.”

The researchers have produced this video about their research,

There’s a reference to some work done at Rice University (Texas, US) with Teijin Armid (Japanese-Dutch company) and Technion Institute (Israel) with spinning carbon nanotubes into threads that look like black cotton (you’ll see the threads in the video). It’s this work that has made the latest research in Finland possible. I have more about the the Rice/Teijin Armid/Technion CNT project in my Jan. 11, 2013 posting, Prima donna of nanomaterials (carbon nanotubes) tamed by scientists at Rice University (Texas, US), Teijin Armid (Dutch/Japanese company), and Technion Institute (based in Israel).

Keeping your chef’s jackets clean and a prize for Teijin Aramid/Rice University

Australian start-up company, Fabricor Workwear launched a Kickstarter campaign on Sept. 18, 2014 to raise funds for a stain-proof and water-repellent chef’s jacket according to a Sept. 25, 2014 news item on Azonano,

An Australian startup is using a patented nanotechnology to create ‘hydrophobic’ chef jackets and aprons. Fabricor says this means uniforms that stay clean for longer, and saving time and money.

The company was started because cofounder and MasterChef mentor Adrian Li, was frustrated with keeping his chef jackets and aprons clean.

“As a chef I find it really difficult to keep my chef jacket white, and we like our jackets white,” Li said. …

The nanotechnology application works by modifying the fabric at a molecular level by permanently attaching hydrophobic ‘whiskers’ to individual fibres which elevate liquids, causing them to bead up and roll off.

The Fabricor: Stain-proof workwear for the hospitality industry Kickstarter campaign has this to say on its homepage (Note: Links have been removed),

Hi Kickstarters,

Thanks for taking the time check out our campaign.

Traditional chef jackets date back to the mid 19th century and since then haven’t changed much.

We’re tired of poor quality hospitality workwear that doesn’t last and hate spending our spare time and money washing or replacing our uniforms.

So we designed a range of stain-resistant Chef Jackets and Aprons using the world’s leading patented hydrophobic nanotechnology that repels water, dirt and oil.

Most stains either run off by themselves or can easily be rinsed off with a little water. This means they don’t need to be washed as often saving you time and money.

We’re really proud of what we’ve created and we hope you you’ll support us.

Adrian Li

Head Chef at Saigon Sally
Mentor on MasterChef Australia – Asian Street Food Challenge
Cofounder at Fabricor Workwear

At this point (Sept. 24, 2014), the campaign has raised approximately $2700US towards a $5000US goal and there are 22 days left to the campaign.

I did find more information at the Fabricor Workwear website in this Sept. 13, 2014 press release,

The fabric’s patented technology can extend the life of the apparel is because the apparel doesn’t have to be washed as often and can be washed in cooler temperatures, the company stated.

Fabricor’s products are not made with spray-application like many on the market which can destroy fabrics and contain carcinogenic chemical. Its hydrophobic properties are embedded into the weave during the production of the fabric.

Li said chefs spend too much money on chef jackets that are poorly designed and don’t last. The long-lasting fabric in Fabricor’s chef’s apparel retains its natural softness and breathability.

It seems to me that the claim about fewer washes can be made for all superhydrophobic textiles. As for carcinogenic chemicals in other superhydrophobic textiles, it’s the first I’ve heard of it, which may or may not be significant. I.e., I look at a lot of material but don’t focus on superhydrophobic textiles here and do not seek out research on risks specific to these textiles.

Teijin Aramid/Rice University

Still talking about textile fibres but on a completely different track, I received a news release this morning (Sept. 25, 2014) from Teijin Aramid about carbon nanotubes and fibres,

Researchers of Teijin Aramid, based in the Netherlands, and Rice University in the USA are awarded with the honorary ‘Paul Schlack Man-Made Fibers Prize’ for corporate-academic partnerships in fiber research. Their new super fibers are now driving innovation in aerospace, healthcare, automotive, and (smart) clothing.

The honorary Paul Schlack prize was granted by the European Man-made Fibers Association to Dr. Marcin Otto, Business Development Manager at Teijin Aramid and Prof. Dr. Matteo Pasquali from Rice University Texas, for the development of a new generation super fibers using carbon nanotubes (CNT). The new super fibers combine high thermal and electrical conductivity, as seen in metals, with the flexibility, robust handling and strength of textile fibers.

“The introduction of carbon nanotube fibers marked the beginning of a series of innovations in various industries”, says Marcin Otto, Business Development Manager at Teijin Aramid. “For example, CNT fibers can be lifesaving for heart patients: one string of CNT fiber in the cardiac muscle suffices to transmit vital electrical pulses to the heart. Or by replacing copper in data cables and light power cables by CNT fibers it’s possible to make satellites, aircraft and high end cars lighter and more robust at the same time.”

Since 1971, the Paul Schlack foundation annually grants one monetary prize to an individual young researcher for outstanding research in the field of fiber research, and an honorary prize to the leader(s) of excellent academic and corporate research partnerships to promote research at universities and research institutes.

For several years, leading researchers at Rice University and Teijin Aramid worked together on the development of CNT production. Teijin Aramid and Rice University published their research findings on carbon nanotubes fibers in the leading scientific journal, Science, beginning of 2013.

Teijin Aramid and some of its carbon nanotube projects have been mentioned here before, notably, in a Jan. 11, 2013 posting and in a Feb. 17, 2014.

Good luck on the Kickstarter campaign and congratulations on the award!

De-icing film for radar domes adapted for use on glass

Interesting to see that graphene is in use for de-icing. From a Sept. 16, 2014 news item  on ScienceDaily,

Rice University scientists who created a deicing film for radar domes have now refined the technology to work as a transparent coating for glass.

The new work by Rice chemist James Tour and his colleagues could keep glass surfaces from windshields to skyscrapers free of ice and fog while retaining their transparency to radio frequencies (RF).

A Sept. 16, 2014 Rice University news release on EurekAlert, which originated the news item, describes the technology and its new application in more detail,

The material is made of graphene nanoribbons, atom-thick strips of carbon created by splitting nanotubes, a process also invented by the Tour lab. Whether sprayed, painted or spin-coated, the ribbons are transparent and conduct both heat and electricity.

Last year the Rice group created films of overlapping nanoribbons and polyurethane paint to melt ice on sensitive military radar domes, which need to be kept clear of ice to keep them at peak performance. The material would replace a bulky and energy-hungry metal oxide framework.

The graphene-infused paint worked well, Tour said, but where it was thickest, it would break down when exposed to high-powered radio signals. “At extremely high RF, the thicker portions were absorbing the signal,” he said. “That caused degradation of the film. Those spots got so hot that they burned up.”

The answer was to make the films more consistent. The new films are between 50 and 200 nanometers thick – a human hair is about 50,000 nanometers thick – and retain their ability to heat when a voltage is applied. The researchers were also able to preserve their transparency. The films are still useful for deicing applications but can be used to coat glass and plastic as well as radar domes and antennas.

In the previous process, the nanoribbons were mixed with polyurethane, but testing showed the graphene nanoribbons themselves formed an active network when applied directly to a surface. They were subsequently coated with a thin layer of polyurethane for protection. Samples were spread onto glass slides that were then iced. When voltage was applied to either side of the slide, the ice melted within minutes even when kept in a minus-20-degree Celsius environment, the researchers reported.

“One can now think of using these films in automobile glass as an invisible deicer, and even in skyscrapers,” Tour said. “Glass skyscrapers could be kept free of fog and ice, but also be transparent to radio frequencies. It’s really frustrating these days to find yourself in a building where your cellphone doesn’t work. This could help alleviate that problem.”

Tour noted future generations of long-range Wi-Fi may also benefit. “It’s going to be important, as Wi-Fi becomes more ubiquitous, especially in cities. Signals can’t get through anything that’s metallic in nature, but these layers are so thin they won’t have any trouble penetrating.”

He said nanoribbon films also open a path toward embedding electronic circuits in glass that are both optically and RF transparent.

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

Functionalized Graphene Nanoribbon Films as a Radiofrequency and Optically Transparent Material by Abdul-Rahman O. Raji, Sydney Salters, Errol L. G. Samuel, Yu Zhu, Vladimir Volman, and James M. Tour. ACS Appl. Mater. Interfaces, Article ASAP DOI: 10.1021/am503478w Publication Date (Web): September 4, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.

De-icing is a matter of some interest in the airlines industry as I noted in my Nov. 19, 2012 posting about de-icing airplane wings.

Following the sound of a nanoparticle through the body

I was hoping for some actual sound files of nanoparticles in the body but for some rason the researchers don’t seem to have made them freely available. However, there is this textual description in a Sept. 5, 2014 news item on Nanowerk,

Nanoparticles have become interesting means for biomedical applications. Thanks to their minute dimensions and large surface areas, they can often penetrate cellular membranes and deliver high payloads of targeting agents and drugs to achieve better specificity and therapeutic effects than non-targeted treatments. Yet, quantitative in vivo measurements of nanoparticle concentrations are essential for nanotechnology-based preclinical research.

To date, tedious ex vivo analysis of nanoparticle concentrations in organs of test animals remains a standard approach in such biodistribution studies. Most current imaging methods remain limited due to several disadvantages and/or high costs. Optoacoustic tomography (OAT), a method that utilizes ultrasound generated by absorption of nanosecond-scale laser pulses to recreate an image of the absorbing volume based on the spatial variation of optical absorption coefficients, is a potential alternative.

Usually, due to the unknown light distribution in a complex optical scattering environment, tomographic images of live animals contain only qualitative information and are not suitable for quantitative biodistribution analysis. …

A Sept. 3, 2014 Wiley-VCH publishers press release by K. Maedefessel-Herrmann, which originated the news item, provides more details about the work,

… A team of researchers from TomoWave Laboratories, Inc., Rice University, and the University of Houston now developed a methodology to correlate changes in optoacoustic signal intensity from organs of live animals detected with OAT in relation to changes of optical absorption coefficient in those organs caused by nanoparticle accumulation.

The researchers quantified localized OAT brightness changes induced by accumulation of single-walled carbon nanotubes (SWCNTs) in liver, kidney and spleen of nude mice. Using the intrinsic fluorescence properties of disaggregated nanotubes, they measured SWCNT concentrations in the parts-per-million range in the harvested organs and defined the corresponding changes in optical absorption coefficient. The observed increases in optoacoustic signal brightness in tissues were compared with the increases in optical absorption coefficients caused by SWCNT accumulation.
The combination of these methods allows one to perform sensitivity calibration of an OAT system for a selected type of animal and for a range of optical absorption coefficient values of their organs to enable non-invasive concentration measurements of optically absorbing nanoparticles and dyes in vivo.

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

Enabling in vivo measurements of nanoparticle concentrations with three-dimensional optoacoustic tomography by Dmitri A. Tsyboulski, Anton V. Liopo, Richard Su, Sergey A. Ermilov, Sergei M. Bachilo, R. Bruce Weisman, and Alexander A. Oraevsky. Journal of Biophotonics, Volume 7, Issue 8, pages 581–588, August 2014. DOI: 10.1002/jbio.201200233  Article first published online: 2 APR 2013

This is an open access article.

Alberta’s summer of 2014 nano funding and the US nano community’s talks with the House of Representatives

I have two items concerning nanotechnology and funding. The first item features Michelle Rempel, Canada’s Minister of State for Western Economic Diversification (WD) who made two funding announcements this summer (2014) affecting the Canadian nanotechnology sector and, more specifically, the province of Alberta.

A June 20, 2014 WD Canada news release announced a $1.1M award to the University of Alberta,

Today, the Honourable Michelle Rempel, Minister of State for Western Economic Diversification, announced $1.1 million to help advance leading-edge atomic computing technologies.

Federal funds will support the University of Alberta with the purchase of an ultra-high resolution scanning tunneling microscope, which will enable researchers and scientists in western Canada and abroad to analyze electron dynamics and nanostructures at an atomic level. The first of its kind in North America, the microscope has the potential to significantly transform the semiconductor industry, as research findings aid in the prototype development and technology commercialization of new ultra low-power and low-temperature computing devices and industrial applications.

This initiative is expected to further strengthen Canada’s competitive position throughout the electronics value chain, such as microelectronics, information and communications technology, and the aerospace and defence sectors. The project will also equip graduate students with a solid foundation of knowledge and hands-on experience to become highly qualified, skilled individuals in today’s workforce.

One month later, a July 21, 2014 WD news release (hosted on the Alberta Centre for Advanced Micro and Nano Products [ACAMP]) announces this award,

Today, the Honourable Michelle Rempel, Minister of State for Western Economic Diversification, announced an investment of $3.3 million toward the purchase and installation of specialized advanced manufacturing and product development equipment at the Alberta Centre for Advanced Micro Nano Technology Products (ACAMP), as well as training on the use of this new equipment for small- and medium-sized enterprises (SMEs).

This support, combined with an investment of $800,000 from Alberta Innovates Technology Futures, will enable ACAMP to expand their services and provide businesses with affordable access to prototype manufacturing that is currently unavailable in western Canada. By helping SMEs accelerate the development and commercialization of innovative products, this project will help strengthen the global competitiveness of western Canadian technology companies.

Approximately 80 Alberta SMEs will benefit from this initiative, which is expected to result in the development of new product prototypes, the creation of new jobs in the field, as well as connections between SMEs and multi-national companies. This equipment will also assist ACAMP’s outreach activities across the western Canadian provinces.

I’m not entirely clear as to whether or not the June 2014 $1.1M award is considered part of the $3.3M award or if these are two different announcements. I am still waiting for answers to a June 20, 2014 query sent to Emily Goucher, Director of Communications to the Hon. Michelle Rempel,

Hi Emily!

Thank you for both the news release and the information about the embargo … happily not an issue at this point …

I noticed Robert Wolkow’s name in the release (I last posted about his work in a March 3, 2011 piece about his and his team’s entry into the Guinness Book of Records for the world’s smallest electron microscope tip (http://www.frogheart.ca/?tag=robert-wolkow) [Note: Wolkow was included in a list of quotees not included here in this July 29, 2014 posting]

I am assuming that the new microscope at the University of Alberta is specific to a different type of work than the one at UVic, which has a subatomic microscope (http://www.frogheart.ca/?p=10426)

Do I understand correctly that an STM is being purchased or is this an announcement of the funds and their intended use with no details about the STM available yet? After reading the news release closely, it looks to me like they do have a specific STM in mind but perhaps they don’t feel ready to make a purchase announcement yet?

If there is information about the STM that will be purchased I would deeply appreciate receiving it.

Thank you for your time.

As I wait, there’s more news from  the US as members of that country’s nanotechnology community testify at a second hearing before the House of Representatives. The first (a May 20, 2014 ‘National Nanotechnology Initiative’ hearing held before the Science, Space, and Technology
Subcommittee on Research and Technology) was mentioned in an May 23, 2014 posting  where I speculated about the community’s response to a smaller budget allocation (down to $1.5B in 2015 from $1.7B in 2014).

This second hearing is being held before the Energy and Commerce Subcommittee on Commerce, Manufacturing and Trade and features an appearance by James Tour from Rice University according to a July 28, 2014 news item on Azonano,

At the hearing, titled “Nanotechnology: Understanding How Small Solutions Drive Big Innovation,” Tour will discuss and provide written testimony on the future of nanotechnology and its impact on U.S. manufacturing and jobs. Tour is one of the most cited chemists in the country, and his Tour Group is a leader in patenting and bringing to market nanotechnology-based methods and materials.

Who: James Tour, Rice’s T.T. and W.F. Chao Chair in Chemistry and professor of materials science and nanoengineering and of computer science.

What: Exploring breakthrough nanotechnology opportunities.

When: 10:15 a.m. EDT Tuesday, July 29.

Where: Room 2322, Rayburn House Office Building, Washington, D.C.

The hearing will explore the current state of nanotechnology and the direction it is headed so that members can gain a better understanding of the policy changes that may be necessary to keep up with advancements. Ultimately, the subcommittee hopes to better understand what issues will confront regulators and how to assess the challenges and opportunities of nanotechnology.

You can find a notice for this July 2014 hearing and a list of witnesses along with their statements here. As for what a second hearing might mean within the context of the US National Nanotechnology Initiative, I cannot say with any certainty. But, this is the first time in six years of writing this blog where there have been two hearings post-budget but as a passive collector of this kind of information this may be a reflection of my information collection strategies rather than a response to a smaller budget allocation. Still, it’s interesting.