Rice University Expands LIG (laser induced graphene) Research and Applications: Supercapacitor, an Electrocatalyst for Fuel Cells, RFID’s and Biological Sensors


J Tour Graphene on Toast 162948_webIMAGE: THIS IS RICE UNIVERSITY GRADUATE STUDENT YIEU CHYAN, LEFT, AND PROFESSOR JAMES TOUR. view more  CREDIT: JEFF FITLOW/RICE UNIVERSITY

Rice University scientists who introduced laser-induced graphene (LIG) have enhanced their technique to produce what may become a new class of edible electronics.

The Rice lab of chemist James Tour, which once turned Girl Scout cookies into graphene, is investigating ways to write graphene patterns onto food and other materials to quickly embed conductive identification tags and sensors into the products themselves.

“This is not ink,” Tour said. “This is taking the material itself and converting it into graphene.”

The process is an extension of the Tour lab’s contention that anything with the proper carbon content can be turned into graphene. In recent years, the lab has developed and expanded upon its method to make graphene foam by using a commercial laser to transform the top layer of an inexpensive polymer film.

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Laser-Induced graphene supercapacitors may be the future of wearables

The foam consists of microscopic, cross-linked flakes of graphene, the two-dimensional form of carbon. LIG can be written into target materials in patterns and used as a supercapacitor, an electrocatalyst for fuel cells, radio-frequency identification (RFID) antennas and biological sensors, among other potential applications.

The new work reported in the American Chemical Society journal ACS Nano demonstrated that laser-induced graphene can be burned into paper, cardboard, cloth, coal and certain foods, even toast.

“Very often, we don’t see the advantage of something until we make it available,” Tour said. “Perhaps all food will have a tiny RFID tag that gives you information about where it’s been, how long it’s been stored, its country and city of origin and the path it took to get to your table.”

He said LIG tags could also be sensors that detect E. coli or other microorganisms on food. “They could light up and give you a signal that you don’t want to eat this,” Tour said. “All that could be placed not on a separate tag on the food, but on the food itself.”

Multiple laser passes with a defocused beam allowed the researchers to write LIG patterns into cloth, paper, potatoes, coconut shells and cork, as well as toast. (The bread is toasted first to “carbonize” the surface.) The process happens in air at ambient temperatures.

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“In some cases, multiple lasing creates a two-step reaction,” Tour said. “First, the laser photothermally converts the target surface into amorphous carbon. Then on subsequent passes of the laser, the selective absorption of infrared light turns the amorphous carbon into LIG. We discovered that the wavelength clearly matters.”

The researchers turned to multiple lasing and defocusing when they discovered that simply turning up the laser’s power didn’t make better graphene on a coconut or other organic materials. But adjusting the process allowed them to make a micro supercapacitor in the shape of a Rice “R” on their twice-lased coconut skin.

Defocusing the laser sped the process for many materials as the wider beam allowed each spot on a target to be lased many times in a single raster scan. That also allowed for fine control over the product, Tour said. Defocusing allowed them to turn previously unsuitable polyetherimide into LIG.

“We also found we could take bread or paper or cloth and add fire retardant to them to promote the formation of amorphous carbon,” said Rice graduate student Yieu Chyan, co-lead author of the paper. “Now we’re able to take all these materials and convert them directly in air without requiring a controlled atmosphere box or more complicated methods.”

The common element of all the targeted materials appears to be lignin, Tour said. An earlier study relied on lignin, a complex organic polymer that forms rigid cell walls, as a carbon precursor to burn LIG in oven-dried wood. Cork, coconut shells and potato skins have even higher lignin content, which made it easier to convert them to graphene.

Tour said flexible, wearable electronics may be an early market for the technique. “This has applications to put conductive traces on clothing, whether you want to heat the clothing or add a sensor or conductive pattern,” he said.

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Rice alumnus Ruquan Ye is co-lead author of the study. Co-authors are Rice graduate student Yilun Li and postdoctoral fellow Swatantra Pratap Singh and Professor Christopher Arnusch of Ben-Gurion University of the Negev, Israel. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice.

The Air Force Office of Scientific Research supported the research.

Dotz Nano makes stunning ASX debut: Commercializing Graphene Quantum Dots: Rice U Developed Technology


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Perth tech company Dotz Nano has made a stunning ASX debut with its shares reaching more than double their issue price on the company’s first day of trade.

The company, a backdoor listing through the shell of former explorer Northern Iron, focuses on the development, manufacture and commercialisation of Graphene Quantum Dots (GQDs).

The company raised $6 million at 20 cents a share. Its shares hit an intraday high of 49 cents before retracing to close up more than 75 per cent at 36.5 cents.

GQDs are nanoparticles which have applications in LED displays, pigments, dyes and detergents as well as energy, electrical and medical applications.

Non-graphene derived quantum dots are already widely used in products such as high-definition TVs, medical imaging and lighting products. However they have limited applications because of their toxicity and production costs.

Dotz Nano said it had exclusive capabilities to extract GQDs from coal rather than graphite, allowing it to produce inexpensive, non-toxic GQDs at ten times the production yield of conventional GQDs.

qds-from-coal-1006_gqd-2-rn-310x302Quantum Dots from Coal + Graphene Could Dramatically Cut the Cost of Energy from Fuel Cells

The company said its patented technology was developed by Professor James Tour of the William Marsh Rice University in Houston, Texas. It also has a strong partnership with the Ben-Gurion University in Israel.

Watch A Video On Graphene-Quantum Dots

Dotz Nano said it was not aware of any other party commercialising GQDs and that it holds five patents covering all major jurisdictions.

Chief executive Moti Gross said the company had first mover advantage in its field.

“We have had extremely encouraging discussions with potential customers, sub-licensees and distributors, as with the Mainami Group in Japan, and there will be no shortage of activity from our potential deal pipeline,” he said.

“We take the opportunity to welcome our new shareholders on board and we look forward to updating the market as we continue to scale our business.”

The company also announced today a memorandum of understanding to establish a $S 20 million research centre at the Nanyang Technological University in Singapore.

MIT: A New kind of super-capacitor made without carbon: Also Read About Rice University’s New Nano-Super Capacitors & Batteries


mit-supercapacitor_0-101016To demonstrate the supercapacitor’s ability to store power, the researchers modified an off-the-shelf hand-crank flashlight (the red parts at each side) by cutting it in half and installing a small supercapacitor in the center, in a conventional button battery case, seen at top. When the crank is turned to provide power to the flashlight, the light continues to glow long after the cranking stops, thanks to the stored energy. Photo: Melanie Gonick

Energy storage devices called supercapacitors have become a hot area of research, in part because they can be charged rapidly and deliver intense bursts of power. However, all supercapacitors currently use components made of carbon, which require high temperatures and harsh chemicals to produce.

Now researchers at MIT and elsewhere have for the first time developed a supercapacitor that uses no conductive carbon at all, and that could potentially produce more power than existing versions of this technology.

The team’s findings are being reported in the journal Nature Materials, in a paper by Mircea Dincă, an MIT associate professor of chemistry; Yang Shao-Horn, the W.M. Keck Professor of Energy; and four others.

“We’ve found an entirely new class of materials for supercapacitors,” Dincă says.

Dincă and his team have been exploring for years a class of materials called metal-organic frameworks, or MOFs, which are extremely porous, sponge-like structures. These materials have an extraordinarily large surface area for their size, much greater than the carbon materials do. That is an essential characteristic for supercapacitors, whose performance depends on their surface area. But MOFs have a major drawback for such applications: They are not very electrically conductive, which is also an essential property for a material used in a capacitor.

“One of our long-term goals was to make these materials electrically conductive,” Dincă says, even though doing so “was thought to be extremely difficult, if not impossible.” But the material did exhibit another needed characteristic for such electrodes, which is that it conducts ions (atoms or molecules that carry a net electric charge) very well.

“All double-layer supercapacitors today are made from carbon,” Dincă says. “They use carbon nanotubes, graphene, activated carbon, all shapes and forms, but nothing else besides carbon. So this is the first noncarbon, electrical double-layer supercapacitor.”

One advantage of the material used in these experiments, technically known as Ni3(hexaiminotriphenylene)2, is that it can be made under much less harsh conditions than those needed for the carbon-based materials, which require very high temperatures above 800 degrees Celsius and strong reagent chemicals for pretreatment.

The team says supercapacitors, with their ability to store relatively large amounts of power, could play an important role in making renewable energy sources practical for widespread deployment. They could provide grid-scale storage that could help match usage times with generation times, for example, or be used in electric vehicles and other applications.

The new devices produced by the team, even without any optimization of their characteristics, already match or exceed the performance of existing carbon-based versions in key parameters, such as their ability to withstand large numbers of charge/discharge cycles. Tests showed they lost less than 10 percent of their performance after 10,000 cycles, which is comparable to existing commercial supercapacitors.

But that’s likely just the beginning, Dincă says. MOFs are a large class of materials whose characteristics can be tuned to a great extent by varying their chemical structure. Work on optimizing their molecular configurations to provide the most desirable attributes for this specific application is likely to lead to variations that could outperform any existing materials. “We have a new material to work with, and we haven’t optimized it at all,” he says. “It’s completely tunable, and that’s what’s exciting.”

While there has been much research on MOFs, most of it has been directed at uses that take advantage of the materials’ record porosity, such as for storage of gases. “Our lab’s discovery of highly electrically conductive MOFs opened up a whole new category of applications,” Dincă says. Besides the new supercapacitor uses, the conductive MOFs could be useful for making electrochromic windows, which can be darkened with the flip of a switch, and chemoresistive sensors, which could be useful for detecting trace amounts of chemicals for medical or security applications. (MIT Article continued below)

rice-nanoporus-battery-102315-untitled-1You will Also Want To Read: Nanoporous Material Combines the Best of Batteries and Supercapacitors for ESS (Energy Storage Systems): Rice University: Dr. James M. Tour

Researchers at Rice University in Houston, Texas, have developed a nanoporous material that has the energy density (the amount of energy stored per unit mass) of an electrochemical battery and the power density (the maximum amount of power that can be supplied per unit mass) of a supercapacitor. It’s important to note that the energy storage device enabled by the material is not claimed to be either of these types of energy storage devices.

Follow the Link Here: New Nanoporous Super Capacitors & Batteries from Rice Univeristy

 

 

(MIT continued … ) While the MOF material has advantages in the simplicity and potentially low cost of manufacturing, the materials used to make it are more expensive than conventional carbon-based materials, Dincă says. “Carbon is dirt cheap. It’s hard to find anything cheaper.” But even if the material ends up being more expensive, if its performance is significantly better than that of carbon-based materials, it could find useful applications, he says.

This discovery is “very significant, from both a scientific and applications point of view,” says Alexandru Vlad, a professor of chemistry at the Catholic University of Louvain in Belgium, who was not involved in this research. He adds that “the supercapacitor field was (but will not be anymore) dominated by activated carbons,” because of their very high surface area and conductivity. But now, “here is the breakthrough provided by Dinca et al.: They could design a MOF with high surface area and high electrical conductivity, and thus completely challenge the supercapacitor value chain! There is essentially no more need of carbons for this highly demanded technology.”

And a key advantage of that, he explains, is that “this work shows only the tip of the iceberg. With carbons we know pretty much everything, and the developments over the past years were modest and slow. But the MOF used by Dinca is one of the lowest-surface-area MOFs known, and some of these materials can reach up to three times more [surface area] than carbons. The capacity would then be astonishingly high, probably close to that of batteries, but with the power performance [the ability to deliver high power output] of supercapacitors.”

The research team included former MIT postdoc Dennis Sheberla (now a postdoc at Harvard University), MIT graduate student John Bachman, Joseph Elias PhD ’16, and Cheng-Jun Sun of Argonne National Laboratory. The work was supported by the U.S. Department of Energy through the Center for Excitonics, the Sloan Foundation, the Research Corporation for Science Advancement, 3M, and the National Science Foundation.

 

Rice University: Graphene Nanoribbons May Help Heal Damaged Spinal Cords: Dr. James M. Tour, PhD


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Rice University researchers James Tour, left, and William Sikkema. (Credit: Jeff Fitlow/Rice University)

Dr. James M. Tour, PhD (named among “The 50 Most Influential Scientists in the World Today” by TheBestSchools.org) at Rice University, stated that a treatment procedure to heal damaged spinal cords by combining graphene nanoribbons produced with a process invented at Rice and a common polymer is expected to gain importance.

As stated in an issue of Nature from 2009, chemists at the Tour lab started their research work with the discovery of a chemical process to unravel graphene nanoribbons from the multiwalled carbon nanotubes, and have been working with graphene nanoribbons for almost 10 years now.

Since then, the researchers have been using nanoribbons to produce better batteries, and improve materials for things such as, deicers for airplane wings and less-permeable containers that can store natural gas.

The recent research work by Rice University scientists has resulted in medical applications of nanoribbons. A material dubbed Texas-PEG has been developed that will help to treat damaged spinal cords or even knit severed spinal cords. Rice logo_rice3

A paper describing the results of preliminary animal-model tests has been published in the current issue of the journal Surgical Neurology International.

William Sikkema, a Rice graduate student and also a co-lead author of the paper has customized these graphene nanoribbons for use in the medical domain. This customized nanoribbon is highly soluble in polyethylene glycol (PEG), which is a biocompatible polymer gel that is generally used in pharmaceutical products, surgeries, and other biological applications.

While mixing biocompatible nanoribbons with PEG after the edges of these biocompatible nanoribbons are functionalized with PEG chains, an electrically active network that helps the damaged spinal cord to reconnect.

“Neurons grow nicely on graphene because it’s a conductive surface and it stimulates neuronal growth,” Tour said.

When studies were conducted at Rice University and at other places, it was observed that the neurons grew along with graphene.

We’re not the only lab that has demonstrated neurons growing on graphene in a petri dish. The difference is other labs are commonly experimenting with water-soluble graphene oxide, which is far less conductive than graphene, or nonribbonized structures of graphene. We’ve developed a way to add water-solubilizing polymer chains to the edges of our nanoribbons that preserves their conductivity while rendering them soluble, and we’re just now starting to see the potential for this in biomedical applications.

Dr. James M. Tour, PhD Chemist, Rice University
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He also stated that ribbonized graphene structures allow smaller amounts to be utilized to preserve a conductive pathway to bridge the severed spinal cord. Tour explained that only 1% of Texas-PEG comprises of nanoribbons, and that is enough to build a conductive scaffold where the spinal cord can reconnect.

Co-authors Bae Hwan Lee and C-Yoon Kim conducted an experiment at Konkuk University in South Korea, and observed that Texas-PEG was successfully able to restore function in a rodent that had a severed spinal cord. Tour explained that the material provided reliable motor and sensory neuronal signals to pass through the gap for 24 hours after total transection of the spinal cord and nearly perfect motor control recovery after 14 days.

This is a major advance over previous work with PEG alone, which gave no recovery of sensory neuronal signals over the same period of time and only 10 percent motor control over four weeks.

Dr. James M. Tour, PhD Chemist, Rice University

The seed to start this project began when Sikkema came across a study undertaken by Italian neurosurgeon Sergio Canavero. Sikkema expected nanoribbons to enhance the research work that was based on PEG’s ability to promote the fusion of cell membranes by adding directional control for neurons and electrical conductivity while they spanned the gap between sections of the spinal cord. Developing contacts with the doctor resulted in a tie up with the South Korean researchers.

Tour told that Texas-PEG’s ability to help patients having spinal cord injuries is too reliable to be ignored. “Our goal is to develop this as a way to address spinal cord injury. We think we’re on the right path,” he said.

This is an exciting neurophysiological analysis following complete severance of a spinal cord. It is not a behavioral or locomotive study of the subsequent repair. The tangential singular locomotive analysis here is an intriguing marker, but it is not in a statistically significant set of animals. The next phases of the study will highlight the locomotive and behavioral skills with statistical relevance to assess whether these qualities follow the favorable neurophysiology that we recorded here.

Dr. James M. Tour, PhD Chemist, Rice University

Kim, co-primary author of the paper, is a research professor in the Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, South Korea, and a researcher at Seoul National University. Lee is an associate professor of physiology at the Yonsei University College of Medicine, Seoul. Tour is the T.T. and W.F. Chao Professor of Chemistry as well as a professor of computer science and of materials science and nanoengineering. Co-authors are In-Kyu Hwang of Konkuk University, Hanseul Oh of Seoul National University and Un Jeng Kim of the Yonsei University College of Medicine.

Source: http://www.rice.edu/