Tag Archives: James Tour

Graphene and radioactive waste

In fact, the material in question is graphene oxide and researchers at Rice University (Texas) and Lomonosov Moscow State University have found that it can rapidly remove radioactive material from water  From the Jan. 8, 2013 news item on ScienceDaily,

A collaborative effort by the Rice lab of chemist James Tour and the Moscow lab of chemist Stepan Kalmykov determined that microscopic, atom-thick flakes of graphene oxide bind quickly to natural and human-made radionuclides and condense them into solids. The flakes are soluble in liquids and easily produced in bulk.

The Rice University Jan. 8, 2013 news release, which originated the news item, was written by Mike Williams and provides additional insight and quotes from the researchers (Note: Links have been removed),

The discovery, Tour said, could be a boon in the cleanup of contaminated sites like the Fukushima nuclear plants damaged by the 2011 earthquake and tsunami. It could also cut the cost of hydraulic fracturing (“fracking”) for oil and gas recovery and help reboot American mining of rare earth metals, he said.

Graphene oxide’s large surface area defines its capacity to adsorb toxins, Kalmykov said. “So the high retention properties are not surprising to us,” he said. “What is astonishing is the very fast kinetics of sorption, which is key.”

“In the probabilistic world of chemical reactions where scarce stuff (low concentrations) infrequently bumps into something with which it can react, there is a greater likelihood that the ‘magic’ will happen with graphene oxide than with a big old hunk of bentonite,” said Steven Winston, a former vice president of Lockheed Martin and Parsons Engineering and an expert in nuclear power and remediation who is working with the researchers. “In short, fast is good.”

Here’s how it works (from the news release; Note: Links have been removed),

The researchers focused on removing radioactive isotopes of the actinides  and lanthanides  – the 30 rare earth elements in the periodic table – from liquids, rather than solids or gases. “Though they don’t really like water all that much, they can and do hide out there,” Winston said. “From a human health and environment point of view, that’s where they’re least welcome.”

Naturally occurring radionuclides are also unwelcome in fracking fluids that bring them to the surface in drilling operations, Tour said. “When groundwater comes out of a well and it’s radioactive above a certain level, they can’t put it back into the ground,” he said. “It’s too hot. Companies have to ship contaminated water to repository sites around the country at very large expense.” The ability to quickly filter out contaminants on-site would save a great deal of money, he said.

He sees even greater potential benefits for the mining industry. Environmental requirements have “essentially shut down U.S. mining of rare earth metals, which are needed for cell phones,” Tour said. “China owns the market because they’re not subject to the same environmental standards. So if this technology offers the chance to revive mining here, it could be huge.”

Tour said that capturing radionuclides does not make them less radioactive, just easier to handle. “Where you have huge pools of radioactive material, like at Fukushima, you add graphene oxide and get back a solid material from what were just ions in a solution,” he said. “Then you can skim it off and burn it. Graphene oxide burns very rapidly and leaves a cake of radioactive material you can then reuse.”

The low cost and biodegradable qualities of graphene oxide should make it appropriate for use in permeable reactive barriers, a fairly new technology for in situ groundwater remediation, he said.

Romanchuk, Slesarev, Kalmykov and Tour are co-authors of the paper with Dmitry Kosynkin, a former postdoctoral researcher at Rice, now with Saudi Aramco. Kalmykov is radiochemistry division head and a professor at Lomonosov Moscow State University. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science at Rice.

Here’s a ‘before’ shot of solution with graphene oxide and an ‘after’ shot where radionuclides have been added and begun to clump,

A new method for removing radioactive material from solutions is the result of collaboration between Rice University and Lomonosov Moscow State University. The vial at left holds microscopic particles of graphene oxide in a solution. At right, graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. Image by Anna Yu. Romanchuk/Lomonosov Moscow State University

A new method for removing radioactive material from solutions is the result of collaboration between Rice University and Lomonosov Moscow State University. The vial at left holds microscopic particles of graphene oxide in a solution. At right, graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. Image by Anna Yu. Romanchuk/Lomonosov Moscow State University

As noted in the ScienceDaily news item, the research has been published in the Royal Society’s Physical Chemistry Chemical Physics journal,

Anna Yu. Romanchuk, Alexander Slesarev, Stepan N. Kalmykov, Dmitry Kosynkin, James M Tour. Graphene Oxide for Effective Radionuclide Removal. Physical Chemistry Chemical Physics, 2012; DOI: 10.1039/C2CP44593J

This article is behind a paywall.

Graphene dreams of the Morph

For anyone who’s not familiar with the Morph, it’s an idea that Nokia and the University of Cambridge’s Nanoscience Centre have been working on for the last few years. Originally announced as a type of flexible phone that you could wrap around your wrist, the Morph is now called a concept.  Here’s an animation illustrating some of the concepts which include flexibility and self-cleaning,

There have been very few announcements of any kind about the Morph or the technology that will support this concept. A few months ago, they did make an announcement about researching graphene as a means of actualizing the concept (noted in my May 6, 2011 posting [scroll down about 1/2 way]).

Interestingly the latest research published  on graphene and the flexible, transparent screens that are necessary to making something like the Morph a reality has come from a lab at Rice University. From the August 1, 2011 news item on Nanowerk,

The lab of Rice chemist James Tour lab has created thin films that could revolutionize touch-screen displays, solar panels and LED lighting. The research was reported in the online edition of ACS Nano (“Rational Design of Hybrid Graphene Films for High-Performance Transparent Electrodes”).

Flexible, see-through video screens may be the “killer app” that finally puts graphene — the highly touted single-atom-thick form of carbon — into the commercial spotlight once and for all, Tour said. Combined with other flexible, transparent electronic components being developed at Rice and elsewhere, the breakthrough could lead to computers that wrap around the wrist and solar cells that wrap around just about anything. [emphasis mine]

The lab’s hybrid graphene film is a strong candidate to replace indium tin oxide (ITO), a commercial product widely used as a transparent, conductive coating. It’s the essential element in virtually all flat-panel displays, including touch screens on smart phones and iPads, and is part of organic light-emitting diodes (OLEDs) and solar cells.

Here’s James Tour and Yu Zhu, the paper’s lead author, explaining how the flexible screen was developed,

There are other flexible screens and competitors to the Morph notably the PaperPhone mentioned in my May 6,2011 posting (scroll down about 2/3 of the way) and in my May 12, 2011 posting featuring an interview with Roel Vertegaal of Queen’s University, Ontario, Canada, about the PaperPhone. (We did not discuss the role that graphene might or might not play in the development of the Paperphone’s screens.)

I wonder what impact this work at Rice will have not only for the Morph and the PaperPhone but on the European Union’s pathfinder research competition (the prize is $1B Euros), mentioned in my June 13, 2011 posting about graphene (scroll down about 1/3 of the way). Graphene is one of the research areas being considered for the prize.

ETA Aug. 5, 2011: Tour’s team just published another paper on graphene, one that proves you can make it from anything containing carbon according the Aug. 4, 2011 news item, One Box of Girl Scout Cookies Worth $15 Billion: Lab Shows Troop How Any Carbon Source Can Become Valuable Graphene, on Science Daily,

The cookie gambit started on a dare when Tour mentioned at a meeting that his lab had produced graphene from table sugar.

“I said we could grow it from any carbon source — for example, a Girl Scout cookie, because Girl Scout Cookies were being served at the time,” Tour recalled. “So one of the people in the room said, ‘Yes, please do it. … Let’s see that happen.’”

Members of Girl Scouts of America Troop 25080 came to Rice’s Smalley Institute for Nanoscale Science and Technology to see the process. Rice graduate students Gedeng Ruan, lead author of the paper, and Zhengzong Sun calculated that at the then-commercial rate for pristine graphene — $250 for a two-inch square — a box of traditional Girl Scout shortbread cookies could turn a $15 billion profit.

Here’s the full reference for this second paper,

Gedeng Ruan, Zhengzong Sun, Zhiwei Peng, James M. Tour. Growth of Graphene from Food, Insects and Waste. ACS Nano, 2011; 110729113834087 DOI: 10.1021/nn202625c

The article is behind a paywall.