Category Archives: nanotechnology

Live webcast about data journalism on July 30, 2014 and a webinar featuring the 2014 NNI (US National Nanotechnology Initiative) EHS (Environment, Health and Safety) Progress Review on July 31, 2014

The Woodrow Wilson International Center for Scholars is hosting a live webcast on data journalism scheduled for July 30, 2014. For those us who are a little fuzzy as to what the term ‘data journalism’ means, this is probably a good opportunity to find out as per the description in the Wilson Center’s July 23, 2014 email announcement,

What is data journalism? Why does it matter? How has the maturing field of data science changed the direction of journalism and global investigative reporting? Our speakers will discuss the implications for policymakers and institutional accountability, and how the balance of power in information gathering is shifting worldwide, with implications for decision-making and open government.

This event will be live webcast and you may follow it on twitter @STIPcommonslab and #DataJournalism

Wednesday, July 30th, 2014
10am – 12pm EST
5th Floor Conference Room
[Woodrow Wilson International Center for Scholars
Ronald Reagan Building and International Trade Center
One Woodrow Wilson Plaza - 1300 Pennsylvania Ave., NW, Washington, DC 20004-3027
T 1-202-691-4000]

Speakers:

Alexander B. Howard
Writer and Editor, TechRepublic and founder of the blog “E Pluribus Unum.” Previously, he was a fellow at the Tow Center for Digital Journalism at Columbia University, the Ash Center at Harvard University and the Washington Correspondent for O’Reilly Media.

Kalev H. Leetaru
Yahoo! Fellow at Georgetown University, a Council Member of the World Economic Forum’s Global Agenda Council on the Future of Government, and a Foreign Policy Magazine Top 100 Global Thinker of 2013. For nearly 20 years he has been studying the web and building systems to interact with and understand the way it is reshaping our global society.

Louise Lief (Moderator)
Public Policy Scholar at the Wilson Center. Her project, “Science and the Media” explores innovative ways to make environmental science more accessible and useful to all journalists. She is investigating how new technologies and civic innovation tools can benefit both the media and science.

I believe you need to RSVP if you are attending in person but it’s not necessary for the livestream.

The other announcement comes via a July 23, 2014 news item on Nanowerk,

The National Nanotechnology Coordination Office (NNCO) will hold a public webinar on Thursday, July 31, 2014, to provide a forum to answer questions related to the “Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative (NNI) 2011 Environmental, Health, and Safety Research Strategy.”

The full notice can be found on the US nano.gov website,

When: The webinar will be live on Thursday, July 31, 2014 from 12:00 pm-1 pm.
Where: Click here to register for the online webcast

While it’s open to the public, I suspect this is an event designed largely for highly interested parties such as the agencies involved in EHS activities, nongovernmental organizations that act as watchdogs, and various government policy wonks. Here’s how they describe their proposed discussions (from the event notice page),

Discussion during the webinar will focus on the research activities undertaken by NNI agencies to advance the current state of the science as highlighted in the Progress Review. Representative research activities as provided in the Progress Review will be discussed in the context of the 2011 NNI EHS Research Strategy’s six core research areas: Nanomaterial Measurement Infrastructure, Human Exposure Assessment, Human Health, the Environment, Risk Assessment and Risk Management Methods, and Informatics and Modeling.

How: During the question-and-answer segment of the webinar, submitted questions will be considered in the order received. A moderator will identify relevant questions and pose them to the panel of NNI agency representatives. Due to time constraints, not all questions may be addressed.  The moderator reserves the right to group similar questions and to skip questions, as appropriate. The NNCO will begin accepting questions and comments via email ([email protected]) at 1 pm on Thursday, July 24th (EDT) until the close of the webinar at 1 pm (EDT) on July 31st.

The Panelists:  The panelists for the webinar are subject matter experts from the Federal Government.

Additional Information: A public copy of the “Progress Review on the Coordinated Implementation of the National Nanotechnology Initiative 2011 Environmental, Health, and Safety Research Strategy” can be accessed at www.nano.gov/2014EHSProgressReview. The 2011 NNI EHS Research Strategy can be accessed at www.nano.gov/node/681.
- See more at: http://www.nano.gov/node/1166#sthash.Ipr0bFeP.dpuf

Gold on the brain, a possible nanoparticle delivery system for drugs

A July 21, 2014 news item on Nanowerk describes special gold nanoparticles that could make drug delivery to cells easier,

A special class of tiny gold particles can easily slip through cell membranes, making them good candidates to deliver drugs directly to target cells.

A new study from MIT materials scientists reveals that these nanoparticles enter cells by taking advantage of a route normally used in vesicle-vesicle fusion, a crucial process that allows signal transmission between neurons.

A July 21, 2014 MIT (Massachusetts Institute of Technology) news release (also on EurekAlert), which originated the news item, provides more details,

The findings suggest possible strategies for designing nanoparticles — made from gold or other materials — that could get into cells even more easily.

“We’ve identified a type of mechanism that might be more prevalent than is currently known,” says Reid Van Lehn, an MIT graduate student in materials science and engineering and one of the paper’s lead authors. “By identifying this pathway for the first time it also suggests not only how to engineer this particular class of nanoparticles, but that this pathway might be active in other systems as well.”

The paper’s other lead author is Maria Ricci of École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. The research team, led by Alfredo Alexander-Katz, an associate professor of materials science and engineering, and Francesco Stellacci from EPFL, also included scientists from the Carlos Besta Institute of Neurology in Italy and Durham University in the United Kingdom.

Most nanoparticles enter cells through endocytosis, a process that traps the particles in intracellular compartments, which can damage the cell membrane and cause cell contents to leak out. However, in 2008, Stellacci, who was then at MIT, and Darrell Irvine, a professor of materials science and engineering and of biological engineering, found that a special class of gold nanoparticles coated with a mix of molecules could enter cells without any disruption.

“Why this was happening, or how this was happening, was a complete mystery,” Van Lehn says.

Last year, Alexander-Katz, Van Lehn, Stellacci, and others discovered that the particles were somehow fusing with cell membranes and being absorbed into the cells. In their new study, they created detailed atomistic simulations to model how this happens, and performed experiments that confirmed the model’s predictions.

Gold nanoparticles used for drug delivery are usually coated with a thin layer of molecules that help tune their chemical properties. Some of these molecules, or ligands, are negatively charged and hydrophilic, while the rest are hydrophobic. The researchers found that the particles’ ability to enter cells depends on interactions between hydrophobic ligands and lipids found in the cell membrane.

Cell membranes consist of a double layer of phospholipid molecules, which have hydrophobic lipid tails and hydrophilic heads. The lipid tails face in toward each other, while the hydrophilic heads face out.

In their computer simulations, the researchers first created what they call a “perfect bilayer,” in which all of the lipid tails stay in place within the membrane. Under these conditions, the researchers found that the gold nanoparticles could not fuse with the cell membrane.

However, if the model membrane includes a “defect” — an opening through which lipid tails can slip out — nanoparticles begin to enter the membrane. When these lipid protrusions occur, the lipids and particles cling to each other because they are both hydrophobic, and the particles are engulfed by the membrane without damaging it.

In real cell membranes, these protrusions occur randomly, especially near sites where proteins are embedded in the membrane. They also occur more often in curved sections of membrane, because it’s harder for the hydrophilic heads to fully cover a curved area than a flat one, leaving gaps for the lipid tails to protrude.

“It’s a packing problem,” Alexander-Katz says. “There’s open space where tails can come out, and there will be water contact. It just makes it 100 times more probable to have one of these protrusions come out in highly curved regions of the membrane.”

This phenomenon appears to mimic a process that occurs naturally in cells — the fusion of vesicles with the cell membrane. Vesicles are small spheres of membrane-like material that carry cargo such as neurotransmitters or hormones.

The similarity between absorption of vesicles and nanoparticle entry suggests that cells where a lot of vesicle fusion naturally occurs could be good targets for drug delivery by gold nanoparticles. The researchers plan to further analyze how the composition of the membranes and the proteins embedded in them influence the absorption process in different cell types. “We want to really understand all the constraints and determine how we can best design nanoparticles to target particular cell types, or regions of a cell,” Van Lehn says.

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

Lipid tail protrusions mediate the insertion of nanoparticles into model cell membranes by Reid C. Van Lehn, Maria Ricci, Paulo H.J. Silva, Patrizia Andreozzi, Javier Reguera, Kislon Voïtchovsky, Francesco Stellacci, & Alfredo Alexander-Katz. Nature Communications 5, Article number: 4482 doi:10.1038/ncomms5482 Published 21 July 2014

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

I last featured this multi-country team’s work on gold nanoparticles in an Aug. 23, 2013 posting.

Steampower via nanotechnology

It seems that researchers at MIT (Massachusetts Institute of Technology (US) have been inspired by steam punk, of a sort. From a July 21, 2014 news item on Nanowerk,

A new material structure developed at MIT generates steam by soaking up the sun.

The structure — a layer of graphite flakes and an underlying carbon foam — is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam. The brighter the light, the more steam is generated.

The new material is able to convert 85 percent of incoming solar energy into steam — a significant improvement over recent approaches to solar-powered steam generation. What’s more, the setup loses very little heat in the process, and can produce steam at relatively low solar intensity. This would mean that, if scaled up, the setup would likely not require complex, costly systems to highly concentrate sunlight.

A July 21, 2014 MIT news release, which originated the news item, details the research,

Hadi Ghasemi, a postdoc in MIT’s Department of Mechanical Engineering, says the spongelike structure can be made from relatively inexpensive materials — a particular advantage for a variety of compact, steam-powered applications.

“Steam is important for desalination, hygiene systems, and sterilization,” says Ghasemi, who led the development of the structure. “Especially in remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful.”

Today, solar-powered steam generation involves vast fields of mirrors or lenses that concentrate incoming sunlight, heating large volumes of liquid to high enough temperatures to produce steam. However, these complex systems can experience significant heat loss, leading to inefficient steam generation.

Recently, scientists have explored ways to improve the efficiency of solar-thermal harvesting by developing new solar receivers and by working with nanofluids. The latter approach involves mixing water with nanoparticles that heat up quickly when exposed to sunlight, vaporizing the surrounding water molecules as steam. But initiating this reaction requires very intense solar energy — about 1,000 times that of an average sunny day.

By contrast, the MIT approach generates steam at a solar intensity about 10 times that of a sunny day — the lowest optical concentration reported thus far. The implication, the researchers say, is that steam-generating applications can function with lower sunlight concentration and less-expensive tracking systems.

“This is a huge advantage in cost-reduction,” Ghasemi says. “That’s exciting for us because we’ve come up with a new approach to solar steam generation.”

The approach itself is relatively simple: Since steam is generated at the surface of a liquid, Ghasemi looked for a material that could both efficiently absorb sunlight and generate steam at a liquid’s surface.

After trials with multiple materials, he settled on a thin, double-layered, disc-shaped structure. Its top layer is made from graphite that the researchers exfoliated by placing the material in a microwave. The effect, Chen says, is “just like popcorn”: The graphite bubbles up, forming a nest of flakes. The result is a highly porous material that can better absorb and retain solar energy.

The structure’s bottom layer is a carbon foam that contains pockets of air to keep the foam afloat and act as an insulator, preventing heat from escaping to the underlying liquid. The foam also contains very small pores that allow water to creep up through the structure via capillary action.

As sunlight hits the structure, it creates a hotspot in the graphite layer, generating a pressure gradient that draws water up through the carbon foam. As water seeps into the graphite layer, the heat concentrated in the graphite turns the water into steam. The structure works much like a sponge that, when placed in water on a hot, sunny day, can continuously absorb and evaporate liquid.

The researchers tested the structure by placing it in a chamber of water and exposing it to a solar simulator — a light source that simulates various intensities of solar radiation. They found they were able to convert 85 percent of solar energy into steam at a solar intensity 10 times that of a typical sunny day.

Ghasemi says the structure may be designed to be even more efficient, depending on the type of materials used.

“There can be different combinations of materials that can be used in these two layers that can lead to higher efficiencies at lower concentrations,” Ghasemi says. “There is still a lot of research that can be done on implementing this in larger systems.”

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

Solar steam generation by heat localization by Hadi Ghasemi, George Ni, Amy Marie Marconnet, James Loomis, Selcuk Yerci, Nenad Miljkovic, & Gang Chen. Nature Communications 5, Article number: 4449 doi:10.1038/ncomms5449 Published 21 July 2014

This paper is behind a paywall but a free preview is available via ReadCube Access.

Trapping gases left from nuclear fuels

A July 20, 2014 news item on ScienceDaily provides some insight into recycling nuclear fuel,

When nuclear fuel gets recycled, the process releases radioactive krypton and xenon gases. Naturally occurring uranium in rock contaminates basements with the related gas radon. A new porous material called CC3 effectively traps these gases, and research appearing July 20 in Nature Materials shows how: by breathing enough to let the gases in but not out.

The CC3 material could be helpful in removing unwanted or hazardous radioactive elements from nuclear fuel or air in buildings and also in recycling useful elements from the nuclear fuel cycle. CC3 is much more selective in trapping these gases compared to other experimental materials. Also, CC3 will likely use less energy to recover elements than conventional treatments, according to the authors.

A July 21, 2014 US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL) news release (also on EurekAlert), which originated the news item despite the difference in dates, provides more details (Note: A link has been removed),

The team made up of scientists at the University of Liverpool in the U.K., the Department of Energy’s Pacific Northwest National Laboratory, Newcastle University in the U.K., and Aix-Marseille Universite in France performed simulations and laboratory experiments to determine how — and how well — CC3 might separate these gases from exhaust or waste.

“Xenon, krypton and radon are noble gases, which are chemically inert. That makes it difficult to find materials that can trap them,” said coauthor Praveen Thallapally of PNNL. “So we were happily surprised at how easily CC3 removed them from the gas stream.”

Noble gases are rare in the atmosphere but some such as radon come in radioactive forms and can contribute to cancer. Others such as xenon are useful industrial gases in commercial lighting, medical imaging and anesthesia.

The conventional way to remove xenon from the air or recover it from nuclear fuel involves cooling the air far below where water freezes. Such cryogenic separations are energy intensive and expensive. Researchers have been exploring materials called metal-organic frameworks, also known as MOFs, that could potentially trap xenon and krypton without having to use cryogenics. Although a leading MOF could remove xenon at very low concentrations and at ambient temperatures admirably, researchers wanted to find a material that performed better.

Thallapally’s collaborator Andrew Cooper at the University of Liverpool and others had been researching materials called porous organic cages, whose molecular structures are made up of repeating units that form 3-D cages. Cages built from a molecule called CC3 are the right size to hold about three atoms of xenon, krypton or radon.

To test whether CC3 might be useful here, the team simulated on a computer CC3 interacting with atoms of xenon and other noble gases. The molecular structure of CC3 naturally expands and contracts. The researchers found this breathing created a hole in the cage that grew to 4.5 angstroms wide and shrunk to 3.6 angstroms. One atom of xenon is 4.1 angstroms wide, suggesting it could fit within the window if the cage opens long enough. (Krypton and radon are 3.69 angstroms and 4.17 angstroms wide, respectively, and it takes 10 million angstroms to span a millimeter.)

The computer simulations revealed that CC3 opens its windows big enough for xenon about 7 percent of the time, but that is enough for xenon to hop in. In addition, xenon has a higher likelihood of hopping in than hopping out, essentially trapping the noble gas inside.

The team then tested how well CC3 could pull low concentrations of xenon and krypton out of air, a mix of gases that included oxygen, argon, carbon dioxide and nitrogen. With xenon at 400 parts per million and krypton at 40 parts per million, the researchers sent the mix through a sample of CC3 and measured how long it took for the gases to come out the other side.

Oxygen, nitrogen, argon and carbon dioxide — abundant components of air — traveled through the CC3 and continued to be measured for the experiment’s full 45 minute span. Xenon however stayed within the CC3 for 15 minutes, showing that CC3 could separate xenon from air.

In addition, CC3 trapped twice as much xenon as the leading MOF material. It also caught xenon 20 times more often than it caught krypton, a characteristic known as selectivity. The leading MOF only preferred xenon 7 times as much. These experiments indicated improved performance in two important characteristics of such a material, capacity and selectivity.

“We know that CC3 does this but we’re not sure why. Once we understand why CC3 traps the noble gases so easily, we can improve on it,” said Thallapally.

To explore whether MOFs and porous organic cages offer economic advantages, the researchers estimated the cost compared to cryogenic separations and determined they would likely be less expensive.

“Because these materials function well at ambient or close to ambient temperatures, the processes based on them are less energy intensive to use,” said PNNL’s Denis Strachan.

The material might also find use in pharmaceuticals. Most molecules come in right- and left-handed forms and often only one form works in people. In additional experiments, Cooper and colleagues in the U.K. tested CC3′s ability to distinguish and separate left- and right-handed versions of an alcohol. After separating left- and right-handed forms of CC3, the team showed in biochemical experiments that each form selectively trapped only one form of the alcohol.

The researchers have provided an image illustrating a CC3 cage,

Breathing room: In this computer simulation, light and dark purple highlight the cavities within the 3D pore structure of CC3. Courtesy:  PNNL

Breathing room: In this computer simulation, light and dark purple highlight the cavities within the 3D pore structure of CC3. Courtesy: PNNL

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

Separation of rare gases and chiral molecules by selective binding in porous organic cages by Linjiang Chen, Paul S. Reiss, Samantha Y. Chong, Daniel Holden, Kim E. Jelfs, Tom Hasell, Marc A. Little, Adam Kewley, Michael E. Briggs, Andrew Stephenson, K. Mark Thomas, Jayne A. Armstrong, Jon Bell, Jose Busto, Raymond Noel, Jian Liu, Denis M. Strachan, Praveen K. Thallapally, & Andrew I. Cooper. Nature Material (2014) doi:10.1038/nmat4035 Published online 20 July 2014

This paper is behind a paywall.

At a distance of less than a light wave, nanocamera takes pictures

A July 17, 2014 University of Illinois College of Engineering news release (also on EurekAlert) features a research breakthrough,

How is it possible to record optically encoded information for distances smaller than the wavelength of light?

Researchers at the University of Illinois at Urbana-Champaign have demonstrated that an array of novel gold, pillar-bowtie nanoantennas (pBNAs) can be used like traditional photographic film to record light for distances that are much smaller than the wavelength of light (for example, distances less than ~600 nm for red light). A standard optical microscope acts as a “nanocamera” whereas the pBNAs are the analogous film.

Here’s an image the researchers have provided to illustrate their work,

We demonstrate the plasmonic equivalent of photographic film for recording optical intensity in the near field. The plasmonic structure is based on gold bowtie nanoantenna arrays fabricated on SiO2 pillars. We show that it can be employed for direct laser writing of image data or recording the polarization structure of optical vector beams.[downloaded from http://pubs.acs.org/doi/abs/10.1021/nl501788a]

We demonstrate the plasmonic equivalent of photographic film for recording optical intensity in the near field. The plasmonic structure is based on gold bowtie nanoantenna arrays fabricated on SiO2 pillars. We show that it can be employed for direct laser writing of image data or recording the polarization structure of optical vector beams.[downloaded from http://pubs.acs.org/doi/abs/10.1021/nl501788a]

The news release describes the technique,

“Unlike conventional photographic film, the effect (writing and curing) is seen in real time,” explained Kimani Toussaint, an associate professor of mechanical science and engineering, who led the research. “We have demonstrated that this multifunctional plasmonic film can be used to create optofluidic channels without walls. Because simple diode lasers and low-input power densities are sufficient to record near-field optical information in the pBNAs, this increases the potential for optical data storage applications using off-the-shelf, low-cost, read-write laser systems.”

“Particle manipulation is the proof-of-principle application,” stated Brian Roxworthy, first author of the group’s paper, “Multifunctional Plasmonic Film for Recording Near-Field Optical Intensity,” published in the journal, Nano Letters. “Specifically, the trajectory of trapped particles in solution is controlled by the pattern written into the pBNAs. This is equivalent to creating channels on the surface for particle guiding except that these channels do not have physical walls (in contrast to those optofluidics systems where physical channels are fabricated in materials such as PDMS).”

To prove their findings, the team demonstrated various written patterns—including the University’s “Block I” logo and brief animation of a stick figure walking—that were either holographically transferred to the pBNAs or laser-written using steering mirrors (see video).

The news release concludes with,

“We wanted to show the analogy between what we have made and traditional photographic film,” Toussaint added. “There’s a certain cool factor with this. However, we know that we’re just scratching the surface since the use of plasmonic film for data storage at very small scales is just one application. Our pBNAs allow us to do so much more, which we’re currently exploring.”

The researchers noted that the fundamental bit size is currently set by the spacing of the antennas at 425-nm. However, the pixel density of the film can be straightforwardly reduced by fabricating smaller array spacing and a smaller antenna size, as well as using a more tightly focusing lens for recording.

“For a standard Blu-ray/DVD disc size, that amounts to a total of 28.6 gigabites per disk,” Roxworthy added. “With modifications to array spacing and antenna features, it’s feasible that this value can be scaled to greater than 75 gigabites per disk. Not to mention, it can be used for other exciting photonic applications, such as lab-on-chip nanotweezers or sensing.”

“In our new technique, we use controlled heating via laser illumination of the nanoantennas to change the plasmonic response instantaneously, which shows an innovative but easy way to fabricate spatially changing plasmonic structures and thus opens a new avenue in the field of nanotech-based biomedical technologies and nano optics,”  said Abdul Bhuiya, a co-author and member of the research team.

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

Multifunctional Plasmonic Film for Recording Near-Field Optical Intensity by Brian J. Roxworthy, Abdul M. Bhuiya, V. V. G. Krishna Inavalli, Hao Chen, and Kimani C. Toussaint , Jr. Nano Lett., Article ASAP DOI: 10.1021/nl501788a Publication Date (Web): July 14, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.

Extracting biomolecules from live cells with carbon nanotubes

Being able to extract biomolecules from living cells means nondestruction of the rest of the cell and the ability to observe the consequences of the extraction. From a July 18, 2014 news item on Azonano,

University of Houston researchers have devised a new method for extracting molecules from live cells without disrupting cell development, work that could provide new avenues for the diagnosis of cancer and other diseases.

The researchers used magnetized carbon nanotubes to extract biomolecules from live cells, allowing them to retrieve molecular information without killing the individual cells. A description of the work appears this week in the Proceedings of the National Academy of Sciences.

A July 16, 2014 University of Houston news release by Jeannie Kever, which originated the news item, provides more detail,

Most current methods of identifying intracellular information result in the death of the individual cells, making it impossible to continue to gain information and assess change over time, said Zhifeng Ren, M.D. Anderson Chair professor of physics and principal investigator at the Center for Superconductivity at UH and lead author of the paper. The work was a collaboration between Ren’s lab and that of Paul Chu, T.L.L. Temple Chair of Science and founding director of the Texas Center for Superconductivity.

Chu, a co-author of the paper, said the new technique will allow researchers to draw fundamental information from a single cell.The researchers said the steps outlined in the paper offer proof of concept. Ren said the next step “will be more study of the biological and chemical processes of the cell, more analysis.”

The initial results hold promise for biomedicine, he said.  “This shows how nanoscience and nanoengineering can help the medical field.”

Cai said the new method will be helpful for cancer drug screening and carcinogenesis study, as well as for studies that allow researchers to obtain information from single cells, replacing previous sampling methods that average out cellular diversity and obscure the specificity of the biomarker profiles.

In the paper, the researchers explain their rationale for the work – most methods for extracting molecular information result in cell death, and those that do spare the cell carry special challenges, including limited efficiency.

This method is relatively straightforward, requiring the use of magnetized carbon nanotubes as the transporter and a polycarbonate filter as a collector, they report. Cells from a human embryonic kidney cancer cell line were used for the experiment.

The work builds on a 2005 paper published by Ren’s group in Nature Methods, which established that magnetized carbon nanotubes can deliver molecular payloads into cells. The current research takes that one step further to move molecules out of cells by magnetically driving them through the cell walls.

The carbon nanotubes were grown with a plasma-enhanced chemical vapor deposition system, with magnetic nickel particles enclosed at the tips. A layer of nickel was also deposited along the surface of individual nanotubes in order to make the nanotubes capable of penetrating a cell wall guided by a magnet.

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

Molecular extraction in single live cells by sneaking in and out magnetic nanomaterials by Zhen Yang, Liangzi Deng, Yucheng Lan, Xiaoliu Zhang, Zhonghong Gao, Ching-Wu Chu, Dong Cai, and Zhifeng Ren. PNAS 2014 ; published ahead of print July 16, 2014, doi:10.1073/pnas.1411802111

This paper is behind a paywall.

Mining uranium from the ocean

We are running short of uranium as terrestrial mining of this element has become more hazardous environmentally. A July 18, 2014 news item on Azonano highlights an ‘ocean mining’ uranium project at the University of Alabama (US),

The U.S. Department of Energy [DOE] selected a University of Alabama [UA] start-up company for an approximate $1.5 million award to refine an alternative material to potentially extract uranium from the ocean.

Uranium, which naturally occurs in seawater and in the Earth’s crust, is the fuel for nuclear power. For decades, scientists have sought a more economical and efficient way to remove it from the ocean, as the terrestrial supply is dwindling and environmentally unfriendly to mine.

A July 17, 2014 University of Alabama news release, which originated the news item, describe the University of Alabama’s unique approach to the problem of extracting uranium from the ocean (Note: A link has been removed),

“Every scientist in the world, except us, who is trying to do this is working with plastics,” said Dr. Gabriela Gurau, a chemist and CEO of the UA-based company, 525 Solutions.

Instead, the UA company is developing an adsorbent, biodegradable material made from the compound chitin, which is found in shrimp shells and in other crustaceans and insects. The researchers have developed transparent sheets, or mats, comprised of tiny chitin fibers, modified for the task. When suspended beneath the ocean’s surface, the mats are designed to withdraw uranium.

“Once you put it in the ocean, it will attract uranium like a magnet, and uranium will stick to it,” said Gurau, a University of Alabama alumna.

If one day implemented, the mats, with uranium attached, would be taken to an industrial plant where the nuclear fuel source would be removed.

Earlier work led by Dr. Robin Rogers, Robert Ramsay Chair of Chemistry at UA and director of UA’s Center for Green Manufacturing, initially proved the concept for extracting uranium using chitin. Rogers is an owner/founder of 525 Solutions and serves as a scientific adviser to the company’s representatives.

“The oceans are estimated to contain more than a thousand times the amount of uranium found in total in any known land deposit,” Rogers said. “Fortunately, the concentration of uranium in the ocean is very, very low, but the volume of the oceans is, of course, very, very high. Assuming we could recover only half of this resource, this much uranium could support 6,500 years of nuclear capacity.”

Removing chitin, in a pure form, from shells had previously proven difficult, but Rogers and his UA colleagues discovered a way to use a relatively new class of solvents, called ionic liquids, for removal. Ionic liquids are liquid salts which have other unique and desirable properties that traditional solvents do not. Rogers is recognized as a world-leader in the field of  ionic liquids.

UA researchers use a time-honored laboratory technique called electrospinning to produce the mats. In this process, the scientists use a specially-prepared, chitin-based, ionic liquid solution, which is loaded in the electrospinning apparatus. Some 30,000 volts of electricity are applied, spinning the fibers into a water bath. After several hours, nanofiber mats, consisting of fibers much thinner than a strand of a spider’s web, form, weaved together into a solid sheet.

The increased surface area the nanomats provide is central to the project, said Dr. Julia Shamshina, the company’s chief technology officer and also a UA alumna.

“The larger the surface area, the larger modifications we can make and the more uranium it will uptake,” Shamshina said. “If you have one very thick fiber and 10 which, when combined, equal the size of the thick fiber, the ten smaller ones will take up hundreds, or even thousands, of times more uranium.”

Rogers extolled the potential environmental benefits of  the company’s approach and addressed cost factors.

“Mining uranium from land is a very dirty, energy intensive process, with a lot of hazardous waste produced,” Rogers said. “If we eliminate land mining by mining from the ocean, we not only clean up the ocean, we eliminate all of the environmental problems with terrestrial mining.

“Research studies have shown that uranium can be extracted from the ocean, but the process remains prohibitively costly,” said Rogers, a  two-time UA graduate. “The search for more effective adsorbents — which is what we’re doing  – is under way and expected to solve this issue.”

Gurau said the two-year grant, from the DOE’s Office of Science through its Small Business Innovation Research and Small Business Technology Transfer programs, will enable the researchers to refine their processes, measure costs and conduct an environmental analysis.

“We need to know if it’s viable from an economic standpoint,” Gurau said. “I think this is a critical step in getting this to the pilot-plant stage.”

Corporate influence, nanotechnology regulation, and Friends of the Earth (FoE) Australia

The latest issue of the newsletter, Chain Reaction # 121, July 2014, published by Friends of the Earth (FoE) Australia features an article by Louise Sales ‘Corporate influence over nanotechnology regulation‘ that has given me pause. From the Sales article,

I recently attended an Organisation for Economic Co-operation and Development (OECD) seminar on the risk assessment and risk management of nanomaterials. This was an eye-opening experience that graphically illustrated the extent of corporate influence over nanotechnology regulation globally. Representatives of the chemical companies DuPont and Evonik; the Nanotechnology Industries Association; and the Business and Industry Advisory Committee to the OECD (BIAC) sat alongside representatives of countries such as Australia, the US and Canada and were given equal speaking time.

BIAC gave a presentation on their work with the Canadian and United States Governments to harmonise nanotechnology regulation between the two countries. [US-Canada Regulatory Cooperative Council] [emphasis mine] Repeated reference to the involvement of ‘stakeholders’ prompted me to ask if any NGOs [nongovernmental organizations] were involved in the process. Only in the earlier stages apparently − ‘stakeholders’ basically meant industry.

A representative of the Nanotechnology Industries Association told us about the European NANoREG project they are leading in collaboration with regulators, industry and scientists. This is intended to ‘develop … new testing strategies adapted to innovation requirements’ and to ‘establish a close collaboration among authorities, industry and science leading to efficient and practically applicable risk management approaches’. In other words industry will be helping write the rules.

Interestingly, when I raised concerns about this profound intertwining of government and industry with one of the other NGO representatives they seemed almost dismissive of my concerns. I got the impression that most of the parties concerned thought that this was just the ‘way things were’. As under-resourced regulators struggle with the regulatory challenges posed by nanotechnology − the offer of industry assistance is probably very appealing. And from the rhetoric at the meeting one could be forgiven for thinking that their objectives are very similar − to ensure that their products are safe. Right? Wrong.

I just published an update about the US-Canada Regulatory Cooperation Council (RCC; in  my July 14, 2014 posting) where I noted the RCC has completed its work and final reports are due later this summer. Nowhere in any of the notices is there mention of BIAC’s contribution (whatever it might have been) to this endeavour.

Interestingly. BIAC is not an OECD committee but a separate organization as per its About us page,

BIAC is an independent international business association devoted to advising government policymakers at OECD and related fora on the many diversified issues of globalisation and the world economy.

Officially recognised since its founding in 1962 as being representative of the OECD business community, BIAC promotes the interests of business by engaging, understanding and advising policy makers on a broad range of issues with the overarching objectives of:

  • Positively influencing the direction of OECD policy initiatives;

  • Ensuring business and industry needs are adequately addressed in OECD policy decision instruments (policy advocacy), which influence national legislation;

  • Providing members with timely information on OECD policies and their implications for business and industry.

Through its 38 policy groups, which cover the major aspects of OECD work most relevant to business, BIAC members participate in meetings, global forums and consultations with OECD leadership, government delegates, committees and working groups.

I don’t see any mention of safety either in the excerpt or elsewhere on their About us page.

As Sales notes in her article,

Ultimately corporations have one primary driver and that’s increasing their bottom line.

I do wonder why there doesn’t seem to have been any transparency regarding BIAC’s involvement with the RCC and why no NGOs (according to Sales) were included as stakeholders.

While I sometimes find FoE and its fellow civil society groups a bit shrill and over-vehement at times, It never does to get too complacent. For example, who would have thought that General Motors would ignore safety issues (there were car crashes and fatalities as a consequence) over the apparently miniscule cost of changing an ignition switch. From What is the timeline of the GM recall scandal? on Vox.com,

March 2005: A GM project engineering manager closed the investigation into the faulty switches, noting that they were too costly to fix. In his words: “lead time for all solutions is too long” and “the tooling cost and piece price are too high.” Later emails unearthed by Reuters suggested that the fix would have cost GM 90 cents per car. [emphasis mine]

March 2007: Safety regulators inform GM of the death of Amber Rose, who crashed her Chevrolet Cobalt in 2005 after the ignition switch shut down the car’s electrical system and air bags failed to deploy. Neither the company nor regulators open an investigation.

End of 2013: GM determines that the faulty ignition switch is to blame for at least 31 crashes and 13 deaths.

According to a July 17, 2014 news item on CBC (Canadian Broadcasting Corporation) news online, Mary Barra, CEO of General Motors, has testified on the mater before the US Senate for a 2nd time, this year,

A U.S. Senate panel posed questions to a new set of key players Thursday [July 17, 2014] as it delves deeper into General Motors’ delayed recall of millions of small cars.

An internal report found GM attorneys signed settlements with the families of crash victims but didn’t tell engineers or top executives about mounting problems with ignition switches. It also found that GM’s legal staff acted without urgency.

GM says faulty ignition switches were responsible for at least 13 deaths. It took the company 11 years to recall the cars.

Barra will certainly be asked about how she’s changing a corporate culture that allowed a defect with ignition switches to remain hidden from the car-buying public for 11 years. It will be Barra’s second time testifying before the panel.

H/T ICON (International Council on Nanotechnology) July 16, 2014 news item. Following on the topic of transparency, ICON based at Rice University in Texas (US) has a Sponsors webpage.

New ways to think about water

This post features two items about water both of which suggest we should reconsider our ideas about it. This first item concerns hydrogen bonds and coordinated vibrations. From a July 16 2014 news item on Azonano,

Using a newly developed, ultrafast femtosecond infrared light source, chemists at the University of Chicago have been able to directly visualize the coordinated vibrations between hydrogen-bonded molecules — the first time this sort of chemical interaction, which is found in nature everywhere at the molecular level, has been directly visualized. They describe their experimental techniques and observations in The Journal of Chemical Physics, from AIP [American Institute of Physics] Publishing.

“These two-dimensional infrared spectroscopy techniques provide a new avenue to directly visualize both hydrogen bond partners,” said Andrei Tokmakoff, the lab’s primary investigator. “They have the spectral content and bandwidth to really interrogate huge parts of the vibrational spectrum of molecules. It’s opened up the ability to look at how very different types of vibrations on different molecules interact with one another.”

A July 15, 2014 AIP news release by John Arnst (also on EurekAlert), which originated the news item, provides more detail,

Tokmakoff and his colleagues sought to use two-dimensional infrared spectroscopy to directly characterize structural parameters such as intermolecular distances and hydrogen-bonding configurations, as this information can be encoded in intermolecular cross-peaks that spectroscopy detects between solute-solvent vibrations.

“You pluck on the bonds of one molecule and watch how it influences the other,” Tokmakoff said. “In our experiment, you’re basically plucking on both because they’re so strongly bound.”

Hydrogen bonds are typically perceived as the attractive force between the slightly negative and slightly positive ends of neutrally-charged molecules, such as water. While water stands apart with its unique polar properties, hydrogen bonds can form between a wide range of molecules containing electronegative atoms and range from weakly polar to nearly covalent in strength. Hydrogen bonding plays a key role in the action of large, biologically-relevant molecules and is often an important element in the discovery of new pharmaceuticals.

For their initial visualizations, Tokmakoff’s group used N-methylacetamide, a molecule called a peptide that forms medium-strength hydrogen-bonded dimers in organic solution due to its polar nitrogen-hydrogen and carbon-oxygen tails. By using a targeted three-pulse sequence of mid-infrared light and apparatus described in their article, Tokmakoff’s group was able to render the vibrational patterns of the two peptide units.

“All of the internal vibrations of hydrogen bonded molecules that we look at become intertwined, inextricably; you can’t think of them as just a simple sum of two parts,” Tokmakoff said.

More research is being planned while Tokmakoff suggests that water must be rethought from an atomistic perspective (from the news release),

Future work in Tokmakoff’s group involves visualizing the dynamics and structure of water around biological molecules such as proteins and DNA.

“You can’t just think of the water as sort of an amorphous solvent, you really have to at least on some level think of it atomistically and treat it that way,” Tokmakoff said. “And if you believe that, it has huge consequences all over the place, particularly in biology, where so much computational biology ignores the fact that water has real structure and real quantum mechanical properties of its own.”

The researchers have provided an illustration of hydrogen’s vibrating bonds,

The hydrogen-bonding interaction causes the atoms on each individual N-methylacetamide molecule to vibrate in unison. CREDIT: L. De Marco/UChicago

The hydrogen-bonding interaction causes the atoms on each individual N-methylacetamide molecule to vibrate in unison.
CREDIT: L. De Marco/UChicago

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

Direct observation of intermolecular interactions mediated by hydrogen bonding by Luigi De Marco, Martin Thämer, Mike Reppert, and Andrei Tokmakoff. J. Chem. Phys. 141, 034502 (2014); http://dx.doi.org/10.1063/1.4885145

This paper is open access. (I was able to view the entire HTML version.)

A July 15, 2014 University of Southampton press release on EurekAlert offers another surprise about water,

University of Southampton researchers have found that rainwater can penetrate below the Earth’s fractured upper crust, which could have major implications for our understanding of earthquakes and the generation of valuable mineral deposits.

The reason that water’s ability to penetrate below the earth’s upper crust is a surprise (from the news release),

It had been thought that surface water could not penetrate the ductile crust – where temperatures of more than 300°C and high pressures cause rocks to flex and flow rather than fracture – but researchers, led by Southampton’s Dr Catriona Menzies, have now found fluids derived from rainwater at these levels.

The news release also covers the implications of this finding,

Fluids in the Earth’s crust can weaken rocks and may help to initiate earthquakes along locked fault lines. They also concentrate valuable metals such as gold. The new findings suggest that rainwater may be responsible for controlling these important processes, even deep in the Earth.

Researchers from the University of Southampton, GNS Science (New Zealand), the University of Otago, and the Scottish Universities Environmental Research Centre studied geothermal fluids and mineral veins from the Southern Alps of New Zealand, where the collision of two tectonic plates forces deeper layers of the earth closer to the surface.

The team looked into the origin of the fluids, how hot they were and to what extent they had reacted with rocks deep within the mountain belt.

“When fluids flow through the crust they leave behind deposits of minerals that contain a small amount of water trapped within them,” says Postdoctoral Researcher Catriona, who is based at the National Oceanography Centre. “We have analysed these waters and minerals to identify where the fluids deep in the crust came from.

“Fluids may come from a variety of sources in the crust. In the Southern Alps fluids may flow upwards from deep in the crust, where they are released from hot rocks by metamorphic reactions, or rainwater may flow down from the surface, forced by the high mountains above. We wanted to test the limits of where rainwater may flow in the crust. Although it has been suggested before, our data shows for the first time that rainwater does penetrate into rocks that are too deep and hot to fracture.”

Surface-derived waters reaching such depths are heated to over 400°C and significantly react with crustal rocks. However, through testing the researchers were able to establish the water’s meteoric origin.

Funding for this research, which has been published in Earth and Planetary Science Letters, was provided by the Natural Environmental Research Council (NERC). Catriona and her team are now looking further at the implications of their findings in relation to earthquake cycles as part of the international Deep Fault Drilling Project [DFDP], which aims to drill a hole through the Alpine Fault at a depth of about 1km later this year.

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

Incursion of meteoric waters into the ductile regime in an active orogen by Catriona D. Menzies, Damon A.H. Teagle, Dave Craw, Simon C. Cox, Adrian J. Boyce, Craig D. Barrie, and Stephen Roberts. Earth and Planetary Science Letters Volume 399, 1 August 2014, Pages 1–13 DOI: 10.1016/j.epsl.2014.04.046

Open Access funded by Natural Environment Research Council

This is the first time I’ve seen the funding agency which made the paper’s open access status possible cited.

20 bromine atoms, a Swiss cross and room temperature

I haven’t featured a teeny, tiny object in quite a while so here’s a Swiss cross composed of 20 bromine atoms,

20 bromine atoms positioned on a sodium chloride surface using the tip of an atomic force microscope at room temperature, creating a Swiss cross with the size of 5.6nm. The structure is stable at room temperature and was achieved by exchanging chlorine with bromine atoms. (Fig: Department of Physics, University of Basel)

20 bromine atoms positioned on a sodium chloride surface using the tip of an atomic force microscope at room temperature, creating a Swiss cross with the size of 5.6nm. The structure is stable at room temperature and was achieved by exchanging chlorine with bromine atoms. (Fig: Department of Physics, University of Basel)

A July 15, 2014 news item on ScienceDaily features the research illustrated by the image,

The manipulation of atoms has reached a new level: Together with teams from Finland and Japan, physicists from the University of Basel were able to place 20 single atoms on a fully insulated surface at room temperature to form the smallest “Swiss cross,” thus taking a big step towards next generation atomic-scale storage devices. …

A July 15, 2014 Universität Basel press release (also on EurekAlert), which originated the news item, explains why this is a breakthrough,

Ever since the 1990s, physicists have been able to directly control surface structures by moving and positioning single atoms to certain atomic sites. A number of atomic manipulations have previously been demonstrated both on conducting or semi-conducting surfaces mainly under very low temperatures. However, the fabrication of artificial structures on an insulator at room temperature is still a long-standing challenge and previous attempts were uncontrollable and did not deliver the desired results.

In this study, an international team of researchers around Shigeki Kawai and Ernst Meyer from the Department of Physics at the University of Basel presents the first successful systematic atomic manipulation on an insulating surface at room temperatures. Using the tip of an atomic force microscope, they placed single bromine atoms on a sodium chloride surface to construct the shape of the Swiss cross. The tiny cross is made of 20 bromine atoms and was created by exchanging chlorine with bromine atoms. It measures only 5.6 nanometers square and represents the largest number of atomic manipulations ever achieved at room temperature.

Together with theoretical calculations the scientists were able to identify the novel manipulation mechanisms to fabricate unique structures at the atomic scale. The study thus shows how systematic atomic manipulation at room temperature is now possible and represents an important step towards the fabrication of a new generation of electromechanical systems, advanced atomic-scale data storage devices and logic circuits.

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

Atom manipulation on an insulating surface at room temperature by Shigeki Kawai, Adam S. Foster, Filippo Federici Canova, Hiroshi Onodera, Shin-ichi Kitamura, & Ernst Meyer. Nature Communications 5, Article number: 4403 doi:10.1038/ncomms5403 Published 15 July 2014

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

The bromine/Swiss cross accomplishment brings to mind Donald M. Eigler and Erhard K. Schweizer of IBM and their spelling of the company name with single xenon atoms in 1989. Here’s what Malcolm W. Browne had to say about it in his April 5, 1990 New York Times article,

Hiram Maxim, the inventor of the machine gun, used to demonstrate his marksmanship by firing patterns of bullets into walls to spell out the initials of potential customers. In a similar vein, I.B.M. announced yesterday that its scientists had spelled out the company’s initials by dragging single atoms into the desired pattern on the surface of a crystal of nickel.

One result of I.B.M.’s tour de force was the cover photograph of the British journal Nature today. In a letter published by the journal, Dr. Donald M. Eigler and Dr. Erhard K. Schweizer of the I.B.M. Almaden Research Center at San Jose, Calif., reported that using an instrument that can discern individual atoms, they had positioned single atoms of xenon into various patterns, including the letters I.B.M.

Browne offers a good description of how a scanning tunneling microscope and the process of moving atoms one atom at a time in the rest of his article.