Tag Archives: Argonne National Laboratory

Nanotechnology-enabled water resource collaboraton between Israel and Chicago

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A June 25, 2013 news item on Azonano describes a collaborative agreement between the University of Chicago and Ben-Gurion University of the Negev (Israel) to work together and fund nanotechnology-enabled solutions for more water in the Middle East and elsewhere,

The University of Chicago and Ben-Gurion University of the Negev will begin funding a series of ambitious research collaborations that apply the latest discoveries in nanotechnology to create new materials and processes for making clean, fresh drinking water more plentiful and less expensive by 2020.

The announcement came June 23 following a meeting in Jerusalem among Israeli President Shimon Peres, Chicago Mayor Rahm Emanuel, University of Chicago President Robert J. Zimmer, Ben-Gurion University President Rivka Carmi and leading scientists in the field. The joint projects will explore innovative solutions at the water-energy nexus, developing more efficient ways of using water to produce energy and using energy to treat and deliver clean water.

There are more details in the June 23, 2013 University of Chicago news release, which originated the news item (Note: Links have been removed),

The University of Chicago also brings to the effort two powerful research partners already committed to clean water research: the Argonne National Laboratory in Lemont, Ill., and the Marine Biological Laboratory in Woods Hole, Mass.

“We feel it is critical to bring outstanding scientists together to address water resource challenges that are being felt around the world, and will only become more acute over time,” said Zimmer. “Our purification challenges in the Great Lakes region right now are different from some of the scarcity issues some of our colleagues at Ben-Gurion are addressing, but our combined experience will be a tremendous asset in turning early-stage technologies into innovative solutions that may have applications far beyond local issues.”

“Clean, plentiful water is a strategic issue in the Middle East and the world at large, and a central research focus of our university for more than three decades,” said Carmi. “We believe that this partnership will enhance state-of-the-art science in both universities, while having a profound effect on the sustainable availability of clean water to people around the globe.”

The first wave of research proposals include fabricating new materials tailored to remove contaminants, bacteria, viruses and salt from drinking water at a fraction of the cost of current technologies; biological engineering that will help plants maximize their own drought-resistance mechanisms; and polymers that can change the water retention properties of soil in agriculture.

UChicago, BGU and Argonne have jointly committed more than $1 million in seed money over the next two years to support inaugural projects, with the first projects getting under way this fall.

One proposed project would attempt to devise multi-functional and anti-fouling membranes for water purification. These membranes, engineered at the molecular level, could be switched or tuned to remove a wide range of biological and chemical contaminants and prevent the formation of membrane-fouling bacterial films. Keeping those membranes free of fouling would extend their useful lives and decrease energy usage while reducing the operational cost of purifying water.

Another proposal focuses on developing polymers for soil infusion or seed coatings to promote water retention. Such polymers conjure visions of smart landscapes that can substantially promote agricultural growth while reducing irrigation needs.

Officials from both the U.S. and Israel hailed the collaboration as an example of the potential for collaborative innovation that can improve quality of life and boost economic vitality.

You can read more about the University of Chicago’s March 8, 2013 memorandum of understanding with the Ben-Gurion University of the Negev in this March 19,2013 University of Chicago news article by Steve Koppes.

Sidenote: In early May 2013, internationally renowned physicist Stephen Hawking participated in an ‘academic’ boycott of Israel over its position on Palestine. The May 9, 2013 article, Stephen Hawking: Furore deepens over Israel boycott, by Harriet Sherwood, Matthew Kalman, and Sam Jones for the Guardian newspaper reveals some of the content of Hawking’s letter to the organizers and his reasons for participating in the boycott,

Hawking, a world-renowned scientist and bestselling author who has had motor neurone disease for 50 years, cancelled his appearance at the high-profile Presidential Conference, which is personally sponsored by Israel’s president, Shimon Peres, after a barrage of appeals from Palestinian academics.

…

The full text of the letter [from Hawking], dated 3 May, said: “I accepted the invitation to the Presidential Conference with the intention that this would not only allow me to express my opinion on the prospects for a peace settlement but also because it would allow me to lecture on the West Bank. However, I have received a number of emails from Palestinian academics. They are unanimous that I should respect the boycott. In view of this, I must withdraw from the conference. Had I attended, I would have stated my opinion that the policy of the present Israeli government is likely to lead to disaster.”

…

But Palestinians welcomed Hawking’s decision. “Palestinians deeply appreciate Stephen Hawking’s support for an academic boycott of Israel,” said Omar Barghouti, a founding member of the Boycott, Divestment and Sanctions movement. “We think this will rekindle the kind of interest among international academics in academic boycotts that was present in the struggle against apartheid in South Africa.”

Steve Caplan in a May 13, 2013 piece (Occam’s Corner hosted by the Guardian) explained why he profoundly disagreed with Hawking’s position (Note: Links have been removed),

My respect for Hawking as a scientist and person of enormous courage has made my dismay at his recent decision all the greater. In these very virtual pages I have previously opined on the folly of imposing an academic boycott on Israel. The UK, which sports many of the supporters of this policy – dubiously known as the Boycott Divestment and Sanctions (BDS) – also appears to be particularly fertile ground for anti-Semitism. To what degree British anti-Semitism, the anti-Israel BDS lobby and legitimate criticism of Israel’s policies are related is an inordinately complex question, but it is clear that anti-Semitism plays a role among some BDS supporters.

The decision by Hawking to join the boycotters of Israel and Israeli academics is particularly ironic in light of the fact that the conference is being hosted in honor of the 90th birthday of Israel’s president, Shimon Peres. More than any other Israeli leader, Peres has been committed to negotiations and comprehensive peace with the Palestinians, and he was awarded the Nobel Peace Prize for his efforts. At 90, despite his figurehead position, Peres remains steadfastly optimistic in his relentless goal of a fair two-state solution for Israel and the Palestinians.

Caplan’s summary of how the ‘Palestine problem’ was created and how we got to the current state of affairs is one of most the clear-headed I’ve seen,

Pinning the blame on one side with a propaganda machine and a sleeve full of slogans is easy to do, but there is nothing simple or straightforward about the Israeli-Palestinian conflict. From the very birth of the State of Israel in 1948, the mode by which the Palestinian refugee problem was created has been debated intensely by historians. There is little question that a combination of intimidation by Israelis and acquiescence of the refugees to calls by Palestinian and Arab leaders to flee (and return with the victorious Arab armies) were the major causes of Palestinian uprooting.

To what degree was each side responsible? The Palestinians and Arab countries initiated the war in 1948, vetoing by force the United Nations Partition Plan to divide the country between Israelis and Palestinians – in an attempt to prevent any Jewish state from arising. And at the time, Israelis doubtlessly showed little concern at the growing numbers of Palestinians who fled or were forced from their homes. And later, after the Six-Day War in 1967, the Israelis displayed poor judgment (that unfortunately continues to this day) in allowing her citizens to build settlements in these conquered territories.

Both sides have suffered from poor leadership over the years.

Caplan also discusses the relationship between Israel’s government and its academics as he explains why he is opposed academic boycotts,

… in any case, Israeli academics and scientists are neither government mouthpieces nor puppets. There have frequently been serious disagreements between the government and the universities in Israel, highlighting the independence of Israel’s academic institutions. One such example is the Israeli government’s decision last year to upgrade the status of a college built in Ariel – a town inside the West Bank – to that of a university. This was vehemently opposed by Israel’s institutions of higher learning (and by perhaps 50% of the general population).

A second example is the unsuccessful attempt by the Israeli government to shut down Ben-Gurion University’s Department of Politics and Government – which was attacked for its leftist views. The rallying opposition and petition by Israeli academics across the country who warned of the danger to academic freedom helped prevent the department’s closure.

You’ll note the reference to Ben-Gurion University in that last paragraph excerpted from Caplan’s piece, which brings this posting back to where it started, collaboration between two universities to come up with solutions that address problems with access to water. In the end, I am inclined to agree with Caplan that we need to open up and maintain the lines of communication.

ETA June 27, 2013: There is no hint in the University of Chicago news releases that these water projects will benefit any parties other than Israel and the US but it is tempting to hope that this work might also have an impact in Palestine given its current water crisis there as described in a June 26, 2013 news item in the World Bulletin (Note: Links have been removed),

A tiny wedge of land jammed between Israel, Egypt and the Mediterranean sea, the Gaza Strip is heading inexorably into a water crisis that the United Nations says could make the Palestinian enclave unliveable in just a few years.

With 90-95 percent of the territory’s only aquifer contaminated by sewage, chemicals and seawater, neighbourhood desalination facilities and their public taps are a lifesaver for some of Gaza’s 1.6 million residents.

But these small-scale projects provide water for only about 20 percent of the population, forcing many more residents in the impoverished Gaza Strip to buy bottled water at a premium.

“There is a crisis. There is a serious deficit in the water resources in Gaza and there is a serious deterioration in the water quality,” said Rebhi El Sheikh, deputy chairman of the Palestinian Water Authority (PWA).

A NASA study of satellite data released this year showed that between 2003 and 2009 the region lost 144 cubic km of stored freshwater – equivalent to the amount of water held in the Dead Sea – making an already bad situation much worse.

But the situation in Gaza is particularly acute, with the United Nations warning that its sole aquifer might be unusable by 2016, with the damage potentially irreversible by 2020.

H/T June 26, 2013 Reuters news item.

Levitator helps turn liquid cement into liquid metal

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Scientists at the Argonne National Laboratory have found a way to transform liquid cement into liquid metal according to a May 27,2013 news item on ScienceDaily,

In a move that would make the Alchemists of King Arthur’s time green with envy, scientists have unraveled the formula for turning liquid cement into liquid metal. This makes cement a semi-conductor and opens up its use in the profitable consumer electronics marketplace for thin films, protective coatings, and computer chips.

“This new material has lots of applications, including as thin-film resistors used in liquid-crystal displays, basically the flat panel computer monitor that you are probably reading this from at the moment,” said Chris Benmore, a physicist from the U.S. Department of Energy’s (DOE) Argonne National Laboratory who worked with a team of scientists from Japan, Finland and Germany to take the “magic” out of the cement-to-metal transformation. Benmore and Shinji Kohara from Japan Synchrotron Radiation Research Institute/SPring-8 led the research effort.

The May 27, 2013 Argonne National Laboratory press release by Tona Kunz details how the cement-to-metal transformation is performed (Note: Links have been removed),

The team of scientists studied mayenite, a component of alumina cement made of calcium and aluminum oxides. They melted it at temperatures of 2,000 degrees Celsius using an aerodynamic levitator with carbon dioxide laser beam heating. The material was processed in different atmospheres to control the way that oxygen bonds in the resulting glass. The levitator keeps the hot liquid from touching any container surfaces and forming crystals. This let the liquid cool into glassy state that can trap electrons in the way needed for electronic conduction. The levitation method was developed specifically for in-situ measurement at Argonne’s Advanced Photon Source by a team led by Benmore.

The scientists discovered that the conductivity was created when the free electrons were “trapped” in the cage-like structures that form in the glass. The trapped of electrons provided a mechanism for conductivity similar to the mechanism that occurs in metals.

To uncover the details of this process, scientists combined several experimental techniques and analyzed them using a supercomputer.  They confirmed the ideas in experiments using different X-ray techniques at Spring 8 in Japan combined with earlier measurements at the Intense Pulsed Neutron Source and the Advanced Photon Source.

As for why transforming liquid cement into liquid metal might be worthwhile (from the Argonne National Laboratory press release),

This change demonstrates a unique way to make metallic-glass material, which has positive attributes including better resistance to corrosion than traditional metal, less brittleness than traditional glass, conductivity, low energy loss in magnetic fields, and fluidity for ease of processing and molding.

Self-assembling chains of nanoparticles

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The Argonne National Laboratory (US) has announced that their researchers have for the first time watched nanoparticles assemble into chains in real-time. From the Apr. 20, 2013 news item on Nanowerk (Note: Links have been removed),

In a new study performed at the Center for Nanoscale Materials at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, researchers have for the first time seen the self-assembly of nanoparticle chains in situ, that is, in place as it occurs in real-time (“In Situ Visualization of Self-Assembly of Charged Gold Nanoparticles”).

The Apr. 19, 2013 Argonne National Laboratory press release by Jared Sagoff, which originated the news item, provides more detail,

The scientists exposed a tiny liquid “cell” or pouch that contained gold nanoparticles covered with a positively charged coating to an intense beam of electrons generated with a transmission electron microscope. Some of the electrons that penetrated the outside of the cell became trapped in the fluid medium in the cell. These “hydrated” electrons attracted the positively charged nanoparticles, which in time reduced the intensity of charge of the positive coating.

As the hydrated electrons reduced the coating’s positive charge, the nanoparticles no longer repelled each other as strongly.  Instead, their newfound relative attraction led the nanoparticles to “jump around” and eventually stick together in long chains. This self-assembly of nanoparticle chains had been detected before in different studies, but this technique allowed researchers, for the first time, to observe the phenomenon as it occurred.

“The moment-to-moment behavior of nanoparticles is something that’s not yet entirely understood by the scientific community,” said Argonne nanoscientist Yuzi Liu, the study’s lead author. “The potential of nanoparticles in all sorts of different applications and devices – from tiny machines to harvesters of new sources of energy – requires us to bring all of our resources to bear to look at how they function on the most basic physical levels.”

Self-assembly is particularly interesting to scientists because it could lead to new materials that could be used to develop new, energy-relevant technologies. “When we look at self-assembly, we’re looking to use nature as a springboard into man-made materials,” said Argonne nanoscientist Tijana Rajh, who directed the group that carried out the study.

Because the particles under study were so tiny – just a few dozen nanometers in diameter – an optical microscope would not have been able to resolve, or see, individual nanoparticles. By using the liquid cell in the transmission electron microscope at the Center for Nanoscale Materials, Liu and his colleagues could create short movies showing the quick movement of the nanoparticles as their coatings contacted the hydrated electrons.

Here’s a video of the self-assembling nanoparticles, provided by the Argonne National Laboratory,

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

In Situ Visualization of Self-Assembly of Charged Gold Nanoparticles by Yuzi Liu, Xiao-Min Lin, Yugang Sun, and Tijana Rajh. J. Am. Chem. Soc., [Journal of the American Chemical Socieyt] 2013, 135 (10), pp 3764–3767
DOI: 10.1021/ja312620e Publication Date (Web): February 22, 2013
Copyright © 2013 American Chemical Society

 

Gold nanoparticle self-assembly visualization at the Argonne National Laboratory (US)

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There’s a Mar. 13, 2013 news item on phys.org which seems to have been written by someone who’s very technical,

The self-assembly of gold nanoparticles (Au NPs) coated with specific organic ions in water was observed by Center for Nanoscale Materials staff in the Nanobio Interfaces, Electronic & Magnetic Materials & Devices, and Nanophotonics groups at the Argonne National Laboratory using in situ transmission electron microscopy (TEM) equipped with a liquid cell. The Au NPs formed one-dimensional chains within a few minutes.

The originating March 2013 article is on an Argonne National Laboratory’s Center for Nanoscale Materials page,

The self-assembly of NPs attracts intense attention for its potential application in the fabrication of hybrid systems with collective properties from different types of materials. The observations provided here clearly elucidate the complex mechanism of charged NP self-assembly processes. They also paint a cautionary tale on using TEM in situ cells to imitate self-assembly processes in actual solution environments. [emphasis mine]

…

The hydrated electrons formed in radiolysis of water decrease the overall positive charge of cetyltrimethylammonium (CTA)-coated Au NPs. The NPs also were coated with negative citrate ions. (With citrate alone, however, the Au NPs remained steady in the liquid cell regardless of electron-beam intensity). The anisotropic attractive interactions, including dipolar and Van der Waals interactions, overcome the repulsion among the NPs and induce the assembly of NPs. The spatial segregation of different sizes of NPs as a result of electric field gradients within the cell was observed as well.

I’m not sure why the observations paint a cautionary tale. Perhaps a reader could enlighten me?

The researchers also provided an image,

Cetyltrimethylammonium-ion-coated gold nanoparticles before (top) and after (bottom) 500 seconds of electron-beam exposure inside a TEM liquid cell at 200 kV. Scale bar: 100 nm. [downloaded from http://nano.anl.gov/news/highlights/2013_gold_nanoparticles.html]

Cetyltrimethylammonium-ion-coated gold nanoparticles before (top) and after (bottom) 500 seconds of electron-beam exposure inside a TEM liquid cell at 200 kV. Scale bar: 100 nm. [downloaded from http://nano.anl.gov/news/highlights/2013_gold_nanoparticles.html]

For anyone who can understand the technical explanations, here’s a citation and a link to the research paper,

In Situ Visualization of Self-Assembly of Charged Gold Nanoparticles by Yuzi Liu, Xiao-Min Lin, Yugang Sun, and Tijana Rajh. J. Am. Chem. Soc., 2013, 135 (10), pp 3764–3767 DOI: 10.1021/ja312620e Publication Date (Web): February 22, 2013

Copyright © 2013 American Chemical Society

The paper is behind a paywall.

 

Picasso, paint, and the hard x-ray nanoprobe

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There’s the paint you put on your walls and there’s the paint you put on your body and there’s the paint artists use for their works of art. Well, it turns out that a very well known artist used common house paint to create some of his masterpieces,

Among the Picasso paintings in the Art Institute of Chicago collection, The Red Armchair is the most emblematic of his Ripolin usage and is the painting that was examined with APS X-rays at Argonne National Laboratory. To view a larger version of the image, click on it. Courtesy Art Institute of Chicago, Gift of Mr. and Mrs. Daniel Saidenberg (AIC 1957.72) © Estate of Pablo Picasso / Artists Rights Society (ARS), New York [downloaded from http://www.anl.gov/articles/high-energy-x-rays-shine-light-mystery-picasso-s-paints]

Among the Picasso paintings in the Art Institute of Chicago collection, The Red Armchair is the most emblematic of his Ripolin usage and is the painting that was examined with APS X-rays at Argonne National Laboratory. To view a larger version of the image, click on it. Courtesy Art Institute of Chicago, Gift of Mr. and Mrs. Daniel Saidenberg (AIC 1957.72) © Estate of Pablo Picasso / Artists Rights Society (ARS), New York [downloaded from http://www.anl.gov/articles/high-energy-x-rays-shine-light-mystery-picasso-s-paints]

The Art Institute of Chicago teamed with the US Argonne National Laboratory to solve a decades-long mystery as to what kind of paint Picasso used. From the Feb. 8, 2013 news item on Azonano,

The Art Institute of Chicago teamed up with Argonne National Laboratory to unravel a decades-long debate among art scholars about what kind of paint Picasso used to create his masterpieces.

The results published last month in the journal Applied Physics A: Materials Science & Processing adds significant weight to the widely held theory that Picasso was one of the first master painters to use common house paint rather than traditional artists’ paint. That switch in painting material gave birth to a new style of art marked by canvasses covered in glossy images with marbling, muted edges, and occasional errant paint drips but devoid of brush marks. Fast-drying enamel house paint enabled this dramatic departure from the slow-drying heavily blended oil paintings that dominated the art world up until Picasso’s time.

The key to decoding this long-standing mystery was the development of a unique high-energy X-ray instrument, called the hard X-ray nanoprobe, at the U.S. Department of Energy’s Advanced Photon Source (APS) X-ray facility and the Center for Nanoscale Materials, both housed at Argonne. The nanoprobe is designed to advance the development of high-performance materials and sustainable energies by giving scientists a close up view of the type and arraignment of chemical elements in material.

At that submicroscopic level is where science and art crossed paths.

The Argonne National Laboratory Feb. 6, 2013 news release by Tona Kunz, which originated the news item,  provides more  technical detail,

Volker Rose, a physicist at Argonne, uses the nanoprobe at the APS [Advanced Photon Source]/CNM [Center for Nanoscale Materials] to study zinc oxide, a key chemical used in wide-band-gap semiconductors. White paint contains the same chemical in varying amounts, depending on the type and brand of paint, which makes it a valuable clue for learning about Picasso’s work.

By comparing decades-old paint samples collected through e-Bay purchases with samples from Picasso paintings, scientists were able to learn that the chemical makeup of paint used by Picasso matched the chemical makeup of the first commercial house paint, Ripolin. Scientists also learned about the correlation of the spacing of impurities at the nanoscale in zinc oxide, offering important clues to how zinc oxide could be modified to improve performance in a variety of products, including sensors for radiation detection, LEDs and energy-saving windows as well as liquid-crystal displays for computers, TVs and instrument panels.

“Everything that we learn about how materials are structured and how chemicals react at the nanolevel can help us in our quest to design a better and more sustainable future,” Rose said.

Physicists weren’t the first to investigate the question,

Many art conservators and historians have tried over the years to use traditional optical and electron microscopes to determine whether Picasso or one of his contemporaries was the first to break with the cultural tradition of professional painters using expensive paints designed specifically for their craft. Those art world detectives all failed, because traditional tools wouldn’t let them see deeply enough into the layers of paint or with enough resolution to distinguish between store-bought enamel paint and techniques designed to mimic its appearance.

“Appearances can deceive, so this is where art can benefit from scientific research,” said Francesca Casadio, senior conservator scientist at the Art Institute of Chicago, and co-lead author on the result publication. “We needed to reverse-engineer the paint so that we could figure out if there was a fingerprint that we could then go look for in the pictures around the world that are suspected to be painted with Ripolin, the first commercial brand of house paint.”

Just as criminals leave a signature at a crime scene, each batch of paint has a chemical signature determined by its ingredients and impurities from the area and time period it was made. These signatures can’t be imitated and lie in the nanoscale range.

Yet until now, it was difficult to differentiate the chemical components of the paint pigments from the chemical components in the binders, fillers, other additives and contaminates that were mixed in with the pigments or layered on top of them. Only the nanoprobe at the APS /CNM can distinguish that level of detail: elemental composition and nanoscale distribution of elements within individualized submicrometeric pigment particles.

“The nanoprobe at the APS and CNM allowed unprecedented visualization of information about chemical composition within a singe grain of paint pigment, significantly reducing doubt that Picasso used common house paint in some of his most famous works,” said Rose, co-lead author on the result publication titled “High-Resolution Fluorescence Mapping of Impurities in the Historical Zinc Oxide Pigments: Hard X-ray Nanoprobe Applications to the Paints of Pablo Picasso.”

The nanoprobe’s high spatial resolution and micro-focusing abilities gave it the unique ability to identify individual chemical elements and distinguish between the size of paint particles crushed by hand in artists’ studios and those crushed even smaller by manufacturing equipment. The nanoprobe peered deeper than previous similar paint studies limited to a one-micrometer viewing resolution. The nanoprobe gave scientists an unprecedented look at 30-nanometer-wide particles of paint and impurities from the paint manufacturing process. For comparison, a typical sheet of copier paper is 100,000 nanometers thick.

Using the nanoprobe, scientists were able to determine that Picasso used enamel paint to create in 1931 The Red Armchair, on display at the Art Institute of Chicago. They were also able to determine the paint brand and from what manufacturing region the paint originated.

X-ray analysis of white paints produced under the Ripolin brand and used in artists’ traditional tube paints revealed that both contained nearly contaminate-free zinc oxide pigment. However, artists’ tube paints contained more fillers of other white-colored pigments than did the Ripolin, which was mostly pure zinc oxide.

Casaido [sic] views this type of chemical characterization of paints as a having a much wider application than just the study of Picasso’s paintings. By studying the chemical composition of art materials, she said, historians can learn about trade movements in ancient times, better determine the time period a piece was created, and even learn about the artist themselves through their choice of materials.

Perhaps not so coincidentally, the Art Institute of Chicago is celebrating the 100 year relationship between Picasso and Chicago, excerpted from their Jan. 14, 2013 news release,

THE ART INSTITUTE HONORS 100-YEAR RELATIONSHIP BETWEEN PICASSO AND CHICAGO WITH LANDMARK MUSEUM–WIDE CELEBRATION

First Large-Scale Picasso Exhibition Presented by the Art Institute in 30 Years Commemorates Centennial Anniversary of the Armory Show

Picasso and Chicago on View Exclusively at the Art Institute February 20–May 12, 2013

…

This winter, the Art Institute of Chicago celebrates the unique relationship between Chicago and one of the preeminent artists of the 20th century—Pablo Picasso—with special presentations, singular paintings on loan from the Philadelphia Museum of Art, and programs throughout the museum befitting the artist’s unparalleled range and influence. The centerpiece of this celebration is the major exhibition Picasso and Chicago, on view from February 20 through May 12, 2013 in the Art Institute’s Regenstein Hall, which features more than 250 works selected from the museum’s own exceptional holdings and from private collections throughout Chicago. Representing Picasso’s innovations in nearly every media—paintings, sculpture, prints, drawings, and ceramics—the works not only tell the story of Picasso’s artistic development but also the city’s great interest in and support for the artist since the Armory Show of 1913, a signal event in the history of modern art.

The Art Institute of Chicago, Francesca Casadio, and art conservation (specifically in regard to Winslow Homer) were mentioned here in an April 11, 2011 posting.

Self-assembling, size-specific nanopores or nanotubes mimic nature

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I guess you can call this biomimicry or biomimetics as it’s also known. From the  State University of New York at Buffalo  July 17, 2012 news releaseby Charlotte Hsu,

Inspired by nature, an international research team has created synthetic pores that mimic the activity of cellular ion channels, which play a vital role in human health by severely restricting the types of materials allowed to enter cells.

The pores the scientists built are permeable to potassium ions and water, but not to other ions such as sodium and lithium ions.

This kind of extreme selectivity, while prominent in nature, is unprecedented for a synthetic structure, said University at Buffalo chemistry professor Bing Gong, PhD, who led the study.

Here’s how they did it (from the news release),

To create the synthetic pores, the researchers developed a method to force donut-shaped molecules called rigid macrocycles to pile on top of one another. [emphasis mine] The scientists then stitched these stacks of molecules together using hydrogen bonding. The resulting structure was a nanotube with a pore less than a nanometer in diameter.

The July 17, 2012 media advisory by Tona Kunz from the Argonne National Laboratory (one of the partners in this research) describes why creating consistently sized nanopores/nanotubes has been so difficult and offers more information about the macrocycles,

Nanopores and their rolled up version, nanotubes, consist of atoms bonded to each other in a hexagonal pattern to create an array of nanometer-scale openings or channels. This structure creates a filter that can be sized to select which molecules and ions pass into drinking water or into a cell. The same filter technique can limit the release of chemical by-products from industrial processes.

Successes in making synthetic nanotubes from various materials have been reported previously, but their use has been limited because they degrade in water, the pore size of water-resistant carbon nanotubes is difficult to control, and, more critically, the inability to assemble them into appropriate filters.

An international team of researchers, with help of the Advanced Photon Source at Argonne National Laboratory, have succeeded in overcoming these hurdles by building self-assembling, size-specific nanopores. This new capability enables them to engineer nanotubes for specific functions and use pore size to selectively block specific molecules and ions.

Scientists used groupings of atoms called ridged macrocycles that share a planar hexahenylene ethynylene core that bears six amide side chains. Through a cellular self-assembly process, the macrocycles stack cofacially, or atom on top of atom. Each layer of the macrocycle is held together by bonding among hydrogen atoms in the amide side chains. This alignment creates a uniform pore size regardless of the length of the nanotube. A slight misalignment of even a few macrocycles can alter the pore size and greatly compromise the nanotube’s functionality.

Here’s an image of the macrocycles supplied by the Agronne National Labortory,

A snapshot of a helical stack of macryocycles generated in the computer simulation.

The size specificity is  important if  nanopores/nanotubes are going to be used in medical applications,

The pore sizes can be adjusted to filter molecules and ions according to their size by changing the macroycle size, akin to the way a space can be put into a wedding ring to make it fit tighter. The channels are permeable to water, which aids in the fast transmission of intercellular information. The synthetic nanopores mimic the activity of cellular ion channels used in the human body. The research lays the foundation for an array of exciting new technology, such as new ways to deliver directly into cells proteins or medicines to fight diseases.

The research group’s paper has appeared in Nature Communications as of July 17, 2012, from Hsu’s news release,

The study’s lead authors are Xibin Zhou of Beijing Normal University; Guande Liu of Shanghai Jiao Tong University; Kazuhiro Yamato, postdoctoral scientist at UB; and Yi Shen of Shanghai Jiao Tong University and the Shanghai Institute of Applied Physics, Chinese Academy of Sciences. Other institutions that contributed to the work include the University of Nebraska-Lincoln and Argonne National Laboratory. Frank Bright, a SUNY Distinguished Professor of chemistry at UB, assisted with spectroscopic studies.

Canadian scientists get more light in deal with the US Argonne National Laboratory

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Canada’s synchrotron, Canadian Light Source (based in Saskatchewan), has signed a new three-year deal with the US Dept. of Energy’s Argonne National Laboratory’s Advanced Photon Source (APS)  that will give Canadian scientists more access to the APS facilities, according to the June 18, 2012 news item at the  Nanowerk website,

Seeking to solve some of today’s greatest global problems, scientists using x-ray light source facilities at national research laboratories in the United States and Canada are sharing more expertise.

The Canadian Light Source (CLS) and the Advanced Photon Source (APS) at the U.S. Department of Energy’s (DOE’s) Argonne National Laboratory agreed in January 2012 to a Partner User Proposal that cements a stronger working relationship between the two facilities for the next three years. These two premier light sources use different but complementary x-ray techniques to probe materials in order to understand chemical and structural behavior.

Tone Kunz’s June 18, 2012 news release for the APS provides details about the deal,

This new agreement will provide Canadian scientists with more research time to use the x-ray light source facilities and more time on a larger number of APS beamlines. Using varied x-ray and imaging capabilities will broaden the range of experiments Canadians may undertake at the APS to augment their research done at the Canadian Light Source. X-ray science offers potential solutions to a broad range of problems in surface, material, environmental and earth sciences, condensed matter physics, chemistry, and geosciences.

Since the Sector 20 beamlines became fully operational, scientists from Canada and other areas who have used these beamlines at the APS have produced an average of 51 scientific publications a year. This research includes the study of more effective mineral exploration strategies, ways to mitigate mine waste and mercury contamination, and novel ways to fabricate nanomaterials for use in fuel cells, batteries, and LEDs.

I had not realized how longstanding the  CLS/APS relationship has been,

Before the Canadian Light Source began operation in 2004, a Canadian group led by Daryl Crozier of Simon Fraser University, working in partnership with colleagues at the University of Washington and the Pacific Northwest National Laboratory, helped found the Sector 20 beamlines at the APS as part of the Pacific Northwest Consortium Collaborative Access Team, or PNC-CAT. Parts of this team were included in the X-ray Science Division of the APS when it was formed.

This long-standing partnership has led to scientifically significant upgrades to the beamline. The new agreement will provide the valuable manpower and expertise to allow the APS to continue to push the innovation envelope. [emphasis mine]

As I was reading Kunz’s news release I kept asking, what’s in it for the APS? Apparently they need more “manpower and expertise.” Unfortunately, their future plans are a little shy of detail,

Scientists from the APS and the Canadian Light Source will work together on R&D projects to improve light-source technology. In particular, scientists will upgrade even further the two beamlines at Sector 20 in four key areas. This will provide a unique capability to prepare and measure in situ films and interfaces, a new technique to create quantitative three-dimensional chemical maps of samples, and improved forms of spectroscopy to expand the range of elements and types of environments that can be examined.

What are the four key areas? For that matter, what is Sector 20? I suspect some of my readers have similar questions about my postings. It’s easy (especially if you write frequently) to forget that your readers may not be as familiar as you are with the subject matter.

(I wrote about the CLS and another deal with a synchrotron in the UK in my May 31, 2011 posting.)

Inspiring kids, again? High schoolers at Argonne National Laboratory

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C. P. Snow’s 1959 lecture and book, Two Cultures, spends a fair chunk of time on the issue of encouraging the next generation to study science and engineering. As Snow perceived the problem, the UK was falling behind both the US and Russia in the science race. I haven’t investigated what the perceptions were in the US and Russia at the time but I have noticed that descriptions of the race to get someone on the moon feature a great deal of anxiety in the US about Russian supremacy in science. Given human nature, I imagine the Russians were worried too. Plus ça change, n’est ce pas?

Today, everyone is worried that someone else is going to get there (wherever that might be) first and there is enormous pressure internationally to inspire the next generation to pursue science, technology, engineering, and mathematics (STEM) careers.

I see that the Argonne National Laboratory in the US has opened up its doors to high schoolers for a special programme. From the June 6, 2012 news item by Tona Kunz on Nanowerk,

In commencement speeches across the country, graduates have , been warned to expect rocky times breaking into the workforce. Unemployment hovers between 8 and 9 percent. Competition is tough.

Unless you studied science or engineering. Those jobs have a 2 percent unemployment rate, which has led some Fortune 500 companies to complain about offices they can’t fill.

So it’s no surprise that when the U.S. Department of Energy’s (DOE) Argonne National Laboratory decided to give high school students a chance to test-drive a science career, it found students, parents and school officials from Naperville, Ill. eager to hop on board.

Kunz’s June 6, 2012 news release on the Argonne National Laboratory website mentions (Note: I have removed links from the excerpt),

…  Teachers received training in the workings of the Advanced Photon Source (APS), the brightest high-energy X-ray machine in the Western Hemisphere, and the Electron Miscroscopy Center (EMC). Students from Naperville’s two high schools then competed for slots on four research teams that used X-ray beams to decipher what matter is made of, how it’s built and how it reacts.

…

More than 5,000 researchers from throughout the world use the APS and EMC annually to target society’s greatest challenges: how to make better pharmaceuticals, sustainable fuels and high-performance materials. These challenges will feed scientific jobs for decades to come.

“I think there is a huge push in our district from the community for STEM (science, technology, engineering and math) education,” said Tricia Noblett, a teacher and science club advisor at Neuqua Valley High School. “I think they are seizing on what has been out there in the media that STEM fields are where the jobs are and that science careers can be interesting.”

Students drew on experiences in their lives to choose research topics and explained their results to scientists at the annual meeting held in May at Argonne for users of the APS, EMC and Center for Nanoscale Materials (CNM).

…

Inspired by the recent cleanup of a contaminated portion of the west branch of the DuPage River near their school, one group of students studied how to increase the efficiency of water filtration systems.

Another group worked with the Naperville wastewater facility to evaluate how corrosion affects the lifespan of water pipes.

And another group looked at how to improve the efficiency of graphene, a nanomaterial that may hold the key to building faster semiconductors for smart phones and the next-generation of research tools.

It’s exciting stuff and I’m always glad to have a chance to pass on information about these kinds of programmes. As for the history, I find it interesting to note the similarities with and the differences from the past.

The quantum mechanics of photosynthesis

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Thankfully, Jared Sagoff included a description of photosynthesis (I’ve long since forgotten the mechanics of the process) in his May 21, 2012 article, Scientists uncover a photosynthetic puzzle, on the US Dept. of Energy’s Argonne National Laboratory website. From Sagoff’s article, here’s the photosynthesis  description along with a description of the quantum effect the scientists observed,

While different species of plants, algae and bacteria have evolved a variety of different mechanisms to harvest light energy, they all share a feature known as a photosynthetic reaction center. Pigments and proteins found in the reaction center help organisms perform the initial stage of energy conversion.

These pigment molecules, or chromophores, are responsible for absorbing the energy carried by incoming light. After a photon hits the cell, it excites one of the electrons inside the chromophore. As they observed the initial step of the process, Argonne scientists saw something no one had observed before: a single photon appeared to excite different chromophores simultaneously.

Here’s a gorgeous image of a leaf provided with the article,

I was aware that scientists are working at hard at duplicating photosynthesis but until reading this upcoming excerpt from Sagoff’s article, I had not appreciated the dimensions of the problem,

The result of the study could significantly influence efforts by chemists and nanoscientists to create artificial materials and devices that can imitate natural photosynthetic systems. Researchers still have a long way to go before they will be able to create devices that match the light harvesting efficiency of a plant.

One reason for this shortcoming, Tiede [Argonne biochemist David Tiede] explained, is that artificial photosynthesis experiments have not been able to replicate the molecular matrix that contains the chromophores. “The level that we are at with artificial photosynthesis is that we can make the pigments and stick them together, but we cannot duplicate any of the external environment,” he said.  “The next step is to build in this framework, and then these kinds of quantum effects may become more apparent.”

Because the moment when the quantum effect occurs is so short-lived – less than a trillionth of a second – scientists will have a hard time ascertaining biological and physical rationales for their existence in the first place. [emphasis mine] “It makes us wonder if they are really just there by accident, or if they are telling us something subtle and unique about these materials,” Tiede said. “Whatever the case, we’re getting at the fundamentals of the first step of energy conversion in photosynthesis.”

Thanks to Nanowerk for the May 24, 2012 news item which drew this article to my attention.

The smallness of the Higgs mass (finding the Higgs boson)

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As I noted last week (in my Dec. 6, 2011 posting), there was a big Dec. 13, 2011 announcement from CERN (European Laboratory for Particle Physics) about the Higgs boson. No, they haven’t found it but researchers believe they’ve discovered a hint of where it might be—this ‘hint’ has made international news.

For anyone who may have some questions about what exactly a Higgs boson is, here’s a video of “Fermilab scientist Don Lincoln [describing] the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass” (from the YouTube description),

Here’s a little more about why there’s so much excitement, from the Dec. 13, 2011 news item on Science Daily,

The Standard Model is the theory that physicists use to describe the behaviour of fundamental particles [the smallest discrete entities that make up matter and are not made up of smaller constituent bits of matter themselves] and the forces that act between them. It describes the ordinary matter from which we, and everything visible in the Universe, are made extremely well. Nevertheless, the Standard Model does not describe the 96% of the Universe that is invisible. One of the main goals of the LHC [Large Hadron Collider] research programme is to go beyond the Standard Model, and the Higgs boson could be the key.

A Standard Model Higgs boson would confirm a theory first put forward in the 1960s, but there are other possible forms the Higgs boson could take, linked to theories that go beyond the Standard Model. A Standard Model Higgs could still point the way to new physics, through subtleties in its behaviour that would only emerge after studying a large number of Higgs particle decays. A non-Standard Model Higgs, currently beyond the reach of the LHC experiments with data so far recorded, would immediately open the door to new physics, whereas the absence of a Standard Model Higgs would point strongly to new physics at the LHC’s full design energy, set to be achieved after 2014. Whether ATLAS [research group at CERN] and CMS [research group at CERN] show over the coming months that the Standard Model Higgs boson exists or not, the LHC programme is opening the way to new physics.

The search for the Higgs boson has been ongoing for some 40 or 50 years and this announcement points to a definitive answer as to its existence by late 2012.

Two groups at CERN have reported on the results of their search for the Higgs boson. From the Dec. 13, 2011 news item on physorg.com,

Two experiments at the Large Hadron Collider have nearly eliminated the space in which the Higgs boson could dwell, scientists announced in a seminar held at CERN today. However, the ATLAS and CMS experiments see modest excesses in their data that could soon uncover the famous missing piece of the physics puzzle.

The experiments revealed the latest results as part of their regular report to the CERN Council, which provides oversight for the laboratory near Geneva, Switzerland.

Theorists have predicted that some subatomic particles gain mass by interacting with other particles called Higgs bosons. The Higgs boson is the only undiscovered part of the Standard Model of physics, which describes the basic building blocks of matter and their interactions.

The experiments’ main conclusion is that the Standard Model Higgs boson, if it exists, is most likely to have a mass constrained to the range 116-130 GeV by the ATLAS experiment, and 115-127 GeV by CMS. Tantalising hints have been seen by both experiments in this mass region, but these are not yet strong enough to claim a discovery.

Scientists (Philip Schuster, Natalia Toro, and Andy Haas) at the Dec. 13, 2011 (9:30 am PST) Perimeter Institute webcast (What the Higgs is going on?), which took place a few hours after the CERN announcement, exhibited a lot of excitement liberally spiced with caution in regard to the announcement.  The webcast is available for viewing and if you’re wondering whether it’s suitable for you, here’s a description from the event webpage,

What is everything in the universe made of? What was the universe like billions of years ago?

These are eternal questions that humans have pondered throughout the ages. Today, we are on the verge of potentially making revolutionary breakthroughs in answering them.

The Large Hadron Collider (LHC) at CERN is a 27-kilometre long underground experiment located on the Swiss-French border near Geneva. It smashes subatomic particles together at vast speeds in an effort to learn more about the fundamental building blocks that make up everything around you. It is the biggest, most ambitious scientific experiment in human history.

On December 13, the LHC will announce its latest findings in its search for the last undiscovered particle in our current model of subatomic particles. This particle is the near-mythical ‘Higgs Boson’ — the particle thought to be involved in giving other particles their mass.

This educational event, geared towards high school students, teachers and the general public, will follow CERN’s announcement and discuss its findings and their background and implications in clear, accessible language.

You can view the webcast from here. The description of how scientists choose which events to measure and the process they use to define whether or not an event is significant adds to one’s appreciation of the work being done in these projects.

Jon Butterworth, a physicist who works at CERN and whose blog is one of the Guardian science blogs, wrote a limerick about it all in his Dec. 13, 2011 posting,

A physicist saw an enigma
And called to his mum “Flying pig, ma!”
She said “Flying pigs?
Next thing you’ll see the Higgs!”
He said “Nah, not until it’s five sigma!”

Five sigma is a measure of certainty. The current results have a 2.3 sigma, which is promising but the gold standard is five.

Here’s the live blog that Alok Jha, science correspondent for the Guardain, kept during the Dec. 13, 2011 announcement (excerpted from the live blog),

1.01pm: Cern’s live webcast has begun, but the seminar has yet to start. The expressions on some of the faces in the audience suggests Christmas is about to come early for the physics community.

1.02pm: Ok the seminar has started, but traffic to the webcast is obviously heavy, breaking up the transmission.

TRIUMF, Canada’s national laboratory for particle and nuclear physics, held a public seminar at 2:30 pm PST (Dec. 13, 2011) on their site at the University of British Columbia. They also have some information on their website about Canadian scientists who are involved in the CERN experiments ( from the Research Highlights page,  Physicists Smell but Don’t Yet Taste Higgs),

In a seminar held at CERN this morning and then repeated across Canada at multiple partnering institutions, the ATLAS and CMS experiments presented the status of their searches for the Standard Model Higgs boson. Finding this particle would snap in the last missing puzzle piece of the Standard Model that describes the universe at its most basic level. Tantalizing hints have been seen by both experiments in the same mass region, but these are not yet strong enough to claim a discovery. The main conclusion is that the Standard Model Higgs boson, if it exists, is most likely to have a mass in the range 115-130 GeV, excluding essentially all other hiding places.

“We are at a crossroads in our understanding of how energy gained mass and became matter in the early universe,” said Rob McPherson, spokesperson of the Canadian team working on the ATLAS project and a professor at the University of Victoria and a research scientist with the Institute of Particle Physics. “If these hints lead to a firm discovery over the coming year, we will be at the start of our investigation of the interactions that lie behind our current theories. If they are not confirmed, we will have to reject our present understanding, throw out our current theories, and start over. It is an extremely interesting time in particle physics.”

So there you have it. They think they observed something but they’re not sure, which makes for a very exciting time (they hope). While I’m not a scientist and cannot fully appreciate this moment, I can remember similar moments in my own work when something seems to be coming into focus. It isn’t my final result but it does hint at what is to come and gives me the resolve (giddy excitement for a few hours or days) I need to continue because a lot of what I do is slogging (I recognize the word play).

On a final note, it seems there was a minor crisis during the presentations in CERN. Lily Asquith, at the Argonne National Laboratory [Chicago, US] writes about it on Jon Butterworth’s blog (Guardian science blogs) in her Dec. 14, 2011 posting,

We have a large windowless meeting room at Argonne with an old-fashioned pull-down projector screen. When I walked in there yesterday morning for the CERN videolink I was greeted by 30-odd ashen-faced physicists. Oh lord, I thought, there has been a terrible accident. …

There stands Fabiola Gianotti [particle physicist in charge of the ATLAS experiment in CERN], our queen, looking fabulous and doing a typically faultless job of presenting a complicated and not-yet-conclusive measurement; taking the work of hundreds of nutty, stressed-out physicists and breathing sense into it.

But I hear only one thing as I walk the corridors of my lab and of the internet:

comic sans [the font Gianotti used for the text in her presentation]

– why‽

…

Do we need to add an additional systematic uncertainty to all our measurements based on this unwise choice of font? Are any of our results still valid? What does this mean for the speed of light?

Please do read the rest of Asquith’s very amusing piece. Who knew physicists are so concerned with fonts?

For the curious, here’s a sample of Comic Sans along with a history excerpt from its Wikipedia essay,

Microsoft designer Vincent Connare says that he began work on Comic Sans in October of 1994. Connare had already created a number of child-oriented fonts for various applications, so when he saw a beta version of Microsoft Bob that used Times New Roman in the word balloons of cartoon characters, he decided to create a new face based on the lettering style of comic books he had in his office, specifically The Dark Knight Returns (lettered by John Costanza) and Watchmen (lettered by Dave Gibbons).

So the font was originally designed for children and comic books, eh?