Tag Archives: DOE

Self-healing diamond-like carbon from the Argonne Lab (US)

Argonne researchers, from left, Subramanian Sankaranarayanan, Badri Narayanan, Ali Erdemir, Giovanni Ramirez and Osman Levent Eryilmaz show off metal engine parts that have been treated with a diamond-like carbon coating similar to one developed and explored by the team. The catalytic coating interacts with engine oil to create a self-healing diamond-like film that could have profound implications for the efficiency and durability of future engines. (photo by Wes Agresta)

Argonne researchers, from left, Subramanian Sankaranarayanan, Badri Narayanan, Ali Erdemir, Giovanni Ramirez and Osman Levent Eryilmaz show off metal engine parts that have been treated with a diamond-like carbon coating similar to one developed and explored by the team. The catalytic coating interacts with engine oil to create a self-healing diamond-like film that could have profound implications for the efficiency and durability of future engines. (photo by Wes Agresta)

An Aug. 5, 2016 news item on ScienceDaily makes the announcement,

Fans of Superman surely recall how the Man of Steel used immense heat and pressure generated by his bare hands to form a diamond out of a lump of coal.

The tribologists — scientists who study friction, wear, and lubrication — and computational materials scientists at the U.S. Department of Energy’s (DOE’s) Argonne National Laboratory will probably never be mistaken for superheroes. However, they recently applied the same principles and discovered a revolutionary diamond-like film of their own that is generated by the heat and pressure of an automotive engine.

An Aug. 5, 2016 Argonne National Laboratory news release (also on EurekAlert) by Greg Cunningham, which originated the news item, explains further,

The discovery of this ultra-durable, self-lubricating tribofilm – a film that forms between moving surfaces — was first reported yesterday in the journal Nature. It could have profound implications for the efficiency and durability of future engines and other moving metal parts that can be made to develop self-healing, diamond-like carbon (DLC) tribofilms.

“This is a very unique discovery, and one that was a little unexpected,” said Ali Erdemir, the Argonne Distinguished Fellow who leads the team. “We have developed many types of diamond-like carbon coatings of our own, but we’ve never found one that generates itself by breaking down the molecules of the lubricating oil and can actually regenerate the tribofilm as it is worn away.”

The phenomenon was first discovered several years ago by Erdemir and his colleague Osman Levent Eryilmaz in the Tribology and Thermal-Mechanics Department in Argonne’s Center for Transportation Research. But it took theoretical insight enhanced by the massive computing resources available at Argonne to fully understand what was happening at the molecular level in the experiments. The theoretical understanding was provided by lead theoretical researcher Subramanian Sankaranarayanan and postdoctoral researcher Badri Narayanan from the Center for Nanoscale Materials (CNM), while the computing power was provided by the Argonne Leadership Computing Facility (ALCF) and the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. CNM, ALCF and NERSC are all DOE Office of Science User Facilities.

The original discovery occurred when Erdemir and Eryilmaz decided to see what would happen when a small steel ring was coated with a catalytically active nanocoating – tiny molecules of metals that promote chemical reactions to break down other materials – then subjected to high pressure and heat using a base oil without the complex additives of modern lubricants. When they looked at the ring after the endurance test, they didn’t see the expected rust and surface damage, but an intact ring with an odd blackish deposit on the contact area.

“This test creates extreme contact pressure and temperatures, which are supposed to cause the ring to wear and eventually seize,” said Eryilmaz. “But this ring didn’t significantly wear and this blackish deposit was visible. We said, ‘This material is strange. Maybe this is what is causing this unusual effect.'”

Looking at the deposit using high-powered optical and laser Raman microscopes, the experimentalists realized the deposit was a tribofilm of diamond-like carbon, similar to several other DLCs developed at Argonne in the past. But it worked even better. Tests revealed the DLC tribofilm reduced friction by 25 to 40 percent and that wear was reduced to unmeasurable values.

Further experiments, led by postdoctoral researcher Giovanni Ramirez, revealed that multiple types of catalytic coatings can yield DLC tribofilms. The experiments showed the coatings interact with the oil molecules to create the DLC film, which adheres to the metal surfaces. When the tribofilm is worn away, the catalyst in the coating is re-exposed to the oil, causing the catalysis to restart and develop new layers of tribofilm. The process is self-regulating, keeping the film at consistent thickness. The scientists realized the film was developing spontaneously between the sliding surfaces and was replenishing itself, but they needed to understand why and how.

To provide the theoretical understanding of what the tribology team was seeing in its experiments, they turned to Sankaranarayanan and Narayanan, who used the immense computing power of ALCF’s 10-petaflop supercomputer, Mira. They ran large-scale simulations to understand what was happening at the atomic level, and determined that the catalyst metals in the nanocomposite coatings were stripping hydrogen atoms from the hydrocarbon chains of the lubricating oil, then breaking the chains down into smaller segments. The smaller chains joined together under pressure to create the highly durable DLC tribofilm.

“This is an example of catalysis under extreme conditions created by friction. It is opening up a new field where you are merging catalysis and tribology, which has never been done before,” said Sankaranarayanan. “This new field of tribocatalysis has the potential to change the way we look at lubrication.”

The theorists explored the origins of the catalytic activity to understand how catalysis operates under the extreme heat and pressure in an engine. By gaining this understanding, they were able to predict which catalysts would work, and which would create the most advantageous tribofilms.

“Interestingly, we found several metals or composites that we didn’t think would be catalytically active, but under these circumstances, they performed quite well,” said Narayanan. “This opens up new pathways for scientists to use extreme conditions to enhance catalytic activity.”

The implications of the new tribofilm for efficiency and reliability of engines are huge. Manufacturers already use many different types of coatings — some developed at Argonne — for metal parts in engines and other applications. The problem is those coatings are expensive and difficult to apply, and once they are in use, they only last until the coating wears through. The new catalyst allows the tribofilm to be continually renewed during operation.

Additionally, because the tribofilm develops in the presence of base oil, it could allow manufacturers to reduce, or possibly eliminate, some of the modern anti-friction and anti-wear additives in oil. These additives can decrease the efficiency of vehicle catalytic converters and can be harmful to the environment because of their heavy metal content.

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

Carbon-based tribofilms from lubricating oils by Ali Erdemir, Giovanni Ramirez, Osman L. Eryilmaz, Badri Narayanan, Yifeng Liao, Ganesh Kamath, & Subramanian K. R. S. Sankaranarayanan. Nature 536, 67–71 (04 August 2016) doi:10.1038/nature18948 Published online 03 August 2016

This paper is behind a paywall.

Pushing efficiency of perovskite-based solar cells to 31%

This atomic force microscopy image of the grainy surface of a perovskite solar cell reveals a new path to much greater efficiency. Individual grains are outlined in black, low-performing facets are red, and high-performing facets are green. A big jump in efficiency could possibly be obtained if the material can be grown so that more high-performing facets develop. (Credit: Berkeley Lab)

This atomic force microscopy image of the grainy surface of a perovskite solar cell reveals a new path to much greater efficiency. Individual grains are outlined in black, low-performing facets are red, and high-performing facets are green. A big jump in efficiency could possibly be obtained if the material can be grown so that more high-performing facets develop. (Credit: Berkeley Lab)

It’s always fascinating to observe a trend (or a craze) in science, an endeavour that outsiders (like me) tend to think of as impervious to such vagaries. Perovskite seems to be making its way past the trend/craze phase and moving into a more meaningful phase. From a July 4, 2016 news item on Nanowerk,

Scientists from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered a possible secret to dramatically boosting the efficiency of perovskite solar cells hidden in the nanoscale peaks and valleys of the crystalline material.

Solar cells made from compounds that have the crystal structure of the mineral perovskite have captured scientists’ imaginations. They’re inexpensive and easy to fabricate, like organic solar cells. Even more intriguing, the efficiency at which perovskite solar cells convert photons to electricity has increased more rapidly than any other material to date, starting at three percent in 2009 — when researchers first began exploring the material’s photovoltaic capabilities — to 22 percent today. This is in the ballpark of the efficiency of silicon solar cells.

Now, as reported online July 4, 2016 in the journal Nature Energy (“Facet-dependent photovoltaic efficiency variations in single grains of hybrid halide perovskite”), a team of scientists from the Molecular Foundry and the Joint Center for Artificial Photosynthesis, both at Berkeley Lab, found a surprising characteristic of a perovskite solar cell that could be exploited for even higher efficiencies, possibly up to 31 percent.

A July 4, 2016 Berkeley Lab news release (also on EurekAlert), which originated the news item, details the research,

Using photoconductive atomic force microscopy, the scientists mapped two properties on the active layer of the solar cell that relate to its photovoltaic efficiency. The maps revealed a bumpy surface composed of grains about 200 nanometers in length, and each grain has multi-angled facets like the faces of a gemstone.

Unexpectedly, the scientists discovered a huge difference in energy conversion efficiency between facets on individual grains. They found poorly performing facets adjacent to highly efficient facets, with some facets approaching the material’s theoretical energy conversion limit of 31 percent.

The scientists say these top-performing facets could hold the secret to highly efficient solar cells, although more research is needed.

“If the material can be synthesized so that only very efficient facets develop, then we could see a big jump in the efficiency of perovskite solar cells, possibly approaching 31 percent,” says Sibel Leblebici, a postdoctoral researcher at the Molecular Foundry.

Leblebici works in the lab of Alexander Weber-Bargioni, who is a corresponding author of the paper that describes this research. Ian Sharp, also a corresponding author, is a Berkeley Lab scientist at the Joint Center for Artificial Photosynthesis. Other Berkeley Lab scientists who contributed include Linn Leppert, Francesca Toma, and Jeff Neaton, the director of the Molecular Foundry.

A team effort

The research started when Leblebici was searching for a new project. “I thought perovskites are the most exciting thing in solar right now, and I really wanted to see how they work at the nanoscale, which has not been widely studied,” she says.

She didn’t have to go far to find the material. For the past two years, scientists at the nearby Joint Center for Artificial Photosynthesis have been making thin films of perovskite-based compounds, and studying their ability to convert sunlight and CO2 into useful chemicals such as fuel. Switching gears, they created pervoskite solar cells composed of methylammonium lead iodide. They also analyzed the cells’ performance at the macroscale.

The scientists also made a second set of half cells that didn’t have an electrode layer. They packed eight of these cells on a thin film measuring one square centimeter. These films were analyzed at the Molecular Foundry, where researchers mapped the cells’ surface topography at a resolution of ten nanometers. They also mapped two properties that relate to the cells’ photovoltaic efficiency: photocurrent generation and open circuit voltage.

This was performed using a state-of-the-art atomic force microscopy technique, developed in collaboration with Park Systems, which utilizes a conductive tip to scan the material’s surface. The method also eliminates friction between the tip and the sample. This is important because the material is so rough and soft that friction can damage the tip and sample, and cause artifacts in the photocurrent.

Surprise discovery could lead to better solar cells

The resulting maps revealed an order of magnitude difference in photocurrent generation, and a 0.6-volt difference in open circuit voltage, between facets on the same grain. In addition, facets with high photocurrent generation had high open circuit voltage, and facets with low photocurrent generation had low open circuit voltage.

“This was a big surprise. It shows, for the first time, that perovskite solar cells exhibit facet-dependent photovoltaic efficiency,” says Weber-Bargioni.

Adds Toma, “These results open the door to exploring new ways to control the development of the material’s facets to dramatically increase efficiency.”

In practice, the facets behave like billions of tiny solar cells, all connected in parallel. As the scientists discovered, some cells operate extremely well and others very poorly. In this scenario, the current flows towards the bad cells, lowering the overall performance of the material. But if the material can be optimized so that only highly efficient facets interface with the electrode, the losses incurred by the poor facets would be eliminated.

“This means, at the macroscale, the material could possibly approach its theoretical energy conversion limit of 31 percent,” says Sharp.

A theoretical model that describes the experimental results predicts these facets should also impact the emission of light when used as an LED. …

The Molecular Foundry is a DOE Office of Science User Facility located at Berkeley Lab. The Joint Center for Artificial Photosynthesis is a DOE Energy Innovation Hub led by the California Institute of Technology in partnership with Berkeley Lab.

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

Facet-dependent photovoltaic efficiency variations in single grains of hybrid halide perovskite by Sibel Y. Leblebici, Linn Leppert, Yanbo Li, Sebastian E. Reyes-Lillo, Sebastian Wickenburg, Ed Wong, Jiye Lee, Mauro Melli, Dominik Ziegler, Daniel K. Angell, D. Frank Ogletree, Paul D. Ashby, Francesca M. Toma, Jeffrey B. Neaton, Ian D. Sharp, & Alexander Weber-Bargioni. Nature Energy 1, Article number: 16093 (2016  doi:10.1038/nenergy.2016.93 Published online: 04 July 2016

This paper is behind a paywall.

Dexter Johnson’s July 6, 2016 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers] website} presents his take on the impact that this new finding may have,

The rise of the crystal perovskite as a potential replacement for silicon in photovoltaics has been impressive over the last decade, with its conversion efficiency improving from 3.8 to 22.1 percent over that time period. Nonetheless, there has been a vague sense that this rise is beginning to peter out of late, largely because when a solar cell made from perovskite gets larger than 1 square centimeter the best conversion efficiency had been around 15.6 percent. …

X-rays reveal memristor workings

A June 14, 2016 news item on ScienceDaily focuses on memristors. (It’s been about two months since my last memristor posting on April 22, 2016 regarding electronic synapses and neural networks). This piece announces new insight into how memristors function at the atomic scale,

In experiments at two Department of Energy national labs — SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory — scientists at Hewlett Packard Enterprise (HPE) [also referred to as HP Labs or Hewlett Packard Laboratories] have experimentally confirmed critical aspects of how a new type of microelectronic device, the memristor, works at an atomic scale.

This result is an important step in designing these solid-state devices for use in future computer memories that operate much faster, last longer and use less energy than today’s flash memory. …

“We need information like this to be able to design memristors that will succeed commercially,” said Suhas Kumar, an HPE scientist and first author on the group’s technical paper.

A June 13, 2016 SLAC news release, which originated the news item, offers a brief history according to HPE and provides details about the latest work,

The memristor was proposed theoretically [by Dr. Leon Chua] in 1971 as the fourth basic electrical device element alongside the resistor, capacitor and inductor. At its heart is a tiny piece of a transition metal oxide sandwiched between two electrodes. Applying a positive or negative voltage pulse dramatically increases or decreases the memristor’s electrical resistance. This behavior makes it suitable for use as a “non-volatile” computer memory that, like flash memory, can retain its state without being refreshed with additional power.

Over the past decade, an HPE group led by senior fellow R. Stanley Williams has explored memristor designs, materials and behavior in detail. Since 2009 they have used intense synchrotron X-rays to reveal the movements of atoms in memristors during switching. Despite advances in understanding the nature of this switching, critical details that would be important in designing commercially successful circuits  remained controversial. For example, the forces that move the atoms, resulting in dramatic resistance changes during switching, remain under debate.

In recent years, the group examined memristors made with oxides of titanium, tantalum and vanadium. Initial experiments revealed that switching in the tantalum oxide devices could be controlled most easily, so it was chosen for further exploration at two DOE Office of Science User Facilities – SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL) and Berkeley Lab’s Advanced Light Source (ALS).

At ALS, the HPE researchers mapped the positions of oxygen atoms before and after switching. For this, they used a scanning transmission X-ray microscope and an apparatus they built to precisely control the position of their sample and the timing and intensity of the 500-electronvolt ALS X-rays, which were tuned to see oxygen.

The experiments revealed that even weak voltage pulses create a thin conductive path through the memristor. During the pulse the path heats up, which creates a force that pushes oxygen atoms away from the path, making it even more conductive. Reversing the voltage pulse resets the memristor by sucking some of oxygen atoms back into the conducting path, thereby increasing the device’s resistance. The memristor’s resistance changes between 10-fold and 1 million-fold, depending on operating parameters like the voltage-pulse amplitude. This resistance change is dramatic enough to exploit commercially.

To be sure of their conclusion, the researchers also needed to understand if the tantalum atoms were moving along with the oxygen during switching. Imaging tantalum required higher-energy, 10,000-electronvolt X-rays, which they obtained at SSRL’s Beam Line 6-2. In a single session there, they determined that the tantalum remained stationary.

“That sealed the deal, convincing us that our hypothesis was correct,” said HPE scientist Catherine Graves, who had worked at SSRL as a Stanford graduate student. She added that discussions with SLAC experts were critical in guiding the HPE team toward the X-ray techniques that would allow them to see the tantalum accurately.

Kumar said the most promising aspect of the tantalum oxide results was that the scientists saw no degradation in switching over more than a billion voltage pulses of a magnitude suitable for commercial use. He added that this knowledge helped his group build memristors that lasted nearly a billion switching cycles, about a thousand-fold improvement.

“This is much longer endurance than is possible with today’s flash memory devices,” Kumar said. “In addition, we also used much higher voltage pulses to accelerate and observe memristor failures, which is also important in understanding how these devices work. Failures occurred when oxygen atoms were forced so far away that they did not return to their initial positions.”

Beyond memory chips, Kumar says memristors’ rapid switching speed and small size could make them suitable for use in logic circuits. Additional memristor characteristics may also be beneficial in the emerging class of brain-inspired neuromorphic computing circuits.

“Transistors are big and bulky compared to memristors,” he said. “Memristors are also much better suited for creating the neuron-like voltage spikes that characterize neuromorphic circuits.”

The researchers have provided an animation illustrating how memristors can fail,

This animation shows how millions of high-voltage switching cycles can cause memristors to fail. The high-voltage switching eventually creates regions that are permanently rich (blue pits) or deficient (red peaks) in oxygen and cannot be switched back. Switching at lower voltages that would be suitable for commercial devices did not show this performance degradation. These observations allowed the researchers to develop materials processing and operating conditions that improved the memristors’ endurance by nearly a thousand times. (Suhas Kumar) Courtesy: SLAC

This animation shows how millions of high-voltage switching cycles can cause memristors to fail. The high-voltage switching eventually creates regions that are permanently rich (blue pits) or deficient (red peaks) in oxygen and cannot be switched back. Switching at lower voltages that would be suitable for commercial devices did not show this performance degradation. These observations allowed the researchers to develop materials processing and operating conditions that improved the memristors’ endurance by nearly a thousand times. (Suhas Kumar) Courtesy: SLAC

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

Direct Observation of Localized Radial Oxygen Migration in Functioning Tantalum Oxide Memristors by Suhas Kumar, Catherine E. Graves, John Paul Strachan, Emmanuelle Merced Grafals, Arthur L. David Kilcoyne3, Tolek Tyliszczak, Johanna Nelson Weker, Yoshio Nishi, and R. Stanley Williams. Advanced Materials, First published: 2 February 2016; Print: Volume 28, Issue 14 April 13, 2016 Pages 2772–2776 DOI: 10.1002/adma.201505435

This paper is behind a paywall.

Some of the ‘memristor story’ is contested and you can find a brief overview of the discussion in this Wikipedia memristor entry in the section on ‘definition and criticism’. There is also a history of the memristor which dates back to the 19th century featured in my May 22, 2012 posting.

DNA as a framework for rationally designed nanostructures

After publishing a June 15, 2016 post about taking DNA (deoxyribonucleic acid) beyond genetics, it seemed like a good to publish a companion piece featuring a more technical explanation of at least one way DNA might provide the base for living computers and robots. From a June 13, 2016 BrookHaven National Laboratory news release (also on EurekAlert),

A cube, an octahedron, a prism–these are among the polyhedral structures, or frames, made of DNA that scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have designed to connect nanoparticles into a variety of precisely structured three-dimensional (3D) lattices. The scientists also developed a method to integrate nanoparticles and DNA frames into interconnecting modules, expanding the diversity of possible structures.

These achievements, described in papers published in Nature Materials and Nature Chemistry, could enable the rational design of nanomaterials with enhanced or combined optical, electric, and magnetic properties to achieve desired functions.

“We are aiming to create self-assembled nanostructures from blueprints,” said physicist Oleg Gang, who led this research at the Center for Functional Nanomaterials (CFN), a DOE Office of Science User Facility at Brookhaven. “The structure of our nanoparticle assemblies is mostly controlled by the shape and binding properties of precisely designed DNA frames, not by the nanoparticles themselves. By enabling us to engineer different lattices and architectures without having to manipulate the particles, our method opens up great opportunities for designing nanomaterials with properties that can be enhanced by precisely organizing functional components. For example, we could create targeted light-absorbing materials that harness solar energy, or magnetic materials that increase information-storage capacity.”

The news release goes on to describe the frames,

Gang’s team has previously exploited DNA’s complementary base pairing–the highly specific binding of bases known by the letters A, T, G, and C that make up the rungs of the DNA double-helix “ladder”–to bring particles together in a precise way. Particles coated with single strands of DNA link to particles coated with complementary strands (A binds with T and G binds with C) while repelling particles coated with non-complementary strands.

They have also designed 3D DNA frames whose corners have single-stranded DNA tethers to which nanoparticles coated with complementary strands can bind. When the scientists mix these nanoparticles and frames, the components self-assemble into lattices that are mainly defined by the shape of the designed frame. The Nature Materials paper describes the most recent structures achieved using this strategy.

“In our approach, we use DNA frames to promote the directional interactions between nanoparticles such that the particles connect into specific configurations that achieve the desired 3D arrays,” said Ye Tian, lead author on the Nature Materials paper and a member of Gang’s research team. “The geometry of each particle-linking frame is directly related to the lattice type, though the exact nature of this relationship is still being explored.”

So far, the team has designed five polyhedral frame shapes–a cube, an octahedron, an elongated square bipyramid, a prism, and a triangular bypyramid–but a variety of other shapes could be created.

“The idea is to construct different 3D structures (buildings) from the same nanoparticle (brick),” said Gang. “Usually, the particles need to be modified to produce the desired structures. Our approach significantly reduces the structure’s dependence on the nature of the particle, which can be gold, silver, iron, or any other inorganic material.”

Nanoparticles (yellow balls) capped with short single-stranded DNA (blue squiggly lines) are mixed with polyhedral DNA frames (from top to bottom): cube, octahedron, elongated square bipyramid, prism, and triangular bipyramid. The frames' vertices are encoded with complementary DNA strands for nanoparticle binding. When the corresponding frames and particles mix, they form a framework. Courtesy of Brookhaven National Laboratory

Nanoparticles (yellow balls) capped with short single-stranded DNA (blue squiggly lines) are mixed with polyhedral DNA frames (from top to bottom): cube, octahedron, elongated square bipyramid, prism, and triangular bipyramid. The frames’ vertices are encoded with complementary DNA strands for nanoparticle binding. When the corresponding frames and particles mix, they form a framework. Courtesy of Brookhaven National Laboratory

There’s also a discussion about how DNA origami was used to design the frames,

To design the frames, the team used DNA origami, a self-assembly technique in which short synthetic strands of DNA (staple strands) are mixed with a longer single strand of biologically derived DNA (scaffold strand). When the scientists heat and cool this mixture, the staple strands selectively bind with or “staple” the scaffold strand, causing the scaffold strand to repeatedly fold over onto itself. Computer software helps them determine the specific sequences for folding the DNA into desired shapes.

The folding of the single-stranded DNA scaffold introduces anchoring points that contain free “sticky” ends–unpaired strings of DNA bases–where nanoparticles coated with complementary single-strand tethers can attach. These sticky ends can be positioned anywhere on the DNA frame, but Gang’s team chose the corners so that multiple frames could be connected.

For each frame shape, the number of DNA strands linking a frame corner to an individual nanoparticle is equivalent to the number of edges converging at that corner. The cube and prism frames have three strands at each corner, for example. By making these corner tethers with varying numbers of bases, the scientists can tune the flexibility and length of the particle-frame linkages.

The interparticle distances are determined by the lengths of the frame edges, which are tens of nanometers in the frames designed to date, but the scientists say it should be possible to tailor the frames to achieve any desired dimensions.

The scientists verified the frame structures and nanoparticle arrangements through cryo-electron microscopy (a type of microscopy conducted at very low temperatures) at the CFN and Brookhaven’s Biology Department, and x-ray scattering at the National Synchrotron Light Source II (NSLS-II), a DOE Office of Science User Facility at Brookhaven.

The team started with a relatively simple form (from the news release),

In the Nature Chemistry paper, Gang’s team described how they used a similar DNA-based approach to create programmable two-dimensional (2D), square-like DNA frames around single nanoparticles.

DNA strands inside the frames provide coupling to complementary DNA on the nanoparticles, essentially holding the particle inside the frame. Each exterior side of the frame can be individually encoded with different DNA sequences. These outer DNA strands guide frame-frame recognition and connection.

Gang likens these DNA-framed nanoparticle modules to Legos whose interactions are programmed: “Each module can hold a different kind of nanoparticle and interlock to other modules in different but specific ways, fully determined by the complementary pairing of the DNA bases on the sides of the frame.”

In other words, the frames not only determine if the nanoparticles will connect but also how they will connect. Programming the frame sides with specific DNA sequences means only frames with complementary sequences can link up.

Mixing different types of modules together can yield a variety of structures, similar to the constructs that can be generated from Lego pieces. By creating a library of the modules, the scientists hope to be able to assemble structures on demand.

Finally, the discussion turns to the assembly of multifuctional nanomaterials (from the news release),

The selectivity of the connections enables different types and sizes of nanoparticles to be combined into single structures.

The geometry of the connections, or how the particles are oriented in space, is very important to designing structures with desired functions. For example, optically active nanoparticles can be arranged in a particular geometry to rotate, filter, absorb, and emit light–capabilities that are relevant for energy-harvesting applications, such as display screens and solar panels.

By using different modules from the “library,” Gang’s team demonstrated the self-assembly of one-dimensional linear arrays, “zigzag” chains, square-shaped and cross-shaped clusters, and 2D square lattices. The scientists even generated a simplistic nanoscale model of Leonardo da Vinci’s Vitruvian Man.

“We wanted to demonstrate that complex nanoparticle architectures can be self-assembled using our approach,” said Gang.

Again, the scientists used sophisticated imaging techniques–electron and atomic force microscopy at the CFN and x-ray scattering at NSLS-II–to verify that their structures were consistent with the prescribed designs and to study the assembly process in detail.

“Although many additional studies are required, our results show that we are making advances toward our goal of creating designed matter via self-assembly, including periodic particle arrays and complex nanoarchitectures with freeform shapes,” said Gang. “Our approach is exciting because it is a new platform for nanoscale manufacturing, one that can lead to a variety of rationally designed functional materials.”

Here’s an image illustrating among other things da Vinci’s Vitruvian Man,

A schematic diagram (left) showing how a nanoparticle (yellow ball) is incorporated within a square-like DNA frame. The DNA strands inside the frame (blue squiggly lines) are complementary to the DNA strands on the nanoparticle; the colored strands on the outer edges of the frame have different DNA sequences that determine how the DNA-framed nanoparticle modules can connect. The architecture shown (middle) is a simplistic nanoscale representation of Leonardo da Vinci's Vitruvian Man, assembled from several module types. The scientists used atomic force microscopy to generate the high-magnification image of this assembly (right). Courtesy Brookhaven National Laboratory

A schematic diagram (left) showing how a nanoparticle (yellow ball) is incorporated within a square-like DNA frame. The DNA strands inside the frame (blue squiggly lines) are complementary to the DNA strands on the nanoparticle; the colored strands on the outer edges of the frame have different DNA sequences that determine how the DNA-framed nanoparticle modules can connect. The architecture shown (middle) is a simplistic nanoscale representation of Leonardo da Vinci’s Vitruvian Man, assembled from several module types. The scientists used atomic force microscopy to generate the high-magnification image of this assembly (right). Courtesy Brookhaven National Laboratory

I enjoy the overviews provided by various writers and thinkers in the field but it’s details such as these that are often most compelling to me.

A treasure trove of molecule and battery data released to the public

Scientists working on The Materials Project have taken the notion of open science to their hearts and opened up access to their data according to a June 9, 2016 news item on Nanowerk,

The Materials Project, a Google-like database of material properties aimed at accelerating innovation, has released an enormous trove of data to the public, giving scientists working on fuel cells, photovoltaics, thermoelectrics, and a host of other advanced materials a powerful tool to explore new research avenues. But it has become a particularly important resource for researchers working on batteries. Co-founded and directed by Lawrence Berkeley National Laboratory (Berkeley Lab) scientist Kristin Persson, the Materials Project uses supercomputers to calculate the properties of materials based on first-principles quantum-mechanical frameworks. It was launched in 2011 by the U.S. Department of Energy’s (DOE) Office of Science.

A June 8, 2016 Berkeley Lab news release, which originated the news item, provides more explanation about The Materials Project,

The idea behind the Materials Project is that it can save researchers time by predicting material properties without needing to synthesize the materials first in the lab. It can also suggest new candidate materials that experimentalists had not previously dreamed up. With a user-friendly web interface, users can look up the calculated properties, such as voltage, capacity, band gap, and density, for tens of thousands of materials.

Two sets of data were released last month: nearly 1,500 compounds investigated for multivalent intercalation electrodes and more than 21,000 organic molecules relevant for liquid electrolytes as well as a host of other research applications. Batteries with multivalent cathodes (which have multiple electrons per mobile ion available for charge transfer) are promising candidates for reducing cost and achieving higher energy density than that available with current lithium-ion technology.

The sheer volume and scope of the data is unprecedented, said Persson, who is also a professor in UC Berkeley’s Department of Materials Science and Engineering. “As far as the multivalent cathodes, there’s nothing similar in the world that exists,” she said. “To give you an idea, experimentalists are usually able to focus on one of these materials at a time. Using calculations, we’ve added data on 1,500 different compositions.”

While other research groups have made their data publicly available, what makes the Materials Project so useful are the online tools to search all that data. The recent release includes two new web apps—the Molecules Explorer and the Redox Flow Battery Dashboard—plus an add-on to the Battery Explorer web app enabling researchers to work with other ions in addition to lithium.

“Not only do we give the data freely, we also give algorithms and software to interpret or search over the data,” Persson said.

The Redox Flow Battery app gives scientific parameters as well as techno-economic ones, so battery designers can quickly rule out a molecule that might work well but be prohibitively expensive. The Molecules Explorer app will be useful to researchers far beyond the battery community.

“For multivalent batteries it’s so hard to get good experimental data,” Persson said. “The calculations provide rich and robust benchmarks to assess whether the experiments are actually measuring a valid intercalation process or a side reaction, which is particularly difficult for multivalent energy technology because there are so many problems with testing these batteries.”

Here’s a screen capture from the Battery Explorer app,

The Materials Project’s Battery Explorer app now allows researchers to work with other ions in addition to lithium.

The Materials Project’s Battery Explorer app now allows researchers to work with other ions in addition to lithium. Courtesy: The Materials Project

The news release goes on to describe a new discovery made possible by The Materials Project (Note: A link has been removed),

Together with Persson, Berkeley Lab scientist Gerbrand Ceder, postdoctoral associate Miao Liu, and MIT graduate student Ziqin Rong, the Materials Project team investigated some of the more promising materials in detail for high multivalent ion mobility, which is the most difficult property to achieve in these cathodes. This led the team to materials known as thiospinels. One of these thiospinels has double the capacity of the currently known multivalent cathodes and was recently synthesized and tested in the lab by JCESR researcher Linda Nazar of the University of Waterloo, Canada.

“These materials may not work well the first time you make them,” Persson said. “You have to be persistent; for example you may have to make the material very phase pure or smaller than a particular particle size and you have to test them under very controlled conditions. There are people who have actually tried this material before and discarded it because they thought it didn’t work particularly well. The power of the computations and the design metrics we have uncovered with their help is that it gives us the confidence to keep trying.”

The researchers were able to double the energy capacity of what had previously been achieved for this kind of multivalent battery. The study has been published in the journal Energy & Environmental Science in an article titled, “A High Capacity Thiospinel Cathode for Mg Batteries.”

“The new multivalent battery works really well,” Persson said. “It’s a significant advance and an excellent proof-of-concept for computational predictions as a valuable new tool for battery research.”

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

A high capacity thiospinel cathode for Mg batteries by Xiaoqi Sun, Patrick Bonnick, Victor Duffort, Miao Liu, Ziqin Rong, Kristin A. Persson, Gerbrand Ceder and  Linda F. Nazar. Energy Environ. Sci., 2016, Advance Article DOI: 10.1039/C6EE00724D First published online 24 May 2016

This paper seems to be behind a paywall.

Getting back to the news release, there’s more about The Materials Project in relationship to its membership,

The Materials Project has attracted more than 20,000 users since launching five years ago. Every day about 20 new users register and 300 to 400 people log in to do research.

One of those users is Dane Morgan, a professor of engineering at the University of Wisconsin-Madison who develops new materials for a wide range of applications, including highly active catalysts for fuel cells, stable low-work function electron emitter cathodes for high-powered microwave devices, and efficient, inexpensive, and environmentally safe solar materials.

“The Materials Project has enabled some of the most exciting research in my group,” said Morgan, who also serves on the Materials Project’s advisory board. “By providing easy access to a huge database, as well as tools to process that data for thermodynamic predictions, the Materials Project has enabled my group to rapidly take on materials design projects that would have been prohibitive just a few years ago.”

More materials are being calculated and added to the database every day. In two years, Persson expects another trove of data to be released to the public.

“This is the way to reach a significant part of the research community, to reach students while they’re still learning material science,” she said. “It’s a teaching tool. It’s a science tool. It’s unprecedented.”

Supercomputing clusters at the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility hosted at Berkeley Lab, provide the infrastructure for the Materials Project.

Funding for the Materials Project is provided by the Office of Science (US Department of Energy], including support through JCESR [Joint Center for Energy Storage Research].

Happy researching!

A new state for water molecules

ORNL researchers discovered that water in beryl displays some unique and unexpected characteristics. (Photo by Jeff Scovil)

ORNL researchers discovered that water in beryl displays some unique and unexpected characteristics. (Photo by Jeff Scovil)

That striking image from the Oak Ridge National Laboratory (ORNL; US) depicting a new state for water molecules looks like mixed media: photography and drawing/illustration. Thankfully, an April 22, 2016 news item on ScienceDaily provides a text description,

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy’s Oak Ridge National Laboratory [ORNL] describe a new tunneling state of water molecules confined in hexagonal ultra-small channels — 5 angstrom across — of the mineral beryl. An angstrom is 1/10-billionth of a meter, and individual atoms are typically about 1 angstrom in diameter.

The discovery, made possible with experiments at ORNL’s Spallation Neutron Source and the Rutherford Appleton Laboratory in the United Kingdom, demonstrates features of water under ultra confinement in rocks, soil and cell walls, which scientists predict will be of interest across many disciplines.

An April 22, 2016 ORNL news release (also on EurekAlert), which originated the news item, offers more detail,

“At low temperatures, this tunneling water exhibits quantum motion through the separating potential walls, which is forbidden in the classical world,” said lead author Alexander Kolesnikov of ORNL’s Chemical and Engineering Materials Division. “This means that the oxygen and hydrogen atoms of the water molecule are ‘delocalized’ and therefore simultaneously present in all six symmetrically equivalent positions in the channel at the same time. It’s one of those phenomena that only occur in quantum mechanics and has no parallel in our everyday experience.”

The existence of the tunneling state of water shown in ORNL’s study should help scientists better describe the thermodynamic properties and behavior of water in highly confined environments such as water diffusion and transport in the channels of cell membranes, in carbon nanotubes and along grain boundaries and at mineral interfaces in a host of geological environments.

ORNL co-author Lawrence Anovitz noted that the discovery is apt to spark discussions among materials, biological, geological and computational scientists as they attempt to explain the mechanism behind this phenomenon and understand how it applies to their materials.

“This discovery represents a new fundamental understanding of the behavior of water and the way water utilizes energy,” Anovitz said. “It’s also interesting to think that those water molecules in your aquamarine or emerald ring – blue and green varieties of beryl – are undergoing the same quantum tunneling we’ve seen in our experiments.”

While previous studies have observed tunneling of atomic hydrogen in other systems, the ORNL discovery that water exhibits such tunneling behavior is unprecedented. The neutron scattering and computational chemistry experiments showed that, in the tunneling state, the water molecules are delocalized around a ring so the water molecule assumes an unusual double top-like shape.

“The average kinetic energy of the water protons directly obtained from the neutron experiment is a measure of their motion at almost absolute zero temperature and is about 30 percent less than it is in bulk liquid or solid water,” Kolesnikov said. “This is in complete disagreement with accepted models based on the energies of its vibrational modes.”

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

Quantum Tunneling of Water in Beryl: A New State of the Water Molecule by Alexander I. Kolesnikov, George F. Reiter, Narayani Choudhury, Timothy R. Prisk, Eugene Mamontov, Andrey Podlesnyak, George Ehlers, Andrew G. Seel, David J. Wesolowski, and Lawrence M. Anovitz.
Phys. Rev. Lett. 116, 167802 – Published 22 April 2016

This paper is behind a paywall.

Doped carbon nanotubes and a new path to quantum encryption

An April 12, 2016 news item on ScienceDaily describes a use for  carbon nanotubes in the field of quantum encryption,

Critical information, ranging from credit card numbers to national security data, is sent in streams of light, or laser pulses. However, the data transmitted in this manner can be stolen by splitting out a few photons (packets of light) from the laser pulse. Such eavesdropping could be prevented by encoding the data into single photons. But that requires generating single photons. Researchers demonstrated a new material, made from tiny carbon tubes, that emits the desired photons at room temperature.

A March 31, 2016 US Department of Energy news release, which originated the news item, explains the concept in more detail,

Digital eavesdropping could be prevented by encoding bits of information in the properties, or quantum mechanical states, of single photons. Single photons emitted by carbon nanotubes altered, or doped with oxygen, are especially attractive for realizing this quantum information technology.

Summary

Single photon generation requires an isolated, quantum mechanical, two-level system that can emit only one photon in one excitation-emission cycle. While artificial nanoscale materials (such as quantum dots and vacancy centers in diamonds) have been explored for single photon generation, none have emerged as the ideal candidate that meets all of the technological requirements. These requirements include the ability to generate single photons in the 1.3 to 1.5 µm fiber optic telecommunication wavelength range at room temperature. Earlier studies revealed that carbon nanotubes were not suited for use in quantum communications because the tubes required extremely low temperatures and had strong photoluminescence fluctuations. In contrast to these earlier findings, researchers led by Han Htoon and Stephen Doorn of the Center for Integrated Nanotechnologies showed that oxygen doping of carbon nanotubes can lead to fluctuation-free photoluminescence emission in the telecommunication wavelength range. Experiments measuring the time-distribution of two successive photon emission events also unambiguously demonstrated single photon emission at room temperature. Furthermore, because oxygen doping is achieved through a simple deposition of a silicon dioxide layer, these doped carbon nanotubes are fully compatible with silicon microfabrication technology and can be fabricated into electrically driven single photon sources. In addition, the silicon dioxide layer encapsulating the nanotubes allows for their easy integration into electronic and photonic integrated circuits. Beyond the implementation of this new method into quantum communication technologies, nanotube-based single photon sources could enable other transformative quantum technologies, including ultra-sensitive absorption measurements, sub-diffraction imaging, and linear quantum computing.

The researchers have provided an illustration of doped carbon nanotubes,

The deposition of a silicon dioxide layer (yellow layer) on a carbon nanotube (gray spheres) introduces solitary oxygen dopants (red spheres). A single photon (red and white star) is emitted when a dopant is excited by a laser pulse (green arrow). Image courtesy of the Center for Integrated Nanotechnologies

The deposition of a silicon dioxide layer (yellow layer) on a carbon nanotube (gray spheres) introduces solitary oxygen dopants (red spheres). A single photon (red and white star) is emitted when a dopant is excited by a laser pulse (green arrow). Image courtesy of the Center for Integrated Nanotechnologies

Here’s a link to and a citation for the paper, which was published a surprisingly long time ago,

Room-temperature single-photon generation from solitary dopants of carbon nanotubes by Xuedan Ma, Nicolai F. Hartmann, Jon K. S. Baldwin, Stephen K. Doorn, & Han Htoon.  Nature Nanotechnology 10, 671–675 (2015)  doi:10.1038/nnano.2015.136 Published online 13 July 2015

This paper is behind a paywall.

Carbon nanotubes transport protons faster than bulk water

An April 4, 2016 news item on Science Daily focuses on carbon nanotubes that measure eight-tenths of a nanometre and transport protons more quickly than bulk water by an order of magnitude,

For the first time, Lawrence Livermore National Laboratory (LLNL) researchers have shown that carbon nanotubes as small as eight-tenths of a nanometer in diameter can transport protons faster than bulk water, by an order of magnitude.

The research validates a 200-year old mechanism of proton transport.

A US Department of Energy Lawrence Livermore National Laboratory (LLNL) news release on EurekAlert, which originated the news item, provides more explanation,

The transport rates in these nanotube pores, which form one-dimensional water wires, also exceed those of biological channels and man-made proton conductors, making carbon nanotubes the fastest known proton conductor. …

Practical applications include proton exchange membranes, proton-based signaling in biological systems and the emerging field of proton bioelectronics (protonics).

“The cool thing about our results is that we found that when you squeeze water into the nanotube, protons move through that water even faster than through normal (bulk) water,” said Aleksandr Noy, an LLNL biophysicist and a lead author of the paper. (Bulk water is similar to what you would find in a cup of water that is much bigger than the size of a single water molecule).

The idea that protons travel fast in solutions by hopping along chains of hydrogen-bonded water molecules dates back 200 years to the work of Theodore von Grotthuss and still remains the foundation of the scientific understanding of proton transport. In the new research, LLNL researchers used carbon nanotube pores to line up water molecules into perfect one-dimensional chains and showed that they allow proton transport rates to approach the ultimate limits for the Grotthuss transport mechanism.

“The possibility to achieve fast proton transport by changing the degree of water confinement is exciting,” Noy said. “So far, the man-made proton conductors, such as polymer Nafion, use a different principle to enhance the proton transport. We have mimicked the way biological systems enhance the proton transport, took it to the extreme, and now our system realizes the ultimate limit of proton conductivity in a nanopore.”

Of all man-made materials, the narrow hydrophobic inner pores of carbon nanotubes (CNT) hold the most promise to deliver the level of confinement and weak interactions with water molecules that facilitate the formation of one-dimensional hydrogen-bonded water chains that enhance proton transport.

Earlier molecular dynamic simulations showed that water in 0.8 nm diameter carbon nanotubes would create such water wires and predicted that these channels would exhibit proton transport rates that would be much faster than those of bulk water. Ramya Tunuguntla, an LLNL postdoctoral researcher and the first author on the paper, said that despite significant efforts in carbon nanotube transport studies, these predictions proved to be hard to validate, mainly because of the difficulties in creating sub-1-nm diameter CNT pores.

However, the Lawrence Livermore team along with colleagues from the Lawrence Berkeley National Lab and UC Berkeley was able to create a simple and versatile experimental system for studying transport in ultra-narrow CNT pores. They used carbon nanotube porins (CNTPs), a technology they developed earlier at LLNL, which uses carbon nanotubes embedded in the lipid membrane to mimic biological ion channel functionality. The key breakthrough was the creation of nanotube porins with a diameter of less than 1 nm, which allowed researchers for the first time to achieve true one-dimensional water confinement.

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

Ultrafast proton transport in sub-1-nm diameter carbon nanotube porins by Ramya H. Tunuguntla, Frances I. Allen, Kyunghoon Kim, Allison Belliveau, & Aleksandr Noy. Nature Nanotechnology (2016) doi:10.1038/nnano.2016.43 Published online 04 April 2016

This paper is behind a paywall.

Nature-inspired nanotubes from the Lawrence Berkeley National* Laboratory

A March 29, 2016 news item on Nanotechnology Now  announces a new technique for nature-inspired self-assembling polymer nanotubes,

When it comes to the various nanowidgets scientists are developing, nanotubes are especially intriguing. That’s because hollow tubes that have diameters of only a few billionths of a meter have the potential to be incredibly useful, from delivering cancer-fighting drugs inside cells to desalinating seawater.

But building nanostructures is difficult. And creating a large quantity of nanostructures with the same trait, such as millions of nanotubes with identical diameters, is even more difficult. This kind of precision manufacturing is needed to create the nanotechnologies of tomorrow.

Help could be on the way. As reported online the week of March 28 [2016] in the journal Proceedings of the National Academy of Sciences [PNAS], researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have discovered a family of nature-inspired polymers that, when placed in water, spontaneously assemble into hollow crystalline nanotubes. What’s more, the nanotubes can be tuned to all have the same diameter of between five and ten nanometers, depending on the length of the polymer chain.

A March 28, 2016 Berkeley Lab news release (also on EurekAlert), which originated the news item, provides more detail,

The polymers have two chemically distinct blocks that are the same size and shape. The scientists learned these blocks act like molecular tiles that form rings, which stack together to form nanotubes up to 100 nanometers long, all with the same diameter.

“This points to a new way we can use synthetic polymers to create complex nanostructures in a very precise way,” says Ron Zuckermann, who directs the Biological Nanostructures Facility in Berkeley Lab’s Molecular Foundry, where much of this research was conducted.

Several other Berkeley Lab scientists contributed to this research, including Nitash Balsara of the Materials Sciences Division and Ken Downing of the Molecular Biophysics and Integrated Bioimaging Division.

“Creating uniform structures in high yield is a goal in nanotechnology,” adds Zuckermann. “For example, if you can control the diameter of nanotubes, and the chemical groups exposed in their interior, then you can control what goes through—which could lead to new filtration and desalination technologies, to name a few examples.”

The research is the latest in the effort to build nanostructures that approach the complexity and function of nature’s proteins, but are made of durable materials. In this work, the Berkeley Lab scientists studied a polymer that is a member of the peptoid family. Peptoids are rugged synthetic polymers that mimic peptides, which nature uses to form proteins. They can be tuned at the atomic scale to carry out specific functions.

For the past several years, the scientists have studied a particular type of peptoid, called a diblock copolypeptoid, because it binds with lithium ions and could be used as a battery electrolyte. Along the way, they serendipitously found the compounds form nanotubes in water. How exactly these nanotubes form has yet to be determined, but this latest research sheds light on their structure, and hints at a new design principle that could be used to build nanotubes and other complex nanostructures.

Diblock copolypeptoids are composed of two peptoid blocks, one that’s hydrophobic one that’s hydrophilic. The scientists discovered both blocks crystallize when they meet in water, and form rings consisting of two to three individual peptoids. The rings then form hollow nanotubes.

Cryo-electron microscopy imaging of 50 of the nanotubes showed the diameter of each tube is highly uniform along its length, as well as from tube to tube. This analysis also revealed a striped pattern across the width of the nanotubes, which indicates the rings stack together to form tubes, and rules out other packing arrangements. In addition, the peptoids are thought to arrange themselves in a brick-like pattern, with hydrophobic blocks lining up with other hydrophobic blocks, and the same for hydrophilic blocks.

“Images of the tubes captured by electron microscopy were essential for establishing the presence of this unusual structure,” says Balsara. “The formation of tubular structures with a hydrophobic core is common for synthetic polymers dispersed in water, so we were quite surprised to see the formation of hollow tubes without a hydrophobic core.”

X-ray scattering analyses conducted at beamline 7.3.3 of the Advanced Light Source revealed even more about the nanotubes’ structure. For example, it showed that one of the peptoid blocks, which is usually amorphous, is actually crystalline.

Remarkably, the nanotubes assemble themselves without the usual nano-construction aids, such as electrostatic interactions or hydrogen bond networks.

“You wouldn’t expect something as intricate as this could be created without these crutches,” says Zuckermann. “But it turns out the chemical interactions that hold the nanotubes together are very simple. What’s special here is that the two peptoid blocks are chemically distinct, yet almost exactly the same size, which allows the chains to pack together in a very regular way. These insights could help us design useful nanotubes and other structures that are rugged and tunable—and which have uniform structures.”

This cryo-electron microscopy image shows the self-assembling nanotubes have the same diameter. The circles are head-on views of nanotubes. The dark-striped features likely result from crystallized peptoid blocks. (Credit: Berkeley Lab)

This cryo-electron microscopy image shows the self-assembling nanotubes have the same diameter. The circles are head-on views of nanotubes. The dark-striped features likely result from crystallized peptoid blocks. (Credit: Berkeley Lab)

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

Self-assembly of crystalline nanotubes from monodisperse amphiphilic diblock copolypeptoid tiles by Jing Sun, Xi Jiang, Reidar Lund, Kenneth H. Downing, Nitash P. Balsara, and Ronald N. Zuckermann. PNAS 2016 ; published ahead of print March 28, 2016, doi: 10.1073/pnas.1517169113

This paper is behind a paywall.

*’Lawrence Berkeley Laboratory’ changed to ‘Lawrence Berkeley National Laboratory’ on April 3, 2016.

US Nanotechnology Initiative for water sustainability

Wednesday, March 23, 2016 was World Water Day and to coincide with that event the US National Nanotechnology Initiative (NNI) in collaboration with several other agencies announced a new ‘signature initiative’. From a March 24, 2016 news item on Nanowerk (Note: A link has been removed),

As a part of the White House Water Summit held yesterday on World Water Day, the Federal agencies participating in the National Nanotechnology Initiative (NNI) announced the launch of a Nanotechnology Signature Initiative (NSI), Water Sustainability through Nanotechnology: Nanoscale Solutions for a Global-Scale Challenge.

A March 23, 2016 NNI news release provides more information about why this initiative is important,

Access to clean water remains one of the world’s most pressing needs. As today’s White House Office of Science and Technology blog post explains, “the small size and exceptional properties of engineered nanomaterials are particularly promising for addressing the key technical challenges related to water quality and quantity.”

“One cannot find an issue more critical to human life and global security than clean, plentiful, and reliable water sources,” said Dr. Michael Meador, Director of the National Nanotechnology Coordination Office (NNCO). “Through the NSI mechanism, NNI member agencies will have an even greater ability to make meaningful strides toward this initiative’s thrust areas: increasing water availability, improving the efficiency of water delivery and use, and enabling next-generation water monitoring systems.”

A March 23, 2016 US White House blog posting by Lloyd Whitman and Lisa Friedersdorf describes the efforts in more detail (Note: A link has been removed),

The small size and exceptional properties of engineered nanomaterials are particularly promising for addressing the pressing technical challenges related to water quality and quantity. For example, the increased surface area—a cubic centimeter of nanoparticles has a surface area larger than a football field—and reactivity of nanometer-scale particles can be exploited to create catalysts for water purification that do not require rare or precious metals. And composites incorporating nanomaterials such as carbon nanotubes might one day enable stronger, lighter, and more durable piping systems and components. Under this NSI, Federal agencies will coordinate and collaborate to more rapidly develop nanotechnology-enabled solutions in three main thrusts: [thrust 1] increasing water availability; [thrust 2] improving the efficiency of water delivery and use; and [thrust 3] enabling next-generation water monitoring systems.

A technical “white paper” released by the agencies this week highlights key technical challenges for each thrust, identifies key objectives to overcome those challenges, and notes areas of research and development where nanotechnology promises to provide the needed solutions. By shining a spotlight on these areas, the new NSI will increase Federal coordination and collaboration, including with public and private stakeholders, which is vital to making progress in these areas. The additional focus and associated collective efforts will advance stewardship of water resources to support the essential food, energy, security, and environment needs of all stakeholders.

We applaud the commitment of the Federal agencies who will participate in this effort—the Department of Commerce/National Institute of Standards and Technology, Department of Energy, Environmental Protection Agency, National Aeronautics and Space Administration, National Science Foundation, and U.S. Department of Agriculture/National Institute of Food and Agriculture. As made clear at this week’s White House Water Summit, the world’s water systems are under tremendous stress, and new and emerging technologies will play a critical role in ensuring a sustainable water future.

The white paper (12 pp.) is titled: Water Sustainability through Nanotechnology: Nanoscale Solutions for a Global-Scale Challenge and describes the thrusts in more detail.

A March 22, 2016 US White House fact sheet lays out more details including funding,

Click here to learn more about all of the commitments and announcements being made today. They include:

  • Nearly $4 billion in private capital committed to investment in a broad range of water-infrastructure projects nationwide. This includes $1.5 billion from Ultra Capital to finance decentralized and scalable water-management solutions, and $500 million from Sustainable Water to develop water reclamation and reuse systems.
  • More than $1 billion from the private sector over the next decade to conduct research and development into new technologies. This includes $500 million from GE to fuel innovation, expertise, and global capabilities in advanced water, wastewater, and reuse technologies.
  • A Presidential Memorandum and supporting Action Plan on building national capabilities for long-term drought resilience in the United States, including by setting drought resilience policy goals, directing specific drought resilience activities to be completed by the end of the year, and permanently establishing the National Drought Resilience Partnership as an interagency task force responsible for coordinating drought-resilience, response, and recovery efforts.
  • Nearly $35 million this year in Federal grants from the Environmental Protection Agency, the National Oceanic and Atmospheric Administration, the National Science Foundation, and the U.S. Department of Agriculture to support cutting-edge water science;
  • The release of a new National Water Model that will dramatically enhance the Nation’s river-forecasting capabilities by delivering forecasts for approximately 2.7 million locations, up from 4,000 locations today (a 700-fold increase in forecast density).

This seems promising and hopefully other countries will follow suit.