“Programmable Matter” using Nanocrystals


When University of Pennsylvania nano-scientists created beautiful, tiled patterns with flat nano-crystals, they were left with a mystery: why did some sets of crystals arrange themselves in an alternating, herringbone style, even though it wasn’t the simplest pattern? To find out, they turned to experts in computer simulation at the University of Michigan and the Massachusetts Institute of Technology.

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These transmission electron microscope images show the two different patterns the nano-crystals could be made to pack in. 

The result gives nanotechnology researchers a new tool for controlling how objects one-millionth the size of a grain of sand arrange themselves into useful materials, it gives a means to discover the rules for “programming” them into desired configurations.

The study was led by Christopher Murray, a professor with appointments in the Department of Chemistry in the School of Arts and Sciences and the Department of Materials Science and Engineering in the School of Engineering and Applied Sciences. Also on the Penn team were Cherie Kagan, a chemistry, MSE and electrical and systems engineering professor, and postdoctoral researchers Xingchen Ye, Jun Chen and Guozhong Xing. 

They collaborated with Sharon Glotzer, a professor of chemical engineering at Michigan, and Ju Li, a professor of nuclear science and engineering at MIT.

Their research was featured on the cover of the journal Nature Chemistry.

“The excitement in this is not in the herringbone pattern,” Murray said, “It’s about the coupling of experiment and modeling and how that approach lets us take on a very hard problem.”

Previous work in Murray’s group has been focused on creating and arranging them into larger crystal . Ultimately, researchers want to modify patches on in different ways to coax them into more complex patterns. The goal is developing “programming matter,” that is, a method for designing based on the properties needed for a particular job.

“By engineering interactions at the nanoscale,” Glotzer said, “we can begin to assemble target structures of great complexity and functionality on the macroscale.”

Glotzer introduced the concept of nanoparticle “patchiness” in 2004. Her group uses computer simulations to understand and design the patches.

Recently, Murray’s team made patterns with flat nanocrystals made of heavy metals, known to chemists as lanthanides, and fluorine atoms. Lanthanides have valuable properties for solar energy and medical imaging, such as the ability to convert between high- and low-energy light.

They started by breaking down chemicals containing atoms of a lanthanide metal and fluorine in a solution, and the lanthanide and fluorine naturally began to form crystals. Also in the mix were chains of carbon and hydrogen that stuck to the sides of the crystals, stopping their growth at sizes around 100 nanometers, or 100 millionths of a millimeter, at the largest dimensions. By using lanthanides with different atomic radii, they could control the top and bottom faces of the hexagonal crystals to be anywhere from much longer than the other four sides to non-existent, resulting in a diamond shape.

To form tiled patterns, the team purified the nano-crystals and mixed them with a solvent. They spread this mixture in a thin layer over a thick fluid, which supported the crystals while allowing them to move. As the solvent evaporated, the crystals had less space available, and they began to pack together.

The diamond shapes and the very long hexagons lined up as expected, the diamonds forming an argyle-style grid and the hexagons matching up their longest edges like a foreshortened honeycomb. The hexagons whose sides were all nearly the same length should have formed a similar squashed honeycomb pattern, but, instead, they lined up in an alternating herringbone style.

“Whenever we see something that isn’t taking the simplest pattern possible, we have to ask why,” Murray said.

They posed the question to Glotzer’s team.

“They’ve been world leaders in understanding how these shapes could work on nanometer scales, and there aren’t many groups that can make the crystals we make,” Murray said. “It seemed natural to bring these strengths together.”

Glotzer and her group built a computer model that could recreate the self-assembly of the same range of shapes that Murray had produced. The simulations showed that if the equilateral hexagons interacted with one another only through their shapes, most of the crystals formed the foreshortened honeycomb pattern, not the herringbone.

“That’s when we said, ‘Okay, there must be something else going on. It’s not just a packing problem,'” Glotzer said. Her team, which included graduate student Andres Millan and research scientist Michael Engel, then began playing with interactions between the edges of the particles. They found that that if the edges that formed the points were stickier than the other two sides, the hexagons would naturally arrange in the herringbone pattern.

The teams suspected that the source of the stickiness was those carbon and hydrogen chains. Perhaps they attached to the point edges more easily, the team members thought. Since experiment doesn’t yet offer a way to measure the number of hydrocarbon chains on the sides of such tiny particles, Murray asked MIT’s Ju Li to calculate how the chains would attach to the edges at a quantum mechanical level.

Li’s group confirmed that, because of the way that the different facets cut across the lattice of the metal and fluorine atoms, more hydrocarbon chains could stick to the four edges that led to points than the remaining two sides. As a result, the particles become patchy.

“Our study shows a way forward making very subtle changes in building block architecture and getting a very profound change in the larger self-assembled pattern,” Glotzer said. “The goal is to have knobs that you can change just a little and get a big change in structure, and this is one of the first papers that shows a way forward for how to do that.”

 

 

 

 

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A nanotechnology holy grail in label-free cancer marker detection: Single molecules


QDOTS imagesCAKXSY1K 8(Nanowerk News) Just months after setting a record for  detecting the smallest single virus in solution, researchers at the Polytechnic  Institute of New York University (NYU-Poly) have announced a new breakthrough:  They used a nano-enhanced version of their patented microcavity biosensor to  detect a single cancer marker protein, which is one-sixth the size of the  smallest virus, and even smaller molecules below the mass of all known markers.  This achievement shatters the previous record, setting a new benchmark for the  most sensitive limit of detection, and may significantly advance early disease  diagnostics.  Unlike current technology, which attaches a fluorescent molecule,  or label, to the antigen to allow it to be seen, the new process detects the  antigen without an interfering label.
Stephen Arnold, university professor of applied  physics and member of the Othmer-Jacobs Department of Chemical and Biomolecular  Engineering, published details of the achievement in Nano Letters (“Label-Free Detection of Single Protein Using a  Nanoplasmonic-Photonic Hybrid Microcavity”), a publication of the American  Chemical Society.
nanoshell
The  detection of single thyroid cancer marker (Thyroglobulin, Tg) and bovine serum  albumin (BSA) proteins with masses of only 1 ag and 0.11 ag (66 kDa),  respectively.
In 2012, Arnold and his team were able to detect in solution the  smallest known RNA virus, MS2, with a mass of 6 attograms. Now, with  experimental work by postdoctoral fellow Venkata Dantham and former student  David Keng, two proteins have been detected: a human cancer marker protein  called Thyroglobulin, with a mass of just 1 attogram, and the bovine form of a  common plasma protein, serum albumin, with a far smaller mass of 0.11 attogram.  “An attogram is a millionth of a millionth of a millionth of a gram,” said  Arnold, “and we believe that our new limit of detection may be smaller than 0.01  attogram.”
This latest milestone builds on a technique pioneered by Arnold  and collaborators from NYU-Poly and Fordham University.  In 2012, the  researchers set the first sizing record by treating a novel biosensor with  plasmonic gold nano-receptors, enhancing the electric field of the sensor and  allowing even the smallest shifts in resonant frequency to be detected. Their  plan was to design a medical diagnostic device capable of identifying a single  virus particle in a point-of-care setting, without the use of special assay  preparations.
At the time, the notion of detecting a single  protein—phenomenally smaller than a virus—was set forth as the ultimate goal.
Proteins run the body,” explained Arnold. “When the immune  system encounters virus, it pumps out huge quantities of antibody proteins, and  all cancers generate protein markers. A test capable of detecting a single  protein would be the most sensitive diagnostic test imaginable.”
To the surprise of the researchers, examination of their  nanoreceptor under a transmission electron microscope revealed that its gold  shell surface was covered with random bumps roughly the size of a protein.  Computer mapping and simulations created by Stephen Holler, once Arnold’s  student and now assistant professor of physics at Fordham University, showed  that these irregularities generate their own highly reactive local sensitivity  field extending out several nanometers, amplifying the capabilities of the  sensor far beyond original predictions. “A virus is far too large to be aided in  detection by this field,” Arnold said. “Proteins are just a few nanometers  across—exactly the right size to register in this space.”
The implications of single protein detection are significant and  may lay the foundation for improved medical therapeutics.  Among other advances,  Arnold and his colleagues posit that the ability to follow a signal in real  time—to actually witness the detection of a single disease marker protein and  track its movement—may yield new understanding of how proteins attach to  antibodies.
Arnold named the novel method of label-free detection  “whispering gallery-mode biosensing” because light waves in the system reminded  him of the way that voices bounce around the whispering gallery under the dome  of St. Paul’s Cathedral in London. A laser sends light through a glass fiber to  a detector. When a microsphere is placed against the fiber, certain wavelengths  of light detour into the sphere and bounce around inside, creating a dip in the  light that the detector receives. When a molecule like a cancer marker clings to  a gold nanoshell attached to the microsphere, the microsphere’s resonant  frequency shifts by a measureable amount.
The research has been supported by a grant from the National  Science Foundation (NSF). This summer, Arnold will begin the next stage of  expanding the capacity for these biosensors. The NSF has awarded a new $200,000  grant to him in collaboration with University of Michigan professor Xudong Fan.  The grant will support the construction of a multiplexed array of plasmonically  enhanced resonators, which should allow a variety of protein to be identified in  blood serum within minutes.
Source: Polytechnic Institute of New York  University

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Gadget Genius: Nanotechnology Breakthrough Is Big Deal for Electronics


201306047919620July 26, 2013 — University of Akron researchers have developed new materials that function on a nanoscale, which could lead to the creation of lighter laptops, slimmer televisions and crisper smartphone visual displays

Known as “giant surfactants” — or surface films and liquid solutions — the researchers, led by Stephen Z.D. Cheng, dean of UA’s College of Polymer Science and Polymer Engineering, used a technique known as nanopatterning to combine functioning molecular nanoparticles with polymers to build these novel materials.

The giant surfactants developed at UA are large, similar to macromolecules, yet they function like molecular surfactants on a nanoscale, Cheng says. The outcome? Nanostructures that guide the size of electronic products.

More efficient designs possible

Nanopatterning, or self-assembling molecular materials, is the genius behind the small, light and fast world of modern-day gadgetry, and now it has advanced one giant step thanks to the UA researchers who say these new materials, when integrated into electronics, will enable the development of ultra-lightweight, compact and efficient devices because of their unique structures.

During their self-assembly, molecules form an organized lithographic pattern on semiconductor crystals, for use as integrated circuits. Cheng explains that these self-assembling materials differ from common block copolymers (a portion of a macromolecule, comprising manyunits, that has at least one feature which is not present in the adjacent portions) because they organize themselves in a controllable manner at the molecular level.

“The IT industry wants microchips that are as small as possible so that they can manufacture smaller and faster devices,” says Cheng, who also serves as the R.C. Musson and Trustees Professor of Polymer Science at UA.

He points out that the current technique can produce the spacing of 22 nanometers only, and cannot go down to the 10 nanometers or less necessary to create tiny, yet mighty, devices. The giant surfactants, however, can dictate smaller-scale electronic components.

“This is exactly what we are pursuing — self-assembling materials that organize at smaller sizes, say, less than 20 or even 10 nanometers,” says Cheng, equating 20 nanometers to 1 /4,000th the diameter of a human hair.

Team’s work has commercial applications

An international team of experts, including George Newkome, UA vice president for research, dean of the Graduate School, and professor of polymer science at UA; Er-Qiang Chen of Peking University in China; Rong-Ming Ho of National Tsinghua University in Taiwan; An-Chang Shi of McMaster University in Canada; and several doctoral and postdoctoral researchers from Cheng’s group, have shown how well-ordered nanostructures in various states, such as in thin films and in solution, offer extensive applications in nanotechnology.

The team’s study is highlighted in a pending patent application through the University of Akron Research Foundation and in a recent journal article, “Giant surfactants provide a versatile platform for sub-10-nm nanostructure engineering” published in Proceedings of the National Academy of Sciences of the United States of America (110, 10078-10083, 2013).

“These results are not only of pure scientific interest to the narrow group of scientists, but also important to a broad range of industry people,” says Cheng, noting that his team is testing real-world applications in nanopatterning technologies and hope to see commercialization in the future.

The five most important names in renewable energy that you’ve never heard of


By Bill White

wind transmission lines
Shutterstock

abu-dhabi-solarFive people will make a decision soon that will have an outsized impact on the future of renewable energy in America. I’m not talking about big shots like Obama, Koch, Boehner, Bloomberg, or Steyer. I’m talking about names many have never heard of:  Moeller, Norris, LaFleur, Clark, and Binz (if he is confirmed). These are the chief electricity officers of the United States of America — they are the commissioners of the Federal Energy Regulatory Commission (FERC).

You’ve probably heard this before: “Scientists agree that in order to avoid the worst consequences of climate change, we must generate 80 percent of our energy from renewable sources by 2050.”  No single entity will play as crucial a role as FERC in ensuring that the infrastructure exists to handle new renewable energy generation.

President Obama’s climate plan is a courageous step forward and deserves the widespread media coverage it has received. But only the acceleration of utility-scale renewable energy projects can take us where we need to go.

Modernizing our nation’s power system is a daunting task, but there are good reasons to be optimistic. America has enough wind and solar to power the entire country more than a dozen times over. And with the cost of wind and solar going down every day, rapid development of large-scale generation projects appears inevitable.

But if you place the map of regions with the best wind and solar energy on top of a map of our current transmission system, you won’t find too much overlap. Transmission is the key to unlocking America’s virtually unlimited renewable resources and delivering their energy to users.

Unlike our interstate highway system, which is funded by taxpayers, high-voltage transmission lines are built with private capital. Investors will put money into transmission projects as long as they generate returns that are attractive relative to similar types of investments. This is where FERC steps in. They set the return on equity (ROE) for transmission projects across the nation.

As you might imagine, the higher the ROE, the more incentive there is to build transmission. A company would never invest in our grid if the maximum ROE was 1 percent — meaning it would take 100 years to recoup the costs of a project. And if it was 100 percent, we would end up building much more transmission than we need and sticking consumers with the bill.

Recent history also tells us that the cost of inadequate transmission is steep. Electric customers are still paying billions of dollars per year for congestion, poor reliability, and overpriced power from dirty, outdated, and inefficient power plants — all of which are the direct result of three decades of underinvestment in transmission. Renewable energy was locked out of a strained and inadequate grid. In the mid-2000s, FERC recognized the chronic neglect of transmission investments as a major burden on ratepayers and a barrier to modernizing our electric system, and stepped in to raise transmission ROEs.

That decision helped spur a wave of new transmission investments that are reducing costs to consumers and expanding access to renewable energy. For example, the Midwest ISO has begun a new set of transmission lines called the MVP projects. The average consumer is seeing $23 in savings for every $11 spent these new lines.

Why is transmission such a great deal for electric customers? It’s the smallest part of an electric bill — 11 percent on average — compared with 58 percent for generation and 31 percent for distribution. Transmission pays for itself quickly by relieving costly congestion, moving cheap and clean renewable power to customers, making the grid more reliable and secure, and putting old and inefficient power plants out of business. Simply put, transmission is essential infrastructure for competition, consumer choice, economic efficiency, and environmental protection.

Despite the well-documented value that transmission investments deliver to ratepayers and the environment, FERC has been hearing complaints recently that ROEs for transmission projects are too high, and that ratepayers need relief. These complaints are misguided, and their timing could not be worse. Never in our history has so much depended on expanding and modernizing our electric transmission system.

Our chief electricity officers may never get the ROE for transmission “just right”; the uncertainty of markets, interest rates, and the economy probably make that lofty goal impossible to achieve. But they can — and they must — ensure that ROEs remain at levels that ensure a steady and stable flow of private capital into urgently needed transmission investments. Failing to do so would stall renewable energy development and with it progress on reducing emissions, and would increase the cost of electricity for everyone.

The president’s climate plan is moving forward. State renewable energy standards are helping expedite that progress. The falling costs of wind and solar are driving growth. But none of that will matter if the infrastructure to deliver renewable energy to customers is not built.

Five FERC commissioners will make a little-noticed decision in the near future, one that will either keep us on the right track, or throw a major obstacle — one that we can ill-afford — on the road to achieving our nation’s renewable energy future and stabilizing our world’s climate.

Bill White manages the National Clean Energy Transmission Initiative for the Energy Future Coalition. During the Clinton administration, he served as senior advisor to EPA Administrator Carol Browner.

Investing in Renewable Energy and Efficiency Can Significantly Lower Water Use


QDOTS imagesCAKXSY1K 8The U.S. could dramatically lower the power industry’s draw on strained water supplies by replacing aging power plants with water-smart options such as renewable energy and efficiency, according to a study recently released by the Union of Concerned Scientists-led “Energy and Water in a Warming World” Initiative.

Water-Smart Power: Strengthening the U.S. Electricity System in a Warming World claims the choices the industry makes now will decide how much the energy sector will tax the nation’s threatened water supplies and contribute to climate change in the decades to come.

More than 40 percent of U.S. freshwater withdrawals are used for power plant cooling, the report says. These plants also lose several billion gallons of freshwater every day through evaporation and increasing demand and drought are putting a greater strain on water resources.

Low water levels and high water temperatures also can cause power plants to cut their electricity output in order to avoid overheating or harming local water bodies. Such energy and water collisions can leave customers with little or no electricity or with added costs because their electric supplier has to purchase power from elsewhere, as occurred during the past two summers.

However, low natural gas prices and a rash of retirements of old and uncompetitive coal-fired power plants have prompted significant change in the power industry.

“Our electricity system clearly isn’t able to effectively meet our needs as we battle climate change and face a future of expanding electricity demand and increasing water strain,” said Doug Kenney, director of the Western Water Policy Program at the University of Colorado Law School. “As old plants are retired or retrofitted and new plants are built, we’ve got to untangle our competing demands for water and energy.”

Examining different paths the nation’s electricity production can take in the coming decades, the study says that while utilities’ ongoing shift to natural gas would decrease water use in the coming decades, its ongoing requirements could still harm water-strained areas. This shift to natural gas also would do little to lower the power sector’s carbon emissions.

“In our water-constrained world, a 20-year delay in tackling the problem leaves the power industry unnecessarily vulnerable to drought and exacerbates competition with other water users,” said John Rogers, co-manager of EW3 and a senior energy analyst with UCS’s Climate and Energy Program. “We can bring water use down faster and further, but only by changing how we get our electricity.”

According to the report, strong investments in renewables and energy efficiency could greatly reduce power generation’s water use and carbon emissions. Under such a scenario, water withdrawals would drop by 97 percent from current levels by 2050, with most of that drop within the next 20 years. This approach also would cut carbon emissions by 90 percent from current levels. A renewables path would also be a much cheaper path for consumers, the report found.

“We have a tremendous opportunity before us,” said Robert Jackson, an environmental scientist at Duke University. “By increasing energy efficiency and renewables, we can cut greenhouse gas emissions and water use, improve the quality of our water and air, and save money and lives at the same time. How often do we get a chance like that?”

The study concludes that many short-term options exist to reduce power sector water and climate risks such as prioritizing low-carbon, water-smart energy choices, such as renewable energy and energy efficiency; upgrading power plant cooling systems with technologies that ease local water stress; and instituting integrated resource planning that connects energy and water decision making.

Last month, Coca-Cola announced a new set of environmental goals, including returning 100 percent of the water from its manufacturing facilities back to the environment at a level that supports aquatic life by 2020. On Tuesday, Molson Coors Brewing Company announced that in 2012, its water intensity was seven percent lower than in 2008. Since 2008, the company reduced total water consumption by over 12.6 million hectoliters, equivalent to 504 Olympic swimming pools. Lower than expected volumes made it difficult to reduce water intensity and caused the company to fall short of its 2012 target of 15 percent reduction.

Using nanoparticles to remove pollutants and contaminants from wastewater


201306047919620(Nanowerk News) The Fraunhofer Institute for  Interfacial Engineering and Biotechnology IGB and its European partners have  developed several effective processes for eliminating persistent pollutants from  wastewater. Some of these processes generate reactive species which can be used  to purify even highly polluted landfill leachate while another can also remove  selected pollutants which are present in very small quantities with polymer  adsorber particles.
Biological stages in wastewater treatment plants are not able to  remove substances such as drugs, found in the wastewater of medical centers, or  halogenated compounds and cyanides from industrial wastewater. This is why  antibiotics and hormonally active substances such as bisphenol A from plastics  manufacturing have already accumulated in the environment and can be traced in  ground water and even in some samples of drinking water. Such persistent  pollutants require a special purifying treatment to remove them from wastewater.  Our tests have shown that oxidative processes with hydrogen peroxide or ozone as  the oxidizing agent are especially effective.
It is usually necessary to adapt or combine various processes in  order to be able to degrade the many different components present in industrial  wastewater in an effective and efficient manner. The Fraunhofer Institute for  Interfacial Engineering and Biotechnology IGB runs a pilot plant in Stuttgart  for testing standard processes either individually or in any desired  combination. The IGB has added two new methods which generate reactive species,  especially hydroxyl radicals, efficiently. Hydroxyl radicals oxidize pollutants  into smaller, more degradable organic molecules or mineralize them completely to  carbon dioxide. In the first method, reactive molecules are generated  electrochemically in a combined anode/cathode process and in the second by means  of atmospheric pressure plasma. Neither method requires the addition of  additives.
Oxidative electrochemical treatment of landfill  leachate
Within the CleanLeachate project funded by the EU (grant  agreement no 262335), http://www.cleanleachate.eu), the Fraunhofer IGB has developed an  oxidative process which does not require additives and which is, thanks to its  electrochemical operating principal, suitable for treating extremely turbid  wastewaters. A consortium of six partners from five European countries is  currently treating highly polluted leachate from landfill sites with a combined  anode/cathode process, in which a membrane separates an electrolytic cell into  two separate chemical reaction areas. Top priority was given to choosing the  most suitable electrode material, especially for the anodes, where the hydroxyl  radicals are generated as reactive species when voltage is applied. The polluted  water flows past the anode where it is oxidized and is then pumped to the  cathode where the components are reduced.
The treatment is now being tested in continuous operation on a  landfill site in Czechia. This has lead to improvements such as the lowering of  the chemical oxygen demand and the overall nitrogen concentrations to below  legal limits and the fulfilment of wastewater regulations. To make the process  ready for marketing, a prototype was automated and made portable to test further  types of wastewater, while gathering experience and reliable data for further  optimization steps.
Open plasma processes for water purification
Another new approach for purifying water involves the use of an  atmospheric pressure plasma. A plasma is an ionized gas containing not only ions  and electrons but also chemical radicals and electronically excited particles as  well as short wave radiation. Plasma can be ignited by means of an  electromagnetic field e.g. by applying high voltage. The plasma glow is  characteristic and can be seen in the fluorescent lamps of neon signs used for  advertising purposes. In a technical sense, plasma processes have already been  used specifically for modifying and cleaning surfaces for a long time now.
Open plasma reactor
Open  plasma reactor. (© Fraunhofer IGB)
This principle is currently being applied by the partners of a  joint water plasma project, funded by the EU, entitled “Water decontamination  technology for the removal of recalcitrant xenobiotic compounds based on  atmospheric plasma technology”, grant agreement no. 262033, http://www.waterplasma.eu,  in which a plasma is used for purifying water in an oxidative process. The  result is a plasma reactor in which the reactive species formed in the plasma  can be transferred directly to the contaminated water. The reactor is “open” so  that the plasma is in direct contact with a flowing water film. The plasma  reactor is designed in such a way that a plasma can be ignited and maintained  between a grounded electrode in the form of a stainless steel cylinder within  the reactor and a copper network acting as high voltage electrode. To do so,  high voltage is applied. The copper network is on a glass cylinder which acts as  a dielectrical barrier, also shielding the reactor to the outside. Polluted  water is pumped upwards through the stainless steel cylinder in the center of  the plasma reactor. When the water flows down the outer surface of the cylinder,  it passes through the plasma zone between the stainless steel cylinder and the  copper network where the pollutants are oxidized.
In laboratory experiments, Fraunhofer researchers were able to  decolor a methylene blue solution completely within a few minutes. Cyanide was  also broken down effectively by 90 percent within only 2 minutes. Based on such  promising results, the process is now being tested on a larger scale. One of the  project partners is working with a demonstrator which can purify 240 liters of  contaminated water in one hour. The results will be used to continually optimize  the design of the reactor and its process controls. The ultimate aim is to bring  the reactor to market together with further partners from industry. The open  plasma process has a high potential due to the fact that there is no barrier  between the plasma, where the oxidative radicals are formed, and the  contaminated water.
Removing trace substances with selective adsorber  particles
Pollutants can also be removed effectively from wastewater with  selective adsorbers. An adsorption stage is particularly effective when  pollutants are strongly diluted, present in low concentrations or highly  specific. The process is also advisable when a wastewater component is degraded  to a toxic metabolite in biological purification stages. In such cases, it could  be better to remove the substance selectively by pre-treating the wastewater  before it reaches the wastewater plant.
To this aim, the Fraunhofer IGB has developed a single stage,  cost-effective process for producing polymer adsorber particles. In NANOCYTES®,  our patented process, functional monomers are transformed into small  nanoscopically sized polymeric adsorber particles, so-called specific polymeric  adsorber particles (SPA)[GDC1] , with a cross-linking agent. The selectivity of  the adsorber particles can be increased by adding the target molecules to be  removed from the water to the mixture. The trick works like this: once the  monomers have been polymerized, the target molecules can be removed from the  adsorber particles. They leave behind a kind of “imprint” which adsorbs the  target pollutants.
These particles possess a high specific surface area and the  particle surface is easily accessible without limitations. In addition this  approach offers a large flexibility in the design of the surface chemical  properties and the adsorption behavior. A large variety of different monomers  (mono-, bi- and trifunctional) can be used. They are selected on the basis of  physico-chemical properties such as solubility, miscibility and non-covalent  interactions with the target molecules. The particle properties can therefore be  tailor-made for special separation problems.
Fraunhofer researchers have been able to remove bisphenol A and  penicillin G selectively from wastewater. The adsorber particles are chemically  and thermically stable and can be used for a wide range of applications e.g. as  a layer in a composite membrane or as a matrix on packing materials. Once the  pollutants have been adsorbed, the adsorber particles can be regenerated and  re-used. An adsorption column is available at the Fraunhofer IGB for research  experiments.
Systems solutions for water supply and water  treatment
These innovative processes for water treatment complement the  Fraunhofer IGB’s portfolio in the fields of water purification and water  treatment. Together with further processes for water treatment and recovering  wastewater components as energy and fertilizing salts, the Fraunhofer IGB is  steadily optimizing wastewater treatment plants and improving DEUS 21, a system  for the semi-decentralized purification of household wastewater.
Source: McGill University

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Global Quantum Dots (QD) Market worth of $7480.25 Million by 2022


Montreal, Canada | Posted on May 21st, 2012

QDOTS imagesCAKXSY1K 8ELECTRONICS.CA PUBLICATIONS, the electronics industry market research and knowledge network, announces the release of a comprehensive global report on Quantum Dots market.

 

 

According to the report titled, “Quantum Dots (QD) Market – Global Forecast & Analysis 2012 – 2022”  the total market for Quantum dots is expected to reach $7480.25 million ($7.48 Billion) by 2022, at a CAGR of 55.2% from 2012 to 2022.
Quantum Dots (QD) is the most advanced area of “semiconductor nanoparticles”, which is undergoing massive research. QDs are semiconductor nanoparticles, and, as the name suggests, have size from 2 nm to 10 nm. Due to their miniature property; they are highly versatile and flexible. The uniqueness of QD material lays in the fact that its power intensity depends on the input source and size of QD.

There are several ways to confine excitons in semiconductors, resulting in different methods to produce quantum dots. In general, quantum wires, wells, and dots are grown by advanced epitaxial techniques in nanocrystals produced by chemical methods or by ion implantation, or in nanodevices made by state-of-the-art lithographic techniques.
In the present scenario of QD technology market, Healthcare is the only industry, which has gained significant market share. Healthcare needs high precision in tissue labeling, cancer therapy, tumor detection, etc. and QD-based devices work for the same.
Lighting industry is huge; and after the introduction of efficient lighting like LED, this industry has taken a huge leap. LED lighting and fixtures market is growing by leaps and bounds since the last few years and expected to expand further. Now companies are looking for the alternate technology for LED lighting. QD lighting will fulfill the need; it is highly efficient and cost-effective. QD Vision has collaborated with Nexxus Lighting to launch its first QD LED light, and soon it will capture the market. Likewise, the company is also working on QD display.
QD technology will play a crucial role in solar energy-oriented industry as well. Researchers have developed QD-based solar cell, which is 50% as efficient as conventional solar cell. University of Toronto has achieved an efficiency of 4.2% conversion with solar cell based on colloidal QDs (CQD). Researchers are also working on QD-based paint that can be applied to panels or walls to capture solar energy.
Global Quantum Dots Market for technology-products and applications is expected to reach $7480.25 million by 2022, at an estimated CAGR of 55.2% from 2012 to 2022. Americas are holding a leadership position in QD technology market on the whole; followed by Europe and APAC. In the market of ROW, Middle East and Africa are the largest contributors.
Details of the new report, table of contents and ordering information can be found on Electronics.ca Publications’ web site.  View the report:

http://www.electroiq.com/articles/sst/2012/05/quantum-dots-see-55-cagr-on-led-display-other-applications.html

 

There Are Endless Electronics We Could Build With This New Stretchy Material


stretchy-electronics-4Flexible electronics are the gateway to a new generation of phones, brain  implants, artificial limbs, solar cells, and limitless other devices that  benefit from the ability to bend, fold, and rollup.

 

 

 

 

The problem is figuring out how to make them.

Stretchability and conductivity are difficult properties to combine.  Materials that are good conductors do not stretch well and materials that do  stretch well are not good conductors.

This happens because the stretching of solid material lengthens chemical  bonds, changing the distance between atoms, and in turn, decreasing  conductivity. Alternatively, the crystalline structures of metals, which makes  them good conductors of heat and electricity, are hard to mold since their  internal bonds are not very forgiving.

“This is the story throughout the entire family of stretchable conductors,”  said study researcher Nicholas Kotov, a professor of engineering at the University of  Michigan, who may have developed the best stretchy conductor yet.

The new material is made from gold nanoparticles that are embedded in a  flexible synthetic material called polyurethane. The bendy film, described in a  paper published in Nature on  Wednesday, July 17, can conduct electricity even when stretched to more than  twice its original length.

Scientists used electron microscope images to see what happened when the  material was stretched. It turns out that the gold nanoparticles aligned into  chains when pulled — instead of becoming disorganized — creating a good  conducting pathway. Importantly, the nanoparticles rearranged themselves when  the strain was released, meaning the process is reversible.

Stretchy Electronics

Michigan  Engineering

The gold nanoparticles are produced in the lab, represented  by this deep purple substance.

 The secret lies in the gold nanoparticles, which were made in the lab so that  they they would have a very thin shells on their surface. The thin shells are  much better than thicker traditional shells.

“This is important because the shell stabilizes the particles and typically  prevents the transfer of electrons from one nanoparticle to the other,” Kotov  told Business Insider.

Without a thick shell, the electrons can hop from one nanoparticle to another  more easily and are able to conduct electricity very well.

The practical applications of elastic metal are far-reaching, but  Kotov is particularly interested in how his material can be used to improve  medical devices.

There are a number of implantable devices for the brain, heart, and muscles.  The problem with these rigid electrodes is that the human tissue easily  recognizes them as foreign materials and generates scar tissue as a response,  explains Kotov. The scar tissue reduces the performance of implantable devices.  A pliable material that is more akin to our soft tissue is key to longer-term  implants.

The search for a material that has the unusual combination of stretchability  and electrical conductivity is ongoing, but this is a critical step forward.

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Another nanotechnology milestone by NASA engineers (w/video)


QDOTS imagesCAKXSY1K 8(Nanowerk News) A NASA engineer has achieved yet  another milestone in his quest to advance an emerging super-black nanotechnology  that promises to make spacecraft instruments more sensitive without enlarging  their size.

 

A team led by John Hagopian, an optics engineer at NASA’s  Goddard Space Flight Center in Greenbelt, Md., has demonstrated that it can grow  a uniform layer of carbon nanotubes through the use of another emerging  technology called atomic layer deposition or ALD. The marriage of the two  technologies now means that NASA can grow nanotubes on three-dimensional  components, such as complex baffles and tubes commonly used in optical  instruments.           Optics engineer John Hagopian works with a nanotube material sample Optics engineer John Hagopian works with a nanotube material sample.  

“The significance of this is that we have new tools that can  make NASA instruments more sensitive without making our telescopes bigger and  bigger,” Hagopian said. “This demonstrates the power of nanoscale technology,  which is particularly applicable to a new class of less-expensive tiny  satellites called Cubesats that NASA is developing to reduce the cost of space  missions.”

Since beginning his research and development effort five years  ago, Hagopian and his team have made significant strides applying the  carbon-nanotube technology to a number of spaceflight applications, including,  among other things, the suppression of stray light that can overwhelm faint  signals that sensitive detectors are supposed to retrieve.

Super Absorbency

During the research, Hagopian tuned the nano-based super-black  material, making it ideal for this application, absorbing on average more than  99 percent of the ultraviolet, visible, infrared and far-infrared light that  strikes it — a never-before-achieved milestone that now promises to open new  frontiers in scientific discovery. The material consists of a thin coating of  multi-walled carbon nanotubes about 10,000 times thinner than a strand of human  hair.

Once a laboratory novelty grown only on silicon, the NASA team  now grows these forests of vertical carbon tubes on commonly used spacecraft  materials, such as titanium, copper and stainless steel. Tiny gaps between the  tubes collect and trap light, while the carbon absorbs the photons, preventing  them from reflecting off surfaces. Because only a small fraction of light  reflects off the coating, the human eye and sensitive detectors see the material  as black.

Before growing this forest of nanotubes on instrument parts,  however, materials scientists must first deposit a highly uniform foundation or  catalyst layer of iron oxide that supports the nanotube growth. For ALD,  technicians do this by placing a component or some other substrate material  inside a reactor chamber and sequentially pulsing different types of gases to  create an ultra-thin film whose layers are literally no thicker than a single  atom. Once applied, scientists then are ready to actually grow the carbon  nanotubes. They place the component in another oven and heat the part to about  1,832  F (750 C). While it heats, the component is bathed in carbon-containing  feedstock gas.

“The samples we’ve grown to date are flat in shape,” Hagopian  explained. “But given the complex shapes of some instrument components, we  wanted to find a way to grow carbon nanotubes on three-dimensional parts, like  tubes and baffles. The tough part is laying down a uniform catalyst layer.  That’s why we looked to atomic layer deposition instead of other techniques,  which only can apply coverage in the same way you would spray something with  paint from a fixed angle.”
ALD to the Rescue
ALD, first described in the 1980s and later adopted by the  semiconductor industry, is one of many techniques for applying thin films.  However, ALD offers an advantage over competing techniques. Technicians can  accurately control the thickness and composition of the deposited films, even  deep inside pores and cavities. This gives ALD the unique ability to coat in and  around 3-D objects.
NASA Goddard co-investigator Vivek Dwivedi, through a  partnership with the University of Maryland at College Park, is now advancing  ALD reactor technology customized for spaceflight applications.
Lachlan Hyde works with an atomic layer deposition system
Lachlan Hyde, an expert in atomic layer deposition at Australia’s  Melbourne Centre for Nanofabrication, works with one of the organization’s two  ALD systems. (Image: MCN)
To determine the viability of using ALD to create the catalyst  layer, while Dwivedi was building his new ALD reactor, Hagopian engaged through  the Science Exchange the services of the Melbourne Centre for Nanofabrication  (MCN), Australia’s largest nanofabrication research center. The Science Exchange  is an online community marketplace where scientific service providers can offer  their services. The NASA team delivered a number of components, including an  intricately shaped occulter used in a new NASA-developed instrument for  observing planets around other stars.
Through this collaboration, the Australian team fine-tuned the  recipe for laying down the catalyst layer — in other words, the precise  instructions detailing the type of precursor gas, the reactor temperature and  pressure needed to deposit a uniform foundation. “The iron films that we  deposited initially were not as uniform as other coatings we have worked with,  so we needed a methodical development process to achieve the outcomes that NASA  needed for the next step,” said Lachlan Hyde, MCN’s expert in ALD.
The Australian team succeeded, Hagopian said. “We have  successfully grown carbon nanotubes on the samples we provided to MCN and they  demonstrate properties very similar to those we’ve grown using other techniques  for applying the catalyst layer. This has really opened up the possibilities for  us. Our goal of ultimately applying a carbon-nanotube coating to complex  instrument parts is nearly realized.”
Source: NASA

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Cancer nanotechnology: Nanoparticles with protein ‘passports’ evade immune system (w/video)


QDOTS imagesCAKXSY1K 8(Nanowerk News) Scientists have found a way to sneak  nanoparticles carrying tumor-fighting drugs past cells of the immune system,  which would normally engulf the particles, preventing them from reaching their  target. The technique takes advantage of the fact that all cells in the human  body display a protein on their membranes that functions as a specific  ‘passport’ in instructing immune cells not to attack them. By attaching a small  piece of this protein to nanoparticles, scientists were able to fool immune  cells in mice into recognizing the particles as ‘self’ rather than foreign,  thereby increasing the amount of medication delivered to tumors (“Minimal “Self” Peptides That Inhibit Phagocytic Clearance and  Enhance Delivery of Nanoparticles”).
peptide attached to nanoparticle
A  minimal peptide ‘passport’ (yellow) can be attached to therapeutic nanoparticles  so that it binds to an immune cell receptor (grey) and prevents engulfment.  
Cancer Nanotechnology
Current approaches to chemotherapy leave patients with severe  side effects because anti-cancer drugs meant to destroy tumors inadvertently  kill healthy cells in the body. But scientists have recently developed  nanoparticles that can ferry toxic medications directly to tumors while sparing  healthy tissue. Because of their small size, nanoparticles escape from leaky  blood vessels that are characteristic of tumors and accumulate in the cancerous  tissue. Tumor cells take up the particles which release their toxic contents  once inside. This localized delivery system allows doctors to give patients  higher doses of medications than would normally be tolerated.
Previous attempts have been made to ward off attack by the  immune system by coating nanoparticles densely with polyethylene glycol (PEG)  “brushes” that physically block the adhesion of proteins that normally deposit  onto foreign bodies to attract macrophages. While these brushes delay the onset  of the immune response, they don’t prevent it.
The inspiration for Discher’s breakthrough work dates back  thirteen years when a group of researchers showed with genetically engineered  mice that a protein called CD47—which is found in the cell membranes of nearly  all mammals—interacts with a receptor on macrophages called SIRPa, and, in doing  so, signals that the cell is native and shouldn’t be destroyed. The findings  hinged on deleting mouse CD47 and raised many questions, including how such mice  survive and whether there was relevance to humans.
Discher, who was engineering nanoparticles that self-assemble  into various shapes at the time of the discovery, realized that the CD47-SIRPa  mechanism for self-recognition could, in principle, be exploited to help  nanoparticles sneak past the immune system. But it was also clear that human  versions of purified proteins needed to be studied for any translation to  humans.
In 2008, Discher’s lab demonstrated that human CD47 acts  similarly to mouse CD47 as a “marker of self” via signaling through the SIRPa  receptor. Shortly thereafter, a group of researchers elucidated the combined  structure of human CD47 and SIRPa in atomic detail. Discher’s lab used this  information to conduct computer simulations and identify the smallest portion of  CD47 that could still bind to SIRPa. The result was a short peptide that  Discher’s lab chemically synthesized and attached to standard nanoparticles.
“Reducing CD47 to an essential peptide was a key step,” said  Discher. “Sequencing of thousands of human genomes around the world has recently  revealed many variations in the sequences of CD47 and SIRPa. We needed to  engineer a ‘universal’ peptide that could bind SIRPa and function in all humans  despite these differences.”
Stealth nanoparticles avoid immune response
To test whether their peptide could help nanoparticles evade the  immune system, Discher’s team injected both peptide-bound nanoparticles and  nanoparticles lacking CD47 into mice. Both types of nanoparticles contained a  fluorescent dye that allowed the scientists to track the particles. In an  article published on February 22, 2013 in Science, the researchers reported that  in just thirty minutes post-injection of the particles, the mice’s blood  contained four times as many nanoparticles containing CD47 peptide as particles  without the peptide, suggesting that CD47-bound particles were being viewed by  macrophages as being similar to cells that belonged in the body.
Encouraged by these initial results, the team next filled their  CD47-bound nanoparticles, as well as PEG-coated nanoparticles without CD47, with  the anticancer drug paclitaxel plus a tumor-targeting antibody. The team  separately injected both types of nanoparticles as well as Cremophore—the  standard carrier for paclitaxel—into mice with human-like tumors. After just one  day, the tumors in mice injected with CD47-bound nanoparticles were 70% the size  of those injected with the PEG-coated nanoparticles. Additionally, CD47-bound  nanoparticles were just as good or better at shrinking the tumors as Cremophore  without causing any side effects. The team went on to document the molecular  changes that occur inside macrophages when CD47 inhibits engulfment, suggesting  additional medications might be used to inhibit clearance.
                     
Macrophage engulfs foreign cells
“Clinical trials using nanoparticles to deliver anticancer drugs  are currently underway, but clearance by the immune system remains a significant  hurdle,” said Karen Peterson, Ph.D., Senior Advisor of Extramural Programs at  NIBIB. “Discher’s work is an elegant approach, which could enable other  nanotherapeutics to be effective in clinical trials by providing a molecular  “authentication” that the body does not recognize as foreign.”
Peterson also noted the combination of bioengineering and  computer modeling that went into generating the peptide; Discher’s ability to  test the function of differently sized peptides via computer simulation first,  and then produce a man-made peptide based on these simulations allowed him to  eliminate some of the guessing game, saving time and money in the long-run.
Future applications
Discher speculates that his CD47 peptide could be similarly used  to prevent immune clearance of viruses used to deliver genes for gene-therapy  treatment or to enhance biocompatibility and durability of larger foreign  objects such as pacemakers and implants, whose parts can degrade over time due  to attacks by the immune system.
Source: By Margot Kern, National Institute of Biomedical  Imaging and Bioengineering

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