Researchers at A*STAR Discover Nano-Structured Coatings Absorb Pollutants from Drinking Water


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Low-cost iron hydroxide coatings with unique fin-like shapes can clean heavily contaminated water with a simple dipping procedure.

As one of the primary components of rust, iron hydroxides normally pose corrosive risks to health. A team at Agency for Science, Technology and Research (A*STAR), Singapore, has found a way to turn these compounds into an environmentally friendly coating that repeatedly absorbs large amounts of pollutants, such as dyes, from drinking water at room temperature.

Conventional activated charcoal treatments have trouble removing heavy metals and bulky organic compounds from water. Instead, iron hydroxides are being increasingly used because they can form stable chemical bonds to these unwanted pollutants. Researchers have recently found that turning iron particles into miniscule nanomaterials boosts their active surface areas and enhances chemical absorption processes.

Separating iron hydroxide nanomaterials from water, however, remains difficult. Commercial filtration systems and experimental magnetic treatments introduce significant complexity and cost into treatment plants. Failure to remove these substances may lead to acute or chronic health issues if they are ingested.

To improve handling of the nanosized iron hydroxides, Sing Yang Chiam from A*STAR’s Institute of Materials Research and Engineering and co-workers decided to attach them to a solid, sponge-like support known as nickel foam. This type of material could safely trap and remove contaminants by immersion into dirty water, and then be regenerated with a simple chemical treatment. But immobilizing the nanoparticles also diminishes their valuable high surface areas — a paradox the team had to solve.

“We were not totally convinced that a coating approach could perform as well as traditional powders and particles,” says Chiam. “So we were really pleased when some nice test results came through.”

The A*STAR team found their answer by synthesizing iron hydroxide coatings with a hierarchy of structural features, from nano- to micrometer scales. To do so, they turned to electrodeposition, a green synthesis method that deposits aqueous metal ions on to nickel foam at mild voltages. After optimizing the uniformity and adhesion of their multiscale coatings, they tested their material in water contaminated by a ‘Congo red’ dye pollutant. Within half an hour, the water became almost colorless, with over 90 per cent of the dye attached to the special coating.

 

astar-pollutants-170126103405_1_540x360The Institute of Materials Research and Engineering team. Credit: © 2017 A*STAR Institute of Materials Research and Engineering

 

Close-up views of the coating’s nanostructure using scanning electron microscopy revealed that elongated, fin-like protrusions were key to recovering active surface area for high-performance pollutant removal. “Even though these coatings have some of the highest capacities ever reported, they are only operating at a fraction of their theoretical capacity,” says Chiam. “We are really excited about tapping their potential.”


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Materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Content may be edited for style and length.


Journal Reference:

  1. Junyi Liu, Lai Mun Wong, Gurudayal Gurudayal, Lydia Helena Wong, Sing Yang Chiam, Sam Fong Yau Li, Yi Ren. Immobilization of dye pollutants on iron hydroxide coated substrates: kinetics, efficiency and the adsorption mechanism. J. Mater. Chem. A, 2016; 4 (34): 13280 DOI: 10.1039/C6TA03088B
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Nanocrack Coating Enhances Performance of Membranes for Water Filtration, Fuel Cells


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A team of researchers with members from institutions in South Korea and Australia has developed a coating for membranes used in fuel cells and many other applications that allows it to continue to perform at a high level even as temperatures rise and humidity drops to levels that normally cause performance to suffer.

In their paper published in the journal Nature, the team describes their coating, how it works and the different materials that can be improved through its use. Jovan Kamcev and Benny Freeman with the University of Texas at Austin have published a News & Views article in the same journal issue describing the work done by the team and the many ways that the membrane coating has been successfully tested.

Nano Crack 043016 572200eda62c4

A hydrophobic coating layer provides a self-controlled mechanism for water conservation using nanometre-sized cracks (nanocracks) tuned by membrane swelling behaviour in response to external humidity conditions, which act as nanovalves. …more

Membranes are a critical part of machines that rely on ionic or size separation—some well-known applications are water filtration efforts, energy generation in fuel cells and flow batteries and by reverse electrodialysis. Though useful, membranes also have a reputation of being rather fragile, resulting in expensive repairs, replacement or performance degradation.

One such example is that most membranes need to be kept moist to work properly, which can become problematic in certain environments. Water filtration in a hot Middle Eastern desert, for example, suffers when temperatures soar and humidity levels drop. In this new effort, the research team reports that they have developed a coating for membranes that works similarly to stomatal pores in a cactus plant—the pores open to allow for taking in carbon dioxide during times of higher humidity, such as at night and then close again as the humidity levels drop during the heat of the day.

The membrane coating is made by placing a thin layer of fluorine-related material that is water repellant over the membrane, in a low-humidity environment—under high humidity conditions, nanocracks appear in the material, allowing the water in the air to pass through to the membrane below. But, as temperatures rise and drop, the material tightens, closing the gaps where the cracks exist, preventing the water in the from evaporating. Kamcev and Benny Freeman report that the has been tested successfully on a wide variety of applications under various environmental conditions, and that thus far, it has proven able to protect delicate membranes in severe environments, allowing for their use in a much broader range to applications.

Explore further: Self-assembling, biomimetic membranes may aid water filtration

More information: Chi Hoon Park et al. Nanocrack-regulated self-humidifying membranes, Nature (2016). DOI: 10.1038/nature17634

Abstract
The regulation of water content in polymeric membranes is important in a number of applications, such as reverse electrodialysis and proton-exchange fuel-cell membranes. External thermal and water management systems add both mass and size to systems, and so intrinsic mechanisms of retaining water and maintaining ionic transport1, 2, 3 in such membranes are particularly important for applications where small system size is important.

For example, in proton-exchange membrane fuel cells, where water retention in the membrane is crucial for efficient transport of hydrated ions1, 4, 5, 6, 7, by operating the cells at higher temperatures without external humidification, the membrane is self-humidified with water generated by electrochemical reactions5, 8. Here we report an alternative solution that does not rely on external regulation of water supply or high temperatures. Water content in hydrocarbon polymer membranes is regulated through nanometre-scale cracks (‘nanocracks’) in a hydrophobic surface coating.

These cracks work as nanoscale valves to retard water desorption and to maintain ion conductivity in the membrane on dehumidification. Hydrocarbon fuel-cell membranes with surface nanocrack coatings operated at intermediate temperatures show improved electrochemical performance, and coated reverse-electrodialysis membranes show enhanced ionic selectivity with low bulk resistance.

 

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Scientists Discover Nanotechnology Coating That Can Kill 99.9 Percent Of Superbugs


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A nanotechnology coating could control the spread of potentially deadly antibiotic-resistant superbugs that are very difficult to kill, a new study found.

This new breakthrough will allow ordinary items like smartphones, door handles and telephones to be protected against antibiotic-resistant bacteria, which are expected to kill about 10 million people around the world by 2050. A team of researchers from Institute of Technology Sligo found a way that could stem the spread of deadly and hard-to-treat superbugs.

“It’s absolutely wonderful to finally be at this stage. This breakthrough will change the whole fight against superbugs. It can effectively control the spread of bacteria,”said Professor Suresh Pillai from IT Sligo.

The nanotechnology has a 99.9 percent kill rate of potentially fatal bacteria, the researchers found. It contains a potent antimicrobial solution that is robust enough to kill pathogens and even inhibit their growth.

A wide range of items could be used as long as they’re made from metal, ceramic or glass including screens of tablets, smartphones and computers. It could also be used on door handles, television sets, urinals, refrigerators, ATM’s and ceramic tiles or floors.

It will be very useful in hospitals and other medical facilities that face the problem of superbug infections or what is commonly called nosocomial infections. Other common public areas that can use this nanotechnology are public swimming pools, buildings and transportation.

One of the most dominant nosocomial bacteria, those that develop and spread in hospitals, is Methicillin Resistant Staphylococcus aureus (MRSA). This group of bacteria could survive on hospital surfaces for up to five months.

Current methods are not efficient enough in eradicating Staphylococcus aureus. Existing hygiene coatings used today have two drawbacks – it relies on ultraviolet lights to generate electrons and reactive species and a purely photocatalytic hygiene coating is inactive when in the dark.

The nanotechnology, however, will effectively and completely kill superbugs from the surface of items. This is a water-based solution that can be sprayed on while manufacturing glass, metal or ceramic materials.

The transparent coating will be baked into the material, forming a hard surface that is resistant to superbugs including MRSA, some fungi and Escherichia coli. The team is now studying on how the material could be incorporated into paint and plastics to explore a wider use of the discovery.

The study was published in the journal Nature.

Flake-Like Nanoparticles Offer Reliable Rust Protection


Nano rust-resistance 041516 -steel-guard-nano-coat-tm-500x500Large quantities of steel are used in architecture, bridge construction and ship-building. Structures of this type are intended to be long-lasting. Furthermore, even in the course of many years, they must not lose any of their qualities regarding strength and safety. For this reason, the steel plates and girders used must have extensive and durable protection against corrosion. In particular, the steel is attacked by oxygen in the air, water vapor and salts. Nowadays, various techniques are used to prevent the corrosive substances from penetrating into the material. One common method is to create an anti-corrosion coating by applying layers of zinc-phosphate. Now, research scientists at INM — Leibniz Institute for New Materials developed a special type of zinc-phosphate nanoparticles. In contrast to conventional, spheroidal zinc-phosphate nanoparticles, the new nanoparticles are flake-like. They are ten times as long as they are thick. As a result of this anisotropy, the penetration of gas molecules into the metal is slowed down.

The developers will be demonstrating their results and the possibilities they offer at stand B46 in hall 2 at this year’s Hanover Trade Fair as part of the leading trade show Research & Technology which takes place from 25th to 29th April.

“In first test coatings, we were able to demonstrate that the flake-type nanoparticles are deposited in layers on top of each other thus creating a wall-like structure,” explained Carsten Becker-Willinger, Head of Nanomers® at INM. “This means that the penetration of gas molecules through the protective coating is longer because they have to find their way through the ´cracks in the wall´.” The result, he said, was that the corrosion process was much slower than with coatings with spheroidal nanoparticles where the gas molecules can find their way through the protective coating to the metal much more quickly.

In further series of tests, the scientists were able to validate the effectiveness of the new nanoparticles. To do so, they immersed steel plates both in electrolyte solutions with spheroidal zinc-phosphate nanoparticles and with flake-type zinc-phosphate nanoparticles in each case. After just half a day, the steel plates in the electrolytes with spheroidal nanoparticles were showing signs of corrosion whereas the steel plates in the electrolytes with flake-type nanoparticles were still in perfect condition and shining, even after three days. The researchers created their particles using standard, commercially available zinc salts, phosphoric acid and an organic acid as a complexing agent. The more complexing agent they added, the more anisotropic the nanoparticles became.

INM conducts research and development to create new materials — for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future?

Four research thrusts determine the current developments at INM:

  • New materials for energy application,
  • New concepts for medical surfaces,
  • New surface materials for tribological systems and
  • Nano safety and nano bio.

Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces. INM — Leibniz Institute for New Materials, situated in Saarbrücken, is an internationally leading center for materials research. It is an institute of the Leibniz Association and has about 220 employees.

 


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The above post is reprinted from materials provided by INM – Leibniz-Institut für Neue Materialien gGmbH. Note: Materials may be edited for content and length.


 

INM – Leibniz-Institut für Neue Materialien gGmbH. “Flake-like nanoparticles offer reliable rust

What’s New in Nanotechnology? Diagnostics? Pharmaceuticals? All Will Boost Nanocoatings Market


Nanotech_cell_cultures%20copyA look at nanotech for healthcare diagnostics and treatment, and how medical and pharmaceutical applications will boost the global nanocoatings market.

“The healthcare industry is rapidly moving towards miniaturization of equipment and use of nanotechnology for diagnostics and treatment,” says BCC Research Analyst Vijay Laxmi.

“In keeping with this trend, manufacturers are focusing on producing MEMS (MicroElectroMechanical Systems),” he notes. “Growing demand for minimally invasive surgeries and the presence of high unmet medical needs in emerging Latin American and Asia-Pacific economies are responsible for the growth of the market and also present significant opportunities for the disposable sensors.”

With a growing demand for disposable medical devices that are safe and cost-effective to use, disposable medical sensors have surged in demand, according to BCC Research.

In its new report, BCC Research says that manufacturers, in an attempt to cater to the changing dynamics of the market, are shifting their focus towards developing disposable medical sensors.

The global disposable medical sensors market was valued at $3.8 billion in 2013 and is expected to grow at a compound annual growth rate (CAGR) of 10.2% to reach an estimated value of $6.8 billion in 2019. Increasing demand for diagnostic and monitoring devices such as cardiac pacemakers and blood glucose monitors are the key drivers of this segment.

Growth drivers include an increasing geriatric population coupled with spreading prevalence of target diseases pertaining to cardiovascular, audiology, and urology systems. Rising usage rates of insulin and infusion pumps due to pervasive levels of diabetes is predicted to further boost market growth.

Nanocoatings market

Meanwhile, the nanocoatings market growth is likely to provide intriguing application possibilities in healthcare. Globally, the nanocoatings market is forecast to grow at at a 24.7% CAGR, according to a new report from Transparency Market Research (TMR).

TMR estimates that the global nanocoatings market will be worth US$6.75 billion by 2019. TMR reports that the global nanocoatings market was US$1.45 billion in 2012. The 24.7% CAGR growth between 2013 and 2019, says the report, will come from coatings used in the automotive and medical and pharmaceutical industries.

TMR analysts say anti-microbial nanocoatings registered the highest demand and accounted for 29.6% of global demand in 2012. This product type finds extensive application in the healthcare, food production, and water treatment sectors.

However, the fastest growth will be exhibited by anti-fingerprint nanocoatings, where the electronics, automotive, packaging, and healthcare sectors will make the largest contribution to demand.

In 2012, medical and healthcare sector accounted for the highest demand for nanocoatings, which represented 14% of that year’s global demand. TMR suggests that several types of medical equipment and implants are accented with nanocoatings. TMR anticipates that the use of nanocoatings in the healthcare sector is likely to continue in the coming years, driving the nanocoatings market significantly.

New Nanocomposites for Aerospace and Automotive Industries


newnanocompoThe Center for Research in Advanced Materials (CIMAV) has developed reinforced graphite nanoplatelets seeking to improve the performance of solar cell materials.

The work, done by Liliana Licea Jiménez, uses this material because it has a large power capacity. These polymer-based nanocomposites are reinforced with graphite nanoplatelets for use in industry.

Nanocomposites are formed by two or more phases, in this case by reinforced graphite nanoplatelets.

“The sectors focused on the use of these are diverse; nanoplatelets impart new properties to materials; this allows us to move into the automotive, construction, aerospace, textile and electronics sectors which are demanding and where the use of nanomaterials is an opportunity,” explains Licea Jiménez.

According to the specialist at CIMAV, the research is already applied in some concept testing for mechanical and thermal modification in the construction industry. Additionally, are already used in fenders and panels in the automotive and .

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The development of nanocomposites in this research center is an opportunity for different industry sectors; graphite nanoplatelets give added value to the product, as they improve its mechanical, thermal and electrical properties. And they have an impact on the industry because the business demands are increasing and the use of nanocomposites is an opportunity to improve the product.

“Even some of the companies we have worked with mentioned in several forums that they have had a good response in the use of these nanomaterials.” She also affirms that the nanocomposites Laboratory in Monterey has achieved success, but recognizes that they need to engage with sectors such as aeronautics, among other areas.

Jimenez Licea indicates that in addition to companies in the northern state of Nuevo Leon, there are companies in other states that have shown interest in polymer ; “It is an advantage to work with research projects demanded by the industry, because they have a specific function for each company.”

This is because each nanocomposite is a material that has two or more constituents, in this case the polymer and a nano-sized reinforcing material: the nanoplatelets.

Explore further: Improvement in polymers for aviation

MIT’s Material Scientist Rubner Collaborates with CE Cohen for Coatings & Synthetic “Backpacks”


1-Michael_Rubner_Lab_DPMaterials scientist Mike Rubner’s collaboration with chemical engineer Robert Cohen yields anti-fog coatings, synthetic “backpacks” for living cells.

For more than two decades, MIT Professor Michael F. Rubner has been discovering new ways to build up layer-by-layer water-based, non-toxic polymers with special properties such as coatings with the ability to prevent fog and frost from forming and cellular patches, or “backpacks,” that could boost the immune system.

“We do a lot of fundamental work, so we seek to understand how molecules adsorb out of aqueous solutions onto surfaces … then from that understanding, all these applications start to pop out,” says Rubner, the TDK Professor of Polymer Materials Science and Engineering. Early studies focused on how pH and charge density affect the way charged polymers and particles adhere to surfaces.

Rubner’s decade-plus partnership with MIT Department of Chemical Engineering Professor Robert E. Cohen has produced more than 60 scientific papers. “We started doing joint research through [Center for Materials Science and Engineering] funding. Bob had certain unique capabilities in nanoreactor technology and block co-polymer technology, and I was developing this layer-by-layer field, and we decided that there was a unique opportunity to bring those two worlds together,” Rubner recalls.

As they merged their research, the Rubner group and Cohen group held joint meetings. “It’s a beautiful illustration of how MIT faculty can work together and collaborate, and do things that are significantly better than what the individual faculty members could do. That’s really the mission of CMSE, to bring people together that otherwise wouldn’t come together and have great things happen,” Rubner explains.

Directing CMSE 

Rubner also directs MIT’s Center for Materials Science and Engineering (CMSE), which fosters interdisciplinary research and offers a variety of educational outreach projects, including jointly hosting the annual Summer Scholars program with the Materials Processing Center.

CMSE sponsors researchers at levels from seed funding through Interdisciplinary Research Groups (IRG). CMSE is funded by the National Science Foundation under its Materials Research Science and Engineering Center (MRSEC) program. About 1,200 different researchers use CMSE shared experimental facilities each year. Educational programs bring area high school teachers to campus for hands-on lab experience each summer while other programs reach students from kindergarten through high school.

Convening practitioners 

Rubner was co-organizer with Stevens Institute of Technology Associate Professor 
of Chemistry Svetlana Sukhishvili of the Layer-by-Layer (LbL) Assemblies: Science and Technology Conference in Hoboken, N.J., June 23-25.

“Professor Rubner has made contributions to science and technology of polymer coatings that seem, to me, quite unparalleled. Michael’s pioneering work on hydrogen-bonded, weak polyelectrolyte and polyelectrolyte-nanoparticle layer-by-layer (LbL) coatings has lead to the development of new types of superhydrophobic, superhydrophilic, and antireflective coatings,” Sukhishvili says. “Another novel direction pioneered by Rubner’s group is the use of the LbL technology to tag live cells. Specifically, their group has succeeded in attaching functional LbL-based backpacks to immune cells. This work opens many opportunities in using the LbL-modified immune cells in cancer therapy. More recently, the Rubner/Cohen group has reported on LbL films that respond very differently to liquid water or water vapor. This recent exciting work has lead to the development of new types of antifogging coatings with frost-resisting capabilities.”

More than 100 people participated in the LbL conference at Stevens. “The field is still alive and doing well,” Rubner says.

Interdisciplinary collaborations

MIT professors John JoannopoulosYoel Fink and Edwin L. “Ned” Thomas (now dean of the Brown School of Engineering at Rice University) began their quest for a perfect mirror years ago with CMSE seed funding, Rubner says. They eventually developed omnidirectional reflectors, leading to the spinoff company OmniGuide, which makes minimally invasive laser surgical equipment. “They evolved from seed funding into an IRG, and that’s been a very successful venture,” Rubner says.

His own collaboration with Cohen over the past dozen years follows the collaborative model, Rubner explains. The pair jointly supervise about three-quarters of their undergraduates, graduate students and postdocs. The groups ran as high as two dozen members over the years but contracted with the Great Recession in 2008 and recently was made up of about a dozen. The groups graduated about half their members this year, so they are looking to grow again.

“We run it like one gigantic shared facility,” Rubner says of the two labs. “Basically all of his group and all of my group come together on a weekly basis to discuss our research, and make presentations,” he says. “Even folks who are not directly supervised by us as a team are still involved.”

Group members have access to both Cohen’s and Rubner’s labs. “When we recruit new students or postdocs, we say, ‘By the way, you’re going to have two bosses. You might find that a little intimidating, but on the other hand, you’re going to have twice the resources,” Rubner says.

Controlling water adhesion

Rubner’s early research focused on how the pH of a solution influences the way polymers adsorb onto surfaces from aqueous (water-based) solutions — in particular, on charged polymers for which the charge density of the polymers varies with changes in pH. “You change the pH of the solution, you get a different charge density, a different way the polymer adsorbs onto the surface. I devoted a lot of time to understanding that from a fundamental standpoint,” Rubner explains.

“Pretty much everything we do since then in all these applications that we’ve been talking about including backpacks and anti-fogging and Zwitter wettability is based on the fundamental knowledge we gained from trying to answer that very simple question: How does pH of a water-solution influence the way macromolecules adsorb onto surfaces?” he says.

The group developed thin films to control water on surfaces, mimicking the way lotus and other plants shed water from their leaves. “We published a paper many years back on superhydrophobicity. Superhydrophobic surfaces, where water droplets just roll off the surface, provide a self-cleaning capability,” Rubner says. One ACS Nano Letters paper from 2004, “Stable Superhydrophobic Coatings from Polyelectrolyte Multilayers” has been cited by other researchers nearly 500 times.

“That started us thinking about what else can we do in this area where we control surface chemistry, structure, and topology to create interesting effects and control the way water interacts with surfaces in novel ways,” Rubner explains. The next target was understanding superhydrophilic surfaces on which water immediately spreads. “The advantage of superhydrophilic surfaces is that they can prevent fogging from occurring,” Rubner says.

“Fogging is the condensation of microscopic droplets of water on the surface that scatter light,” he explains. “That’s why you can’t see through fog. If you spread that water into a sheet, the water’s still there. You can’t stop water from condensing onto a surface under certain conditions, but if you spread it into a sheet, you can’t see it. It’s transparent; it’s like a sheet of glass.”

Recognizing the anti-fogging capability of superhydrophilic coatings, Rubner, Cohen, and colleagues published several papers, including “Durable Antifog Films from Layer-by-Layer Molecularly Blended Hydrophilic Polysaccharides,” in the American Chemical Society publication Langmuir in December 2010. The work demonstrated that polymer-based polysaccharide coatings were durable and resisted fogging. The researchers received several U.S. patents, and mainstream media from Canada to New Zealand reported on their anti-fog coatings.

Despite the positive results, the question kept coming up: What happens if the temperature at the surface is below freezing and the water freezes? SWhen water freezes, it’s no longer transparent; it turns into frost,” Rubner explains. “So we said, ‘Hmm, that’s interesting. That means you really can’t use these coatings under conditions that your lenses (for example) are below the freezing point of water or if they drop below the freezing point of water.’ So they were anti-fogging, but they weren’t anti-frost.” The group then turned to addressing that question.

“We changed our formulation and developed a system that sucks up the water like a sponge, but the water that enters the coating is in what is called a non-freezing state. It’s hydrogen-bonded to the (polymer) matrix that we created,” Rubner says. “As a result, there is either a strong melting point depression or no melting point at all. … If the water stays strongly interacting with our matrix, there is no water-to-water contact, and whatever water gets into the film — and there is a large amount of it — can’t freeze.”

Distinctly different effects

While the new formulation solved the freezing issue by absorbing water vapor, the researchers were able to design coatings that simultaneously appear to be water resistant, thus combining both water-spreading resistance and water-absorbing properties in a single coating. They call this new phenomenon “Zwitter wettability.”

“Zwitter wettability means it has at the same time two distinctly different effects,” Rubner explains. “It’s hydrophobic to water droplets but very hydrophilic to water vapor, meaning water molecules enter very quickly into the coating, into this non-freezing state, but if you put a drop of water onto it, it behaves like a Teflon surface.”

The results were published in the ACS Nano article, “Zwitter-Wettability and Antifogging Coatings with Frost-Resisting Capabilities,” in January 2013. One potential application of the Zwitter-wettability coatings is the inside of freezer doors at grocery stores. “There is capacity limit to any coating we create, but in that application it’s perfect, because you open the door, we suck up the water, we prevent if from freezing. You close the door, the curtain of air is there; it just removes the water out of the coating. Equilibrium forces it out again. So you can do that many, many times, and you’ll never see frost,” Rubner explains.

Commercialization is still pending. “There’s interest, and we’re collaborating with a company to move forward on trying to develop this into a real technology,” he says.

“We can take our coatings, expose them to water vapor so they suck water up like a sponge, and we can determine how much water they picked up. It’s a very large amount; the coating swells. If we then freeze it, without any excess water on top, incubate it at a low enough temperature that water would normally freeze – it stays completely clear even though it’s loaded with water,” Rubner says.

Rubner was named a 2014 Materials Research Society Fellow “For pioneering research in layer-by-layer assembly of functional thin films; inspirational mentoring of two generations of materials scientists; and visionary leadership in the materials community worldwide.”

Molecular backpacks

Another line of research in the Cohen and Rubner groups is polymer patches for living cells, which they call “backpacks.” Created with layer-by-layer processing, the backpacks are a marriage between synthetic materials and the living natural world, Rubner says. Joint research with University of California at Santa Barbara chemical engineering Professor Samir Mitragotri is testing in rats how effectively immune cells with added backpacks can carry drugs to disease sites. “I think it’s a very exciting opportunity to use the backpacks for drug delivery,” Mitragotri says.

“The idea is we want to use the body’s own cells to deliver drugs to specific tissues within the body. The drugs by themselves have a very difficult time reaching many organs in the body,” Mitragotri explains. For instance, cancer may be highly localized, but injecting anti-cancer drugs into the blood spreads the drugs throughout the body rather than targeting the disease site. Additionally, drugs injected into the blood may not be able to penetrate certain areas of the brain. But natural immune cells can access parts of the body that synthetic materials cannot, he says. Hitchhiking on those immune cells may provide a new path for drug delivery.

“We rely on the immune cells to carry drugs to specific tissues. We expect this to be broadly applicable because immune cells access different tissues in various diseases. This can be a broad strategy that can be used for treatment of multiple diseases. Backpacks can encapsulate different drugs and can also encapsulate imaging agents, so could potentially be used to image certain sites in the body as well,” Mitragotri says. He expects results to be published soon.

The animal experiments are an outgrowth of Rubner and Cohen’s earlier collaborative work with Professor Darrell Irvine of the departments of Materials Science and Engineering and Biological Engineering, including the 2008 Nano Letters article, “Surface Functionalization of Living Cells with Multilayer Patches.”

“We developed the backpacks and the protocols for attaching them to the cells,” Rubner explains. Techniques they used include the layer-by-layer assembly of the backpacks, docking chemistry for adhering to the living cells and release chemistry for freeing the drugs at the disease site.

Making the switch 

Rubner recalls that when he made the decision a little over two decades ago to focus on layer-by-layer assembly, he was working with Langmuir-Blodgett films, a process in which structures of many layers are built up by repeatedly dipping a substrate into a solution in which molecules interact at the interface of air and water, adding a single layer at a time. “I had three $60,000 Langmuir-Blodgett troughs for doing that. When I made the decision to move in LbL, layer-by-layer, I took those three $60,000 Langmuir-Blodgett troughs and pulled them out of my lab in one afternoon. Gave them away. Threw them out. And moved everything into this area, because I thought it was going to be a much more important area than L-B, Langmuir-Blodgett,” Rubner says. Layer-by-layer processes have turned out be very versatile with applications ranging from optics to biological uses. “My original idea that this was going to be important turned out to be true,” Rubner says.

Carbon Nanotubes to Improve Coatings


image descriptionResin coatings are widely used in various sectors, like the aeronautical and automotive sectors, and in the structural components of aircraft and vehicles, in particular. Research by the UPV/EHU-University of the Basque Country has used carbon nanotubes to improve the properties of these coatings.

The research has been conducted within the POCO European project and seeks to come up with strategies to spread carbon nanotubes properly throughout different polymers. Carbon nanotubes improve the conductivity of these coatings, repair any scratches they may have and have excellent mechanical properties: they are tough and rigid and, what is more, conduct electricity. Epoxy resins, by contrast, are insulating materials. So if these nanotubes are added to them, the coatings are also turned into conductors. “However, to transmit or enhance these properties better, the carbon nanotubes must be properly spread throughout the material,” pointed out the UPV/EHU chemist Galder Kortaberria. But this advantage turns into a problem for the nanotubes because they tend to form clusters and often group together. So they cause problems when it comes to being expanded across a matrix. So for that very reason strategies or methods are needed to help the carbon nanotubes spread as much as possible within the polymer matrix.

image description

A new development: the use of copolymers

Different strategies are used to spread the carbon nanotubes across the polymer matrix. Firstly, electric and magnetic fields. Since carbon nanotubes are conductors, they position and align themselves in the desired direction when they come up against an electric field. What is more, the surface of these nanotubes can be changed by means of chemical treatments until a specific affinity or compatibility is achieved with the epoxy. Finally, this UPV/EHU research team has put forward a new strategy: the use of copolymers, in other words, blocks of two different polymers joined to each other by means of chemical bonds. In this case, the styrene-butadiene-styrene copolymer was used.

The first step was to chemically transform one of the blocks of the copolymer (the butadiene in this case), to make it compatible with the epoxy resin matrix. The other block, by contrast, was divided, but as it has a covalent bond with the butadiene, the division was on a nanometric scale and nanostructures were produced. “That way the carbon nanotubes disperse much better across the epoxy matrix, without forming clusters,” pointed out Kortaberria. In general, “all the coatings we prepared were more stable than the ones based on the epoxy alone. The most stable coating is the one that has 0.2% of carbon nanotubes,” he added. The research team saw that the coating properties could be improved by varying the quantities of copolymers and nanotubes, thermal stability and behaviour, in particular, when handling temperature, and that coatings suitable for industry could be designed.

“The spread of the nanotubes has improved considerably with the use of copolymers, and the properties of the epoxy resin-based coatings are maintained; in some cases they have even improved,” asserted Kortaberria. “All this makes it possible to produce coatings suitable for industry with enhanced characteristics,” he added.

Source: nanoBasque

Oklahoma Nanotechnology Company Secures $2.7M to Expand Manufacturing Capacity


 

Food and NT 4153936-3x2-340x227A Norman-based technology company has secured $2.7 million in financing to add staff and expand its production capacity.

SouthWest NanoTechnologies Inc. produces carbon nanotube materials used in printed electronics, energy storage and composites applications.

“We need to add to our capacity to meet the demand for our specialty multi-wall products driven by our strategic partnerships and distribution agreements,” company President Dave Arthur said in a news release.

“This additional funding will also be used for (research and development) to develop additional carbon nanotube materials and inks that meet customer specifications.”

SouthWest NanoTechnologies will use its new funding to expand its Norman plant and fill about eight available positions for scientists, engineers and technical support personnel.

Arthur said the company’s Norman plant has only one shift of workers, but he hopes to increase that to three by the end of the year to churn out more nanotubes.

“We’re shipping as much of that material as we can make,” he said.

The company is getting $1.7 million as part of a $4 million round of convertible notes.

The other $1 million is from a venture debt transaction.

Arthur said the company also intends to invest in ramping up its catalyst operations, which provide the feedstock to make nanotubes.

SouthWest NanoTechnologies has licensed its catalyst to an Asian nanotube manufacturer to serve that market, he said.

Such deals could be expanded to include manufacturers around the world as the technology becomes more widespread.

Dave Arthur w300-97e212016cc04a09d6d1ac403be54d47

               

Dave Arthur, SouthWest NanoTechnologies Inc. president

 

 

 

Arthur said in the next five years or so carbon nanotubes could be used to enhance cement and asphalt, reducing infrastructure costs and making it easier to detect cracks.

Genesis Nanotech Headlines Are Out!


Organ on a chip organx250Genesis Nanotech Headlines Are Out! Read All About It!

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SUBCOMMITTE EXAMINES BREAKTHROUGH NANOTECHNOLOGY OPPORTUNITIES FOR AMERICA

Chairman Terry: “Nanotech is a true science race between the nations, and we should be encouraging the transition from research breakthroughs to commercial development.”

WASHINGTON, DCThe Subcommittee on Commerce, Manufacturing, and Trade, chaired by Rep. Lee Terry (R-NE), today held a hearing on:

“Nanotechnology: Understanding How Small Solutions Drive Big Innovation.”

 

 

electron-tomography

“Great Things from Small Things!” … We Couldn’t Agree More!