Thin-film organic electronic devices are at the core of the fast growing plastic electronics industry that aims to deliver flexible, lightweight and cheap electronics products to consumers in many different shapes and forms such as disposable or wraparound displays, cheap identification tags, low cost solar cells and chemical and pressure sensitive sensors.

The performance of devices like organic light emitting diodes (OLEDs), flexible solar cells, or plastic electronics is sensitive to moisture because water and oxygen molecules seep past the protective plastic layer over time and degrade the organic materials which form the core of these products. To protect these sensitive devices, barrier technologies have been developed that protect them from environmental degradation. State-of-the-art barrier materials employ metal oxide (MOx) thin films, commonly from aluminum or silicon oxides, which provide excellent protection from atmospheric oxygen and water, but still suffer from two problem areas:
1) Defects such as pinholes, cracks and grain boundaries are common in thin oxide barrier films when fabricated onto plastic substrates. These defects cause a ‘pore effect’, where oxygen and water molecules are able to seep through and penetrate the plastic barrier. 2) MOx films are brittle, which can result in cracks upon repeated flexing.

A new study demonstrates a nanocomposite material that can initiate self-healing upon the influx of water through pores and cracks by delivering titanium dioxide nanoparticles to the defective site, which ultimately slows the rate of moisture diffusion to the reactive electronic device.

"The concept of self-healing has become a popular theme in the field of material science" Kenneth J. Balkus, Jr. tells Nanowerk. "While the idea of self-healing has been around for many years, recent studies on the autonomic healing of structural polymers has brought about a new wave of research." (We have reported on several recent activities in this area in previous Spotlights: Nanomaterial, heal thyself and Self-healing nanotechnology anticorrosion coatings as alternative to toxic chromium)
Balkus, a professor of chemistry at the University of Texas at Dallas, points out that, while these studies present a novel method for the autonomic healing of polymer matrices, the application of this strategy to self-healing metal oxides is not possible since the fundamental property of metal oxide thin films in permeation barriers that makes them appealing is their ability to exclude water and oxygen, a feat that polymeric healing cannot achieve.

"This challenge has led us to develop a method to encapsulate highly reactive materials in a polymer shell," says Harvey A. Liu, a student in Balkus's group and first author of a recent paper in Advanced Functional Materials that describes this work ("A Delivery System for Self-Healing Inorganic Films").
"Since the major source of device failure is the influx of moisture through stress-induced cracks, as well as through defects, we have developed a system that is not only physically responsive to flexing, but also chemically responsive to the influx of moisture," Liu describes the team's work. "In order to perform this action we have employed a water-degradable polymer, poly(lactic acid) (PLA), as the shell structure to encapsulate the healing agent, titanium tetrachloride. TiCl4 was chosen because of its rapid reactivity, volatility, and its ability to propagate repair without the introduction of a catalyst."

Liu explains how their proposed delivery system for healing agents works: "The permeation barrier consists of a metal oxide and a polymer. Integrated within the polymer layer are porous fibers composed of a water-degradable polymer encapsulating a reactive metal oxide precursor. The influx of atmospheric moisture through holes in the inorganic layer caused by stress-induced cracks or defects leads to the hydrolysis of the degradable polymer. The degradation of the polymer releases the metal oxide precursor, which diffuses into the crack and subsequently reacts with moisture to form a solid metal oxide to seal the crack."
Liu points out that their strategy does not solve the problem of cracking within the permeation barrier, but it does provide the potential for prolonging the effectiveness of the permeation barriers in excluding moisture, thus prolonging the lifetime of the organic electronic devices.

Interestingly, the technique developed by Balkus's team not only addresses self-healing of thin metal oxide films but can also be considered a method to store and release a highly reactive material in a biodegradable biocompatible polymer; something that could find uses in other areas, for instance drug delivery.
The team is currently exploring the use of new metal oxide precursors and attempts to extend this methodology to other types of films such as coatings for corrosion prevention.

By Michael Berger. Copyright 2008 Nanowerk LLC

Reblog this post [with Zemanta]

This week Nature Nanotechnology journal reveals how scientists from the London Centre for Nanotechnology (LCN) at UCL are using a novel nanomechanical approach to investigate the workings of vancomycin, one of the few antibiotics that can be used to combat so-called ‘superbugs’, such as MRSA.

The researchers, led by Dr Rachel McKendry and Professor Gabriel Aeppli, developed ultra-sensitive probes capable of providing new insight into how antibiotics work, paving the way for the development of more effective new drugs.

“There has been an alarming growth in antibiotic-resistant hospital superbugs such as MRSA and vancomycin-resistant Enterococci (VRE),” said Dr McKendry. “This is a major global health problem and is driving the development of new technologies to investigate antibiotics and how they work.

“The cell wall of these bugs is weakened by the antibiotic, ultimately killing the bacteria,” she continued.

“Our research on cantilever sensors – tiny levers no wider than a human hair – suggests that the cell wall is disrupted by a combination of a local antibiotic and a polymer known as a mucopeptide binding together, and the spatial mechanical connectivity of these events.

“Investigating both these binding and mechanical influences on the cells’ structure could lead to the development of more powerful and effective antibiotics in future.”

During the study Dr McKendry, Joseph Ndieyira, Moyu Watari and co-workers used these cantilever arrays to examine the process that ordinarily takes place in the body when vancomycin binds itself to the surface of the bacteria.

They coated the cantilever array with polymers known as mucopeptides from bacterial cell walls and found that, as the antibiotic attaches itself it generates a surface stress on the bacteria, which can be detected by a tiny bending of the cantilever sensors.

The team suggests that this stress contributes to the disruption of the cell walls and the breakdown of the bacteria.

The interdisciplinary team went on to compare how vancomycin interacts with both non-resistant and resistant strains of bacteria. The ‘superbugs’ are resistant to antibiotics because of a simple mutation that deletes a single hydrogen bond from the structure of their cell walls.

This small change makes it approximately 1,000 times harder for the antibiotic to attach itself to the bug, leaving it much less able to disrupt the cells’ structure, and therefore therapeutically ineffective.

“This work at the LCN demonstrates the effectiveness of silicon-based cantilevers for drug screening applications,” says Professor Gabriel Aeppli, Director of the LCN.

“According to the Health Protection Agency, during 2007 there were around 7,000 cases of MRSA and more than a thousand cases of VRE in England alone. In recent decades the introduction of new antibiotics has slowed to a trickle but without effective new drugs the number of these fatal infections will increase.”

The research was funded by the EPSRC (Speculative Engineering Programme), the IRC in Nanotechnology (Cambridge, UCL and Bristol), the Royal Society and the BBSRC.

Futuristic electronics and energy technologies pave the way for 21st Century applications

Washington, DC – The future of how the world communicates, and how we power our lives, will likely come from the same source. According to the latest NanoFrontiers newsletter and Trips to the Nanofrontier podcast, nanotechnology will be central to developing advanced, “faster, better, cheaper” electronics and “green” energy technologies.

In the latest installment of the podcast series Trips to the Nanofrontier, journalist Karen Schmidt interviews Dr. Jim Heath about how computers, healthcare applications and other devices will use nanotechnology to exchange and obtain information more effectively.

But to power these new applications, as well as every other modern human activity, officials from industry and government are searching for new technologies that will foster more efficient and less-polluting energy sources, according to the latest NanoFrontiers newsletter, Nanotechnology: Energizing the Future. From nanotech-enabled solar panels to long-lasting automobile batteries that contain nanoparticles, the emerging technology is a cornerstone of 21st Century energy sources.

“We see a future where vehicles run on electricity and are equipped with clever ways of making electricity on board, making us less dependent on gasoline. It’s the next great paradigm shift in our industry, an opportunity largely due to the rapid advancement in battery cell technology” that results from nanotechnology, according to Bob Lutz, General Motors vice chairman of Global Product Development, who is quoted in the report.

A U.S. research team led by Chinese scientists has created a nanotube-based dry adhesive that surpasses the stickiness of gecko feet -- no easy feat, since the animals can cling to nearly any type of surface.

Geckos rely on aligned microscopic hairs for their gravity-defying climbs. Their design mimics this arrangement, with a vertically aligned array of straight carbon nanotubes topped by a layer of curly, entangled nanotubes, Wang Zhonglin, the lead researcher from Georgia Institute of Technology, told Xinhua on Thursday.

Just as in the gecko foot, the combination produces an adhesive with superior strength in the shear direction -- clinging against the pull of gravity -- and regular strength in the normal, perpendicular direction, which allows the adhesive to be easily pulled away from a surface. The shear adhesive force of the nanotube array is almost 10 times that of the gecko foot.

Though the material might seem most appropriate for use by Spider-man, the real applications may be less glamorous. Because carbon nanotubes conduct heat and electrical current, the bionic gecko feet could be used to connect electronic devices.

Another application might be for adhesives that work long-term in space. "In space, there is a vacuum and traditional kinds of adhesives dry out, but nanotube dry adhesives would not be bothered by the space environment," said Dai Liming, another lead researcher from University of Dayton.

Their paper will appear in the Oct issue of journal Science. For the future, the researchers hope to learn more about the surface interactions so they can further increase the adhesive force. They also want to study the long-term durability of the adhesive, which in a small number of tests became stronger with each attachment.

Landmark poll shows little knowledge of emerging technologies

Washington, DC — A groundbreaking poll finds that almost half of U.S. adults have heard nothing about nanotechnology, and nearly nine in 10 Americans say they have heard just a little or nothing at all about the emerging field of synthetic biology, according to a new report released by the Project and Peter D. Hart Research. Both technologies involve manipulating matter at an incredibly small scale to achieve something new.

This new insight into limited public awareness of emerging technologies comes as a major leadership change is about to take hold in the nation’s capital. Public policy experts are concerned, regardless of party, that the federal government is behind the curve in engaging citizens on the potential benefits and risks posed by technologies that could have a significant impact on society.

“Early in the administration of the next president, scientists are expected to take the next major step toward the creation of synthetic forms of life. Yet the results from the first U.S. telephone poll about synthetic biology show that most adults have heard just a little or nothing at all about it,” says PEN Director David Rejeski. The poll findings are contained a report published today, The American Public’s Awareness Of And Perceptions About Potential Risks and Benefits of Nanotechnology & Synthetic Biology.

Synthetic biology is the use of advanced science and engineering to construct or re-design living organisms–like bacteria–so that they can carry out specific functions. This emerging technology is likely to develop rapidly in the coming years, much as nanotechnology did in the last decade. In the near future the first synthetic biology “blockbuster” drug is anticipated to hit the market—an affordable treatment for the 500 million people in the world suffering from malaria.

The poll, which was conducted by the same firm that produces the well-known NBC News/Wall Street Journal polls, found that about two-thirds of adults say they have heard nothing at all about synthetic biology, and only 2 percent say they have heard “a lot” about the new technology. Even with this very low level of awareness, a solid two-thirds of adults are willing to express an initial opinion on the potential benefits versus risks tradeoff of synthetic biology.

This survey was informed by two focus groups conducted in August in suburban Baltimore. This is the first time—to the pollsters’ knowledge—that synthetic biology has been the subject of a representative national telephone survey.

At the same time, the poll found that about half of adults say they have heard nothing at all about nanotechnology. About 50 percent of adults are too unsure about nanotechnology to make an initial judgment on the possible tradeoffs between benefits and risks. Of those people who are willing to make an initial judgment, they think benefits will outweigh risks by a three to one margin when compared to those who believe risks will outweigh benefits. The plurality of respondents, however, believes that risks and benefits will be about equal. A major industry forecasting firm determined that last year nanotech goods in the global marketplace totaled $147 billion.

According to the poll, the level of U.S. public awareness about nanotechnology has not changed measurably since 2004 when Hart Research conducted the first poll on the topic on behalf of the PEN.

Nanotechnology could be the answer to ensuring a safe supply of drinking water for regions of the world stricken by periodic drought or where water contamination is rife. Writing in the International Journal of Nuclear Desalination, researchers in India explain how carbon nanotubes could replace conventional materials in water-purification systems.

Water shortages and lack of access to safe drinking water will continue to grow as major global problems. At present, more than one billion people lack access to safe drinking water and 2.4 billion people lack access to proper sanitation, nearly all of them in the developing countries. At present a third of the world's population live in water-stressed countries, and by 2025, this is expected to rise to two-thirds.

S. Kar, R.C. Bindal, S. Prabhakar, P.K. Tewari, K. Dasgupta, and D. Sathiyamoorthy of the Bhabha Atomic Research Centre (BARC) in Mumbai, India, explain how new water purification technologies are constantly being investigated but to be viable in the developing world these have to be relatively simple and inexpensive to install, operate, and maintain.

They have turned to nanostructured, the carbon nanotubes, hollow carbon fibers less than a billionth the thickness of a human hair. The unique chemical properties of carbon nanotubes mean that only very small molecules, such as water molecules can pass along their interiors, whereas viruses, bacteria, toxic metal ions, and large noxious organic molecules cannot.

The team points out that the smooth and water repellant interior of carbon nanotubes means that a filter based on this technology would be very efficient, allowing a high flow rate of water through the filter without fouling. Importantly, the power needed to drive water through such a system will be low compared to conventional membrane technology.

However, to be useful as a nanotech filtration system for contaminated water, these nanoscale structures need to be engineered to form well-defined arrangements to allow the efficient decontamination of water. The team has now investigated the potential of forming water filtration systems based on carbon nanotubes that could remove arsenic, fluoride, heavy metals and toxic organic chemicals. Carbon nanotubes have impressive credentials for water purification, the researchers say.

Written by Ariel Schwartz

Flower-shaped nanoparticles, or “nanoflowers”, might lead to superior batteries in the near future. Chemist Gaoping Cao and colleagues report in the latest issue of Nano Letters that they are working on developing nanoflowers which could lead to longer battery life for cell phones, laptops, and more.

While nanoflowers are not new, Cao claims that previously discovered forms of the nanoparticle weren’t able to provide the longer battery life that will be necessary for electronics of the future.

In Cao’s study, scientists grew clusters of carbon nanotubes—each 50,000 times smaller than a strand of human hair—that have strong electrical conductivity. They then put manganese oxide on top of the nanotubes. The process resulted in dandelion-shaped nanoclusters that will ultimately lead to a battery system with a higher energy storage capacity, longer life, and greater efficiency that current batteries.

And while I would be happy to have a more self-sustaining laptop, perhaps the nanoflowers will have even more important uses— like keeping future plug-in hybrid vehicles running for longer.

Photo Credit: Nanowerk

The images allow the viewer to explore structures that would otherwise only be seen by analytical chemists. State-of-the-art technologies such as scanning electron microscopy and transmission electron microscopy help to create a genuinely different view of the world. These spectacular pictures come all from current research at BASF.

A fungus as a living factory

The filamentous fungus Aspergillus niger has the natural capacity to produce various technically useful enzymes such as phytase, glucanase and xylanase. However it is only able to produce these biocatalysts in small quantities. The microorganism was genetically modified to enable it to manufacture large quantities of phytase and other enzymes – as a kind of living factory. Aspergillus niger is cultured in fermenters. These are special sterile reactors in which the fungus produces the enzyme phytase from sugar and salts in a series of biochemical reactions. The picture shows the so-called mycelium, a collection of filamentous cells, of Aspergillus niger. The filaments have a diameter of around two to five micrometers.

Crystalline forms of boscalid

The picture shows crystalline particles of the crop protectant boscalid, which fights fungi in crops such as fruit, vegetables and vines but also in cereals and canola (oil seed rape). Boscalid consists of one to 10 micrometer sized particles that are distributed evenly on the leaf surface, forming a protective coating. An extremely important area of application is viniculture, where boscalid is available under the brand name Cantus® and is mainly used against the fungus Botrytis cinerea, also known as gray mold.

Proteins for surfaces

The spherical spores produced by the fungus Emericella nidulans are coated in a thin layer of the protein hydrophobin. Hydrophobin ensures that water rolls off the spores. Other fungi, such as mushrooms, also have a layer of hydrophobin on their caps. BASF researchers have succeeded in transferring the gene responsible for hydrophobin production to Escherichia coli bacteria. With the help of the bacteria, hydrophobin can be produced as a so-called performance protein on a large scale. Hydrophobin has versatile properties. It can change surfaces to such a degree that they become water resistant. BASF is the world’s first company to manufacture hydrophobin on an industrial scale using biotechnology.

Switching off genes for improved starch

The genetically modified potato Amflora produces a special starch with potential applications in the paper, textile and adhesive industries. The starch in conventional potatoes consists of two components – amylopectin and amylose. Certain industrial applications require only amylopectin. However, separating the two components is energy intensive and thus uneconomical. BASF scientists have succeeded in using gene technology to switch off the gene responsible for synthesizing the undesired amylose in potatoes. This led to the development of Amflora, a potato that only produces the desired starch component amylopectin. This optimized starch makes printer paper glossier and keeps adhesives liquid for longer. The image shows the surface of a potato leaf covered with superfine hairs and glandular cells that are invisible to the naked eye.

Securing the integrity of rock formations

These tiny particles have enormous strength since they stabilize loose rock in mining or tunnel construction, for example. The material that makes it possible is Meyco® MP 364 Flex, a resin produced from the reaction of two liquid components: modified polyisocyanate and a water glass solution. Both components are mixed on site using a static in-line mixer and pressed into the rock on the construction site. It hardens in just a few minutes, stabilizing the rock. Another advantage of the resin is that it is extremely difficult to ignite, and thus plays an important role in fire control, for example in tunnels.

Spiky spheres used as an adhesive

These spiky structures are polyvinylpyrrolidone (PVP) spheres. They have a diameter of around 100 µm and are extremely porous. This means that they dissolve in water very quickly, which can save a lot of time during certain processes in which they are used. Researchers are still investigating potential applications for these spiky spheres but they could be similar to those of conventional polyvinylpyrrolidone, which has good adhesive properties and is used in the pharmaceutical industry for tablets or as a binder. The cosmetics industry uses it in hair gel and hair spray and it is also deployed as an oilfield chemical.

Microstructures made from designer proteins

Self-assembling R16 type proteins, pictured here, are able to form spherical structures. Because the R16 protein is not found in this form in nature, BASF scientists have designed the synthetic protein in the laboratory using gene technology. Nature however provided them with a template: The R16 protein is modelled on silk proteins as well as the elastic protein resilin found in insects. During the production of the one to 10 micrometer-sized spheres, individual protein units join together in a kind of self-organizing process. Because the protein spheres demonstrate a skin smoothening effect, for example, an application in the cosmetics industry is a possibility.

Healthy fatty acids from plants

Researchers at BASF Plant Science have succeeded in genetically optimizing canola (oil seed rape) plants to make them capable of producing unsaturated omega-3 fatty acids. These fatty acids have a positive effect on human health because they lower the risk of stroke and cardiovascular disease. The human body is unable to produce these unsaturated fatty acids itself. This can only be done by deep-sea algae. BASF scientists have transferred the genes of the deep-sea algae responsible for the production of the fatty acids into canola plants. The oil will be added to foods such as yogurt and cheese or sold as food supplements in the form of oil capsules, for example. The electron microscopic image shows canola pollen on a petal.

Elastic fibers

For more than forty years, spandex fibers have ensured the permanent elasticity of many textiles, such as swimsuits, sportswear and hosiery. Seen through an electron microscope, the fibers consist of several filaments. One of the raw materials of these fibers is PolyTHF®, which BASF supplies to spandex manufacturers. The textile producers often combine the spandex fibers with polyamide (nylon), cotton or polyester fibers to give the textiles the desired elasticity. A spandex fiber of the most common thickness has an average diameter of around 70 micrometers, which is equivalent to the diameter of a normal human hair. Just 250 grams of spandex fiber of this thickness wound onto a bobbin can be up to 45 kilometers long.

Thermal insulation with cavities

The insulating material Styrodur® C (XPS) protects buildings from high and low temperatures. This BASF product, in the form of green rigid foam panels, is directly available to end customers in the construction industry. Its material structure is more homogeneous and fine-pored than conventional Styropor and thus much more stable. This is why Styrodur C is mainly used for insulation in applications under pressure load, such as floors. The material is made from polystyrene and foamed with CO2. Thanks to its many small cavities, the foam weighs very little. In contrast to solid structures such as steel or glass, the air contained in the cavities is a poor conductor of heat, which makes Styrodur C a good insulating material.

Unique iridescent colors

These thin platelets create a special iridescent effect in cosmetics. Known as UltradescenceTM pigments, they are made of pure titanium dioxide and are found in many cosmetic articles, such as lip gloss, powder, luminous foundation or lotions. By varying the thickness of the titanium dioxide platelets, BASF scientists can create any color they want. Because the platelets are only around 5 micrometers long and 0.6 micrometers wide, they are especially well suited for cosmetic products. Users do not feel the particles. The iridescent effect is created by the titanium dioxide: It reflects light like myriads of tiny mirrors without absorbing any of it. Ultradescence is currently available in green, gold, red, violet and blue.

Spherical catalysts

These tiny spheres are zeolite crystals that act as catalysts to speed up the chemical reaction in the production of amines. The amines produced with this catalyst are used in the manufacture of automobile tires. wThe zeolite crystals are interspersed with micropores. Like many natural enzymes, these pores contain acidic centers that activate the starting materials and thus speed up the reaction. Producing amines with the help of zeolite catalysts conserves resources and is safe because, in contrast to conventional methods, there is no waste and problematic raw materials can be avoided.

Zinc oxide particles protect against sunburn

Z-COTE® is a special zinc oxide which, used in sun creams, offers protection against sunburn. The nanopowder is used as a broadband filter against harmful UVA and UVB radiation. The fine zinc oxide particles in Z-COTE act as inorganic UV filters by reflecting the incident UV light like tiny mirrors. Since conventional zinc oxide pigments are white, they can produce an undesired whitening effect on the skin. This is prevented by reducing the size of the pigment particles to about 200 nanometers which makes them transparent. An additional benefit: the zinc oxide particles have an antimicrobial action and can also relieve skin irritation.

Pickering emulsions: dispersing water insoluble substances in water

An emulsion is a mixture of two liquids such as water and oil. One liquid is present in the form of droplets and is dispersed in the other liquid. Depending on which liquid is in droplet form, we speak of an oil-in-water or a water-in-oil emulsion. Emulsifiers and surfactants are important components of emulsions, as they promote the formation of droplets and thereby stabilize the mixture. But certain solids can also be added to stabilize an emulsion, that is, to prevent it from separating out into two different liquids. These solid-stabilized and thus surfactant-free emulsions are called Pickering emulsions. They are named after their discoverer S.U. Pickering and can be seen in this picture. With this technique, a hydrophobic – in other words, not miscible with water – active agent is enclosed in micrometer sized oil droplets. These are stabilized by nanometer sized particles made of a biodegradable polymer. Systems like this are suitable for introducing hydrophobic agents such as agrochemicals, pharmaceutical active ingredients or vitamins into aqueous formulations. Pickering emulsions are also used in cosmetic products such as sun creams.

Paliocrom keeps cars gleaming

Because of their smooth surface, Paliocrom® Orange pigments are used mainly for automotive coatings. They consist of aluminum flakes coated with a thin layer of iron oxide measuring only a few nanometers. Even at 1600 fold magnification the extremely thin iron oxide films are still smooth – and thus optimally reflect the light. They also guarantee bright colors. The high covering power of the pigments is also important for automotive coatings. Paliocrom Orange is particularly suitable for orange shades and red metallics.

Astacin Novomatt keeps leather matt, supple and clean

The leather matting agent Astacin Novomatt® is used for coating leather surfaces. The dispersion is suitable for any leather surface. In particular, Astacin Novomatt is ideally suited for the treatment of automotive leather. The inorganic or organic matting agents based on the aqueous acrylate or polyurethane dispersions used for coating are distinguished by their long service life on the leather surface. Besides the matting effect, Astacin Novomatt also endows the leather with a soft handle and protects it against soiling.

Nanocubes act as a storage medium for hydrogen

The desire to be mobile and yet not to be without communication and entertainment had led to ever smaller and lighter electronic devices. Whether it’s laptops, cell phones or CD players, a key issue is how to power these portable devices. What batteries do today could in the future be done by mini fuel cells. Hydrogen could act as a source of energy provided that the problem of storage for its use in mobile devices can be solved. A possible storage medium for hydrogen would be nanocubes made of metal organic frameworks (MOFs), whose properties are currently being tested by BASF researchers.


BASF is working on a new generation of foams with a cell size no longer in micro but in nanometer size. The idea behind these nanocellular foams is to reduce the cell size until they correspond to the mean free path of a gas molecule. This would cause the exchange of heat, which is the result of collisions between gas molecules, to come to a virtual standstill. The resulting foams would have thermal insulating properties similar to those of vacuum plates without the need to use a vacuum. This would improve the insulating performance of a foam by more than 50 % or reduce by more than half the material thickness required for a given insulating performance.

SlurryGloss - an environmentally friendly automotive coating

The clearcoat SlurryGloss is used in automotive production line coating. Unlike other car coatings, it is environmentally friendlier because organic solvents were replaced by water. The coating particles seen in the picture are formed during a certain production step known as dispersing of the binders in the aqueous phase. After the coating is applied, the particles melt during the baking process to produce a colorless, high-gloss clearcoat. This coat is particularly resistant to light, weatherproof and scratch-resistant and is also resistant to aggressive contaminants such as bird droppings. The network outside the coating particles consists of additives which – in combination with the adjusted particle size – are important for application of the clearcoat film and for its flow characteristics on the substrate.

Versatile range of uses for carbonyl iron powder

Carbonyl iron powder (CIP) was industrially produced for the first time by BASF 80 years ago. It has a wide variety of applications, for example in metal injection molding in conventional powder metallurgy, in the production of diamond tools, microwave absorbing materials and in inductor cores of electronic components. CIP is also incorporated in magnetic printing inks used to create security features on credit cards, tickets, banknotes or passports. CIP's unique electromagnetic properties, among others, make it superior to competitor materials. CIP is produced by the thermal decomposition of iron pentacarbonyl. During this decomposition process, spherical iron particles with the characteristic shell structure are formed.

Nanotechnology makes textile fibers dirt-repellent

Nanoparticles give the surface of these textile fibers a structure with an effect similar to that of the lotus plant’s leaves. From the leaves of this plant water and dirt just roll off. This effect makes the fibers water- and dirt-repellent. Tiny particles measuring less than 100 nanometers on the textile fibers produce a similar self-cleaning effect. These surfaces are coated with billions of these nanoparticles so close together that a speck of dust wouldn't fit between them. Between a particle of dirt and the surface of the textile fibers, a layer of air is formed on which the impurities "hover" – and can simply be washed off with water. Even stubborn dirt is then easy to remove. The nanocoating has so far been applied mainly to engineering textiles, such as fabrics for tents, awnings or sunshades. But materials used for work clothing and home textiles will also be benefiting from this new technology in future.

Keroflux optimizes diesel fuels

Diesel fuels are complex mixtures of hydrocarbons containing wax particles known as paraffins. At low temperatures these paraffins form large plate-like crystals that adversely affect the flow properties of diesel fuel. The consequence: after cold winter nights diesel engines may have difficulty starting. To prevent this happening, flow improvers like Keroflux® are used to reduce the crystalline growth of the paraffins. More precisely: the Keroflux wax dispersers can disperse and reduce the size of paraffin crystals and prevent paraffin deposits forming in diesel tanks. Diesel powered vehicles then start without problem even at low temperatures

Neopor insulates better

Neopor® is the improved form of Styropor®, BASF's classic among insulating materials. Neopor is made of blowing agent-containing and thus expandable polystyrene granules. The photo shows the bead-shaped particles after processing into foam blocks. Using an innovative technique, BASF has succeeded in integrating infrared absorbers and reflectors into the foam. They prevent the conduction of heat even at low material densities. Thus, Neopor provides a much better insulating performance than classical material because it insulates as good as, for example, Styropor, using much less material. This means that foam manufacturers save up to 50 percent on raw materials. Neopor panels are also approximately half the weight of their Styropor counterparts.

Silver flakes make plastics conductive

Silver is the most electrically conductive of all metals. When tiny flakes of silver are combined with non-conductive materials - such as plastics - the conductivity of the silver flakes can greatly extend the range of possible uses of plastics. Conductive plastics are in demand in the electronics industry, for example, as they are highly suitable for applications in which high-quality components have to be protected against electrostatic discharge or stray electromagnetic radiation – in the housings of electric motors, for instance. Conductive plastics also open up new possibilities for designing electronic components and equipment. Acknowledgements to BASF

Watchdog group slams FDA for continued delay and inaction
The Food and Drug Administration came under heavy fire today at a meeting it held to once again solicit comments regarding the agency’s oversight of nanomaterials. The FDA held a similar meeting in October 2006. A coalition of nonprofit consumer and environmental groups accused the agency of being derelict in its duty to protect Americans from harmful products.
“Emerging science raises concerns about potential human health threats from Nanoparticles, but the FDA allows them to be put into our cosmetics, our medicines—even our food,” said Ian Illuminato of Friends of the Earth. “More than two years after being warned about these dangers, the FDA still refuses to act. It’s unacceptable.”
At the 2006 meeting, many scientists and nonprofit groups—including Friends of the Earth and the International Center for Technology Assessment (ICTA)—gave presentations and submitted comments detailing why FDA oversight of nanotechnology was inadequate. The organizations also urged Americans to send written comments to the FDA and demand stronger oversight.
“Despite having received thousands of comments from Americans concerned about the threat that nanomaterials pose to human health and the environment, FDA still refuses to regulate such materials, adapt regulations for the new properties and risks of nanotechnology, or even require products be labeled,” said Jaydee Hanson, the International Center for Technology Assessment’s (ICTA) policy director. “This meeting is more of the same: all talk, no action. The agency has not even tried to address the public’s vocal concerns.”
The manufacture of products using nanotechnology—a powerful platform for manipulating matter at the level of atoms and molecules in order to alter their properties—has exploded in recent years. Hundreds of consumer products incorporating nanomaterials are now on the market, including cosmetics, sunscreens, sporting goods, clothing, electronics, baby and infant products, and food and food packaging. But evidence indicates that current nanomaterials may pose significant health, safety, and environmental hazards. Studies have raised doubts about the safety of nanoparticles, suggesting that their tiny size may make them more toxic, that they may produce unpredictable immunological responses, and that some can penetrate major organs including the brain.
In May 2006, a coalition including ICTA and Friends of the Earth filed the first legal action on the risks of Nanotechnology, a legal petition to the FDA calling on the agency to regulate nanomaterials in consumer products. “FDA has had the blueprint on how to move forward with nanotechnology pending before it for over two years, wrapped with a bow,” said ICTA staff attorney George Kimbrell. “That the agency has failed to act is more of this administration’s anti-science, anti-regulatory political agenda that will pass the buck to the next administration to tackle.”
FDA called today’s meeting to again request public comments regarding the agency's oversight of Nanomaterials in various consumer products. The public meeting was also held with an eye towards implementing guidelines proposed by an FDA task force. The task force’s report is not new—it came out in August 2007—and did not recommend any mandatory action by the agency.
About Friends of the Earth
Friends of the Earth ( ) is the U.S. voice of the world’s largest grassroots environmental network, with member groups in 70 countries. Since 1969, Friends of the Earth has been at the forefront of high-profile efforts to create a more healthy, just world.
About The International Center for Technology Assessment
The International Center for Technology Assessment is a non-profit, non-partisan group that assesses a full range of technologies for their effects on the environment, human health, and social justice. Its latest work on nanotechnology can be found at: .

New ECS Professor Darren Bagnall manages an energetic research group within the Nano Group that is investigating new types of solar cell based on nanotechnology.
He is one of a number of staff in the School of Electronics and Computer Science (ECS) who will be moving this month into the new Mountbatten Building, a £55M development for leading-edge research in nanotechnology and optoelectronics.

This is an incredibly exciting time for us’, he says. ‘Over the last few years there has been a massive increase in funding for research into renewable energy. Even with currently available technology photovoltaics will probably provide 50 per cent of the world’s energy in around 40 years time, but what we actually want is to use nanotechnology so that solar cells are efficient and reliable, and yet so cheap that they can be afforded by the tens of thousands of villages around the world that currently do not have electricity.’

Some of Darren’s most eye-catching work includes the use of nanostructures that copy the complex patterns that produce extreme colour effects on moth-eyes and butterfly wings. He is also exploring the use of metallic nanoparticles – plasmonics - that can help to trap light within thin semiconductor layers in a solar cell.

Growing up in Stoke-on-Trent, Darren was a keen science student from an early age. His interest in electronics was probably triggered when his Dad, who was in the nightclub business, brought home a broken pinball machine. ‘It was no use to anyone’, says Darren, ‘but provided a whole load of sensors, switches and actuators that my brother and I used to build some crazy systems.’ The interest that developed from this led Darren to do a degree in electronics at Salford University, where he became interested in semiconductor devices and went on to do a PhD in Photovoltaics.

After his PhD, Darren went to Strathclyde University to develop blue laser diodes. Although they could not be manufactured in the 80s, blue laser diodes were known to be important requirements particularly for what has become known as Blu Ray technology. At Strathclyde Darren developed mono-layer quantum well lasers based on ZnCdSe, and was subsequently offered a research fellowship in Japan at the prestigious Institute of Materials Research of Tohoku University. During this time he made one of his most notable research contributions in producing the first zinc oxide laser. ‘This paper has helped kick-start a whole new research front and our paper now has over 1000 citations,’ he says.

After spending three years in Japan, Darren wanted to return to the UK and he was delighted when he was appointed to a lectureship at ECS. ‘I found the infrastructure and the cleanrooms amazing’, he said. ‘I was also really struck by the tremendous ambition and energy in ECS.’

Since arriving in Southampton Darren has had the opportunity to use his experience in optoelectronics and apply it to working with silicon, a material that can be made to interact with light only with extreme ingenuity: ‘What we can do is create nanoscale features that are much smaller than the wavelength of light and thereby trick light into doing things it wouldn’t normally do.’

For example, Darren has shown that if tens of thousands of nanoscale swastikas are arranged on a square millimetre, he can ‘twist’ light in accordance with the rotation of the swastikas and thereby create artificial ‘metamaterials’ that control polarization. It is this concept of the metamaterials and their application to photovoltaics that drives his current research.

Darren’s commitment and optimism carried him through the fire which destroyed £50M worth of ECS research three years ago. Although each of his team lost at least a year’s work, he feels the episode has now given them a unique opportunity.
‘We are now in a position where we have a great deal of knowledge and yet have the chance to redesign our experiments right from the very beginning,’ he said. ‘Although this will take us some time, I expect it to yield some very exciting results.’
Darren’s first aim in the new facility will be to make the first 20 per cent efficient solar cell based on thin film silicon – ‘It won’t be easy’, he says, ‘but we think we know the way to do it.’

Meanwhile, Darren does not confine all of his energy to the University. He is also something of a fitness fanatic. In the past he has raced triathlons, marathons and fell races at a high level, and still holds ambitions to complete an Ironman triathlon and to swim Loch Lomond.

Most serious of all he wants to get back into his old habit of beating Dr Neil Broderick on their regular runs around the New Forest. ‘It’s such an amazing place and we’re very lucky to have it on our doorstep,’ he says. Of course, now I tend to find it’s at its best when we’re running towards the pub! And especially when Australia hasn’t managed to keep up.’

NanoMarkets, a leading industry analyst firm based here, today announced its next report on thin-film and organic photovoltaics markets. The report titled, "The Future of Thin-Film and Organic Photovoltaics Manufacturing" will be available the week of September 8th. Additional details about the report including a preview are available on the firm's website at

About the Report:

The rapid and recent commercialization of thin-film and organic PV has automatically put the spotlight on manufacturing issues. There are many different approaches being used today from traditional sputtering to avant-garde functional printing approaches. In some cases the old and the new are combined in the same fabrication plant. Some solar panel firms are going with a turnkey plant supplied by a large equipment manufacturer. Others are building their own plants from scratch.

With so much diversity and change in this field, NanoMarkets believes that the time is right for this new report which surveys the manufacturing of thin-film PV (TFPV) and organic PV (OPV.) One goal of this report is to analyze the underlying performance of the plants built to date and to both understand where the challenges are and where the solutions to these challenges may be coming from. Another goal is to forecast the aggregate capacity of TFPV and OPV plants that are currently being built throughout the world or likely to be built in the near future. A third is to project the expenditures of TFPV firms on production equipment over an eight year period.

One question that this report deals with specifically is the thorny question as to how important the future role of printing will be to the PV sector and which equipment firms are having success selling into this sector. We also discuss such matters as the tradeoffs between low manufacturing costs and cell efficiencies, the importance of economies of scale, integration of manufacturing facilities, approaches to manufacturing new cell types, etc.

This report analyzes the state of the art in fabrication of both the manufacture of the photoactive layers themselves and the metallization process. We analyze the available data on how successful each approach to the manufacture of thin-film and organic PV is currently being and where the firms active in this space are looking for improvements and breakthroughs. In addition to the analysis itself, this report includes profiles of the manufacturing operations of 15 firms involved in producing solar products in the TFPV and OPV sector.

About NanoMarkets:

NanoMarkets tracks and analyzes emerging market opportunities in electronics created by developments in advanced materials. The firm has published numerous reports related to organic, thin film and printable electronics materials and applications and maintains a blog at that comments on industry trends and events. For a full listing of the firm's reports and downloadable white papers and report summaries please visit

Scientists grow 'nanonets' able to snare added energy transfer
New structure improves material used in microelectronics and water-splitting
Researchers at Boston College report creating nanonets, pictured here magnified 50,000 times. The novel nano-scale structure was grown from titanium and silicon in a two-dimensional network of wires that resembles...

CHESTNUT HILL, MA (September 2, 2008) – Using two abundant and relatively inexpensive elements, Boston College chemists have produced nanonets, a flexible webbing of nano-scale wires that multiplies surface area critical to improving the performance of the wires in electronics and energy applications.
When pushed by the pin-like tip of a scanning tunneling microscope, the nanonet rolls up. When the device is removed, the nanonet unfurls, demonstrating a remarkable flexibility in this new...

Researchers grew wires from titanium and silicon into a two-dimensional network of branches that resemble flat, rectangular netting, Assistant Professor of Chemistry Professor Dunwei Wang and his team report in the international edition of the German Chemical Society journal Angewandte Chemie.

By creating nanonets, the team conquered a longstanding engineering challenge in nanotechnology: creating a material that is extremely thin yet maintains its complexity, a structural design large or long enough to efficiently transfer an electrical charge.

"We wanted to create a nano structure unlike any other with a relatively large surface area," said Wang. "The goal was to increase surface area and maintain the structural integrity of the material without sacrificing surface area and thereby improving performance."

Tests showed an improved performance in the material's ability to conduct electricity through high quality connections of the nanonet, which suggest the material could lend itself to applications from electronics to energy-harvesting, Wang said. Titanium disilicide (TiSi2) has been proven to absorb light across a wide range of the solar spectrum, is easily obtained, and is inexpensive. Metal silicides are also found in microelectronics devices.
Nanonets grown by Boston College Assistant Professor of Chemistry Dunwei Wang and his research team are shown in this photo fully extended (a). At right is the tip of a...

The nanonets grew spontaneously from the bottom-up through simple chemical reactions, unprovoked by a catalyst, according to Wang and co-authors, post doctoral researcher Xiaohua Liu and graduate students Sa Zhou and Yongjing Lin.

Basic nano structures are commonly created in zero or one dimension, such as a dot composed of a small number of atoms. The most complex structures grow in three dimensions – somewhat resembling the branches of a tree. Working in 2D, Wang's team produced a web that under a microscope resembles a tree with all branches growing in the same perpendicular direction from the trunk.

Using titanium disilicide intrigued Wang because of the material's superior conductivity. Late last year, researchers at the Max Planck Institute for Bioinorganic Chemistry observed that a titanium disilicide semiconductor photo catalyst splits water into hydrogen and oxygen. The semiconductor also stores the gases produced, enabling the simple separation of hydrogen and oxygen. So-called water splitting may play a key role in producing hydrogen for fuel.

"We're excited to have discovered this unique structure and we are already at work to gauge just how much the nanonet can improve the performance of a material that is already used in electronics and clean energy applications," said Wang.

Nanotechnology Consumer Products Are in Your Mouth and On Your Face

WASHINGTON — New nanotechnology consumer products are coming on the market at the rate of three to four per week, a finding based on the latest update to the nanotechnology consumer product inventory maintained by the Project on Emerging Nanotechnologies (PEN).

One of the new items among the more than 600 products now in the inventory is Swissdent Nanowhitening Toothpaste with “calcium peroxides, in the form of nano-particles.” Today, in testimony before the U.S. Senate Committee on Commerce, Science & Transportation, PEN Project Director David Rejeski cited Ace Silver Plus—another of the nine nano toothpastes in the inventory—as an example of the upsurge in nanotechnology consumer products in stores. The hearing marks the start of U.S. Senate debate on the future direction of the annual $1.5 billion federal investment in nanotechnology research and development (R&D).

The number of consumer products using nanotechnology has grown from 212 to 609 since PEN launched the world’s first online inventory of manufacturer-identified nanotech goods in March 2006. Health and fitness items, which include cosmetics and sunscreens, represent 60 percent of inventory products. The colorful and searchable list of nanotechnology merchandise—containing everything from nanotech diamonds and cooking oil, to golf clubs and iPhones—is available free at

There are 35 automotive products in the PEN inventory, including the Hummer H2. General Motors Corporation bills the H2 as having a cargo bed that “uses about seven pounds of molded in color nanocomposite parts for its trim, center bridge, sail panel and box rail protector.”

Nanoscale silver is the most cited nanomaterial used. It is found in 143 products or over 20 percent of the inventory. Carbon, including carbon nanotubes and fullerenes, is the second highest nanoscale material cited. Other nanoscale materials explicitly referenced in products are zinc (including zinc oxide) and titanium (including titanium dioxide), silica and gold.

While polls show most Americans know little or nothing about nanotechnology, last year nanotechnology was incorporated into more than $88 billion worth of products sold. By 2014, Lux Research estimates $2.6 trillion in manufactured goods will incorporate nanotechnology—or about 15 percent of total global output. Despite a 2006 worldwide investment of $12.4 billion in nanotech R&D, comparatively little was spent on examining nanotechnology’s potential environmental, health and safety risks.

“Public trust is the ‘dark horse’ in nanotechnology’s future,” says Rejeski in his testimony. “If government and industry do not work to build public confidence in nanotechnology, consumers may reach for the ‘No-Nano’ label in the future and investors will put their money elsewhere.”

According to Rejeski, “The use of nanotechnology in consumer products and industrial applications is growing rapidly, with the products listed in the PEN inventory showing just the tip of the iceberg. Public perceptions about risks—real and perceived—can have large economic consequences. How consumers respond to these early products—in food, electronics, health care, clothing and cars—is a litmus test for broader market acceptance of nanotechnologies in the future.”

Medical gauze hasn't changed much since World War I: Medics can only stuff it into a gushing wound and pray.

Now chemists have infused cotton gauze with nanoparticles, giving it a vastly improved ability to halt blood loss -- even in tight spots like the neck or groin where it's hard to apply pressure. The new material could help save lives on the battlefield and in civilian situations, where trauma victims often bleed to death before they can be transported to a hospital or other medical facility.

"We are currently testing bandages because hemorrhage is a leading cause of death in military trauma patients," says Richard McCarron, head of trauma and resuscitative medicine at the Naval Medical Research Center in Silver Spring, Md. "The recent tests with Combat Gauze indicate that it decreased blood loss and improved survival."

In this video, researchers test Combat Gauze on an anesthetized pig. The pig's aorta is slit, then the gauze is applied for a brief time, which stops the flow of blood. Warning: Content may be disturbing to some viewers.

For more, visit video.

The lifesaving fabric McCarron refers to is made by Z-Medica, a medical products company based in Connecticut. According to Z-Medica CEO Ray Huey, the new product has already saved two lives.

"In 2002, following the September 11 attacks, the military was looking at new technologies to stop bleeding," Huey says.

When the Navy conducted a test of high-tech medical products, Huey says the clear winner was Z-Medica's first product, QuikClot, a grainy powder that can be dumped into gushing wounds to stanch bleeding. Shortly thereafter, the military started sending it to troops in Iraq and Afghanistan.

Unfortunately, the soldiers reported some problems: QuikClot would get hot when it came into contact with blood or water, and in some instances it caused serious burns. While burns are better than bleeding to death, it still wasn't an optimal solution.

The Navy turned to Galen Stucky, one of the top names in inorganic materials research, to work out the kinks. Stucky and several graduate students were able to solve the heating problem, file several patents, and form a business relationship with Z-Medica.

Ironically, the solution to the heating problem lay in replacing QuikClot with a material that has been used in medical tests for more than 50 years. The key ingredient in the new gauze is kaolin clay, which is often used to make pottery and happens to be rich in aluminosilicate nanoparticles -- which trigger blood clotting.

"Kaolin clay has been used since the 1950s as an activating agent for a clotting test that medical doctors routinely perform," says graduate student April Sawvel, who worked on the project. "We tested it against the original granular QuikClot and discovered that it worked just as well, but without the large heat release associated with the original QuikClot formulation."

Although researchers have raised concerns about the safety of nanoparticles, the aluminosilicates found in kaolin clay have been used on the human body, and introduced into it, for eons. Furthermore, by triggering blood clotting, the nanoparticles should effectively trap themselves at the site of the injury -- so they don't wind up wandering deep into the body.

Immediately following the researchers' discovery, Z-Medica quickly moved to combine the clay with gauze, making it much easier to use.

"We immediately started looking at ways to impregnate gauze with this material," Huey says. "We very quickly prototyped some material. When I say very quickly, I mean within less than two weeks."

Less than a year later, QuickClot Combat Gauze is in the hands of Special Forces operators, the Coast Guard and emergency-room doctors.

CAMBRIDGE, Mass. — In a surprise development that could have implications for powering electronics, cars and even the military, researchers at MIT have created the world's first batteries constructed at the nano scale by microscopic viruses.

A much-buzzed-about paper published in the Proceedings of the National Academy of Sciences earlier this month details the team's success in creating two of the three parts of a working battery—the positively charged anode and the electrolyte. But team leader Angela Belcher told PM Wednesday that the team has been seriously working on cathode technology for the past year, creating several complete prototypes.

"We haven't published those yet, actually. We're just getting ready to write them up and send them off," says Belcher, who won a MacArthur genius grant for her work in 2004 and a Breakthrough Award from PM in 2006. "The cathode material has been a little more difficult, but we have several different candidates, and we have made full, working batteries."

Instead of physically arranging the component parts, researchers genetically engineer viruses to attract individual molecules of materials they're interested in, like cobalt oxide, from a solution, autonomously forming wires 17,000 times thinner than a sheet of paper that pack themselves together to form electrodes smaller than a human cell.

"Once you do the genetic engineering with the viruses themselves, you pour in the solution and they grow the right combination of these materials on them," Belcher says.

The team is working on three main architectures: Filmlike structures—as small as a human cell—could form a clear film to power lab-on-a-chip applications to laminate into smart cards, or even to interface with implanted medical devices. Meshlike architectures—billions of tiny nano-components all interfaced together—might one day replace conventional batteries in larger applications such as laptops and cars. And fiberlike configurations—spun from liquid crystal like a spider's silk—might one day be woven into textiles, providing a wearable power source for the military. "We definitely don't have full batteries on those [fiber architectures]. We've only worked on single electrodes so far, but the idea is to try to make these fiber batteries that could be integrated into textiles and woven into lots of different shapes," Belcher says.

The M13 viruses used by the team can't reproduce by themselves and are only capable of infecting bacteria. At just 880 nanometers long—500 times smaller than a grain of salt—the bugs allow researchers to work at room temperatures and pressures with molecular precision, using and wasting fewer hazardous materials in the process. Now that they've demonstrated the construction of such tiny electronic components is possible, the challenge facing researchers is how to make them practical.

"What we're working on is not thinking about a particular device application, but trying to improve the quality of the anode and cathode materials—using biology just to make a higher quality material for energy density," Belcher says. "We haven't ruled out cars. That's a lot of amplification. But right now the thing is trying to make the best material possible, and if we get a really great material, then we have to think about how do you scale it.

Sound waves, moving from left to right, encounter an object surrounded by an “acoustic cloak” that causes the waves to re-form as if the object weren’t there.
Credit: New Journal of Physics

Acoustic Cloaking
Design for meta­materials that deflect sound waves

Source: "Acoustic cloaking in two dimensions: a feasible approach"
Daniel Torrent and José Sánchez-Dehesa
New Journal of Physics
10: 63015-63025

Results: Designs have been drawn up for a material that could lead to the first acoustic cloaking device. Computer models suggest that alternating layers of two types of patterned, elastic rods, called sonic crystals, would direct sound waves around an object so that they re-formed on the other side with no distortion, as if the sound waves had never encountered the object.

Why it matters: The cloak could make ships invisible to sonar and improve the acoustics of concert halls by allowing sound to pass around load-bearing columns. Buildings covered in the material would be shielded from street noise. Other researchers have designed and built materials that can cloak objects from microwaves, but they divert only particular wavelengths. The new research predicts that an acoustic cloak would shield objects from a broad spectrum of sounds, from high pitches to low.

Methods: The researchers developed computer models based on previous theoretical work and used them to simulate the movement of sound waves around acoustic cloaks with varying numbers of layers. The models showed that sound waves flow best around materials made of 200 layers of composite sonic crystals.

Next steps: The designed material would work only in two dimensions--with sound waves traveling in a plane. The researchers will extend their theoretical work, developing new designs for materials that work in three dimensions, and then build and test them.

Testing Nanotoxicity
A rapid assay offers a much-needed way to evaluate nano­materials' safety

Source: "Perturbational profiling of nanomaterial biologic activity"
Stanley Y. Shaw et al.
Proceedings of the National Academy of Sciences
105: 7387-7392

Results: Researchers have developed a way to evaluate the safety of nanoparticles by quickly comparing them to nanoparticles already tested for toxicity. They determined the effects of different doses of nanoparticles on a ­variety of cell types in culture. Then they performed tests in mice, showing that their tests on cells could predict which nanoparticles would have effects in animals similar to those of previously screened nanoparticles.

Why it matters: Hundreds of products containing nanomaterials are already on the market, and more are under development. Few if any of the materials have been thoroughly tested. The new assay is faster and cheaper than testing in animals but appears to give a good approximation of the results; it represents an important step toward speeding up the process of evaluating new nanomaterials. The approach could help researchers choose between similar nanoparticles on the basis of potential safety risks.

Methods: The researchers tested 50 nanoparticles, most of which are being developed for medical imaging, in the four cell types that they are most likely to encounter in the body. Each nanoparticle was tested at four different concentrations in mouse immune cells, human liver cells, and two types of human blood-­vessel cells. Automated systems collected data on cell death, metabolic changes, and other signs of toxicity.

Next steps: The experiment, which focused mostly on iron-containing nanoparticles and tiny semiconductor particles called quantum dots, now needs to be extended to other nanomaterials. The assay works well for nanoparticles entering the body intravenously, but to test the properties of nanomaterials that might enter in other ways, including inhalation, future assays will need to use different cell types, such as lung cells.


Researchers from Monash University have designed a nano-sized "trojan horse" particle to ensure healing antioxidants can be better absorbed by the human body.

Dr Ken Ng and Dr Ian Larson from the University's Faculty of Pharmacy and Pharmaceutical Sciences have designed a nanoparticle, one thousandth the thickness of a human hair, that protects antioxidants from being destroyed in the gut and ensures a better chance of them being absorbed in the digestive tract.

Antioxidants are known to neutralise the harmful effect of free radicals and other reactive chemical species that are constantly generated by our body and are thought to promote better health.

Normally our body's own antioxidant defence is sufficient, but in high-risk individuals, such as those with a poor diet or those at risk of developing atherosclerosis, diabetes or Alzheimer's disease, a nutritional source of antioxidants is required.

Dr Larson said orally delivered antioxidants were easily destroyed by acids and enzymes in the human body, with only a small percentage of what is consumed actually being absorbed.

The solution is to design a tiny sponge-like chitosan biopolymeric nanoparticle as a protective vehicle for antioxidants. Chitosan is a natural substance found in crab shells.

"Antioxidants sit within this tiny trojan horse, protecting it from attack from digestive juices in the stomach," Dr Larson said.

"Once in the small intestine the nanoparticle gets sticky and bonds to the intestinal wall. It then leaks its contents directly into the intestinal cells, which allows them to be absorbed directly into the blood stream.

"We hope that by mastering this technique, drugs and supplements also vulnerable to the digestive process can be better absorbed by the human body."

The research project will proceed to trials early in 2009.

Dr Ng said although the research was still in its early stages, the longer term aim of the project would be to include similarly treated nanoparticles into food items, similar to adding Omega-3 to bread or milk.

"For catechins — the class of antioxidants under examination and among the most potent dietary antioxidants -- only between 0.1 and 1.1 per cent of the amount consumed makes it into our blood. If we can improve that rate, the benefits are enormous."

Consumer Product Safety Commission Not Ready For Nanotech

Agency lacks budget, authority and expertise to ensure nanoproducts are safe

Washington, DC — The inability of the Consumer Product Safety Commission (CPSC) to carry out its mandate with respect to simple, low-tech products such as children’s jewelry and toy trains bodes poorly for its ability to oversee the safety of complex, high-tech products made using nanotechnology, according to a new report released by the Project on Emerging Nanotechnologies (PEN).

Two nanotech products under the jurisdiction of the CPSC are being used in the Olympic Games in Beijing – a pair of running shoes and a swimsuit. The products can be found in PEN’s consumer product inventory, which now contains more than 800 manufacturer-identified, nanotechnology-enabled items.

“The agency lacks the budget, the statutory authority and the scientific expertise to ensure the hundreds of nanoproducts now on the market, among them baby bottle nipples, infant teething rings, paints, waxes, kitchenware and appliances, are safe. This problem will only worsen as more sophisticated nanotechnology-based products begin to enter the consumer market,” argues E. Marla Felcher, who teaches at Harvard University’s Kennedy School of Government and is the author of the report, The Consumer Product Safety Commission and Nanotechnology.

The CPSC is charged with protecting the public against unreasonable risks of injury or death associated with consumer products. More than 15,000 consumer goods fall under the CPSC’s jurisdiction, including toys and baby products, sports equipment, fitness equipment, home improvement and garden equipment, clothing, appliances, electronics and computers. The consumer product inventory maintained by PEN indicates that nanotechnology has already found its way into every one of these product categories.

“During the fall of 2007, many Americans faced a hazard in their products that had been banned for 30 years — lead. As millions of children’s toys coated with lead paint were recalled, it became clear that government oversight had failed, and that the CPSC, the agency primarily responsible for the oversight of these toys, was stretched too thin from years of neglect, underfunding and the challenges posed by an increasingly global manufacturing system,” says PEN Director David Rejeski. “It is against this background that we need to ask the question: Is the CPSC adequately prepared to deal with nanotechnology, which is now associated with more than 800 manufacturer-identified consumer products ranging from infant pacifiers to paints to appliances to clothing?”

The release of PEN’s new report comes on the heels of the president signing legislation that eliminates lead in toys and either permanently or temporarily bans six types of phthalates in children’s products, which are under the CPSC’s jurisdiction. Phthalates are a broad family of chemicals primarily used to make vinyl soft and flexible and are found in thousands of products including toys, garden hoses, wiring and cables, construction materials, flooring, automotive interiors and medical devices.

Felcher’s report identifies many similarities between the issues raised by phthalates and nanomaterials: many of the same products that contain phthalates are now being made with nanomaterials (e.g., infants’ pacifiers and teething rings); both phthalates and nanomaterials can enter the human body through multiple pathways, such as the lungs or digestive tract; and jurisdiction over phthalates in the United States, like jurisdiction over nanomaterials, is spread over multiple agencies, including the Environmental Protection Agency and the Food & Drug Administration.

But despite these similarities, phthalates and nanomaterials differ in two important respects, Felcher says. First, phthalates have been the subject of thousands of scientific studies documenting their effect on the health of animals and humans—some demonstrating a link between the chemicals and decreased sperm count and sexual malformation in boys—while little is known about possible chronic hazards associated with nanomaterials. Second, nanomaterials are scientifically far more diverse than phthalates, increasing the complexity involved in understanding their toxicology.

“It took decades of research before lawmakers found the political will to keep lead and phthalates out of toys. It could take a very long time to research and ensure that potentially dangerous nanomaterials are kept out, too,” says Rejeski.

The new PEN report includes a number of recommendations Felcher believes will help the CPSC to improve its oversight of nanomaterials in consumer products, including:

  • Building the CPSC’s nanotechnology knowledge base and expertise.

  • Identifying companies and industries that are currently manufacturing nanoproducts and request that they submit research studies, risk assessment data and any information they possess that will enable the CPSC scientists to assess nanoproduct safety.

  • Urging Congress to amend the Consumer Product Safety Act to give the CPSC the authority to require manufacturers to identify any nanomaterials in their products.

  • Encouraging Congress to adopt a section of the Consumer Product Safety Act bill recommended by the National Commission on Product Safety in its 1970 Final Report, which would give the CPSC the authority to promulgate safety standards for “new” consumer products based on new and emerging technologies, including nanotechnology.