Tag Archives: Dr. Andrew Maynard

It’s a very ‘carbony’ time: graphene jacket, graphene-skinned airplane, and schwarzite

In August 2018, I been stumbled across several stories about graphene-based products and a new form of carbon.

Graphene jacket

The company producing this jacket has as its goal “… creating bionic clothing that is both bulletproof and intelligent.” Well, ‘bionic‘ means biologically-inspired engineering and ‘intelligent‘ usually means there’s some kind of computing capability in the product. This jacket, which is the first step towards the company’s goal, is not bionic, bulletproof, or intelligent. Nonetheless, it represents a very interesting science experiment in which you, the consumer, are part of step two in the company’s R&D (research and development).

Onto Vollebak’s graphene jacket,

Courtesy: Vollebak

From an August 14, 2018 article by Jesus Diaz for Fast Company,

Graphene is the thinnest possible form of graphite, which you can find in your everyday pencil. It’s purely bi-dimensional, a single layer of carbon atoms that has unbelievable properties that have long threatened to revolutionize everything from aerospace engineering to medicine. …

Despite its immense promise, graphene still hasn’t found much use in consumer products, thanks to the fact that it’s hard to manipulate and manufacture in industrial quantities. The process of developing Vollebak’s jacket, according to the company’s cofounders, brothers Steve and Nick Tidball, took years of intensive research, during which the company worked with the same material scientists who built Michael Phelps’ 2008 Olympic Speedo swimsuit (which was famously banned for shattering records at the event).

The jacket is made out of a two-sided material, which the company invented during the extensive R&D process. The graphene side looks gunmetal gray, while the flipside appears matte black. To create it, the scientists turned raw graphite into something called graphene “nanoplatelets,” which are stacks of graphene that were then blended with polyurethane to create a membrane. That, in turn, is bonded to nylon to form the other side of the material, which Vollebak says alters the properties of the nylon itself. “Adding graphene to the nylon fundamentally changes its mechanical and chemical properties–a nylon fabric that couldn’t naturally conduct heat or energy, for instance, now can,” the company claims.

The company says that it’s reversible so you can enjoy graphene’s properties in different ways as the material interacts with either your skin or the world around you. “As physicists at the Max Planck Institute revealed, graphene challenges the fundamental laws of heat conduction, which means your jacket will not only conduct the heat from your body around itself to equalize your skin temperature and increase it, but the jacket can also theoretically store an unlimited amount of heat, which means it can work like a radiator,” Tidball explains.

He means it literally. You can leave the jacket out in the sun, or on another source of warmth, as it absorbs heat. Then, the company explains on its website, “If you then turn it inside out and wear the graphene next to your skin, it acts like a radiator, retaining its heat and spreading it around your body. The effect can be visibly demonstrated by placing your hand on the fabric, taking it away and then shooting the jacket with a thermal imaging camera. The heat of the handprint stays long after the hand has left.”

There’s a lot more to the article although it does feature some hype and I’m not sure I believe Diaz’s claim (August 14, 2018 article) that ‘graphene-based’ hair dye is perfectly safe ( Note: A link has been removed),

Graphene is the thinnest possible form of graphite, which you can find in your everyday pencil. It’s purely bi-dimensional, a single layer of carbon atoms that has unbelievable properties that will one day revolutionize everything from aerospace engineering to medicine. Its diverse uses are seemingly endless: It can stop a bullet if you add enough layers. It can change the color of your hair with no adverse effects. [emphasis mine] It can turn the walls of your home into a giant fire detector. “It’s so strong and so stretchy that the fibers of a spider web coated in graphene could catch a falling plane,” as Vollebak puts it in its marketing materials.

Not unless things have changed greatly since March 2018. My August 2, 2018 posting featured the graphene-based hair dye announcement from March 2018 and a cautionary note from Dr. Andrew Maynard (scroll down ab out 50% of the way for a longer excerpt of Maynard’s comments),

Northwestern University’s press release proudly announced, “Graphene finds new application as nontoxic, anti-static hair dye.” The announcement spawned headlines like “Enough with the toxic hair dyes. We could use graphene instead,” and “’Miracle material’ graphene used to create the ultimate hair dye.”

From these headlines, you might be forgiven for getting the idea that the safety of graphene-based hair dyes is a done deal. Yet having studied the potential health and environmental impacts of engineered nanomaterials for more years than I care to remember, I find such overly optimistic pronouncements worrying – especially when they’re not backed up by clear evidence.

These studies need to be approached with care, as the precise risks of graphene exposure will depend on how the material is used, how exposure occurs and how much of it is encountered. Yet there’s sufficient evidence to suggest that this substance should be used with caution – especially where there’s a high chance of exposure or that it could be released into the environment.

The full text of Dr. Maynard’s comments about graphene hair dyes and risk can be found here.

Bearing in mind  that graphene-based hair dye is an entirely different class of product from the jacket, I wouldn’t necessarily dismiss risks; I would like to know what kind of risk assessment and safety testing has been done. Due to their understandable enthusiasm, the brothers Tidball have focused all their marketing on the benefits and the opportunity for the consumer to test their product (from graphene jacket product webpage),

While it’s completely invisible and only a single atom thick, graphene is the lightest, strongest, most conductive material ever discovered, and has the same potential to change life on Earth as stone, bronze and iron once did. But it remains difficult to work with, extremely expensive to produce at scale, and lives mostly in pioneering research labs. So following in the footsteps of the scientists who discovered it through their own highly speculative experiments, we’re releasing graphene-coated jackets into the world as experimental prototypes. Our aim is to open up our R&D and accelerate discovery by getting graphene out of the lab and into the field so that we can harness the collective power of early adopters as a test group. No-one yet knows the true limits of what graphene can do, so the first edition of the Graphene Jacket is fully reversible with one side coated in graphene and the other side not. If you’d like to take part in the next stage of this supermaterial’s history, the experiment is now open. You can now buy it, test it and tell us about it. [emphasis mine]

How maverick experiments won the Nobel Prize

While graphene’s existence was first theorised in the 1940s, it wasn’t until 2004 that two maverick scientists, Andre Geim and Konstantin Novoselov, were able to isolate and test it. Through highly speculative and unfunded experimentation known as their ‘Friday night experiments,’ they peeled layer after layer off a shaving of graphite using Scotch tape until they produced a sample of graphene just one atom thick. After similarly leftfield thinking won Geim the 2000 Ig Nobel prize for levitating frogs using magnets, the pair won the Nobel prize in 2010 for the isolation of graphene.

Should you be interested, in beta-testing the jacket, it will cost you $695 (presumably USD); order here. One last thing, Vollebak is based in the UK.

Graphene skinned plane

An August 14, 2018 news item (also published as an August 1, 2018 Haydale press release) by Sue Keighley on Azonano heralds a new technology for airplans,

Haydale, (AIM: HAYD), the global advanced materials group, notes the announcement made yesterday from the University of Central Lancashire (UCLAN) about the recent unveiling of the world’s first graphene skinned plane at the internationally renowned Farnborough air show.

The prepreg material, developed by Haydale, has potential value for fuselage and wing surfaces in larger scale aero and space applications especially for the rapidly expanding drone market and, in the longer term, the commercial aerospace sector. By incorporating functionalised nanoparticles into epoxy resins, the electrical conductivity of fibre-reinforced composites has been significantly improved for lightning-strike protection, thereby achieving substantial weight saving and removing some manufacturing complexities.

Before getting to the photo, here’s a definition for pre-preg from its Wikipedia entry (Note: Links have been removed),

Pre-preg is “pre-impregnated” composite fibers where a thermoset polymer matrix material, such as epoxy, or a thermoplastic resin is already present. The fibers often take the form of a weave and the matrix is used to bond them together and to other components during manufacture.

Haydale has supplied graphene enhanced prepreg material for Juno, a three-metre wide graphene-enhanced composite skinned aircraft, that was revealed as part of the ‘Futures Day’ at Farnborough Air Show 2018. [downloaded from https://www.azonano.com/news.aspx?newsID=36298]

A July 31, 2018 University of Central Lancashire (UCLan) press release provides a tiny bit more (pun intended) detail,

The University of Central Lancashire (UCLan) has unveiled the world’s first graphene skinned plane at an internationally renowned air show.

Juno, a three-and-a-half-metre wide graphene skinned aircraft, was revealed on the North West Aerospace Alliance (NWAA) stand as part of the ‘Futures Day’ at Farnborough Air Show 2018.

The University’s aerospace engineering team has worked in partnership with the Sheffield Advanced Manufacturing Research Centre (AMRC), the University of Manchester’s National Graphene Institute (NGI), Haydale Graphene Industries (Haydale) and a range of other businesses to develop the unmanned aerial vehicle (UAV), which also includes graphene batteries and 3D printed parts.

Billy Beggs, UCLan’s Engineering Innovation Manager, said: “The industry reaction to Juno at Farnborough was superb with many positive comments about the work we’re doing. Having Juno at one the world’s biggest air shows demonstrates the great strides we’re making in leading a programme to accelerate the uptake of graphene and other nano-materials into industry.

“The programme supports the objectives of the UK Industrial Strategy and the University’s Engineering Innovation Centre (EIC) to increase industry relevant research and applications linked to key local specialisms. Given that Lancashire represents the fourth largest aerospace cluster in the world, there is perhaps no better place to be developing next generation technologies for the UK aerospace industry.”

Previous graphene developments at UCLan have included the world’s first flight of a graphene skinned wing and the launch of a specially designed graphene-enhanced capsule into near space using high altitude balloons.

UCLan engineering students have been involved in the hands-on project, helping build Juno on the Preston Campus.

Haydale supplied much of the material and all the graphene used in the aircraft. Ray Gibbs, Chief Executive Officer, said: “We are delighted to be part of the project team. Juno has highlighted the capability and benefit of using graphene to meet key issues faced by the market, such as reducing weight to increase range and payload, defeating lightning strike and protecting aircraft skins against ice build-up.”

David Bailey Chief Executive of the North West Aerospace Alliance added: “The North West aerospace cluster contributes over £7 billion to the UK economy, accounting for one quarter of the UK aerospace turnover. It is essential that the sector continues to develop next generation technologies so that it can help the UK retain its competitive advantage. It has been a pleasure to support the Engineering Innovation Centre team at the University in developing the world’s first full graphene skinned aircraft.”

The Juno project team represents the latest phase in a long-term strategic partnership between the University and a range of organisations. The partnership is expected to go from strength to strength following the opening of the £32m EIC facility in February 2019.

The next step is to fly Juno and conduct further tests over the next two months.

Next item, a new carbon material.

Schwarzite

I love watching this gif of a schwarzite,

The three-dimensional cage structure of a schwarzite that was formed inside the pores of a zeolite. (Graphics by Yongjin Lee and Efrem Braun)

An August 13, 2018 news item on Nanowerk announces the new carbon structure,

The discovery of buckyballs [also known as fullerenes, C60, or buckminsterfullerenes] surprised and delighted chemists in the 1980s, nanotubes jazzed physicists in the 1990s, and graphene charged up materials scientists in the 2000s, but one nanoscale carbon structure – a negatively curved surface called a schwarzite – has eluded everyone. Until now.

University of California, Berkeley [UC Berkeley], chemists have proved that three carbon structures recently created by scientists in South Korea and Japan are in fact the long-sought schwarzites, which researchers predict will have unique electrical and storage properties like those now being discovered in buckminsterfullerenes (buckyballs or fullerenes for short), nanotubes and graphene.

An August 13, 2018 UC Berkeley news release by Robert Sanders, which originated the news item, describes how the Berkeley scientists and the members of their international  collaboration from Germany, Switzerland, Russia, and Italy, have contributed to the current state of schwarzite research,

The new structures were built inside the pores of zeolites, crystalline forms of silicon dioxide – sand – more commonly used as water softeners in laundry detergents and to catalytically crack petroleum into gasoline. Called zeolite-templated carbons (ZTC), the structures were being investigated for possible interesting properties, though the creators were unaware of their identity as schwarzites, which theoretical chemists have worked on for decades.

Based on this theoretical work, chemists predict that schwarzites will have unique electronic, magnetic and optical properties that would make them useful as supercapacitors, battery electrodes and catalysts, and with large internal spaces ideal for gas storage and separation.

UC Berkeley postdoctoral fellow Efrem Braun and his colleagues identified these ZTC materials as schwarzites based of their negative curvature, and developed a way to predict which zeolites can be used to make schwarzites and which can’t.

“We now have the recipe for how to make these structures, which is important because, if we can make them, we can explore their behavior, which we are working hard to do now,” said Berend Smit, an adjunct professor of chemical and biomolecular engineering at UC Berkeley and an expert on porous materials such as zeolites and metal-organic frameworks.

Smit, the paper’s corresponding author, Braun and their colleagues in Switzerland, China, Germany, Italy and Russia will report their discovery this week in the journal Proceedings of the National Academy of Sciences. Smit is also a faculty scientist at Lawrence Berkeley National Laboratory.

Playing with carbon

Diamond and graphite are well-known three-dimensional crystalline arrangements of pure carbon, but carbon atoms can also form two-dimensional “crystals” — hexagonal arrangements patterned like chicken wire. Graphene is one such arrangement: a flat sheet of carbon atoms that is not only the strongest material on Earth, but also has a high electrical conductivity that makes it a promising component of electronic devices.

schwarzite carbon cage

The cage structure of a schwarzite that was formed inside the pores of a zeolite. The zeolite is subsequently dissolved to release the new material. (Graphics by Yongjin Lee and Efrem Braun)

Graphene sheets can be wadded up to form soccer ball-shaped fullerenes – spherical carbon cages that can store molecules and are being used today to deliver drugs and genes into the body. Rolling graphene into a cylinder yields fullerenes called nanotubes, which are being explored today as highly conductive wires in electronics and storage vessels for gases like hydrogen and carbon dioxide. All of these are submicroscopic, 10,000 times smaller than the width of a human hair.

To date, however, only positively curved fullerenes and graphene, which has zero curvature, have been synthesized, feats rewarded by Nobel Prizes in 1996 and 2010, respectively.

In the 1880s, German physicist Hermann Schwarz investigated negatively curved structures that resemble soap-bubble surfaces, and when theoretical work on carbon cage molecules ramped up in the 1990s, Schwarz’s name became attached to the hypothetical negatively curved carbon sheets.

“The experimental validation of schwarzites thus completes the triumvirate of possible curvatures to graphene; positively curved, flat, and now negatively curved,” Braun added.

Minimize me

Like soap bubbles on wire frames, schwarzites are topologically minimal surfaces. When made inside a zeolite, a vapor of carbon-containing molecules is injected, allowing the carbon to assemble into a two-dimensional graphene-like sheet lining the walls of the pores in the zeolite. The surface is stretched tautly to minimize its area, which makes all the surfaces curve negatively, like a saddle. The zeolite is then dissolved, leaving behind the schwarzite.

soap bubble schwarzite structure

A computer-rendered negatively curved soap bubble that exhibits the geometry of a carbon schwarzite. (Felix Knöppel image)

“These negatively-curved carbons have been very hard to synthesize on their own, but it turns out that you can grow the carbon film catalytically at the surface of a zeolite,” Braun said. “But the schwarzites synthesized to date have been made by choosing zeolite templates through trial and error. We provide very simple instructions you can follow to rationally make schwarzites and we show that, by choosing the right zeolite, you can tune schwarzites to optimize the properties you want.”

Researchers should be able to pack unusually large amounts of electrical charge into schwarzites, which would make them better capacitors than conventional ones used today in electronics. Their large interior volume would also allow storage of atoms and molecules, which is also being explored with fullerenes and nanotubes. And their large surface area, equivalent to the surface areas of the zeolites they’re grown in, could make them as versatile as zeolites for catalyzing reactions in the petroleum and natural gas industries.

Braun modeled ZTC structures computationally using the known structures of zeolites, and worked with topological mathematician Senja Barthel of the École Polytechnique Fédérale de Lausanne in Sion, Switzerland, to determine which of the minimal surfaces the structures resembled.

The team determined that, of the approximately 200 zeolites created to date, only 15 can be used as a template to make schwarzites, and only three of them have been used to date to produce schwarzite ZTCs. Over a million zeolite structures have been predicted, however, so there could be many more possible schwarzite carbon structures made using the zeolite-templating method.

Other co-authors of the paper are Yongjin Lee, Seyed Mohamad Moosavi and Barthel of the École Polytechnique Fédérale de Lausanne, Rocio Mercado of UC Berkeley, Igor Baburin of the Technische Universität Dresden in Germany and Davide Proserpio of the Università degli Studi di Milano in Italy and Samara State Technical University in Russia.

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

Generating carbon schwarzites via zeolite-templating by Efrem Braun, Yongjin Lee, Seyed Mohamad Moosavi, Senja Barthel, Rocio Mercado, Igor A. Baburin, Davide M. Proserpio, and Berend Smit. PNAS August 14, 2018. 201805062; published ahead of print August 14, 2018. https://doi.org/10.1073/pnas.1805062115

This paper appears to be open access.

Better hair dyes with graphene and a cautionary note

Beauty products aren’t usually the first applications that come to mind when discussing graphene or any other research and development (R&D) as I learned when teaching a course a few years ago. But research and development  in that field are imperative as every company is scrambling for a short-lived competitive advantage for a truly new products or a perceived competitive advantage in a field where a lot of products are pretty much the same.

This March 15, 2018 news item on ScienceDaily describes graphene as a potential hair dye,

Graphene, a naturally black material, could provide a new strategy for dyeing hair in difficult-to-create dark shades. And because it’s a conductive material, hair dyed with graphene might also be less prone to staticky flyaways. Now, researchers have put it to the test. In an article published March 15 [2018] in the journal Chem, they used sheets of graphene to make a dye that adheres to the surface of hair, forming a coating that is resistant to at least 30 washes without the need for chemicals that open up and damage the hair cuticle.

Courtesy: Northwestern University

A March 15, 2018 Cell Press news release on EurekAlert, which originated the news item, fills in more the of the story,

Most permanent hair dyes used today are harmful to hair. “Your hair is covered in these cuticle scales like the scales of a fish, and people have to use ammonia or organic amines to lift the scales and allow dye molecules to get inside a lot quicker,” says senior author Jiaxing Huang, a materials scientist at Northwestern University. But lifting the cuticle makes the strands of the hair more brittle, and the damage is only exacerbated by the hydrogen peroxide that is used to trigger the reaction that synthesizes the dye once the pigment molecules are inside the hair.

These problems could theoretically be solved by a dye that coats rather than penetrates the hair. “However, the obvious problem of coating-based dyes is that they tend to wash out very easily,” says Huang. But when he and his team coated samples of human hair with a solution of graphene sheets, they were able to turn platinum blond hair black and keep it that way for at least 30 washes–the number necessary for a hair dye to be considered “permanent.”

This effectiveness has to do with the structure of graphene: it’s made of up thin, flexible sheets that can adapt to uneven surfaces. “Imagine a piece of paper. A business card is very rigid and doesn’t flex by itself. But if you take a much bigger sheet of newspaper–if you still can find one nowadays–it can bend easily. This makes graphene sheets a good coating material,” he says. And once the coating is formed, the graphene sheets are particularly good at keeping out water during washes, which keeps the water from eroding both the graphene and the polymer binder that the team also added to the dye solution to help with adhesion.

The graphene dye has additional advantages. Each coated hair is like a little wire in that it is able to conduct heat and electricity. This means that it’s easy for graphene-dyed hair to dissipate static electricity, eliminating the problem of flyaways on dry winter days. The graphene flakes are large enough that they won’t absorb through the skin like other dye molecules. And although graphene is typically black, its precursor, graphene oxide, is light brown. But the color of graphene oxide can be gradually darkened with heat or chemical reactions, meaning that this dye could be used for a variety of shades or even for an ombre effect.

What Huang thinks is particularly striking about this application of graphene is that it takes advantage of graphene’s most obvious property. “In many potential graphene applications, the black color of graphene is somewhat undesirable and something of a sore point,” he says. Here, though, it’s applied to a field where creating dark colors has historically been a problem.

The graphene used for hair dye also doesn’t need to be of the same high quality as it does for other applications. “For hair dye, the most important property is graphene being black. You can have graphene that is too lousy for higher-end electronic applications, but it’s perfectly okay for this. So I think this application can leverage the current graphene product as is, and that’s why I think that this could happen a lot sooner than many of the other proposed applications,” he says.

Making it happen is his next goal. He hopes to get funding to continue the research and make these dyes a reality for the people whose lives they would improve. “This is an idea that was inspired by curiosity. It was very fun to do, but it didn’t sound very big and noble when we started working on it,” he says. “But after we deep-dived into studying hair dyes, we realized that, wow, this is actually not at all a small problem. And it’s one that graphene could really help to solve.”

Northwestern University’s Amanda Morris also wrote a March 15, 2018 news release (it’s repetitive but there are some interesting new details; Note: Links have been removed),

It’s an issue that has plagued the beauty industry for more than a century: Dying hair too often can irreparably damage your silky strands.

Now a Northwestern University team has used materials science to solve this age-old problem. The team has leveraged super material graphene to develop a new hair dye that is less harmful [emphasis mine], non-damaging and lasts through many washes without fading. Graphene’s conductive nature also opens up new opportunities for hair, such as turning it into in situ electrodes or integrating it with wearable electronic devices.

Dying hair might seem simple and ordinary, but it’s actually a sophisticated chemical process. Called the cuticle, the outermost layer of a hair is made of cells that overlap in a scale-like pattern. Commercial dyes work by using harsh chemicals, such as ammonia and bleach, to first pry open the cuticle scales to allow colorant molecules inside and then trigger a reaction inside the hair to produce more color. Not only does this process cause hair to become more fragile, some of the small molecules are also quite toxic.

Huang and his team bypassed harmful chemicals altogether by leveraging the natural geometry of graphene sheets. While current hair dyes use a cocktail of small molecules that work by chemically altering the hair, graphene sheets are soft and flexible, so they wrap around each hair for an even coat. Huang’s ink formula also incorporates edible, non-toxic polymer binders to ensure that the graphene sticks — and lasts through at least 30 washes, which is the commercial requirement for permanent hair dye. An added bonus: graphene is anti-static, so it keeps winter-weather flyaways to a minimum.

“It’s similar to the difference between a wet paper towel and a tennis ball,” Huang explained, comparing the geometry of graphene to that of other black pigment particles, such as carbon black or iron oxide, which can only be used in temporary hair dyes. “The paper towel is going to wrap and stick much better. The ball-like particles are much more easily removed with shampoo.”

This geometry also contributes to why graphene is a safer alternative. Whereas small molecules can easily be inhaled or pass through the skin barrier, graphene is too big to enter the body. “Compared to those small molecules used in current hair dyes, graphene flakes are humongous,” said Huang, who is a member of Northwestern’s International Institute of Nanotechnology.

Ever since graphene — the two-dimensional network of carbon atoms — burst onto the science scene in 2004, the possibilities for the promising material have seemed nearly endless. With its ultra-strong and lightweight structure, graphene has potential for many applications in high-performance electronics, high-strength materials and energy devices. But development of those applications often require graphene materials to be as structurally perfect as possible in order to achieve extraordinary electrical, mechanical or thermal properties.

The most important graphene property for Huang’s hair dye, however, is simply its color: black. So Huang’s team used graphene oxide, an imperfect version of graphene that is a cheaper, more available oxidized derivative.

“Our hair dye solves a real-world problem without relying on very high-quality graphene, which is not easy to make,” Huang said. “Obviously more work needs to be done, but I feel optimistic about this application.”

Still, future versions of the dye could someday potentially leverage graphene’s notable properties, including its highly conductive nature.

“People could apply this dye to make hair conductive on the surface,” Huang said. “It could then be integrated with wearable electronics or become a conductive probe. We are only limited by our imagination.”

So far, Huang has developed graphene-based hair dyes in multiple shades of brown and black. Next, he plans to experiment with more colors.

Interestingly, the tiny note of caution”less harmful” doesn’t appear in the Cell Press news release. Never fear, Dr. Andrew Maynard (Director Risk Innovation Lab at Arizona State University) has written a March 20, 2018 essay on The Conversation suggesting a little further investigation (Note: Links have been removed),

Northwestern University’s press release proudly announced, “Graphene finds new application as nontoxic, anti-static hair dye.” The announcement spawned headlines like “Enough with the toxic hair dyes. We could use graphene instead,” and “’Miracle material’ graphene used to create the ultimate hair dye.”

From these headlines, you might be forgiven for getting the idea that the safety of graphene-based hair dyes is a done deal. Yet having studied the potential health and environmental impacts of engineered nanomaterials for more years than I care to remember, I find such overly optimistic pronouncements worrying – especially when they’re not backed up by clear evidence.

Tiny materials, potentially bigger problems

Engineered nanomaterials like graphene and graphene oxide (the particular form used in the dye experiments) aren’t necessarily harmful. But nanomaterials can behave in unusual ways that depend on particle size, shape, chemistry and application. Because of this, researchers have long been cautious about giving them a clean bill of health without first testing them extensively. And while a large body of research to date doesn’t indicate graphene is particularly dangerous, neither does it suggest it’s completely safe.

A quick search of scientific papers over the past few years shows that, since 2004, over 2,000 studies have been published that mention graphene toxicity; nearly 500 were published in 2017 alone.

This growing body of research suggests that if graphene gets into your body or the environment in sufficient quantities, it could cause harm. A 2016 review, for instance, indicated that graphene oxide particles could result in lung damage at high doses (equivalent to around 0.7 grams of inhaled material). Another review published in 2017 suggested that these materials could affect the biology of some plants and algae, as well as invertebrates and vertebrates toward the lower end of the ecological pyramid. The authors of the 2017 study concluded that research “unequivocally confirms that graphene in any of its numerous forms and derivatives must be approached as a potentially hazardous material.”

These studies need to be approached with care, as the precise risks of graphene exposure will depend on how the material is used, how exposure occurs and how much of it is encountered. Yet there’s sufficient evidence to suggest that this substance should be used with caution – especially where there’s a high chance of exposure or that it could be released into the environment.

Unfortunately, graphene-based hair dyes tick both of these boxes. Used in this way, the substance is potentially inhalable (especially with spray-on products) and ingestible through careless use. It’s also almost guaranteed that excess graphene-containing dye will wash down the drain and into the environment.

Undermining other efforts?

I was alerted to just how counterproductive such headlines can be by my colleague Tim Harper, founder of G2O Water Technologies – a company that uses graphene oxide-coated membranes to treat wastewater. Like many companies in this area, G2O has been working to use graphene responsibly by minimizing the amount of graphene that ends up released to the environment.

Yet as Tim pointed out to me, if people are led to believe “that bunging a few grams of graphene down the drain every time you dye your hair is OK, this invalidates all the work we are doing making sure the few nanograms of graphene on our membranes stay put.” Many companies that use nanomaterials are trying to do the right thing, but it’s hard to justify the time and expense of being responsible when someone else’s more cavalier actions undercut your efforts.

Overpromising results and overlooking risk

This is where researchers and their institutions need to move beyond an “economy of promises” that spurs on hyperbole and discourages caution, and think more critically about how their statements may ultimately undermine responsible and beneficial development of a technology. They may even want to consider using guidelines, such as the Principles for Responsible Innovation developed by the organization Society Inside, for instance, to guide what they do and say.

If you have time, I encourage you to read Andrew’s piece in its entirety.

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

Multifunctional Graphene Hair Dye by Chong Luo, Lingye Zhou, Kevin Chiou, and Jiaxing Huang. Chem DOI: https://doi.org/10.1016/j.chempr.2018.02.02 Publication stage: In Press Corrected Proof

This paper appears to be open access.

*Two paragraphs (repetitions) were deleted from the excerpt of Dr. Andrew Maynard’s essay on August 14, 2018

Untangling carbon nanotubes at McMaster University (Canada)

Carbon nanotubes can be wiggly, entangled things (more about McMaster in a bit) as Dr. Andrew Maynard notes in this video (part of his Risk Bites video series) describing carbon nanotubes, their ‘infinite’ variety, and risks,

Researchers at Canada’s McMaster University have found a way to untangle carbon nanotubes according to an Aug. 16, 2016 news item on Nanowerk (Note: A link has been removed),

Imagine an electronic newspaper that you could roll up and spill your coffee on, even as it updated itself before your eyes.

It’s an example of the technological revolution that has been waiting to happen, except for one major problem that, until now, scientists have not been able to resolve.

Researchers at McMaster University have cleared that obstacle by developing a new way to purify carbon nanotubes – the smaller, nimbler semiconductors that are expected to replace silicon within computer chips and a wide array of electronics (Chemistry – A European Journal, “Influence of Polymer Electronics on Selective Dispersion of Single-Walled Carbon Nanotubes”).

“Once we have a reliable source of pure nanotubes that are not very expensive, a lot can happen very quickly,” says Alex Adronov, a professor of Chemistry at McMaster whose research team has developed a new and potentially cost-efficient way to purify carbon nanotubes.

The researchers have provided a gorgeous image,

Artistic rendition of a metallic carbon nanotube being pulled into solution, in analogy to the work described by the Adronov group. Image: Alex Adronov McMaster

Artistic rendition of a metallic carbon nanotube being pulled into solution, in analogy to the work described by the Adronov group. Image: Alex Adronov McMaster University

An Aug. 15, 2016 McMaster University news release, which originated the news item, provides a beginner’s introduction to carbon nanotubes and describes the purification process that will make production of carbon nanotubes easier,

Carbon nanotubes – hair-like structures that are one billionth of a metre in diameter but thousands of times longer ­– are tiny, flexible conductive nano-scale materials, expected to revolutionize computers and electronics by replacing much larger silicon-based chips.

A major problem standing in the way of the new technology, however, has been untangling metallic and semiconducting carbon nanotubes, since both are created simultaneously in the process of producing the microscopic structures, which typically involves heating carbon-based gases to a point where mixed clusters of nanotubes form spontaneously as black soot.

Only pure semiconducting or metallic carbon nanotubes are effective in device applications, but efficiently isolating them has proven to be a challenging problem to overcome. Even when the nanotube soot is ground down, semiconducting and metallic nanotubes are knotted together within each grain of powder. Both components are valuable, but only when separated.

Researchers around the world have spent years trying to find effective and efficient ways to isolate carbon nanotubes and unleash their value.

While previous researchers had created polymers that could allow semiconducting carbon nanotubes to be dissolved and washed away, leaving metallic nanotubes behind, there was no such process for doing the opposite: dispersing the metallic nanotubes and leaving behind the semiconducting structures.

Now, Adronov’s research group has managed to reverse the electronic characteristics of a polymer known to disperse semiconducting nanotubes – while leaving the rest of the polymer’s structure intact. By so doing, they have reversed the process, leaving the semiconducting nanotubes behind while making it possible to disperse the metallic nanotubes.

The researchers worked closely with experts and equipment from McMaster’s Faculty of Engineering and the Canada Centre for Electron Microscopy, located on the university’s campus.

“There aren’t many places in the world where you can do this type of interdisciplinary work,” Adronov says.

The next step, he explains, is for his team or other researchers to exploit the discovery by finding a way to develop even more efficient polymers and scale up the process for commercial production.

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

Influence of Polymer Electronics on Selective Dispersion of Single-Walled Carbon Nanotubes by *Darryl Fong*, William J. Bodnaryk, Dr. Nicole A. Rice, Sokunthearath Saem, Prof. Jose M. Moran-Mirabal, Prof. Alex Adronov. Chemistry A European Journal DOI: 10.1002/chem.201603553 First published: 16 August 2016

This paper appears to be open access.

*’Daryl Fon’ changed to ‘Darryl Fong’ on Oct. 3, 2016.

Dunkin’ Donuts and nano titanium dioxide

It’s been a busy few days for titanium dioxide, nano and otherwise, as the news about its removal from powdered sugar in Dunkin’ Donuts products ripples through the nano blogosphere. A March 6, 2015 news item on Azonano kicks off the discussion with an announcement,

Dunkin’ Brands, the parent company of the Dunkin’ Donuts chain, has agreed to remove titanium dioxide, a whitening agent that is commonly a source of nanomaterials, from all powdered sugar used to make the company’s donuts. As a result of this progress, the advocacy group As You Sow has withdrawn a shareholder proposal asking Dunkin’ to assess and reduce the risks of using nanomaterials in its food products.

Here’s a brief recent history of Dunkin’ Donuts and nano titanium dioxide from my Aug. 21, 2014 posting titled, FOE, nano, and food: part two of three (the problem with research),

Returning to the ‘debate’, a July 11, 2014 article by Sarah Shemkus for a sponsored section in the UK’s Guardian newspaper highlights an initiative taken by an environmental organization, As You Sow, concerning titanium dioxide in Dunkin’ Donuts’ products (Note: A link has been removed),

The activists at environmental nonprofit As You Sow want you to take another look at your breakfast doughnut. The organization recently filed a shareholder resolution asking Dunkin’ Brands, the parent company of Dunkin’ Donuts, to identify products that may contain nanomaterials and to prepare a report assessing the risks of using these substances in foods.

Their resolution received a fair amount of support: at the company’s annual general meeting in May, 18.7% of shareholders, representing $547m in investment, voted for it. Danielle Fugere, As You Sow’s president, claims that it was the first such resolution to ever receive a vote. Though it did not pass, she says that she is encouraged by the support it received.

“That’s a substantial number of votes in favor, especially for a first-time resolution,” she says.

The measure was driven by recent testing sponsored by As You Sow, which found nanoparticles of titanium dioxide in the powdered sugar that coats some of the donut chain’s products. [emphasis mine] An additive widely used to boost whiteness in products from toothpaste to plastic, microscopic titanium dioxide has not been conclusively proven unsafe for human consumption. Then again, As You Sow contends, there also isn’t proof that it is harmless.

“Until a company can demonstrate the use of nanomaterials is safe, we’re asking companies either to not use them or to provide labels,” says Fugere. “It would make more sense to understand these materials before putting them in our food.”

As I understand it, Dunkin’ Donuts will be removing all titanium dioxide, nano-sized or other, from powdered sugar used in its products. It seems As You Sow’s promise to withdraw its July 2104 shareholder resolution is the main reason for Dunkin’ Donuts’ decision. While I was and am critical of Dunkin’ Donuts’ handling of the situation with As You Sow, I am somewhat distressed that the company seems to have acquiesced on the basis of research which is, at best, inconclusive.

Dr. Andrew Maynard, director of the University of Michigan Risk Science Centre, has written a substantive analysis of the current situation regarding nano titanium dioxide in a March 12, 2015 post on his 2020 Science blog (Note: Links have been removed),

Titanium dioxide (which isn’t the same thing as the metal titanium) is an inert, insoluble material that’s used as a whitener in everything from paper and paint to plastics. It’s the active ingredient in many mineral-based sunscreens. And as a pigment, is also used to make food products look more appealing.

Part of the appeal to food producers is that titanium dioxide is a pretty dull chemical. It doesn’t dissolve in water. It isn’t particularly reactive. It isn’t easily absorbed into the body from food. And it doesn’t seem to cause adverse health problems. It just seems to do what manufacturers want it to do – make food look better. It’s what makes the powdered sugar coating on donuts appear so dense and snow white. Titanium dioxide gives it a boost.

And you’ve probably been consuming it for years without knowing. In the US, the Food and Drug Administration allows food products to contain up to 1% food-grade titanium dioxide without the need to include it on the ingredient label. Help yourself to a slice of bread, a bar of chocolate, a spoonful of mayonnaise or a donut, and chances are you’ll be eating a small amount of the substance.

Andrew goes on to describe the concerns that groups such as You As Sow have (Note: Links have been removed),

For some years now, researchers have recognized that some powders become more toxic the smaller the individual particles are, and titanium dioxide is no exception. Pigment grade titanium dioxide – the stuff typically used in consumer products and food – contains particles around 200 nanometers in diameter, or around one five hundredth the width of a human hair. Inhale large quantities of these titanium dioxide particles (I’m thinking “can’t see your hand in front of your face” quantities), and your lungs would begin to feel it.

If the particles are smaller though, it takes much less material to cause the same effect.

But you’d still need to inhale very large quantities of the material for it to be harmful. And while eating a powdered donut can certainly be messy, it’s highly unlikely that you’re going to end up stuck in a cloud of titanium dioxide-tinted powdered sugar coating!

… Depending on what they are made of and what shape they are, research has shown that some nanoparticles are capable of getting to parts of the body that are inaccessible to larger particles. And some particles are more chemically reactive because of their small size. Some may cause unexpected harm simply because they are small enough to throw a nano-wrench into the nano-workings of your cells.

This body of research is why organizations like As You Sow have been advocating caution in using nanoparticles in products without appropriate testing – especially in food. But the science about nanoparticles isn’t as straightforward as it seems.

As Andrew notes,

First of all, particles of the same size but made of different materials can behave in radically different ways. Assuming one type of nanoparticle is potentially harmful because of what another type does is the equivalent of avoiding apples because you’re allergic to oysters.

He describes some of the research on nano titanium dioxide (Note: Links have been removed),

… In 2004 the European Food Safety Agency carried out a comprehensive safety review of the material. After considering the available evidence on the same materials that are currently being used in products like Dunkin’ Donuts, the review panel concluded that there no evidence for safety concerns.

Most research on titanium dioxide nanoparticles has been carried out on ones that are inhaled, not ones we eat. Yet nanoparticles in the gut are a very different proposition to those that are breathed in.

Studies into the impacts of ingested nanoparticles are still in their infancy, and more research is definitely needed. Early indications are that the gastrointestinal tract is pretty good at handling small quantities of these fine particles. This stands to reason given the naturally occurring nanoparticles we inadvertently eat every day, from charred foods and soil residue on veggies and salad, to more esoteric products such as clay-baked potatoes. There’s even evidence that nanoparticles occur naturally inside the gastrointestinal tract.

He also probes the issue’s, nanoparticles, be they titanium dioxide or otherwise, and toxicity, complexity (Note: Links have been removed),

There’s a small possibility that we haven’t been looking in the right places when it comes to possible health issues. Maybe – just maybe – there could be long term health problems from this seemingly ubiquitous diet of small, insoluble particles that we just haven’t spotted yet. It’s the sort of question that scientists love to ask, because it opens up new avenues of research. It doesn’t mean that there is an issue, just that there is sufficient wiggle room in what we don’t know to ask interesting questions.

… While there is no evidence of a causal association between titanium dioxide in food and ill health, some studies – but not all by any means – suggest that large quantities of titanium dioxide nanoparticles can cause harm if they get to specific parts of the body.

For instance, there are a growing number of published studies that indicate nanometer sized titanium dioxide particles may cause DNA damage at high concentrations if it can get into cells. But while these studies demonstrate the potential for harm to occur, they lack information on how much material is needed, and under what conditions, for significant harm. And they tend to be associated with much larger quantities of material than anyone is likely to be ingesting on a regular basis.

They are also counterbalanced by studies that show no effects, indicating that there is still considerable uncertainty over the toxicity or otherwise of the material. It’s as if we’ve just discovered that paper can cause cuts, but we’re not sure yet whether this is a minor inconvenience or potentially life threatening. In the case of nanoscale titanium dioxide, it’s the classic case of “more research is needed.”

I strongly suggest reading Andrew’s post in its entirety either here on the University of Michigan website or here on The Conversation website.

Dexter Johnson in a March 11, 2015 post on his Nanoclast blog also weighs in on the discussion. He provides a very neat summary of the issues along with these observations (Note Links have been removed),

With decades of TiO2 being in our food supply and no reports of toxic reactions, it would seem that the threshold for proof is extremely high, especially when you combine the term “nano” with “asbestos”.

As You Sow makes sure to point out that asbestos is a nanoparticle. While the average diameter of an asbestos fiber is around 20 to 90 nm, their lengths varied between 200 nm and 200 micrometers.

The toxic aspect of asbestos was not its diameter, but its length. …

In addition to his summary Dexter highlights As You Sows attempt to link titanium dioxide nanoparticles to asbestos. I suggest reading his post for an informed description of what made asbestos so toxic (here) and why the linkage seems specious at this time.

For anyone interested in how As You Sow managed to introduce asbestos toxicity issues into a discussion about nano titanium dioxide and food products, there’s this from As You Sow’s FAQs (frequently asked questions) about nanomaterials in food page,

Why are nanomaterials in food important to investors?

When technology is used before ensuring that it is safe for humans and the environment, and before regulatory standards exist, companies can be exposed to significant financial, legal, and reputational risk. The limited studies that exist on nanomaterials, including nanoscale titanium dioxide*, have indicated that ingestion of these particles may pose health hazards.

The inaction of regulators does not protect companies, especially when the regulators themselves warn of the dangers of nanoparticles’ largely unknown risks. Draft guidance issued by the U.S. Food and Drug Administration raises questions about the safety of nanoparticles and demonstrates the general lack of knowledge about the technology and its effects. (1)

Asbestos litigation is a good example of the risks that can arise from using an emerging technology before it is proven safe. Use of asbestos (a nanomaterial) has created the longest, most expensive mass tort in national history with total U.S. costs now standing at over $250 billion. (2) If companies been asked to investigate and minimize or avoid risks prior to adopting asbestos technology, a sad and expensive chapter in worker harm could have been avoided.

* Titanium dioxide is a common pigment and FDA-approved food additive. It is used as a whitener, a dispersant, and a thickener.

While I don’t particularly appreciate fear-mongering as a tactic, the strategy of targeting investors and their concerns, seems to have helped As You Sow win its way.

Quality carbon nanotubes

Before launching into this latest item about carbon nanotubes (CNTs), I have an April 11, 2013 posting which offers a brief overview of the topic and a link to my Mar. 14, 2013 posting titled: The long, the short, the straight, and the curved of them: all about carbon nanotubes, which holds an embedded video by Dr. Andrew Maynard where he describes their somewhat ‘unruly’ nature.

These postings will help those unfamiliar with carbon nanotubes to better understand the importance of a June 14, 2014 news item on Nanowerk announcing a new CNT characterization and certification service for single-walled CNTs,

Intertek, a leading quality solutions provider to industries worldwide, today announced a comprehensive facility for characterising key structural and quality parameters of single-walled carbon nanotubes (SWNTs).

A June 12, 2014 Intertek press release, which originated the news item, describes the company’s reasons for adding this to their suite of services,

Carbon nanotubes are very thin tubes of elemental carbon with exceptional mechanical, optical and electrical properties that have the potential to significantly improve the performance of a wide range of materials by altering their fundamental properties. Recent advancements in manufacturing processes mean that SWNTs are now becoming available in sufficient quantity for industrial-scale evaluation and application and so it is increasingly important to be able to verify their quality though robust analytical testing. Applications currently being explored include additives for batteries, composites for the automotive and aerospace industry, electrodes and semiconductor devices such as transistors.

With dimensions of approximately 1/100000th the thickness of a single human hair, SWNTs can present analytical challenges for assessing their quality and structure. No single technique can adequately characterise a nanotube product, and so a diverse set of complementary analytical techniques which have exquisite precision and sensitivity are required. This comprehensive analytical service is commercially available to both manufacturers of nanotubes and to developers who wish to incorporate nanotubes into their products.

It seems to me this is a necessary step on the road to commercializing products utilizing single-walled CNTs.

Tech worries: nanotechnology and nickel on Slate

Dr. Andrew Maynard’s May 20, 2014 article (Small Packages; A new case study on the health risks of nanotech doesn’t tell the whole story) for Slate magazine does much to calm any fears there might be in the wake of a recent case study about the consequences of handling nickel nanoparticles in the workplace,

… The report describes a chemist who developed symptoms that included throat irritation, nasal congestion, facial flushing, and skin reactions to jewelry containing nickel, after starting to work with a powder consisting of nanometer-sized nickel particles. According to the report’s lead author, this is “case one in our modern economy” of exposure to a product of nanotechnology leading to an individual becoming ill.

… And this is why the case of the nickel nanoparticles above needs to be approached with some caution. Many people have an allergic skin reaction to nickel, and research has shown that inhaling nickel particles can cause people to become sensitized to the metal. It’s also well known that fine powders will become airborne more easily than coarse ones when they’re handled, and that the finer the powder you inhale, the more potent it is in your lungs. So it shouldn’t come as a surprise that handling nickel nanopowder in an open lab without exposure controls is not a great idea. In other words, the reported incident was more a case of bad exposure management than nanoparticle risk.

That said, the case does highlight the level of respect with which any new or unusual material should be treated. …

Reinforcing Andrew’s comments about nickel sensitivities, there’s a recent report about smartphones and metal sensitivities. From a May 21, 2014 article by Sarah Knapton for The Telegraph (UK), Note: A link has been removed,

If you have ever noticed swelling, redness, itching or blistering near your cheekbones, ears, jaw or hands, you may be allergic to your phone.

A new study suggests the nickel, chromium and cobalt found in common phones made by BlackBerry, Samsung and LG among others, can cause skin irritations.

Danish and US researchers found at least 37 incidents since 2000 where contact dermatitis was caused by mobile phones.

Here are links to and citations for the nickel case study and to the smartphone paper,

Occupational handling of nickel nanoparticles: A case report by W. Shane Journeay, MD, and Rose H. Goldman, MD. American Journal of Industrial Medicine Article first published online: 8 MAY 2014 DOI: 10.1002/ajim.22344

Mobile Phone Dermatitis in Children and Adults: A Review of the Literature by Clare Richardson, Carsten R. Hamann, Dathan Hamann, and Jacob P. Thyssen. Pediatric Allergy, Immunology, and Pulmonology. Online Ahead of Print: March 5, 2014. doi:10.1089/ped.2013.0308.

The nickel paper is behind a paywall and the smartphone paper is open access.

One comment, the smartphone literature search yielded a small sample, on the other hand, if there isn’t category for the problem, it might not get into reports and be studied.

Getting back to Andrew’s article, it is illuminating and frustratingly opaque (perhaps there was an editing issue?),

Over a couple of days in London last summer, I found myself mulling over a very similar question with a small group of colleagues. We were a pretty eclectic group—engineers, designers, toxicologists, business leaders, academics, policy wonks—but we had one thing in common: We wanted get a better handle on how dangerous realistic products of nanotechnology might be, and how these dangers might be avoided.

… Our approach was to imagine products based on engineered nanomaterials that were technologically feasible and would also have a reasonable chance of surviving a cut-throat economy—products like active food packaging labels that indicated the presence of contaminants; helium-filled balloons with solar cell skins; and materials templated from viruses to generate hydrogen and oxygen from water. We then tried to imagine how these plausible products could potentially release dangerous materials into the environment.

To our surprise, we struggled to come up with scenarios that scared us.

It sounds like this session was organized as a think tank. It would have been nice to know who organized it, who were their invitees, and what was their expertise. On that note, there is this about Andrew at the end of the Slate article,

Andrew Maynard is a leading expert on the responsible development and use of emerging technologies and is the director of the U-M [University of Michigan] Risk Science Center.

Having stumbled across Andrew many times over the years within the ‘nano blogosphere’ and having him kindly answer my amateurish questions about reading research, I feel  confidence when reading his opinion pieces that he is well informed and has carefully considered not only questions I might ask but others as well.

While I might like to know more about that 2013 think tank session in London (UK), this section towards the end of the piece suggests that Andrew has not, in an excess of enthusiasm, thrown in his lot with some hype happy group,

… the case [nickel inhalation] does highlight the level of respect with which any new or unusual material should be treated. This was also one of the conclusions from those two days in London. Just because the risks of many nanotechnology products seem relatively small, doesn’t mean that we can afford to be complacent. There’s still the possibility that someone will create a particularly dangerous new material, or will use a material that seems safe in a dangerous way. As a society we need to be vigilant when it comes to advanced materials, whether they are branded with the nano insignia or not.

As for Knapton article and smartphone research, I haven’t come to any particular conclusions but I am going to keep an eye out for evidence, anecdotal or otherwise. A friend of mine, who sometimes suffers from skin sensitivities, just switched over to her first Blackberry.

Silver ions in the environment

Earlier this week (Feb. 24, 2014), I published a post featuring Dr. Andrew Maynard, Director of the University of Michigan’s Risk Science Center in an introductory video describing seven surprising facts about silver nanoparticles. For those who want to delve more deeply, there’s a Feb. 25, 2014 news item on Nanowerk describing some Swiss research into silver nanoparticles and ions in aquatic environments,

It has long been known that, in the form of free ions, silver particles can be highly toxic to aquatic organisms. Yet to this day, there is a lack of detailed knowledge about the doses required to trigger a response and how the organisms deal with this kind of stress. To learn more about the cellular processes that occur in the cells, scientists from the Aquatic Research Institute, Eawag [Swiss Federal Institute of Aquatic Science and Technology], subjected algae to a range of silver concentrations.

In the past, silver mostly found its way into the environment in the vicinity of silver mines or via wastewater [emphasis mine] emanating from the photo industry. More recently, silver nanoparticles have become commonplace in many applications – as ingredients in cosmetics, food packaging, disinfectants, and functional clothing. Though a recent study conducted by the Swiss National Science Foundation revealed that the bulk of silver nanoparticles is retained in wastewater treatment plants, only little is known about the persistence and the impact of the residual nano-silver in the environment.

The Feb. 25, 2014 Eawag media release, which originated the news item, describes the research in further detail,

Smitha Pillai from the Eawag Department of Environmental Toxicology and her colleagues from EPF Lausanne and ETH Zürich studied the impact of various concentrations of waterborne silver ions on the cells of the green algae Chlamydomonas reinhardtii. Silver is chemically very similar to copper, an essential metal due to its importance in several enzymes. Because of that, silver can exploit the cells’ copper transport mechanisms and sneak into them undercover. This explains why, already after a short time, concentrations of silver in the intracellular fluid can reach up to one thousand times those in the surrounding environment.

A prompt response

Because silver damages key enzymes involved in energy metabolism, even low concentrations can cut photosynthesis and growth rates by a half in just 15 minutes. Over the same time period, the researchers also detected changes in the activity of about 1000 other genes and proteins, which they interpreted as a response to the stressor – an attempt to repair silver-induced damage. At low concentrations, the cells’ photosynthesis apparatus recovered within five hours, and recovery mechanisms were sufficient to deal with all but the highest concentrations tested.

A number of unanswered questions

At first glance, the results are reassuring because the silver concentrations that the algae are subject to in the environment are rarely as high as those applied in the lab, which allows them to recover quickly – at least externally. But the experiments also showed that even low silver concentrations have a significant effect on intracellular processes and that the algae divert their energy to repairing damage incurred. This can pose a problem when other stressors act in parallel, such as increased UV-radiation or other chemical compounds. Moreover, it remains unknown to this day whether the cells have an active mechanism to shuttle out the silver. Lacking such a mechanism, the silver could have adverse effects on higher organisms, given that algae are at the bottom of the food chain.

You can find the researchers’ paper here,

Linking toxicity and adaptive responses across the transcriptome, proteome, and phenotype of Chlamydomonas reinhardtii exposed to silver by Smitha Pillai, Renata Behra, Holger Nestler, Marc J.-F. Suter, Laura Sigg, and Kristin Schirmer. Proceedings of the National Academy of Sciences (PNAS) – early edition 18.February 2014, www.pnas.org/cgi/doi/10.1073/pnas.1319388111

The paper is available through the PNAS open access option.

I have published a number of pieces about aquatic enviornments and wastewater and nanotechnology-enabled products as useful for remediation efforts and as a source of pollution. Here’s a Feb. 28, 2013 posting where I contrasted two pieces of research on silver nanoparticles. The first was research in an aquatic environment and the other concerned wastewater.

Surprising facts about silver nanoparticles from the University of Michigan

Dr. Andrew Maynard, Director of the University of Michigan’s Risk Science Center, has featured seven surprising facts about silver nanoparticles in his latest video in the Risk Bites series. Before getting to the video,here’s an introduction to the topic of silver nanoparticles from a Feb. 18, 2014 posting by Ishani Hewage on the University of Michigan’s Risk Sense blog (Note: A link has been removed),

Silver – known for its germ-killing capabilities – has been used for thousands of years. In recent times though, concerns have been raised over the potential health and environmental risks associated with one particular form of silver that has been used increasingly in a range of products: engineered silver nanoparticle. In this week’s Risk Bites, Andrew Maynard, director of the Risk Science Center, rounds-up seven aspects of silver nanoparticles that might help you weigh up their risks and benefits.

“Silver has long been used for its medicinal properties,” says Andrew. “People used to intentionally dose themselves with silver nanoparticles in the form a silver laced tonic as a cure-all.”

Nowadays, the use of silver nanoparticles is not just limited to the medical field. The military, athletes and manufactures are increasingly using them to develop smart new technologies that inhibit bacterial growth and enhance overall performance.  These microscopically small particles make it easier to get silver into products without compromising them …

Without more ado, here’s the video, ‘7 surprising facts about silver nanoparticles and health’:

Both the blog posting and this link will lead you to more information about silver nanoparticles.

Rising from the dead: the inventory of nanotechnology-based consumer products

The inventory of nanotechnology-based consumer products or the Consumer Products Inventory (CPI) is still cited in articles about nanotechnology and its pervasive use in consumer products despite the fact that the inventory was effectively rendered inactive (i.e., dead) in 2009 and that  it was a voluntary system with no oversight, meaning whoever made the submission to the inventory could make any claims they wanted. Now that it’s 2013, things are about to change according to an Oct. 28, 2013 news item on ScienceDaily,

As a resource for consumers, scientists, and policy makers, the Virginia Tech Center for Sustainable Nanotechnology (VTSuN) has joined the Woodrow Wilson International Center for Scholars to renew and expand the Nanotechnology Consumer Product Inventory, an important source of information about products using nanomaterials.

“We want people to appreciate the revolution, such as in electronics and medicine. But we also want them to be informed,” said Nina Quadros, a research scientist at Virginia Tech’s Institute for Critical Technology and Applied Science and associate director of VTSuN, who leads a team of Virginia Tech faculty members and students on this project. Todd Kuiken, senior program associate, and David Rajeski, director of the science and technology innovation program, lead this project at the Wilson Center.

The Oct. 28, 2013 Virginia Tech (Virginia Polytechnic Institute and State University) news release by Susan Trulove (which originated the news item),provides a brief history of the inventory and a description of its revivification,

The Wilson Center and the Project on Emerging Nanotechnology created the inventory in 2005. It grew from 54 to more than 1,000 products, many of which have come and gone. The inventory became the most frequently cited resource, showcasing the widespread applications of nanotechnology. However, in 2009, the project was no longer funded.

“I used it in publications and presentations when talking about all the ways nano is part of people’s lives in consumer products,” said Matthew Hull, who manages the Institute for Critical Technology and Applied Science’s investment portfolio in nanoscale science and engineering, which includes the Center for Sustainable Nanotechnology. “But the inventory was criticized by researchers, regulators, and manufacturers for the lack of scientific information available to support product claims.”

In a meeting with his friend, Andrew Maynard, director of the University of Michigan Risk Science Center, who had initiated the inventory when he was at the Wilson Center, Hull proposed leveraging Institute for Critical Technology and Applied Science and Center for Sustainable Nanotechnology resources to improve the inventory.

“My role was to ask ‘what if’ and [the Virginia Tech Center for Sustainable Nanotechnology] ran with it,” said Hull.

A partnership was formed and, with funding from the Virginia Tech institute, the Center for Sustainable Nanotechnology restructured the inventory to improve the reliability, functionality, and scientific credibility of the database.

“Specifically, we added scientific significance and usefulness by including qualitative and quantitative descriptors for the products and the nanomaterials contained in these products, such as size, concentration, and potential exposure routes,” said Quadros. For example, an intentional exposure route would be the way a medicine is administered. An unintentional exposure would be when a child chews on a toy that has been treated with silver nanoparticles that are used as an antimicrobial. The potential health effect of nanomaterials on children was Quadros doctoral research and she used the inventory to find products designed for children that use nanomaterials, such as plush toys.

“One of the best things about the new version of the inventory is the additional information and the ability to search by product type or the type of nanomaterial,” she said. “When researchers were first attempting to assess the potential environmental impacts of nanotechnology, one main challenge was understanding how these nanomaterials might end up in the environment in the first place. After searching the CPI and seeing the vast applications of nanotechnologies in consumer products it was easier to narrow down scenarios.”

For example, Quadros said many silver nanoparticles are used in clothing for antimicrobial protection, so we can infer that some silver nanoparticles may end up in wastewater treatment plants after clothes washing. This helped justify some of the research on the effects of silver nanoparticle in the biological wastewater treatment processes. Currently, the inventory lists 188 products under the ‘clothing’ category.”

This team also included published scientific data related to those products, where available, and developed a metric to assess the reliability of the data on each inventory entry.

The team interviewed more than 50 nanotechnology experts with more than 350 combined years of experience in nanotechnology, Quadros said. “Their answers provided valuable guidance to help us address diverse stakeholder needs.”

In addition, the site’s users can log in and add information based on their own expertise. “Anyone can suggest edits. The curator and reviewer will approve the edits, and then the new information will go live,” Quadros said.

“We’ve added the horsepower of [the Center for Sustainable Nanotechnology], but opened it by means of crowdsourcing to new information, such as refuting or supporting claims made about products,” Hull said.

“The goal of this work is to create a living, growing inventory for the exchange of accurate information on nano­enabled consumer products,” Quadros said. “Improved information sharing will allow citizens, manufacturers, scientists, policymakers, and others to better understand how nanotechnology is being used in the consumer marketplace,” she said.

As of October 2013,

The inventory currently lists more than 1,600 consumer products that claim to contain nanotechnology or have been found to contain nanomaterials.

Quadros will give a presentation about the inventory at the Sustainable Nanotechnology Organization conference in Santa Barbara on Nov. 3-5 and will present to the U.S. Environmental Protection Agency and the National Science Foundation in the spring.

Key collaborators at Virginia Tech are Sean McGinnis, an associate research professor in the materials science and engineering department; Linsey Marr, professor of civil and environmental engineering; her postdoc, Eric Vejerano, who was instrumental in development of product categories; and Michael Hochella, a university distinguished professor in the geosciences department and Virginia Tech Center for Sustainable Nanotechnology director.

You can find the Consumer Products Inventory here where it is still hosted by the Woodrow Wilson Center’s Project on Emerging Nanotechnologies. The website for the Second Sustainable Nanotechnology Organization Conference where Quadros will be presenting can be found here and is where this conference description can be found,

The objective of this conference is to bring together scientific experts from academia, industry, and government agencies from around the world to present and discuss current research findings on the subject of nanotechnology and sustainability.

The conference program will address the critical aspects of sustainable nanotechnology such as life cycle assessment, green synthesis, green energy, industrial partnerships, environmental and biological fate, and the overall sustainability of engineered nanomaterials. In principle, this involves the fundamental/applied research on the chemistry of producing new green nanomaterials; eco-manufacturing processing of nanomaterials and products, using nanotechnology to benefit society, and examining possible harmful effects of nanotechnology.

The conference will also foster new collaborations between academic and industrial participants. This community of users, researchers and developers of engineered nanomaterials will provide a long-term, scientific assessment of where the science is for sustainable nano, where it should be heading, and what steps academics, government agencies and others can take now to reach targeted goals. In addition, the conference will serve as the platform to initiate the formation of the Sustainable Nanotechnology Organization (SNO), a non-profit, international professional society dedicated to advancing sustainable nanotechnology through education, research, and promotion of responsible development of nanotechnology.

Finally because I can resist no longer, especially so near to Hallowe’en, I guess you could call the ‘renewed’ CPI, a zombie CPI as it’s back from the dead and it needs brains,

Zombies in Moscow, 26 April 2009 Credit: teujene [downloaded from http://en.wikipedia.org/wiki/File:Zombies_in_Moscow.jpg]

Zombies in Moscow, 26 April 2009 Credit: teujene [downloaded from http://en.wikipedia.org/wiki/File:Zombies_in_Moscow.jpg]