Category Archives: environment

Abakan makes good on Alberta (Canada) promise (coating for better pipeline transport of oil)

It took three years but it seems that US company Abakan Inc.’s announcement of a joint research development centre at the Northern Alberta Institute of Technology (NAIT), (mentioned here in a May 7, 2012 post [US company, Abakan, wants to get in on the Canadian oils sands market]), has borne fruit. A June 8, 2015 news item on Azonano describes the latest developments,

Abakan Inc., an emerging leader in the advanced coatings and metal formulations markets, today announced that it has begun operations at its joint-development facility in Edmonton, Alberta.

Abakan’s subsidiary, MesoCoat Inc., along with the lead project partner, Northern Alberta Institute of Technology (NAIT) will embark on an 18-month collaborative effort to establish a prototype demonstration facility for developing, testing and commercializing wear-resistant clad pipe and components. Western Economic Diversification Canada is also supporting this initiative through a $1.5 million investment toward NAIT. Improvements in wear resistance are expected to make a significant impact in reducing maintenance and downtime costs while increasing productivity in oil sands and other mining applications.

A June 4, 2015 Abakan news release, which originated the news item, provides more detail about the proposed facility, the difficulties encountered during the setup, and some interesting information about pipes,

Abakan shipped its CermaClad high-speed large-area cladding system for installation at the Northern Alberta Institute of Technology’s (NAIT) campus in Edmonton, Alberta in early 2015. Despite delays associated with the installation of some interrelated equipment and machinery, the CermaClad system and other ancillary equipment are now installed at the Edmonton facility. The Edmonton facility is intended to serve as a pilot-scale wear-resistant clad pipe manufacturing facility for the development and qualification of wear-resistant clad pipes, and as a stepping stone for setting-up a full-scale wear-resistant clad pipe manufacturing facility in Alberta. The new facility will also serve as a platform for Abakan’s introduction to the Alberta oil sands market, which, with proven reserves estimated at more than 169 billion barrels, is one of the largest oil resources in the world and a major source of oil for Canada, the United States and Asia. Since Alberta oil sands production is expected to increase significantly over the next decade, producers want to extend the life of the carbon steel pipes used for the hydro-transportation of tailings with harder, tougher coatings that protect pipes from the abrasiveness of tar-like bituminous oil sands.

“Our aim is to fast-track market entry of our wear-resistant clad pipe products for the transportation of oil sands and mining slurries. We have received commitments from oil sands producers in Canada and mining companies in Mexico and Brazil to field-test CermaClad wear-resistant clad pipe products as soon as our system is ready for testing. Apart from our work with conventional less expensive chrome carbide and the more expensive tungsten carbide wear-resistant cladding on pipes, Abakan also expects to introduce new iron-based structurally amorphous metal (SAM) alloy cladding that in testing has exhibited better performance than tungsten carbide cladding, but at a fraction of the cost.” Robert Miller stated further that “although more expensive than the more widely used chrome carbide cladding, our new alloy cladding is expected to be a significantly better value proposition when you consider an estimated life of three times that of chrome carbide cladding and those cost efficiencies that correspond to less downtime revenue losses, and lower maintenance and replacement costs.”

The costs associated with downtime and maintenance in the Alberta oil sands industry estimated at more than $10 billion a year are expected to grow as production expands, according to the Materials and Reliability in Oil Sands (MARIOS) consortium in Alberta. The development of Alberta’s oil sands has been held up by the lack of materials for transport lines and components that are resistant to the highly abrasive slurry. Due to high abrasion, the pipelines have to be rotated every three to four months and replaced every 12 to 15 months. [emphasis mine] The costs involved just in rotating and replacing the pipes is approximately $2 billion annually. The same is true of large components, for example the steel teeth on the giant electric shovels used to recover oil sands, must be replaced approximately every two days.

Abakan’s combination of high productivity coating processes and groundbreaking materials are expected to facilitate significant efficiencies associated with the extraction of these oil resources. Our proprietary materials combined with CermaClad large-area based fusion cladding technology, have demonstrated in laboratory tests a three to eight times improvement in wear and corrosion resistance when compared with traditional weld overlays at costs comparable to rubber and metal matrix composite alternatives. Abakan intends to complete development and initiate field-testing by end of year 2016 and begin the construction of a full-scale wear-resistant clad pipe manufacturing facility in Alberta in early-2017.

Given that there is extensive talk about expanding oil pipelines from Alberta to British Columbia (where I live), the information about the wear and tear is fascinating and disturbing. Emotions are high with regard to the proposed increase in oil flow to the coast as can be seen in a May 27, 2015 article by Mike Howell for the Vancouver Courier about a city hall report on the matter,

A major oil spill in Vancouver waters could potentially expose up to one million people to unsafe levels of a toxic vapour released from diluted bitumen, city council heard Wednesday in a damning city staff report on Kinder Morgan’s proposal to build a pipeline from Alberta to Burnaby [British Columbia].

In presenting the report, deputy city manager Sadhu Johnston outlined scenarios where exposure to the chemical benzene could lead to adverse health effects for residents and visitors, ranging from dizziness to nausea to possible death.

“For folks that are on the seawall, they could be actually struck with this wave of toxic gases that could render them unable to evacuate,” said Johnston, noting 25,000 residents live within 300 metres of the city’s waterfront. “These are serious health impacts. So this is not just about oil hitting shorelines, this is about our residents being exposed to very serious health effects.

  • Kinder Morgan’s own estimate is that pipeline leaks under 75 litres per hour may not be detected.

While I find the presentation’s hysteria a little off-putting, it did alert me to one or two new issues, benzene gas and when spillage from the pipes raises an alarm. For anyone curious about benzene gas and other chemical aspects of an oil spill, there’s a US National Oceanic and Atmospheric Administration (NOAA) webpage titled, Chemistry of an Oil Spill.

Getting back to the pipes, that figure of 75 litres per hour puts a new perspective on the proposed Abakan solution and it suggests that whether or not more and bigger pipes are in our future, we should do a better of job of protecting our environment now. That means better cladding for the pipes and better dispersants and remediation for water, earth, air when there’s a spill.

Policing, detecting, and arresting pollution

The title for a May 13, 2015 news item on ScienceDaily was certainly eye-catching,

Nano-policing pollution

Pollutants emitted by factories and car exhausts affect humans who breathe in these harmful gases and also aggravate climate change up in the atmosphere. Being able to detect such emissions is a critically needed measure.

New research by the Nanoparticles by Design Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), in collaboration with the Materials Center Leoben Austria and the Austrian Centre for Electron Microscopy and Nanoanalysis has developed an efficient way to improve methods for detecting polluting emissions using a sensor at the nanoscale. …

A May 13, 2015 OIST press release (also on EurekAlert) by Joykrit Mitra, which originated the news item, details the research (Note: A link has been removed),

The researchers used a copper oxide nanowire decorated with palladium nanoparticles to detect carbon monoxide, a common industrial pollutant.  The sensor was tested in conditions similar to ambient air since future devices developed from this method will need to operate in these conditions.

Copper oxide is a semiconductor and scientists use nanowires fabricated from it to search for potential application in the microelectronics industry. But in gas sensing applications, copper oxide was much less widely investigated compared to other metal oxide materials.

A semiconductor can be made to experience dramatic changes in its electrical properties when a small amount of foreign atoms are made to attach to its surface at high temperatures.  In this case, the copper oxide nanowire was made part of an electric circuit. The researchers detected carbon monoxide indirectly, by measuring the change in the resulting circuit’s electrical resistance in presence of the gas. They found that copper oxide nanowires decorated with palladium nanoparticles show a significantly greater increase in electrical resistance in the presence of carbon monoxide than the same type of nanowires without the nanoparticles.

The OIST Nanoparticles by Design Unit used a sophisticated technique that allowed them to first sift nanoparticles according to size, then deliver and deposit the palladium nanoparticles onto the surface of the nanowires in an evenly distributed manner. This even dispersion of size selected nanoparticles and the resulting nanoparticles-nanowire interactions are crucial to get an enhanced electrical response.  The OIST nanoparticle deposition system can be tailored to deposit multiple types of nanoparticles at the same time, segregated on distinct areas of the wafer where the nanowire sits. In other words, this system can be engineered to be able to detect multiple kinds of gases.  The next step is to detect different gases at the same time by using multiple sensor devices, with each device utilizing a different type of nanoparticle.

Compared to other options being explored in gas sensing which are bulky and difficult to miniaturize, nanowire gas sensors will be cheaper and potentially easier to mass produce.

The main energy cost in operating this kind of a sensor will be the high temperatures necessary to facilitate the chemical reactions for ensuring certain electrical response. In this study 350 degree centigrade was used.  However, different nanowire-nanoparticle material configurations are currently being investigated in order to lower the operating temperature of this system.

“I think nanoparticle-decorated nanowires have a huge potential for practical applications as it is possible to incorporate this type of technology into industrial devices,” said Stephan Steinhauer, a Japan Society for the Promotion of Science (JSPS) postdoctoral research fellow working under the supervision of Prof. Mukhles Sowwan at the OIST Nanoparticles by Design Unit.

The researchers have provided this image showing their work,

Palladium nanoparticles were deposited on the entire wafer in an evenly distributed fashion, as seen in the background.  They also attached on the surface of the copper oxide wire in the same evenly distributed manner, as seen in the foreground.   On the upper right is a top view of a single palladium nanoparticle photographed with a transmission electron microscope(TEM) which can only produce black and white images. The nanoparticle is made up of columns consisting of palladium atoms stacked on top of each other.  Courtesy OIST

Palladium nanoparticles were deposited on the entire wafer in an evenly distributed fashion, as seen in the background. They also attached on the surface of the copper oxide wire in the same evenly distributed manner, as seen in the foreground.
On the upper right is a top view of a single palladium nanoparticle photographed with a transmission electron microscope(TEM) which can only produce black and white images. The nanoparticle is made up of columns consisting of palladium atoms stacked on top of each other. Courtesy OIST

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

Single CuO nanowires decorated with size-selected Pd nanoparticles for CO sensing in humid atmosphere by Stephan Steinhauer, Vidyadhar Singh, Cathal Cassidy, Christian Gspan, Werner Grogger, Mukhles Sowwan, and Anton Köck. Nanotechnology 2015 Volume 26 Number 17 doi:10.1088/0957-4484/26/17/175502

This paper is behind a paywall.

Nanopollution of marine life

Concerns are being raised about nanosunscreens and nanotechnology-enabled marine paints and their effect on marine life, specifically, sea urchins. From a May 13, 2015 news item on Nanowerk (Note: A link has been removed),

Nanomaterials commonly used in sunscreens and boat-bottom paints are making sea urchin embryos more vulnerable to toxins, according to a study from the University of California, Davis [UC Davis]. The authors said this could pose a risk to coastal, marine and freshwater environments.

The study, published in the journal Environmental Science and Technology (“Copper Oxide and Zinc Oxide Nanomaterials Act as Inhibitors of Multidrug Resistance Transport in Sea Urchin Embryos: Their Role as Chemosensitizers”), is the first to show that the nanomaterials work as chemosensitizers. In cancer treatments, a chemosensitizer makes tumor cells more sensitive to the effects of chemotherapy.

Similarly, nanozinc and nanocopper made developing sea urchin embryos more sensitive to other chemicals, blocking transporters that would otherwise defend them by pumping toxins out of cells.

A May 12, 2015 UC Davis news release, which originated the news item, includes some cautions,

Nanozinc oxide is used as an additive in cosmetics such as sunscreens, toothpastes and beauty products. Nanocopper oxide is often used for electronics and technology, but also for antifouling paints, which prevent things like barnacles and mussels from attaching to boats.

“At low levels, both of these nanomaterials are nontoxic,” said co-author Gary Cherr, professor and interim director of the UC Davis Bodega Marine Laboratory, and an affiliate of the UC Davis Coastal Marine Sciences Institute. “However, for sea urchins in sensitive life stages, they disrupt the main defense mechanism that would otherwise protect them from environmental toxins.”

Science for safe design

Nanomaterials are tiny chemical substances measured in nanometers, which are about 100,000 times smaller than the diameter of a human hair. Nano-sized particles can enter the body through the skin, ingestion, or inhalation. They are being rapidly introduced across the fields of electronics, medicine and technology, where they are being used to make energy efficient batteries, clean up oil spills, and fight cancer, among many other uses. However, relatively little is known about nanomaterials with respect to the environment and health.

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

Copper Oxide and Zinc Oxide Nanomaterials Act as Inhibitors of Multidrug Resistance Transport in Sea Urchin Embryos: Their Role as Chemosensitizers by Bing Wu, Cristina Torres-Duarte, Bryan J. Cole, and Gary N. Cherr. Environ. Sci. Technol., 2015, 49 (9), pp 5760–5770 DOI: 10.1021/acs.est.5b00345 Publication Date (Web): April 7, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

While this research into nanoparticles as chemosensitizers is, according to UC Davis, the first of its kind, the concern over nanosunscreens and marine waters has been gaining traction over the last few years. For example, there’s  research featured in a June 10, 2013 article by Roberta Kwok for the University of Washington’s ‘Conservation This Week’ magazine,

Sunscreen offers protection from UV rays, reduces the risk of skin cancer, and even slows down signs of aging. Unfortunately, researchers have found that sunscreen also pollutes the ocean.

Although people have been using these products for decades, “the effect of sunscreens, as a source of introduced chemicals to the coastal marine system, has not yet been addressed,” a research team writes in PLOS ONE. Sunscreens contain chemicals not only for UV protection, but also for coloring, fragrance, and texture. And beaches are becoming ever-more-popular vacation spots; for example, nearly 10 million tourists visited Majorca Island in the Mediterranean Sea in 2010.

Here’s a link to the 2013 PLOS ONE paper,

Sunscreen Products as Emerging Pollutants to Coastal Waters by Antonio Tovar-Sánchez, David Sánchez-Quiles, Gotzon Basterretxea, Juan L. Benedé, Alberto Chisvert, Amparo Salvador, Ignacio Moreno-Garrido, and Julián Blasco. PLOS ONE DOI: 10.1371/journal.pone.0065451 Published: June 5, 2013

This is an open access journal.

Outcomes for US-European Union bridging Nano environment, health, and safety (EHS) research workshop

According to Lynn Bergeson in an April 14, 2015 news item on Nanotechnology Now, a US-European Union (EU) workshop on nanosafety has published a document,

The National Nanotechnology Initiative (NNI) published on March 23, 2015, the outcomes of the March 12-13, 2015, joint workshop held by the U.S. and the European Union (EU), “Bridging NanoEHS Research Efforts.” …

A US National Nanotechnology Initiative (NNI) ??, ??, 2015 notice on the nano.gov site provides more details,

Workshop participants reviewed progress toward COR [communities of research] goals and objectives, shared best practices, and identified areas for cross-COR collaboration.  To address new challenges the CORs were realigned and expanded with the addition of a COR on nanotechnology characterization. The seven CORs now address:

Characterization
Databases and Computational Modeling
Exposure through Product Life
EcoToxicity
Human Toxicity
Risk Assessment
Risk Management and Control

The CORs support the shared goal of responsible nanotechnology development as outlined in the U.S. National Nanotechnology Initiative EHS Research Strategy, and the research strategy of the EU NanoSafety Cluster. The CORs directly address several priorities described in the documents above, including the creation of a comprehensive nanoEHS knowledge base and international cooperation on the development of best practices and consensus standards.

The CORs are self-run, with technical support provided by the European Commission and the U.S. National Nanotechnology Coordination Office. Each Community has European and American co-chairs who convene meetings and teleconferences, guide the discussions, and set the group’s agenda. Participation in the CORs is free and open to any interested individuals. More information is available at www.us-eu.org.

The workshop was organized by the European Commission and the U.S. National Nanotechnology Initiative under the auspices of the agreement for scientific and technological cooperation between the European Union and the United States.

Coincidentally, I received an April 13, 2015 notice about the European Commission’s NanoSafety Cluster’s Spring 2015 newsletter concerning their efforts but found no mention of the ‘bridging workshop’. Presumably, information was not available prior to the newsletter’s deadline.

In my April 8, 2014 posting about a US proposed rule for reporting nanomaterials, I included information about the US and its efforts to promote or participate in harmonizing the nano situation internationally. Scroll down about 35% of the way to find information about the Canada-U.S. Regulatory Cooperation Council (RCC) Nanotechnology Initiative, the Organisation for Economic Cooperation and Development (OECD) effort, and the International Organization for Standardization (ISO) effort.

Taking the baking out of aircraft manufacture

It seems that ovens are an essential piece of equipment when manufacturing aircraft parts but that may change if research from MIT (Massachusetts Institute of Technology) proves successful. An April 14, 2015 news item on ScienceDaily describes the current process and the MIT research,

Composite materials used in aircraft wings and fuselages are typically manufactured in large, industrial-sized ovens: Multiple polymer layers are blasted with temperatures up to 750 degrees Fahrenheit, and solidified to form a solid, resilient material. Using this approach, considerable energy is required first to heat the oven, then the gas around it, and finally the actual composite.

Aerospace engineers at MIT have now developed a carbon nanotube (CNT) film that can heat and solidify a composite without the need for massive ovens. When connected to an electrical power source, and wrapped over a multilayer polymer composite, the heated film stimulates the polymer to solidify.

The group tested the film on a common carbon-fiber material used in aircraft components, and found that the film created a composite as strong as that manufactured in conventional ovens — while using only 1 percent of the energy.

The new “out-of-oven” approach may offer a more direct, energy-saving method for manufacturing virtually any industrial composite, says Brian L. Wardle, an associate professor of aeronautics and astronautics at MIT.

“Typically, if you’re going to cook a fuselage for an Airbus A350 or Boeing 787, you’ve got about a four-story oven that’s tens of millions of dollars in infrastructure that you don’t need,” Wardle says. “Our technique puts the heat where it is needed, in direct contact with the part being assembled. Think of it as a self-heating pizza. … Instead of an oven, you just plug the pizza into the wall and it cooks itself.”

Wardle says the carbon nanotube film is also incredibly lightweight: After it has fused the underlying polymer layers, the film itself — a fraction of a human hair’s diameter — meshes with the composite, adding negligible weight.

An April 14, 2015 MIT news release, which originated the news item, describes the origins of the team’s latest research, the findings, and the implications,

Carbon nanotube deicers

Wardle and his colleagues have experimented with CNT films in recent years, mainly for deicing airplane wings. The team recognized that in addition to their negligible weight, carbon nanotubes heat efficiently when exposed to an electric current.

The group first developed a technique to create a film of aligned carbon nanotubes composed of tiny tubes of crystalline carbon, standing upright like trees in a forest. The researchers used a rod to roll the “forest” flat, creating a dense film of aligned carbon nanotubes.

In experiments, Wardle and his team integrated the film into airplane wings via conventional, oven-based curing methods, showing that when voltage was applied, the film generated heat, preventing ice from forming.

The deicing tests inspired a question: If the CNT film could generate heat, why not use it to make the composite itself?

How hot can you go?

In initial experiments, the researchers investigated the film’s potential to fuse two types of aerospace-grade composite typically used in aircraft wings and fuselages. Normally the material, composed of about 16 layers, is solidified, or cross-linked, in a high-temperature industrial oven.

The researchers manufactured a CNT film about the size of a Post-It note, and placed the film over a square of Cycom 5320-1. They connected electrodes to the film, then applied a current to heat both the film and the underlying polymer in the Cycom composite layers.

The team measured the energy required to solidify, or cross-link, the polymer and carbon fiber layers, finding that the CNT film used one-hundredth the electricity required for traditional oven-based methods to cure the composite. Both methods generated composites with similar properties, such as cross-linking density.

Wardle says the results pushed the group to test the CNT film further: As different composites require different temperatures in order to fuse, the researchers looked to see whether the CNT film could, quite literally, take the heat.

“At some point, heaters fry out,” Wardle says. “They oxidize, or have different ways in which they fail. What we wanted to see was how hot could this material go.”

To do this, the group tested the film’s ability to generate higher and higher temperatures, and found it topped out at over 1,000 F. In comparison, some of the highest-temperature aerospace polymers require temperatures up to 750 F in order to solidify.

“We can process at those temperatures, which means there’s no composite we can’t process,” Wardle says. “This really opens up all polymeric materials to this technology.”

The team is working with industrial partners to find ways to scale up the technology to manufacture composites large enough to make airplane fuselages and wings.

“There needs to be some thought given to electroding, and how you’re going to actually make the electrical contact efficiently over very large areas,” Wardle says. “You’d need much less power than you are currently putting into your oven. I don’t think it’s a challenge, but it has to be done.”

Gregory Odegard, a professor of computational mechanics at Michigan Technological University, says the group’s carbon nanotube film may go toward improving the quality and efficiency of fabrication processes for large composites, such as wings on commercial aircraft. The new technique may also open the door to smaller firms that lack access to large industrial ovens.

“Smaller companies that want to fabricate composite parts may be able to do so without investing in large ovens or outsourcing,” says Odegard, who was not involved in the research. “This could lead to more innovation in the composites sector, and perhaps improvements in the performance and usage of composite materials.”

It can be interesting to find out who funds the research (from the news release),

This research was funded in part by Airbus Group, Boeing, Embraer, Lockheed Martin, Saab AB, TohoTenax, ANSYS Inc., the Air Force Research Laboratory at Wright-Patterson Air Force Base, and the U.S. Army Research Office.

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

Impact of carbon nanotube length on electron transport in aligned carbon nanotube networks by Jeonyoon Lee, Itai Y. Stein, Mackenzie E. Devoe, Diana J. Lewis, Noa Lachman, Seth S. Kessler, Samuel T. Buschhorn, and Brian L. Wardle. Appl. Phys. Lett. 106, 053110 (2015); http://dx.doi.org/10.1063/1.4907608

This paper is behind a paywall.

Netting oil spills the nano way

Given current local events (April 8, 2015 oil spill in English Bay of 2700 litres (or more) of fuel in Vancouver, Canada), this news item about a mesh useful for oil cleanups seems quite timely. From an April 15, 2015 news item on ScienceDaily,

The unassuming piece of stainless steel mesh in a lab at The Ohio State University doesn’t look like a very big deal, but it could make a big difference for future environmental cleanups.

Water passes through the mesh but oil doesn’t, thanks to a nearly invisible oil-repelling coating on its surface.

In tests, researchers mixed water with oil and poured the mixture onto the mesh. The water filtered through the mesh to land in a beaker below. The oil collected on top of the mesh, and rolled off easily into a separate beaker when the mesh was tilted.

The mesh coating is among a suite of nature-inspired nanotechnologies under development at Ohio State and described in two papers in the journal Nature Scientific Reports. Potential applications range from cleaning oil spills to tracking oil deposits underground.

An April 15, 2015 Ohio State University news release (also on EurekAlert*) by Pam Frost Gorder, which originated the news item, expands on the theme (unusually I’ve left the links undisturbed),

“If you scale this up, you could potentially catch an oil spill with a net,” said Bharat Bhushan, Ohio Eminent Scholar and Howard D. Winbigler Professor of mechanical engineering at Ohio State.

The work was partly inspired by lotus leaves, whose bumpy surfaces naturally repel water but not oil. To create a coating that did the opposite, Bhushan and postdoctoral researcher Philip Brown chose to cover a bumpy surface with a polymer embedded with molecules of surfactant—the stuff that gives cleaning power to soap and detergent.

They sprayed a fine dusting of silica nanoparticles onto the stainless steel mesh to create a randomly bumpy surface and layered the polymer and surfactant on top.

The silica, surfactant, polymer, and stainless steel are all non-toxic and relatively inexpensive, said Brown. He estimated that a larger mesh net could be created for less than a dollar per square foot.

Because the coating is only a few hundred nanometers (billionths of a meter) thick, it is mostly undetectable. To the touch, the coated mesh doesn’t feel any bumpier than uncoated mesh. The coated mesh is a little less shiny, though, because the coating is only 70 percent transparent.

The researchers chose silica in part because it is an ingredient in glass, and they wanted to explore this technology’s potential for creating smudge-free glass coatings. At 70 percent transparency, the coating could work for certain automotive glass applications, such as mirrors, but not most windows or smartphone surfaces.

“Our goal is to reach a transparency in the 90-percent range,” Bhushan said. “In all our coatings, different combinations of ingredients in the layers yield different properties. The trick is to select the right layers.”

He explains that combinations of layers yield nanoparticles that bind to oil instead of repelling it. Such particles could be used to detect oil underground or aid removal in the case of oil spills.

The shape of the nanostructures plays a role, as well. In another project, research assistant Dave Maharaj is investigating what happens when a surface is made of nanotubes. Rather than silica, he experiments with molybdenum disulfide nanotubes, which mix well with oil. The nanotubes are approximately a thousand times smaller than a human hair.

Maharaj measured the friction on the surface of the nanotubes, and compressed them to test how they would hold up under pressure.

“There are natural defects in the structure of the nanotubes,” he said. “And under high loads, the defects cause the layers of the tubes to peel apart and create a slippery surface, which greatly reduces friction.”

Bhushan envisions that the molybdenum compound’s compatibility with oil, coupled with its ability to reduce friction, would make it a good additive for liquid lubricants. In addition, for micro- and nanoscale devices, commercial oils may be too sticky to allow for their efficient operation. Here, he suspects that the molybdenum nanotubes alone could be used to reduce friction.

This work began more than 10 years ago, when Bhushan began building and patenting nano-structured coatings that mimic the texture of the lotus leaf. From there, he and his team have worked to amplify the effect and tailor it for different situations.

“We’ve studied so many natural surfaces, from leaves to butterfly wings and shark skin, to understand how nature solves certain problems,” Bhushan said. “Now we want to go beyond what nature does, in order to solve new problems.”

“Nature reaches a limit of what it can do,” agreed Brown. “To repel synthetic materials like oils, we need to bring in another level of chemistry that nature doesn’t have access to.”

This work was partly funded by the American Chemical Society Petroleum Research Fund, the National Science Foundation, and Dexerials Corporation (formerly a chemical division of Sony Corp.) in Japan.

Here are links to and citations for the papers,

Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation by Philip S. Brow & Bharat Bhushan. Scientific Reports 5, Article number: 8701 doi:10.1038/srep08701 Published 03 March 2015

Nanomechanical behavior of MoS2 and WS2 multi-walled nanotubes and Carbon nanohorns by Dave Maharaj, & Bharat Bhushan. Scientific Reports 5, Article number: 8539 doi:10.1038/srep08539 Published 23 February 2015

Both papers are open access.

* EurekAlert link added Apr.16, 2015 at 1300 PST.

Filtration membranes with twice as much ability to remove unwanted materials from water

A March 26, 2015 news item on Nanowerk offers information about a new method for removing pollutants from water and some insight into the situation regarding bisphenol A (BPA) in Europe,

New types of membrane adsorbers remove unwanted particles from water and also, at the same time, dissolved substances such as the hormonally active bis-phenol A or toxic lead. To do this, researchers at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB imbed selective adsorber particles in filtration membranes.

It was not until January 2015 that the European Food Safety Authority (EFSA) lowered the threshold value for bisphenol A in packaging. The hormonally active bulk chemical is among other things a basic material for polycarbonate from which, for example, CDs, plastic tableware or spectacles glasses are manufactured. Due to its chemical structure, bisphenol A is not completely degraded in the biological stages of treatment plants and is discharged into rivers and lakes by the purification facility.

Activated carbon or adsorber materials are already used to remove chemicals, anti-biotics [sic] or heavy metals from waste or process water. However, a disadvantage of these highly porous materials is the long contact time that the pollutants require to diffuse into the pores. So that as many of the harmful substances as possible are captured even in a shorter time, the treatment plants use larger quantities of adsorbers in correspondingly large treatment basins. However, activated carbon can only be regenerated with a high energy input, resulting for the most part in the need to dispose of large quantities of material contaminated with pollutants.

Also, membrane filtration with nanofiltration or reverse osmosis membranes, which can remove the contaminating substances, is not yet cost-effective for the removal of dissolved molecules from high-volume flows such as process or wastewater. Membranes filter the water through their pores when a pressure is built up on one side of the membrane, thus holding back larger molecules and solid particles. But the smaller the membrane pores are, the higher the pressure – and therefore the more energy – that is required to separate the substances from water.

A March 24, 2015 Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) press release, which originated the news item, goes on to describe their team’s new approach,

Researchers at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB in Stuttgart have opted for a new approach that combines the advantages of both methods. When manufacturing the membranes they add small, polymeric adsorber particles. The resulting membrane adsorbers can – in addition to their filtration function – adsorptively bind substances dissolved in water. “We make use of the porous structure of the membrane located underneath the separation layer. The pores have a highly specific surface so that as many particles as possible can be imbedded, and they also provide optimum accessibility,” says Dr. Thomas Schiestel, Head of the “Inorganic Interfaces and Membranes” working group at the Fraunhofer IGB.

“Unlike conventional adsorbers, our membrane adsorbers transport the pollutants convectively. This means that, with the water flowing rapidly through the membrane pores, a contact time lasting only a few seconds is sufficient to adsorb pollutants on the particle surface,” says the scientist. Up to 40 percent of the weight of the membrane adsorbers is accounted for by the particles, so their binding capacity is correspondingly high. At the same time the membrane adsorbers can be operated at low pressures. As the membranes can be packed very tightly, very large volumes of water can be treated even with small devices.

Functional adsorber particles

The researchers manufacture the adsorber particles in a one-step, cost-efficient process. In this patented process monomeric components are polymerized with the help of a crosslinking agent to generate 50 to 500 nanometer polymer globules. “Depending on which substances are to be removed from the water, we select the most suitable one from a variety of monomers with differing functional groups,” Schiestel explains. The spectrum here ranges from pyridine, which tends to be hydrophobic, by way of cationic ammonium compounds and includes anionic phosphonates.

Selective removal of pollutants and metals

The researchers were able to show in various tests that the membrane adsorbers remove pollutants very selectively by means of the particles, which are customized for the particular contaminant in question. For example, membrane adsorbers with pyridine groups bind the hydrophobic bisphenol A especially well, whereas those with amino groups adsorb the negatively charged salt of the antibiotic penicillin G.

“The various adsorber particles can even be combined in one membrane. In this way we can remove several micropollutants simultaneously with just one membrane adsorber,” says Schiestel, pointing out a further advantage. Equipped with different functional groups, the membrane adsorbers can also remove toxic heavy metals such as lead or arsenic from the water. Phosphonate membrane adsorbers, for example, adsorb more than 5 grams of lead per square meter of membrane surface area – 40 percent more than a commercially available membrane adsorber.

Cost-effective and regenerable

So that the membrane adsorbers can be used several times, the adsorbed pollutants have to be detached once again from the particles in the membrane. “Membrane adsorbers for bisphenol A can be fully regenerated by a shift of the pH value,” Schiestel explains. The concentrated pollutants can then be disposed off cost-effectively or broken down using suitable oxidative processes.

The regenerability of the membrane adsorbers also makes possible a further application: reutilization of the separated molecules. This additionally makes the technology attractive for recovering valuable precious metals or rare earth metals.

The Fraunhofer IGB is presenting the membrane adsorbers and other innovative technologies for water purification at the “Wasser Berlin International” Trade Fair and Congress from 24th to 27th March 2015 in Berlin. The IGB is in Hall 2.2, Stand 422.

While it’s too late to attend the presentation, here are two links and citations to papers concerning the work,

Removal of micropollutants from water by nanocomposite membrane adsorbers by Klaus Niedergall, Monika Bach, Thomas Hirth, Günter E.M. Tovar, and Thomas Schiestel. Separation and Purification Technology, Volume 131, 27 June 2014 DOI: 10.1016/j.seppur.2014.04.032

Nanostructured Composite Adsorber Membranes for the Reduction of Trace Substances in Water: The Example of Bisphenol A by Klaus Niedergall, Monika Bach, Thomas Schiestel, and Günter E.M. Tovar. Ind. Eng. Chem. Res., 2013, 52 (39), pp 14011–14018 DOI: 10.1021/ie303264r Publication Date (Web): May 16, 2013

Copyright © 2013 American Chemical Society

Both articles are behind a paywall.

NANoREG halfway through its project (Environment, Health & Safety) term

A March 18, 2015 news item on Nanowerk announces a third NANoReg newsletter marking the halfway point in the project’s term (Note: Links have been removed),

NANoREG is the first FP7 project to deliver the answers needed by regulators and legislators on EHS [Environment, Health & Safety] by linking them to a scientific evaluation of data and test methods.

Time wise, the NANoREG project is now halfway. After setting the basic conditions for its R&D work, the project now focuses on the generation of reliable and comparable experimental data on the EHS aspects of the selected NANoREG nanomaterials. These data will form the basis for the main “end products” of the NANoREG project: the Regulatory Framework and the NANoREG Toolbox. Highlights of this experimental work and results will be shared with you in this 3rd NANoREG Newsletter (pdf).

The editorial for the 3rd issue of the NANoREG newsletter, which seems to have originated the news item, describes upcoming initiatives,

The Regulatory Framework and the NANoREG Toolbox just mentioned will be developed in close cooperation with organisations involved in standardisation and in the regulatory aspects of nanomaterials like ECHA [European Chemicals Agency], OECD [Organization for Economic Cooperation and Development], CEN [European Committee for Standardization] and ISO [International Standards Organization]. The results of other EU FP7 [Framework Programme 7] and H2020 [Horizon 2020] [research funding] projects will also be taken into account when developing these products. One of these projects is the H2020 project NANoREG II that focuses on Safe by design and that will start in the 2nd or 3rd quarter of 2015.

The coordinated and integrated approach in developing the Framework and the NANoREG Toolbox is one of the main elements of the H2020 funded Coordination and Support Action (CSA) “ProSafe” that recently had its Kick-Off meeting in Aix-en-Provence, France. Just like NANoREG this CSA is coordinated by the Dutch Ministry of Infrastructure and the Environment and as such executed by me. Other elements of this CSA are – among others – the expansions of the involvement of EU and non-EU countries in the NANoREG project in order to broaden the platform of support for the NANoREG results world-wide (“NANoREG+”), the exploitation of synergies between the NANoREG project and other “nanosafety” projects and data management.

The outcome of the CSA will be a White Paper that can be used by policy makers, regulators and industry to establish methods for measuring and assessing the EHS aspects of nanomaterials and that will give guidance to industry how to implement “safe by design“. A forerunner of the White Paper will be subject of a three days scientific conference to be held at the end of 2016. It will include the results of the NANoREG project, the results of the evaluation of EHS data available at the OECD and results from other sources. After consulting Risk assessors and policymakers, the White Paper will be published in the first quarter of 2017.

This project has reached out beyond Europe for partners (from the editorial for the 3rd NANoREG newsletter),

It is quite a challenge we face. Given the expertise and scientific authority of our partners, including the Czech-,Brazilian- and South Korean parties that recently joined the NANoREG project, I am confident however that we will succeed in reaching our goal: creating a solid basis for a balanced combination of nanosafety and innovation that will be beneficial to society.

I hope NANoREG is successful with its goal of “creating a solid basis for a balanced combination of nanosafety and innovation that will be beneficial to society.”

I last wrote about NANoREG in a March 21, 2014 posting.

Removing titanium dioxide nanoparticles from water may not be that easy

A March 10, 2015 news item on Nanowerk highlights some research into the removal of nanoscale titanium dioxide particles from water supplies (Note: A link has been removed),

The increased use of engineered nanoparticles (ENMs) in commercial and industrial applications is raising concern over the environmental and health effects of nanoparticles released into the water supply. A timely study that analyzes the ability of typical water pretreatment methods to remove titanium dioxide, the most commonly used ENM, is published in Environmental Engineering Science (“Titanium Dioxide Nanoparticle Removal in Primary Prefiltration Stages of Water Treatment: Role of Coating, Natural Organic Matter, Source Water, and Solution Chemistry”). The article is available free on the Environmental Engineering Science website until April 10, 2015.

A March 10, 2015 Mary Ann Liebert, Inc., publishers news release (also on EurekAlert), which originated the news item, provides more details about the work (Note: A link has been removed),

Nichola Kinsinger, Ryan Honda, Valerie Keene, and Sharon Walker, University of California, Riverside, suggest that current methods of water prefiltration treatment cannot adequately remove titanium dioxide ENMs. They describe the results of scaled-down tests to evaluate the effectiveness of three traditional methods—coagulation, flocculation, and sedimentation—in the article “Titanium Dioxide Nanoparticle Removal in Primary Prefiltration Stages of Water Treatment: Role of Coating, Natural Organic Matter, Source Water, and Solution Chemistry.”

“As nanoscience and engineering allow us to develop new exciting products, we must be ever mindful of associated consequences of these advances,” says Domenico Grasso, PhD, PE, DEE, Editor-in-Chief of Environmental Engineering Science and Provost, University of Delaware. “Professor Walker and her team have presented an excellent report raising concerns that some engineered nanomaterials may find their ways into our water supplies.”

“While further optimization of such treatment processes may allow for improved removal efficiencies, this study illustrates the challenges that we must be prepared to face with the emergence of new engineered nanomaterials,” says Sharon Walker, PhD, Professor of Chemical and Environmental Engineering, University of California, Riverside.

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

Titanium Dioxide Nanoparticle Removal in Primary Prefiltration Stages of Water Treatment: Role of Coating, Natural Organic Matter, Source Water, and Solution Chemistry by Nichola Kinsinger, Ryan Honda, Valerie Keene, and Sharon L. Walker. Environmental Engineering Science. doi:10.1089/ees.2014.0288.

This paper is freely available until April 10, 2015.

Interestingly Sharon Walker and Nichola Kinsinger recently co-authored a paper (mentioned in my March 9, 2015 post) about copper nanoparticles and water treatment which concluded this about copper nanoparticles in water supplies,

The researchers found that the copper nanoparticles, when studied outside the septic tank, impacted zebrafish embryo hatching rates at concentrations as low as 0.5 parts per million. However, when the copper nanoparticles were released into the replica septic tank, which included liquids that simulated human digested food and household wastewater, they were not bioavailable and didn’t impact hatching rates.

Taking these these two paper into account (and the many others I’ve read), there is no simple or universal answer to the question of whether or not ENPs or ENMs are going to pose environmental problems.

Do-it-yourself sensors possible with biocatalytic pen technology

The engineers at the University of California at San Diego (UCSD) are envisioning a future where anyone can create a biosensor anywhere. From a March 3, 2015 news item on Azonano,

A new simple tool developed by nanoengineers at the University of California, San Diego, is opening the door to an era when anyone will be able to build sensors, anywhere, including physicians in the clinic, patients in their home and soldiers in the field.

The team from the University of California, San Diego, developed high-tech bio-inks that react with several chemicals, including glucose. They filled off-the-shelf ballpoint pens with the inks and were able to draw sensors to measure glucose directly on the skin and sensors to measure pollution on leaves.

A March 2, 2015 UCSD news release by Ioana Patringenaru, which originated the news item, describes the researchers’ hopes for this technology,

Skin and leaves aren’t the only media on which the pens could be used. Researchers envision sensors drawn directly on smart phones for personalized and inexpensive health monitoring or on external building walls for monitoring of toxic gas pollutants. The sensors also could be used on the battlefield to detect explosives and nerve agents.

The team, led by Joseph Wang, the chairman of the Department of NanoEngineering at the University of California, San Diego, published their findings in the Feb. 26 [2015] issue of Advanced Healthcare Materials. Wang also directs the Center for Wearable Sensors at UC San Diego.

“Our new biocatalytic pen technology, based on novel enzymatic inks, holds considerable promise for a broad range of applications on site and in the field,” Wang said.

The news release goes on to describe one of the key concerns with developing the ink,

The biggest challenge the researchers faced was making inks from chemicals and biochemicals that aren’t harmful to humans or plants; could function as the sensors’ electrodes; and retain their properties over long periods in storage and in various conditions. Researchers turned to biocompatible polyethylene glycol, which is used in several drug delivery applications, as a binder. To make the inks conductive to electric current they used graphite powder. They also added chitosan, an antibacterial agent which is used in bandages to reduce bleeding, to make sure the ink adhered to any surfaces it was used on. The inks’ recipe also includes xylitol, a sugar substitute, which helps stabilize enzymes that react with several chemicals the do-it-yourself sensors are designed to monitor.

There’s a backstory to this research,

Wang’s team has been investigating how to make glucose testing for diabetics easier for several years. The same team of engineers recently developed non-invasive glucose sensors in the form of temporary tattoos. In this study, they used pens, loaded with an ink that reacts to glucose, to draw reusable glucose-measuring sensors on a pattern printed on a transparent, flexible material which includes an electrode. Researchers then pricked a subject’s finger and put the blood sample on the sensor. The enzymatic ink reacted with glucose and the electrode recorded the measurement, which was transmitted to a glucose-measuring device. Researchers then wiped the pattern clean and drew on it again to take another measurement after the subject had eaten.

Researchers estimate that one pen contains enough ink to draw the equivalent of 500 high-fidelity glucose sensor strips. Nanoengineers also demonstrated that the sensors could be drawn directly on the skin and that they could communicate with a Bluetooth-enabled electronic device that controls electrodes called a potentiostat, to gather data.

As mentioned earlier, there are more applications being considered (from the news release),

The pens would also allow users to draw sensors that detect pollutants and potentially harmful chemicals sensors on the spot. Researchers demonstrated that this was possible by drawing a sensor on a leaf with an ink loaded with enzymes that react with phenol, an industrial chemical, which can also be found in cosmetics, including sunscreen. The leaf was then dipped in a solution of water and phenol and the sensor was connected to a pollution detector. The sensors could be modified to react with many pollutants, including heavy metals or pesticides.

Next steps include connecting the sensors wirelessly to monitoring devices and investigating how the sensors perform in difficult conditions, including extreme temperatures, varying humidity and extended exposure to sunlight.

The researchers’ have provided a picture of the pen and a leaf,

Researchers drew sensors capable of detecting pollutants on a leaf. Courtesy: University of California at San Diego

Researchers drew sensors capable of detecting pollutants on a leaf. Courtesy: University of California at San Diego

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

Biocompatible Enzymatic Roller Pens for Direct Writing of Biocatalytic Materials: “Do-it-Yourself” Electrochemical Biosensors by Amay J. Bandodkar, Wenzhao Jia, Julian Ramírez, and Joseph Wang. Advanced Healthcare Materials DOI: 10.1002/adhm.201400808 Article first published online: 26 FEB 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This article is behind a paywall.