Category Archives: environment

Sustainable Nanotechnologies (SUN) project draws to a close in March 2017

Two Oct. 31, 2016 news item on Nanowerk signal the impending sunset date for the European Union’s Sustainable Nanotechnologies (SUN) project. The first Oct. 31, 2016 news item on Nanowerk describes the projects latest achievements,

The results from the 3rd SUN annual meeting showed great advancement of the project. The meeting was held in Edinburgh, Scotland, UK on 4-5 October 2016 where the project partners presented the results obtained during the second reporting period of the project.

SUN is a three and a half year EU project, running from 2013 to 2017, with a budget of about €14 million. Its main goal is to evaluate the risks along the supply chain of engineered nanomaterials and incorporate the results into tools and guidelines for sustainable manufacturing.

The ultimate goal of the SUN Project is the development of an online software Decision Support System – SUNDS – aimed at estimating and managing occupational, consumer, environmental and public health risks from nanomaterials in real industrial products along their lifecycles. The SUNDS beta prototype has been released last October, 2015, and since then the main focus has been on refining the methodologies and testing them on selected case studies i.e. nano-copper oxide based wood preserving paint and nano- sized colourants for plastic car part: organic pigment and carbon black. Obtained results and open issues were discussed during the third annual meeting in order collect feedbacks from the consortium that will inform, in the next months, the implementation of the final version of the SUNDS software system, due by March 2017.

An Oct. 27, 2016 SUN project press release, which originated the news item, adds more information,

Significant interest has been payed towards the results obtained in WP2 (Lifecycle Thinking) which main objectives are to assess the environmental impacts arising from each life cycle stage of the SUN case studies (i.e. Nano-WC-Cobalt (Tungsten Carbide-cobalt) sintered ceramics, Nanocopper wood preservatives, Carbon Nano Tube (CNT) in plastics, Silicon Dioxide (SiO2) as food additive, Nano-Titanium Dioxide (TiO2) air filter system, Organic pigment in plastics and Nanosilver (Ag) in textiles), and compare them to conventional products with similar uses and functionality, in order to develop and validate criteria and guiding principles for green nano-manufacturing. Specifically, the consortium partner COLOROBBIA CONSULTING S.r.l. expressed its willingness to exploit the results obtained from the life cycle assessment analysis related to nanoTiO2 in their industrial applications.

On 6th October [2016], the discussions about the SUNDS advancement continued during a Stakeholder Workshop, where representatives from industry, regulatory and insurance sectors shared their feedback on the use of the decision support system. The recommendations collected during the workshop will be used for the further refinement and implemented in the final version of the software which will be released by March 2017.

The second Oct. 31, 2016 news item on Nanowerk led me to this Oct. 27, 2016 SUN project press release about the activities in the upcoming final months,

The project has designed its final events to serve as an effective platform to communicate the main results achieved in its course within the Nanosafety community and bridge them to a wider audience addressing the emerging risks of Key Enabling Technologies (KETs).

The series of events include the New Tools and Approaches for Nanomaterial Safety Assessment: A joint conference organized by NANOSOLUTIONS, SUN, NanoMILE, GUIDEnano and eNanoMapper to be held on 7 – 9 February 2017 in Malaga, Spain, the SUN-CaLIBRAte Stakeholders workshop to be held on 28 February – 1 March 2017 in Venice, Italy and the SRA Policy Forum: Risk Governance for Key Enabling Technologies to be held on 1- 3 March in Venice, Italy.

Jointly organized by the Society for Risk Analysis (SRA) and the SUN Project, the SRA Policy Forum will address current efforts put towards refining the risk governance of emerging technologies through the integration of traditional risk analytic tools alongside considerations of social and economic concerns. The parallel sessions will be organized in 4 tracks:  Risk analysis of engineered nanomaterials along product lifecycle, Risks and benefits of emerging technologies used in medical applications, Challenges of governing SynBio and Biotech, and Methods and tools for risk governance.

The SRA Policy Forum has announced its speakers and preliminary Programme. Confirmed speakers include:

  • Keld Alstrup Jensen (National Research Centre for the Working Environment, Denmark)
  • Elke Anklam (European Commission, Belgium)
  • Adam Arkin (University of California, Berkeley, USA)
  • Phil Demokritou (Harvard University, USA)
  • Gerard Escher (École polytechnique fédérale de Lausanne, Switzerland)
  • Lisa Friedersdor (National Nanotechnology Initiative, USA)
  • James Lambert (President, Society for Risk Analysis, USA)
  • Andre Nel (The University of California, Los Angeles, USA)
  • Bernd Nowack (EMPA, Switzerland)
  • Ortwin Renn (University of Stuttgart, Germany)
  • Vicki Stone (Heriot-Watt University, UK)
  • Theo Vermeire (National Institute for Public Health and the Environment (RIVM), Netherlands)
  • Tom van Teunenbroek (Ministry of Infrastructure and Environment, The Netherlands)
  • Wendel Wohlleben (BASF, Germany)

The New Tools and Approaches for Nanomaterial Safety Assessment (NMSA) conference aims at presenting the main results achieved in the course of the organizing projects fostering a discussion about their impact in the nanosafety field and possibilities for future research programmes.  The conference welcomes consortium partners, as well as representatives from other EU projects, industry, government, civil society and media. Accordingly, the conference topics include: Hazard assessment along the life cycle of nano-enabled products, Exposure assessment along the life cycle of nano-enabled products, Risk assessment & management, Systems biology approaches in nanosafety, Categorization & grouping of nanomaterials, Nanosafety infrastructure, Safe by design. The NMSA conference key note speakers include:

  • Harri Alenius (University of Helsinki, Finland,)
  • Antonio Marcomini (Ca’ Foscari University of Venice, Italy)
  • Wendel Wohlleben (BASF, Germany)
  • Danail Hristozov (Ca’ Foscari University of Venice, Italy)
  • Eva Valsami-Jones (University of Birmingham, UK)
  • Socorro Vázquez-Campos (LEITAT Technolоgical Center, Spain)
  • Barry Hardy (Douglas Connect GmbH, Switzerland)
  • Egon Willighagen (Maastricht University, Netherlands)
  • Nina Jeliazkova (IDEAconsult Ltd., Bulgaria)
  • Haralambos Sarimveis (The National Technical University of Athens, Greece)

During the SUN-caLIBRAte Stakeholder workshop the final version of the SUN user-friendly, software-based Decision Support System (SUNDS) for managing the environmental, economic and social impacts of nanotechnologies will be presented and discussed with its end users: industries, regulators and insurance sector representatives. The results from the discussion will be used as a foundation of the development of the caLIBRAte’s Risk Governance framework for assessment and management of human and environmental risks of MN and MN-enabled products.

The SRA Policy Forum: Risk Governance for Key Enabling Technologies and the New Tools and Approaches for Nanomaterial Safety Assessment conference are now open for registration. Abstracts for the SRA Policy Forum can be submitted till 15th November 2016.
For further information go to:
www.sra.org/riskgovernanceforum2017
http://www.nmsaconference.eu/

There you have it.

Boron nitride-graphene hybrid nanostructures could lead to next generation ‘green’ cars

An Oct. 24, 2016 phys.org news item describes research which may lead to improved fuel storage in ‘green’ cars,

Layers of graphene separated by nanotube pillars of boron nitride may be a suitable material to store hydrogen fuel in cars, according to Rice University scientists.

The Department of Energy has set benchmarks for storage materials that would make hydrogen a practical fuel for light-duty vehicles. The Rice lab of materials scientist Rouzbeh Shahsavari determined in a new computational study that pillared boron nitride and graphene could be a candidate.

An Oct. 24, 2016 Rice University news release (also on EurekAlert), which originated the news item, provides more detail (Note: Links have been removed),

Shahsavari’s lab had already determined through computer models how tough and resilient pillared graphene structures would be, and later worked boron nitride nanotubes into the mix to model a unique three-dimensional architecture. (Samples of boron nitride nanotubes seamlessly bonded to graphene have been made.)

Just as pillars in a building make space between floors for people, pillars in boron nitride graphene make space for hydrogen atoms. The challenge is to make them enter and stay in sufficient numbers and exit upon demand.

In their latest molecular dynamics simulations, the researchers found that either pillared graphene or pillared boron nitride graphene would offer abundant surface area (about 2,547 square meters per gram) with good recyclable properties under ambient conditions. Their models showed adding oxygen or lithium to the materials would make them even better at binding hydrogen.

They focused the simulations on four variants: pillared structures of boron nitride or pillared boron nitride graphene doped with either oxygen or lithium. At room temperature and in ambient pressure, oxygen-doped boron nitride graphene proved the best, holding 11.6 percent of its weight in hydrogen (its gravimetric capacity) and about 60 grams per liter (its volumetric capacity); it easily beat competing technologies like porous boron nitride, metal oxide frameworks and carbon nanotubes.

At a chilly -321 degrees Fahrenheit, the material held 14.77 percent of its weight in hydrogen.

The Department of Energy’s current target for economic storage media is the ability to store more than 5.5 percent of its weight and 40 grams per liter in hydrogen under moderate conditions. The ultimate targets are 7.5 weight percent and 70 grams per liter.

Shahsavari said hydrogen atoms adsorbed to the undoped pillared boron nitride graphene, thanks to  weak van der Waals forces. When the material was doped with oxygen, the atoms bonded strongly with the hybrid and created a better surface for incoming hydrogen, which Shahsavari said would likely be delivered under pressure and would exit when pressure is released.

“Adding oxygen to the substrate gives us good bonding because of the nature of the charges and their interactions,” he said. “Oxygen and hydrogen are known to have good chemical affinity.”

He said the polarized nature of the boron nitride where it bonds with the graphene and the electron mobility of the graphene itself make the material highly tunable for applications.

“What we’re looking for is the sweet spot,” Shahsavari said, describing the ideal conditions as a balance between the material’s surface area and weight, as well as the operating temperatures and pressures. “This is only practical through computational modeling, because we can test a lot of variations very quickly. It would take experimentalists months to do what takes us only days.”

He said the structures should be robust enough to easily surpass the Department of Energy requirement that a hydrogen fuel tank be able to withstand 1,500 charge-discharge cycles.

Shayeganfar [Farzaneh Shayeganfar], a former visiting scholar at Rice, is an instructor at Shahid Rajaee Teacher Training University in Tehran, Iran.

 

Caption: Simulations by Rice University scientists show that pillared graphene boron nitride may be a suitable storage medium for hydrogen-powered vehicles. Above, the pink (boron) and blue (nitrogen) pillars serve as spacers for carbon graphene sheets (gray). The researchers showed the material worked best when doped with oxygen atoms (red), which enhanced its ability to adsorb and desorb hydrogen (white). Credit: Lei Tao/Rice University

Caption: Simulations by Rice University scientists show that pillared graphene boron nitride may be a suitable storage medium for hydrogen-powered vehicles. Above, the pink (boron) and blue (nitrogen) pillars serve as spacers for carbon graphene sheets (gray). The researchers showed the material worked best when doped with oxygen atoms (red), which enhanced its ability to adsorb and desorb hydrogen (white). Credit: Lei Tao/Rice University

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

Oxygen and Lithium Doped Hybrid Boron-Nitride/Carbon Networks for Hydrogen Storage by Farzaneh Shayeganfar and Rouzbeh Shahsavari. Langmuir,  DOI: 10.1021/acs.langmuir.6b02997 Publication Date (Web): October 23, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

I last featured research by Shayeganfar and  Shahsavari on graphene and boron nitride in a Jan. 14, 2016 posting.

Ocean-inspired coatings for organic electronics

An Oct. 19, 2016 news item on phys.org describes the advantages a new coating offers and the specific source of inspiration,

In a development beneficial for both industry and environment, UC Santa Barbara [University of California at Santa Barbara] researchers have created a high-quality coating for organic electronics that promises to decrease processing time as well as energy requirements.

“It’s faster, and it’s nontoxic,” said Kollbe Ahn, a research faculty member at UCSB’s Marine Science Institute and corresponding author of a paper published in Nano Letters.

In the manufacture of polymer (also known as “organic”) electronics—the technology behind flexible displays and solar cells—the material used to direct and move current is of supreme importance. Since defects reduce efficiency and functionality, special attention must be paid to quality, even down to the molecular level.

Often that can mean long processing times, or relatively inefficient processes. It can also mean the use of toxic substances. Alternatively, manufacturers can choose to speed up the process, which could cost energy or quality.

Fortunately, as it turns out, efficiency, performance and sustainability don’t always have to be traded against each other in the manufacture of these electronics. Looking no further than the campus beach, the UCSB researchers have found inspiration in the mollusks that live there. Mussels, which have perfected the art of clinging to virtually any surface in the intertidal zone, serve as the model for a molecularly smooth, self-assembled monolayer for high-mobility polymer field-effect transistors—in essence, a surface coating that can be used in the manufacture and processing of the conductive polymer that maintains its efficiency.

An Oct. 18, 2016 UCSB news release by Sonia Fernandez, which originated the news item, provides greater technical detail,

More specifically, according to Ahn, it was the mussel’s adhesion mechanism that stirred the researchers’ interest. “We’re inspired by the proteins at the interface between the plaque and substrate,” he said.

Before mussels attach themselves to the surfaces of rocks, pilings or other structures found in the inhospitable intertidal zone, they secrete proteins through the ventral grove of their feet, in an incremental fashion. In a step that enhances bonding performance, a thin priming layer of protein molecules is first generated as a bridge between the substrate and other adhesive proteins in the plaques that tip the byssus threads of their feet to overcome the barrier of water and other impurities.

That type of zwitterionic molecule — with both positive and negative charges — inspired by the mussel’s native proteins (polyampholytes), can self-assemble and form a sub-nano thin layer in water at ambient temperature in a few seconds. The defect-free monolayer provides a platform for conductive polymers in the appropriate direction on various dielectric surfaces.

Current methods to treat silicon surfaces (the most common dielectric surface), for the production of organic field-effect transistors, requires a batch processing method that is relatively impractical, said Ahn. Although heat can hasten this step, it involves the use of energy and increases the risk of defects.

With this bio-inspired coating mechanism, a continuous roll-to-roll dip coating method of producing organic electronic devices is possible, according to the researchers. It also avoids the use of toxic chemicals and their disposal, by replacing them with water.

“The environmental significance of this work is that these new bio-inspired primers allow for nanofabrication on silicone dioxide surfaces in the absence of organic solvents, high reaction temperatures and toxic reagents,” said co-author Roscoe Lindstadt, a graduate student researcher in UCSB chemistry professor Bruce Lipshutz’s lab. “In order for practitioners to switch to newer, more environmentally benign protocols, they need to be competitive with existing ones, and thankfully device performance is improved by using this ‘greener’ method.”

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

Molecularly Smooth Self-Assembled Monolayer for High-Mobility Organic Field-Effect Transistors by Saurabh Das, Byoung Hoon Lee, Roscoe T. H. Linstadt, Keila Cunha, Youli Li, Yair Kaufman, Zachary A. Levine, Bruce H. Lipshutz, Roberto D. Lins, Joan-Emma Shea, Alan J. Heeger, and B. Kollbe Ahn. Nano Lett., 2016, 16 (10), pp 6709–6715
DOI: 10.1021/acs.nanolett.6b03860 Publication Date (Web): September 27, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall but the scientists have made an illustration available,

An artist's concept of a zwitterionic molecule of the type secreted by mussels to prime surfaces for adhesion Photo Credit: Peter Allen

An artist’s concept of a zwitterionic molecule of the type secreted by mussels to prime surfaces for adhesion Photo Credit: Peter Allen

XSEDE: the most advanced, powerful integrated digital resources in the world and nanomaterials

The University of Iowa does not jump to mind when considering powerhouse nanomaterial research; it seems that’s a mistake. An Oct. 19, 2016 news item on Nanowerk sets the record straight,

Chemists at the University of Iowa will research the effects of nanomaterials on the environment and human health using a network of supercomputers funded by the U.S. National Science Foundation.

Sara E. Mason, assistant professor in the Department of Chemistry, won an NSF award that grants her team access to the Extreme Science and Engineering Discovery Environment (XSEDE). The XSEDE project links computers, data, and people from around the world to establish a single, virtual system that scientists can interactively use to conduct research. It was started in 2011 and was renewed by the NSF last August.

The NSF says it “will be the most advanced, powerful, and robust collection of integrated advanced digital resources and services in the world.”

An Oct. 12, 2016 University of Iowa (UI) news release by Richard C. Lewis, which originated the news item, provides a little more detail,

The UI grant, valued at $72,503, essentially gives Mason’s team time on the supercomputer network, which they can access from their desktops. The researchers will use that time to study nanoparticles—matter far too small to be seen by the naked eye and present in a range of products, from sunscreen to advanced batteries for hybrid and electric vehicles.

The team hopes to better define the atom-to-atom interactions of various nanoparticles. Mason says the grant will “super charge” her computational research.

“To me, having four concurrent NSF research grants is a big deal, and now, having the boost of the computer time allows us to do even more,” Mason says. “XSEDE allows us to run simulations using quantum mechanics and highly parallelized computers. The outcome is new chemical insight into natural or widely used nanoparticles. We can then connect the chemistry to broader issues, such as human health and the behavior of nanomaterials in the environment.”

Mason’s group aims to find and design nanomaterials that are more benign to the environment and human health. Part of the search means trying out new elements in computational designs to find out how they interact, as well as their side effects, good or bad.

The XSEDE computers will give them far more computing horsepower to carry out those computational experiments.

“We can collectively get a lot more done in a shorter period of time,” says Joseph Bennett, co-principal investigator on the grant and a post-doctoral researcher in Mason’s group.

The UI is one of 15 institutions affiliated with the NSF-funded Center for Sustainable Nanotechnology, devoted to investigating the fundamental molecular mechanisms by which nanoparticles interact with biological systems.

I wish them good luck.

Nano-spike catalysts offer one step conversion of carbon dioxide to ethanol

An Oct. 12, 2016 news item on ScienceDaily makes an exciting announcement, if carbon-dixoide-conversion-to-fuel is one of your pet topics,

In a new twist to waste-to-fuel technology, scientists at the Department of Energy’s Oak Ridge National Laboratory [ORNL] have developed an electrochemical process that uses tiny spikes of carbon and copper to turn carbon dioxide, a greenhouse gas, into ethanol. Their finding, which involves nanofabrication and catalysis science, was serendipitous.

An Oct. 12, 2016 ORNL news release, which originated the news item, explains in greater detail,

“We discovered somewhat by accident that this material worked,” said ORNL’s Adam Rondinone, lead author of the team’s study published in ChemistrySelect. “We were trying to study the first step of a proposed reaction when we realized that the catalyst was doing the entire reaction on its own.”

The team used a catalyst made of carbon, copper and nitrogen and applied voltage to trigger a complicated chemical reaction that essentially reverses the combustion process. With the help of the nanotechnology-based catalyst which contains multiple reaction sites, the solution of carbon dioxide dissolved in water turned into ethanol with a yield of 63 percent. Typically, this type of electrochemical reaction results in a mix of several different products in small amounts.

“We’re taking carbon dioxide, a waste product of combustion, and we’re pushing that combustion reaction backwards with very high selectivity to a useful fuel,” Rondinone said. “Ethanol was a surprise — it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”

The catalyst’s novelty lies in its nanoscale structure, consisting of copper nanoparticles embedded in carbon spikes. This nano-texturing approach avoids the use of expensive or rare metals such as platinum that limit the economic viability of many catalysts.

“By using common materials, but arranging them with nanotechnology, we figured out how to limit the side reactions and end up with the one thing that we want,” Rondinone said.

The researchers’ initial analysis suggests that the spiky textured surface of the catalysts provides ample reactive sites to facilitate the carbon dioxide-to-ethanol conversion.

“They are like 50-nanometer lightning rods that concentrate electrochemical reactivity at the tip of the spike,” Rondinone said.

Given the technique’s reliance on low-cost materials and an ability to operate at room temperature in water, the researchers believe the approach could be scaled up for industrially relevant applications. For instance, the process could be used to store excess electricity generated from variable power sources such as wind and solar.

“A process like this would allow you to consume extra electricity when it’s available to make and store as ethanol,” Rondinone said. “This could help to balance a grid supplied by intermittent renewable sources.”

The researchers plan to refine their approach to improve the overall production rate and further study the catalyst’s properties and behavior.

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

High-Selectivity Electrochemical Conversion of CO2 to Ethanol using a Copper Nanoparticle/N-Doped Graphene Electrode by Yang Song, Rui Peng, Dale Hensley, Peter Bonnesen, Liangbo Liang, Zili Wu, Harry Meyer III, Miaofang Chi, Cheng Ma, Bobby Sumpter and Adam Rondinone. Chemistry Select DOI: 10.1002/slct.201601169 First published: 28 September 2016

This paper is open access.

Oil spill cleanup nanotechnology-enabled solution from A*STAR

A*STAR (Singapore’s Agency for Science Technology and Research) has developed a new technology for cleaning up oil spills according to an Oct. 11, 2016 news item on Nanowerk,

Oceanic oil spills are tough to clean up. They dye feathers a syrupy sepia and tan fish eggs a toxic tint. The more turbulent the waters, the farther the slick spreads, with inky droplets descending into the briny deep.

Now technology may be able to succeed where hard-working volunteers have failed in the past. Researchers at the A*STAR Institute of Bioengineering and Nanotechnology (IBN) are using nanotechnology to turn an oil spill into a floating mass of brown jelly that can be scooped up before it can make its way into the food chain.

“Nanoscience makes it possible to tailor the essential structures of materials at the nanometer scale to achieve specific properties,” says chemist Yugen Zhang at IBN, who is developing some of the technologies. “Structures and materials in the nanometer size range often take on distinctive properties that are not seen in other size ranges,” adds Huaqiang Zeng, another chemist at IBN.

An Oct. 11, 2016 A*STAR press release, which originated the news item, describes some of problematic solutions before describing the new technology,

There are many approaches to cleaning an oil spill, and none are completely effective. Fresh, thick grease can be set ablaze or contained by floating barriers for skimmers to scoop out. The slick can also be inefficiently hardened, messily absorbed, hazardously dispersed, or slowly consumed by oil-grazing bacteria. All of these are deficient on a large scale, especially in rough waters.

Organic molecules with special gelling abilities offer a cheap, simple and environmentally friendly alternative for cleaning up the mess. Zeng has developed several such molecules that turn crude oil into jelly within minutes.

To create his ‘supergelators’, Zeng designed the molecules to associate with each other without forming physical bonds. When sprayed on contaminated seawater, the molecules immediately bundle into long fibers between 40 and 800 nanometers wide. These threads create a web that traps the interspersed oil in a giant blob that floats on the water’s surface. The gunk can then be swiftly sieved out of the ocean. Valuable crude oil can later be reclaimed using a common technique employed by petroleum refineries called fractional distillation.

Zeng tested the supergelators on four types of crude oil with different densities, viscosities and sulfur levels in a small round dish. The results were impressive. “The supergelators solidified both freshly spilled crude oil and highly weathered crude oil 37 to 60 times their own weight,” says Zeng. The materials used to produce these organic molecules are cheap and non toxic, which make them a commercially viable solution for managing accidents out at sea. Zeng hopes to work with industrial partners to test the nanomolecules on a much larger scale.

Zeng and his colleagues have developed other other ‘water’ applications as well,

Unsalty water

Scientists at IBN are also using nanoscience to remove salt from seawater and heavy metals from contaminated water.

With dwindling global fresh and ground water reserves, many countries are looking to desalination as a viable source of drinking water. Desalination is expected to meet 30 per cent of the water demand of Singapore by 2060, which will mean tripling the country’s current desalination capacity. But desalination demands huge energy consumption and reverse osmosis, the mainstream technology it depends on, has a relatively high cost. Reverse osmosis works by using extreme pressures to squeeze water molecules through tightly knit membranes.

An emerging alternative solution mimics the way proteins embedded in cell membranes, known as aquaporins, channel water in and out. Some research groups have even created membranes made of fatty lipid molecules that can accommodate natural aquaporins. Zeng has developed a cheaper and more resilient replacement.

His building blocks consist of helical noodles with sticky ends that connect to form long spirals. Water molecules can flow through the 0.3 nanometer openings at the center of the spirals, but all the other positively and negatively charged ions that make up saltwater are too bulky to pass. These include sodium, potassium, calcium, magnesium, chlorine and sulfur oxide. “In water, all of these ions are highly hydrated, attached to lots of water molecules, which makes them too large to go through the channels,” says Zeng.

The technology could lead to global savings of up to US$5 billion a year, says Zeng, but only after several more years of testing and tweaking the lipid membrane’s compatibility and stability with the nanospirals. “This is a major focus in my group right now,” he says. “We want to get this done, so that we can reduce the cost of water desalination to an acceptable level.”

Stick and non-stick

Nanomaterials also offer a low-cost, effective and sustainable way to filter out toxic metals from drinking water.

Heavy metal levels in drinking water are stringently regulated due to the severe damage the substances can cause to health, even at very low concentrations. The World Health Organization requires that levels of lead, for example, remain below ten parts per billion (ppb). Treating water to these standards is expensive and extremely difficult.

Zhang has developed an organic substance filled with pores that can trap and remove toxic metals from water to less than one ppb. Each pore is ten to twenty nanometers wide and packed with compounds, known as amines that stick to the metals.

Exploiting the fact that amines lose their grip over the metals in acidic conditions, the valuable and limited resource can be recovered by industry, and the polymers reused.

The secret behind the success of Zhang’s polymers is the large surface area covered by the pores, which translates into more opportunities to interact with and trap the metals. “Other materials have a surface area of about 100 square meters per gram, but ours is 1,000 square meters per gram,” says Zhang. “It is 10 times higher.”

Zhang tested his nanoporous polymers on water contaminated with lead. He sprinkled a powdered version of the polymer into a slightly alkaline liquid containing close to 100 ppb of lead. Within seconds, lead levels reduced to below 0.2 ppb. Similar results were observed for cadmium, copper and palladium. Washing the polymers in acid released up to 93 per cent of the lead.

With many companies keen to scale these technologies for real-world applications, it won’t be long before nanoscience treats the Earth for its many maladies.

I wonder if the researchers have found industrial partners (who could be named) to bring these solutions for oil spill cleanups, desalination, and water purification to the market.

Mimicking rain and sun to test plastic for nanoparticle release

One of Canada’s nanotechnology experts once informed a House of Commons Committee on Health that nanoparticles encased in plastic (he was talking about cell phones) weren’t likely to harm you except in two circumstances (when workers were using them in the manufacturing process and when the product was being disposed of). Apparently, under some circumstances, that isn’t true any more. From a Sept. 30, 2016 news item on Nanowerk,

If the 1967 film “The Graduate” were remade today, Mr. McGuire’s famous advice to young Benjamin Braddock would probably be updated to “Plastics … with nanoparticles.” These days, the mechanical, electrical and durability properties of polymers—the class of materials that includes plastics—are often enhanced by adding miniature particles (smaller than 100 nanometers or billionths of a meter) made of elements such as silicon or silver. But could those nanoparticles be released into the environment after the polymers are exposed to years of sun and water—and if so, what might be the health and ecological consequences?

A Sept. 30, 2016 US National Institute of Standards and Technology (NIST) news release, which originated the news item, describes how the research was conducted and its results (Note: Links have been removed),

In a recently published paper (link is external), researchers from the National Institute of Standards and Technology (NIST) describe how they subjected a commercial nanoparticle-infused coating to NIST-developed methods for accelerating the effects of weathering from ultraviolet (UV) radiation and simulated washings of rainwater. Their results indicate that humidity and exposure time are contributing factors for nanoparticle release, findings that may be useful in designing future studies to determine potential impacts.

In their recent experiment, the researchers exposed multiple samples of a commercially available polyurethane coating containing silicon dioxide nanoparticles to intense UV radiation for 100 days inside the NIST SPHERE (Simulated Photodegradation via High-Energy Radiant Exposure), a hollow, 2-meter (7-foot) diameter black aluminum chamber lined with highly UV reflective material that bears a casual resemblance to the Death Star in the film “Star Wars.” For this study, one day in the SPHERE was equivalent to 10 to 15 days outdoors. All samples were weathered at a constant temperature of 50 degrees Celsius (122 degrees Fahrenheit) with one group done in extremely dry conditions (approximately 0 percent humidity) and the other in humid conditions (75 percent humidity).

To determine if any nanoparticles were released from the polymer coating during UV exposure, the researchers used a technique they created and dubbed “NIST simulated rain.” Filtered water was converted into tiny droplets, sprayed under pressure onto the individual samples, and then the runoff—with any loose nanoparticles—was collected in a bottle. This procedure was conducted at the beginning of the UV exposure, at every two weeks during the weathering run and at the end. All of the runoff fluids were then analyzed by NIST chemists for the presence of silicon and in what amounts. Additionally, the weathered coatings were examined with atomic force microscopy (AFM) and scanning electron microscopy (SEM) to reveal surface changes resulting from UV exposure.

Both sets of coating samples—those weathered in very low humidity and the others in very humid conditions—degraded but released only small amounts of nanoparticles. The researchers found that more silicon was recovered from the samples weathered in humid conditions and that nanoparticle release increased as the UV exposure time increased. Microscopic examination showed that deformations in the coating surface became more numerous with longer exposure time, and that nanoparticles left behind after the coating degraded often bound together in clusters.

“These data, and the data from future experiments of this type, are valuable for developing computer models to predict the long-term release of nanoparticles from commercial coatings used outdoors, and in turn, help manufacturers, regulatory officials and others assess any health and environmental impacts from them,” said NIST research chemist Deborah Jacobs, lead author on the study published in the Journal of Coatings Technology and Research (link is external).

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

Surface degradation and nanoparticle release of a commercial nanosilica/polyurethane coating under UV exposure by Deborah S. Jacobs, Sin-Ru Huang, Yu-Lun Cheng, Savelas A. Rabb, Justin M. Gorham, Peter J. Krommenhoek, Lee L. Yu, Tinh Nguyen, Lipiin Sung. J Coat Technol Res (2016) 13: 735. doi:10.1007/s11998-016-9796-2 First published online 13 July 2016

This paper is behind a paywall.

For anyone interested in the details about the House of Commons nano story I told at the start of this post, here’s the June 23, 2010 posting where I summarized the hearing on nanotechnology. If you scroll down about 50% of the way, you’ll find Dr. Nils Petersen’s (then director of Canada’s National Institute of Nanotechnology) comments about nanoparticles being encased. The topic had been nanosunscreens and he was describing the conditions under which he believed nanoparticles could be dangerous.

Germany has released a review of their research strategy for nanomaterials

A Sept. 24, 2016 posting by Lynn L. Bergeson and Carla N. Hutton on The National Law Review blog features a new report from German authorities (Note: A link has been removed),

On September 19, 2016, the Federal Institute for Occupational Safety and Health (BAuA) published a report entitled Review of the joint research strategy of the higher federal authorities — Nanomaterials and other advanced materials:  Application safety and environmental compatibility.  The report states that in a long-term research strategy, the higher federal authorities responsible for human and environmental safety — the German Environment Agency (UBA), the Federal Institute for Risk Assessment (BfR), BAuA, the Federal Institute for Materials Research and Testing (BAM), and the National Metrology Institute (PTB) — are accompanying the rapid pace of development of new materials from the points of view of occupational safety and health, consumer protection, and environmental protection.

Here’s a link to Review of the joint research strategy of the higher federal authorities — Nanomaterials and other advanced materials:  Application safety and environmental compatibility (PDF) and excerpts from the foreword (Note: There are some differences in formatting between what you see here and what you’ll see in the report),

The research strategy builds on the outcomes so far of the joint research strategy of the higher federal authorities launched in 2008 and first evaluated in 2013, “Nanotechnology: Health and Environmental Risks of Nanomaterials”1, while additionally covering other advanced materials where these pose similar risks to humans and the environment or where such risks need to be studied. It also takes up the idea of application safety of chemical products 2 from the New Quality of Work (INQA) initiative of the Federal Ministry of Labour and Social Affairs (BMAS) and the concept of sustainable
chemistry 3 endorsed by the Federal  Ministry  for  the  Environment, Nature Conservation, Building  and Nuclear Safety (BMUB). Application safety and environmental compatibility are aimed for advanced materials and derived products in order to largely rule out unacceptable risks to humans and the environment. This can be achieved by:

Using safe materials without hazardous properties for humans and the environment (direct application safety); or

Product design for low emissions and environmental compatibility over the entire product lifecycle (integrated application safety); or

Product stewardship, where producers support users in taking technical, organizational, and personal safety measures for the safe use and disposal of products (supported application safety).

As a comprising part of the Federal Government’s Nanotechnology Action Plan 2020, the update of the joint research strategy aims to contribute to governmental research in the following main areas:

 characterising and assessing the human and environmental risks of advanced materials
 Supporting research institutions and business enterprises
 Science-based revision of legal requirements and recommendations
 Public acceptance

The research strategy is to be implemented in projects and other research-related activities. These  include  governmental  research,  tendering  and  extramural  research  funding, and participation in mostly publicly supported projects with third-party funding. Additional activities will take place as part of policy advice and the ongoing work of the sovereign tasks of agencies involved. Interdisciplinary and transdisciplinary approaches will be used to better connect risk and safety research with innovation research and material development. In keeping up with the rapid pace of development, the time horizon for the research strategy is up to 2020. The research objectives address the research approaches likely to be actionable in this period. The research strategy will be supported by a working group and be evaluated and revised by the end of the Nanotechnology Action Plan 2020. tegy will be implemented in projects and other research-related activities, including governmental research, tendering and extramural research funding, and participation in mostly publicly supported projects with third-party funding.  Agencies will use interdisciplinary and transdisciplinary approaches to connect better risk and safety research with innovation research and material development. To keep up with the pace of development, the time horizon for the research strategy extends to 2020.  The research objectives in the report address the research approaches likely to be actionable in this period.  The research strategy will be supported by a working group and be evaluated and revised by the end of the Nanotechnology Action Plan 2020.

It’s always interesting to find out what’s happening elsewhere.

Carbon capture with asphalt

I wish I could turn back the clock a few years, so I could mention this research from Rice University (Texas, US) on using asphalt for carbon capture (more on why at the end of this post). From a Sept. 13, 2016 news item on Nanowerk (Note: A link has been removed),

Rice University laboratory has improved its method to turn plain asphalt into a porous material that can capture greenhouse gases from natural gas.

In research detailed this month in Advanced Energy Materials (“Ultra-High Surface Area Activated Porous Asphalt for CO2 Capture through Competitive Adsorption at High Pressures”), Rice researchers showed that a new form of the material can sequester 154 percent of its weight in carbon dioxide at high pressures that are common at gas wellheads.

A Sept. 12, 2016 Rice University news release, which originated the news item, further describes the work (Note: Links have been removed),

Raw natural gas typically contains between 2 and 10 percent carbon dioxide and other impurities, which must be removed before the gas can be sold. The cleanup process is complicated and expensive and most often involves flowing the gas through fluids called amines that can soak up and remove about 15 percent of their own weight in carbon dioxide. The amine process also requires a great deal of energy to recycle the fluids for further use.

“It’s a big energy sink,” said Rice chemist James Tour, whose lab developed a technique last year to turn asphalt into a tough, sponge-like substance that could be used in place of amines to remove carbon dioxide from natural gas as it was pumped from ocean wellheads.

Initial field tests in 2015 found that pressure at the wellhead made it possible for that asphalt material to adsorb, or soak up, 114 percent of its weight in carbon at ambient temperatures.

Tour said the new, improved asphalt sorbent is made in two steps from a less expensive form of asphalt, which makes it more practical for industry.

“This shows we can take the least expensive form of asphalt and make it into this very high surface area material to capture carbon dioxide,” Tour said. “Before, we could only use a very expensive form of asphalt that was not readily available.”

The lab heated a common type asphalt known as Gilsonite at ambient pressure to eliminate unneeded organic molecules, and then heated it again in the presence of potassium hydroxide for about 20 minutes to synthesize oxygen-enhanced porous carbon with a surface area of 4,200 square meters per gram, much higher than that of the previous material.

The Rice lab’s initial asphalt-based porous carbon collected carbon dioxide from gas streams under pressure at the wellhead and released it when the pressure was released. The carbon dioxide could then be repurposed or pumped back underground while the porous carbon could be reused immediately.

In the latest tests with its new material, Tours group showed its new sorbent could remove carbon dioxide at 54 bar pressure. One bar is roughly equal to atmospheric pressure at sea level, and the 54 bar measure in the latest experiments is characteristic of the pressure levels typically found at natural gas wellheads, Tour said.

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

Ultra-High Surface Area Activated Porous Asphalt for CO2 Capture through Competitive Adsorption at High Pressures by Almaz S. Jalilov, Yilun Li, Jian Tian, James M. Tour.  Advanced Energy Materials DOI: 10.1002/aenm.201600693  First published [online]: 8 September 2016

This paper is behind a paywall.

Finishing the story I started at the beginning of this post, I was at an early morning political breakfast a few years back when someone seated at our table asked me if there were any nanotechnology applications for carbon sequestration/capture. At the time, I could not bring any such applications to mind. (Sigh) Now I have an answer.

Reliable findings on the presence of synthetic (engineered) nanoparticles in bodies of water

An Aug. 29, 2016 news item on Nanowerk announces research into determining the presence of engineered (synthetic) nanoparticles in bodies of water,

For a number of years now, an increasing number of synthetic nanoparticles have been manufactured and incorporated into various products, such as cosmetics. For the first time, a research project at the Technical University of Munich and the Bavarian Ministry of the Environment provides reliable findings on their presence in water bodies.

An Aug. 29, 2016 Technical University of Munich (TUM) press release, which originated the news item, provides more information,

Nanoparticles can improve the properties of materials and products. That is the reason why an increasing number of nanoparticles have been manufactured over the past several years. The worldwide consumption of silver nanoparticles is currently estimated at over 300 metric tons. These nanoparticles have the positive effect of killing bacteria and viruses. Products that are coated with these particles include refrigerators and surgical instruments. Silver nanoparticles can even be found in sportswear. This is because the silver particles can prevent the smell of sweat by killing the bacteria that cause it.

Previously, it was unknown whether and in what concentration these nanoparticles enter the environment and e.g. enter bodies of water. If they do, this poses a problem. That is because the silver nanoparticles are toxic to numerous aquatic organisms, and can upset sensitive ecological balances.

Analytical challenge

In the past, however, nanoparticles have not been easy to detect. That is because they measure only 1 to 100 nanometers across [nanoparticles may be larger than 100nm or smaller than 1nm but the official definitions usually specify up to 100nm although some definitions go up to 1000nm] – a nanometer is a millionth of a millimeter. “In order to know if a toxicological hazard exists, we need to know how many of these particles enter the environment, and in particular bodies of water”, explains Michael Schuster, Professor for Analytical Chemistry at the TU Munich.

This was an analytical challenge for the researchers charged with solving the problem on behalf of the Bavarian Ministry of the Environment. In order to overcome this issue, they used a well-known principle that utilizes the effect of surfactants to separate and concentrate the particles. “Surfactants are also found in washing and cleaning detergents”, explains Schuster. “Basically, what they do is envelop grease and dirt particles in what are called micelles, making it possible for them to float in water.” One side of the surfactant is water-soluble, the other fat-soluble. The fat-soluble ends collect around non-polar, non-water soluble compounds such as grease or around particles, and “trap” them in a micelle. The water-soluble, polar ends of the surfactants, on the other hand, point towards the water molecules, allowing the microscopically small micelle to float in water.

A box of sugar cubes in the Walchensee lake

The researchers applied this principle to the nanoparticles. “When the micelles surrounding the particles are warmed slightly, they start to clump”, explains Schuster. This turns the water cloudy. Using a centrifuge, the surfactants and the nanoparticles trapped in them can then be separated from the water. This procedure is called cloud point extraction. The researchers then use the surfactants that have been separated out in this manner – which contain the particles in an unmodified, but highly concentrated form – to measure how many silver nanoparticles are present. To do this, they use a highly sensitive atomic spectrometer configured to only detect silver. In this manner, concentrations in a range of less than one nanogram per liter can be detected. To put this in perspective, this would be like detecting a box of sugar cubes that had dissolved in the Walchensee lake.

With the help of this analysis procedure, it is possible to gain new insight into the concentration of nanoparticles in drinking and waste water, sewage sludge, rivers, and lakes. In Bavaria, the measurements yielded good news: The concentrations measured in the water bodies were extremely low. In was only in four of the 13 Upper Bavarian lakes examined that the concentration even exceeded the minimum detection limit of 0.2 nanograms per liter. No measured value exceeded 1.3 nanograms per liter. So far, no permissible values have been established for silver nanoparticles.

Representative for watercourses, the Isar river was examined from its source to its mouth at around 30 locations. The concentration of silver nanoparticles was also measured in the inflow and outflow of sewage treatment plants. The findings showed that at least 94 percent of silver nanoparticles are filtered out by the sewage treatment plants.

Unfortunately, the researchers have not published their results.