What if you discovered an Amazing new Material? (The story of) Graphene: The Superstrong, Superthin, and Superversatile Material That Will Revolutionize the World

 

From National Graphene Association: News

With permission from the authors, Les Johnson and Joseph E. Meany, the preface of their new book, Graphene: The Superstrong, Superthin, and Superversatile Material That Will Revolutionize the World, follows. The book was published by Prometheus Books this month, and is available via Amazon, Barnes & Noble, or at an independent bookstore near you.

“What if you discovered an infinitesimally thin material capable of con­ducting electricity, able to suspend millions of times its own weight, and yet porous enough to filter the murkiest water? And what if this substance was created from the same element as that filling the common pencil? This extraordinary material, graphene, is not a work of science fiction. A growing cadre of scientists aims to make graphene a mainstay technological material by the second half of the twenty-first century. Not satisfied with that timeline, some entrepreneurial types would like to see widespread adoption of graphene within the next decade. How could this be possible?

Graphene is elegant. It is created from a single element, carbon, formed by just one type of bond. Despite graphene’s apparent simplicity, isolating the material was an elusive “Holy Grail” for chemists and physicists alike. Even as the periodic table extended beyond the hundred-odd elements naturally found on Earth, galaxies were charted, and the human genome solved, this material, with the simple chemical formula of C, remained a distant goal at the frontiers of science. Why was this? Graphene excels at hiding in plain sight, and the techniques and instrumentation perfected in the last two decades have played a pivotal role in its discovery.

Carbon, the sole constituent of graphene, is all around us. The element is the fourth most common in the entire universe. Most people think of materials in terms of atoms and molecules, where molecules are made from defined types and numbers of atoms. With graphene, counting carbon atoms is inconsequential. Merely the way in which the constituent carbons are bound to one another is crucial, with this feature separating graphene from other wholly carbon materials like diamonds and graphite. At the atomic level, the exclusively carbon graphene resembles a hexagonal “chicken wire” fence, with each carbon atom making up the point of a hexagon. The hexagonal distribution makes graphene’s earth-shattering properties possible, as the distribution allows the individual carbon atoms of graphene to lay flat.

This property of graphene cannot be overlooked. Graphene is a perfect anomaly in the world of chemistry—a flat, two-dimensional molecule, with a single sheet of graphene measuring only one atom thick. You might imme­diately question the structural integrity of graphene due to its delightfully simplistic construction, but the weaving of the carbon hexagons throughout the structure makes the atomically thin material unexpectedly strong.

Proper application of graphene holds the key to revolutionizing mate­rials technology in the latter half of the twenty-first century, but at what cost? Thankfully, not a substantial environmental one. There is a critical difference between graphene and another linchpin of modern technology, rare-earth metals. These hard-won rare-earth metals, metals including tan­talum, neodymium, and lanthanum, are found everywhere, from the inside of our smartphones to pharmaceuticals. Unlike with rare-earth metals, we do not need armies of manual laborers assisted by heavy equipment and an endless parade of fifty-five gallon drums of polluting solvents to find and retrieve graphene, due to one simple fact: graphene’s elemental con­stituent, carbon, is all around us. The most common precursor of graphene today is the mined mineral graphite. Rare-earth metals are scarce, but the integration of graphene into our lives would not be driven by the acqui­sition of raw materials and disputes between superpowers, but would be guided by the possession of knowledge, with patents and technology sepa­rating the victors and the vanquished.

You have experienced synthesizing graphene, maybe even earlier today, on a very small scale. The pressure exerted by your hand and finger­tips likely created a few layers of graphene the last time you ran a pencil across a notepad, turning humble graphite into graphene as you wrote this week’s grocery list. But if graphene can be made by such simple means, and its sole constituent, carbon, leads oxygen, nitrogen, and hydrogen in the hierarchy of elements that construct our living world, why is graphene just now, in the twenty-first century, coming to the forefront of human understanding?

The answer to this question is where the story resides. The story of graphene is a story of accidental discovery. A story of corporations and gov­ernments racing to spend billions of dollars in hopes of funding research and development projects to discover a material still years away from store shelves. A story of new materials that will disrupt the way we create things, and, in doing so, what we can create. The previous technological revolu­tions taught us many things. Each new discovery allowed us to break into new experimental territories and further our understanding of what is pos­sible to accomplish. Chemical batteries allowed energy to be stored for future use (like light at night). Steam power allowed us to generate tremen­dous amounts of energy to accomplish tasks no living thing could. This new revolution may allow us to throw off the shackles of metallic wires.

Since at least the 1950s, people have been trying to take graphite out of the ground and turn it into a pile of black gold. This effort was met with fifty years of resistance from the graphite, which has not so easily been coaxed to divulge its secrets. When graphene was finally isolated and examined, physicists and chemists were astounded at what they found. The history beneath this discovery is not so straightforward, though, and it traces its roots all the way back to 1859 in Great Britain. How appropriate, then, that the country already well-known for its history involving carbon should be the country where single-layer graphite was finally witnessed.

After two researchers in Great Britain, Konstantin Novoselov and Andre Geim, were awarded the Nobel Prize in Physics in 2010, technology magazines everywhere heralded a new era of “wonder materials” based around this atomically thin tessellation of carbon atoms. With its incred­ibly high strength and almost impossibly low electrical resistance, graphene pulled back a hidden curtain, allowing scientists to catch a glimpse of the marvels that lay beyond. With the shrouds lifted, the groundwork was laid to revolutionize how we will go about designing and making everything from cars to vaccines and from food packaging to spaceships.

The economic potential of this material cannot be understated. Being atomically thin, graphene can be incorporated almost seamlessly into any modern product, with appreciable effect. Early investors were burned, however, by entrepreneurs who over-promised and under-delivered on performance aspects for products (especially composites like plastics) that had graphene in them but that did not use graphene in a way that made its incorporation worth the added expense. It was, in some cases, just an added bit of snake oil. As the overall volume from new production methods and the quality of the resulting graphene have both increased with time, we are starting to finally see graphene’s true benefits. Governmental support is higher than ever in many countries, as whomever discovers a high-throughput production method for pristine graphene will reap signifi­cant financial rewards on the world stage.”

Author, Les Johnson

Author, Joe Meany

PROTON TRANSPORT IN GRAPHENE SHOWS PROMISE FOR RENEWABLE ENERGY

RESEARCHERS AT THE UNIVERSITY OF MANCHESTER HAVE DISCOVERED ANOTHER NEW AND UNEXPECTED PHYSICAL EFFECT IN GRAPHENE – MEMBRANES THAT COULD BE USED IN DEVICES TO ARTIFICIALLY MIMIC PHOTOSYNTHESIS.

National Graphene Association

The new findings demonstrated an increase in the rate at which the material conducts protons when it is simply illuminated with sunlight. The ‘photo-proton’ effect, as it has been dubbed, could be exploited to design devices able to directly harvest solar energy to produce hydrogen gas, a promising green fuel. It might also be of interest for other applications, such as light-induced water splitting, photo-catalysis and for making new types of highly efficient photodetectors.

Graphene is a sheet of carbon atoms just one atom thick and has numerous unique physical and mechanical properties. It is an excellent conductor of electrons and can absorb light of all wavelengths.

Researchers recently found that it is also permeable to thermal protons (the nuclei of hydrogen atoms), which means that it might be employed as a proton-conducting membrane in various technology applications.

To find out how light affects the behaviour of protons permeating through the carbon sheet, a team led by Dr Marcelo Lozada-Hidalgo and Professor Sir Andre Geim fabricated pristine graphene membranes and decorated them on one side with platinum nanoparticles. The Manchester scientists were surprised to find that the proton conductivity of these membranes was enhanced 10 times when they were illuminated with sunlight.

Dr Lozada-Hidalgo said: “By far the most interesting application is producing hydrogen in an artificial photosynthetic system based on these membranes.”

Prof Geim is also optimistic: “This is essentially a new experimental system in which protons, electrons and photons are all packed together in an atomically thin volume. I am sure that there is a lot of new physics to be unearthed, and new applications will follow.”

Scientists around the world are busy looking into how to directly use solar energy to produce renewable fuels (such as hydrogen) by mimicking photosynthesis in plants. These man-made ‘leaves’ will require membranes with very sophisticated properties – including mixed proton-electron conductivity, permeability to gases, mechanical robustness and optical transparency.

Currently, researchers use a mixture of proton and electron-conducting polymers to make such structures, but these require some important trade-offs that could be avoided by using graphene.

Using electrical measurements and mass spectrometry, the researchers say that they measured a photoresponsivity of around 104 A/W, which translates into around 5000 hydrogen molecules being formed in response to every solar photon (light particle) incident on the membrane. This is a huge number if compared with the existing photovoltaic devices where many thousands of photons are needed to produce just a single hydrogen molecule.

“We knew that graphene absorbs light of all frequencies and that it is also permeable to protons, but there was no reason for us to expect that the photons absorbed by the material could enhance the permeation rate of protons through it.” says Lozada-Hidalgo.

“The result is even more surprising when we realised that the membrane was many orders of magnitude more sensitive to light than devices that are specifically designed to be light-sensitive. Examples of such devices include commercial photodiodes or those made from novel 2D materials.”

Photodetectors typically harvest light to produce just electricity but graphene membranes produce both electricity and, as a by-product, hydrogen. The speed at which they respond to light in the microsecond range is faster than most commercial photodiodes.

The authors acknowledge support from the Lloyd’s Register Foundation, EPSRC (EP/ N010345/1), the European Research Council ARTIMATTER project (ERC-2012-ADG) and from Graphene Flagship. M.L.-H. acknowledges a Leverhulme Early Career Fellowship.

Source: The University of Manchester

Designing a Graphene Filter to make Seawater Drinkable and … Cheaper

As drinking water grows scarce, desalination might be one way to bridge the gap.

 

A new study released earlier this week in the journal Nature Nanotechnology may be a major step towards making desalinated water—water in which salt is removed to make it safe for drinking—a viable option for more of the world. Researchers from the University of Manchester modified graphene oxide membranes, a type of selectively permeable membrane that allows some molecules to pass while keeping others behind, to let water through while trapping salt ions. It’s essentially a molecular sieve.

Finding new sources of fresh water is important, because roughly 20 percent of the world’s population—1.2 billion people—lack access to clean drinking water, according to the United Nations. It’s a number that’s expected to grow as populations increase and existing water supplies dwindle, in part due to climate change. This reality has led some to suggest that the world’s next “gold rush” will be for water. Others have a less sanguine approach, worrying that the wars of the future will be fought over water. And this concern is not without merit: the war currently raging in Yemen is linked, at least in part, to water conflicts. 

 

But while fresh water is scarce (a scant three percent of the world’s water is fresh) water itself is not. The Earth is more than 70 percent water, but 97 percent is undrinkable because it’s either salt or brackish (a mix of salt and fresh water). The occasional gulp of seawater while swimming aside, drinking saltwater is dangerous for humans—it leads to dehydration and eventually death. Hence the famous lined from the Rhyme of the Ancient Mariner: “water, water everywhere, nor any drop to drink.”

Desalination could be a solution. After all, the technique is already employed in parts of the Middle East and the Cayman Islands. However, the two techniques currently employed—multi-stage flash distillation, which flash heats a portion of the water into steam through a series of heat exchanges, and reverse osmosis, which uses a high-pressure pump to push sea water through reverse osmosis membranes to remove ions and particles from drinking water—have several key drawbacks.

“Current desalination methods are energy intensive and produce adverse environmental impact,” wrote Ram Devanathan a researcher at the Energy and Environment Directorate at Pacific Northwest National Laboratory, in an op-ed that accompanied the study. “Furthermore, energy production consumes large quantities of water and creates wastewater that needs to be treated with further energy input.”

Graphene oxide membranes show promise as a relatively inexpensive alternative, because they can be cheaply produced in a lab—and though water easily passes through them, salts do not. However, when immersed in water on a large-scale, graphene oxide membranes tend to quickly swell. Once swollen, the membranes not only allow water to pass through, but also sodium and magnesium ions, i.e. salt, defeating the purpose of the filtration.

Study author Rahul Nair and his colleagues discovered that by placing walls made of epoxy resin on either side of the graphene oxide, they could stop the expansion. And by restricting the membranes with resin, they were able to fine tune their capillary size to prevent any errant salts from hitching a ride on water molecules.

The next step will be testing it on an industrial scale to see if the method holds up. If it works, many people might just be drinking (a glass of water) to it.

New nanoparticle may aid cancer detection

An intricate pattern – a molecular model of the influenza virus. The influenza virion (as the infectious particle is called) is roughly spherical. It is an enveloped virus – that is, the outer layer is a lipid membrane which is taken from the host cell in which the virus multiplies. 

A new nanoparticle, at the cellular level, may reveal how cancer cells move to different locations in the human body. This process involves co-opting the human body’s inter-cellular delivery service.

The insight into the cellular messenger system comes from Weill Cornell Medicine scientists. The discovery is of importance since it could help medical scientists to understand how cancer cells can spread to various other locations.

 

With the research, the medics have used a novel technique called asymmetric flow field-flow fractionation. Through this the researchers were able to shift and sort a particular type of nano-sized particles termed exosomes. These particles are secreted by cancer cells and they are formed of DNA, RNA, fats and proteins.

 

Exosomes are cell-derived vesicles that are present in many cell fluids, including blood, and urine; they provide a means of intercellular communication and of transmission of macromolecules between cells. In medicine exosomes can potentially be used for prognosis, for therapy, and as biomarkers for health and disease.

 

By using the asymmetric flow field-flow fractionation, the scientists were able to separate out two distinct exosome subtypes. This has led to the discovery of the new type of nanoparticle. Asymmetrical flow field flow fractionation is a common and state-of-the art method for fractionation and separation of macromolecules and particles in a suspension.

 

Metastatic breast cancer in pleural fluid. euthman/flickr

 

Discussing the research with Controlled Environments magazine, lead researcher Dr. David Lyden explains further: We found that exomeres are the most predominant particle secreted by cancer cells. They are smaller and structurally and functionally distinct from exosomes. Exomeres largely fuse with cells in the bone marrow and liver, where they can alter immune function and metabolism of drugs.”

 

The researcher adds: “The latter finding may explain why many cancer patients are unable to tolerate even small doses of chemotherapy due to toxicity.”

 

Importantly exosomes and exomeres have different biophysical characteristics, like stiffness and electric charge. With this, the findings show, the more rigid the particle, the easier it is likely taken up by cells, rendering exomeres more effective messengers of transferring tumor information to recipient cells.

 

The research further shows how exosomes and exomeres differ in relation to their influence in triggering cancer. Exomeres can carry metabolic enzymes to the liver. Here exomeres are able to cause the liver to “reprogram” its metabolic function and trigger tumor progression.

 

The researchers plan to patent the new technology and develop a diagnostic tool to assist with cancer detection. This will help medics to understand how cancers grow and spread to other organs.

 

The research has been published in the journal Nature Cell Biology. The research paper is titled “Identification of distinct nanoparticles and subsets of extracellular vesicles by asymmetric flow field-flow fractionation.”

 

In related news, Digital Journal has previously reported that researchers have used nanotechnology to improve drug delivery. This is in the form of tailorable nanoscale emulsions which effectively interact with their intended targets (see: “Delivering drugs via nanoscale emulsion.”)

 

Essential Science

 

Demonstrating the need for good cleaning and disinfection using ultraviolet light to show how easy it is to miss parts of a surface when cleaning. Tim Sandle

 

This article is part of Digital Journal’s regular Essential Science columns. Each week Tim Sandle explores a topical and important scientific issue. Last week the association between household cleaning chemicals and respiratory problems was examined in light of a new study from the University of Bergen in Norway, which raises concerns about the longer-term health impact.

 

The week before the topic of nanotechnology and the development of a new generation of antimalarial drugs was discussed.

Design for new electrode could boost supercapacitors’ performance – UCLA Researchers Design Super-efficient and Long-lasting electrode for Supercapacitors – 10X Efficiency

IMAGE: THE BRANCH-AND-LEAVES DESIGN IS MADE UP OF ARRAYS OF HOLLOW, CYLINDRICAL CARBON NANOTUBES (THE ‘BRANCHES’) AND SHARP-EDGED PETAL-LIKE STRUCTURES (THE ‘LEAVES’) MADE OF GRAPHENE. view more  CREDIT: UCLA ENGINEERING

Engineers from UCLA, 4 other universities produce nanoscale device that mimics the structure of tree branches

UCLA HENRY SAMUELI SCHOOL OF ENGINEERING OF APPLIED SCIENCE

Mechanical engineers from the UCLA Henry Samueli School of Engineering and Applied Science and four other institutions have designed a super-efficient and long-lasting electrode for supercapacitors. The device’s design was inspired by the structure and function of leaves on tree branches, and it is more than 10 times more efficient than other designs.

 

The branch-and-leaves design is made up of arrays of hollow, cylindrical carbon nanotubes (the “branches”) and sharp-edged petal-like structures (the “leaves”) made of graphene.

The electrode design provides the same amount of energy storage, and delivers as much power, as similar electrodes, despite being much smaller and lighter. In experiments it produced 30 percent better capacitance — a device’s ability to store an electric charge — for its mass compared to the best available electrode made from similar carbon materials, and 30 times better capacitance per area. It also produced 10 times more power than other designs and retained 95 percent of its initial capacitance after more than 10,000 charging cycles.

Their work is described in the journal Nature Communications.

Supercapacitors are rechargeable energy storage devices that deliver more power for their size than similar-sized batteries. They also recharge quickly, and they last for hundreds to thousands of recharging cycles. Today, they’re used in hybrid cars’ regenerative braking systems and for other applications. Advances in supercapacitor technology could make their use widespread as a complement to, or even replacement for, the more familiar batteries consumers buy every day for household electronics.

Engineers have known that supercapacitors could be made more powerful than today’s models, but one challenge has been producing more efficient and durable electrodes. Electrodes attract ions, which store energy, to the surface of the supercapacitor, where that energy becomes available to use. Ions in supercapacitors are stored in an electrolyte solution. An electrode’s ability to deliver stored power quickly is determined in large part by how many ions it can exchange with that solution: The more ions it can exchange, the faster it can deliver power.

Knowing that, the researchers designed their electrode to maximize its surface area, creating the most possible space for it to attract electrons. They drew inspiration from the structure of trees, which are able to absorb ample amounts of carbon dioxide for photosynthesis because of the surface area of their leaves.

“We often find inspiration in nature, and plants have discovered the best way to absorb chemicals such as carbon dioxide from their environment,” said Tim Fisher, the study’s principal investigator and a UCLA professor of mechanical and aerospace engineering. “In this case, we used that idea but at a much, much smaller scale — about one-millionth the size, in fact.”

To create the branch-and-leaves design, the researchers used two nanoscale structures composed of carbon atoms. The “branches” are arrays of hollow, cylindrical carbon nanotubes, about 20 to 30 nanometers in diameter; and the “leaves” are sharp-edged petal-like structures, about 100 nanometers wide, that are made of graphene — ultra thin sheets of carbon. The leaves are then arranged on the perimeter of the nanotube stems. The leaf-like graphene petals also give the electrode stability.

The engineers then formed the structures into tunnel-shaped arrays, which the ions that transport the stored energy flow through with much less resistance between the electrolyte and the surface to deliver energy than they would if the electrode surfaces were flat.

The electrode also performs well in acidic conditions and high temperatures, both environments in which supercapacitors could be used.

###

Fisher directs UCLA’s Nanoscale Transport Research Group and is a member of the California NanoSystems Institute at UCLA. Lei Chen, a professor at Mississippi State, was the project’s other principal investigator. The first authors are Guoping Xiong of the University of Nevada, Reno, and Pingge He of Central South University. The research was supported by the Air Force Office of Scientific Research.

 

Nanotechnology Can Improve Safety, Effectiveness in Drug Delivery – Incorporating Nanotechnology into Drug Discovery could Increase the odds of Success

Formulating a drug that is not only effective, but also safe with limited side effects, is no easy task.

The likelihood of an investigational drug in a Phase 1 trial eventually receiving an FDA approval is only 9.6 percent, according to a recent analysis. At the pre-clinical level, the chances of long-term success are even lower.

Incorporating nanotechnology into drug discovery is one possible approach that could increase the odds of success for certain drug candidates, said Marina Sokolsky-Papkov, PhD, director of the Translational Nanoformulation Research Core Facility at the Center for Nanotechnology in Drug Delivery (CNDD) at the UNC Eshelman School of Pharmacy.

“It has been shown that nanotechnology is able to address a lot of the clinical development challenges that drug candidates usually face,” said Sokolsky-Papkov in an interview with R&D Magazine. “The whole idea is to take the drug, encapsulate it into a nano-carrier, which will have a different distribution profile, and prevent exposure of the drug over the whole body.”

The CNDD was established in June 2007 with the goal of enhancing the efficacy and safety of new drugs and imaging agents through the discovery and application of innovative methods of drug delivery.

To do that they established two core facilities—the Translational Nanoformulation Research Core Laboratory, which  promotes translation of new drug candidates into clinical trials through advanced formulation techniques; and the Nanomedicines Characterization Core Facility, which accelerates translation of new nanomedicines to clinic by providing their comprehensive physicochemical characterization.

“The goal is to promote collaborative research and to promote interactions between people with clinical vision and expertise and expertise in formulation techniques,” said Sokolsky-Papkov. “This will increase the chances of getting these drugs to the market.”

The benefits nano-drug delivery

Although nanomedicine isn’t brand new—the first FDA approval for a nano-based drug was in 1995—researchers are just scratching the surface of the technology’s potential.

The CNDD is investigating the use of nanotechnology to treat a wide variety of conditions, including cancer, stroke, neurodegenerative and neurodevelopmental disorders, nerve agent and pesticide poisoning and other diseases and injuries.

“We use different techniques across the board,” said Sokolsky-Papkov. “Nanotechnology can be used with existing drugs as a way to improve the current formulation or we can take a carrier formulation approach to new drugs out there.”

One approach to nanomedicine is to utilize a nanomaterial, such as liposome, as a more effective drug delivery system for an already existing therapeutic.

Nanoparticles tend to accumulate in areas that are inflamed, which is often the site of disease, explained Sokolsky-Papkov. During an inflammatory response, the blood vessel barrier often becomes “leaky.” This makes it easier for nanoparticles— equipped with a therapeutic agent to fight disease—to enter.

Collaboration with pharma will introduce nanotechnologies in early stage drug development

“If you encapsulate your drug in a certain size range, below 100 nanometers, it will be able to penetrate with leaky vessels and target those areas better,” said Sokolsky-Papkov.

Nanoformulations also provide an opportunity to improve efficacy of certain drugs, as they can increase the accumulation of the drug at the disease site. This is particularly useful when a drug needs to enter a hard-to-penetrate area, such as the brain.

“In our center we have research going on regarding nano-meditated delivery of therapeutic agents for the brain, both small molecule and biologics,” said Sokolsky-Papkov. “We specifically see a significantly higher accumulation of a drug and better efficacy in nanoformulation versus conventional administration systems.”

Because nanoformulations are more targeted to the site of the disease, they can also be used to reduce side effects. In conventional drug administration, the therapeutic hits all of the body’s cells and blood vessels at one high dose at the same time. However, with a nanoformulation, the drug is released in a more sustained manner, resulting in lower overall body exposure overtime. This is less toxic to the system, said Sokolsky-Papkov.

Diagnostic and imaging applications

In addition to drug delivery, nanotechnology can also be utilized in medicine for diagnostic and imaging purposes.

Several magnetic nanoparticles have been approved for clinical use in imaging. The benefits are similar to those seen in nano-drug delivery, said Sokolsky-Papkov.

“This uses the same idea that in areas associated with inflammation the accumulation of an imaging agent will be higher in an inflamed area compared to normal tissue when using nanoparticles” she explained. “Basically these nanoparticles will be labeled so that they can be tracked using standard imaging techniques.” 

During an MRI, magnetic nanoparticles interact with the magnetic field and can be tracked by observing where the image turns darker. This allows for a comparison before and after accumulation of nanoparticles to identify possible disease.

Image … impact on healthcare by delivering disease diagnosis, monitoring, implants, regenerative medicines and drug delivery, drug discovery for biomedicine.

“If you see a lot of accumulation in these areas there is something potentially going on,” said Sokolsky-Papkov.

 

Growth of industry

The field of nanomedicine is rapidly advancing, said Sokolsky-Papkov.

“The clinical models to evaluate the efficacy of nanomedicines are improving over time,” she said. “There is a lot of research and effort going to improve pre-clinical evaluations to increase collaboration between pre-clinical and clinical data, which significantly improves the chances of nano-medicines hitting the market. The number of clinical trials for different nanoformulations is increasing significantly each year.”

 

 

Update: Australia’s CSIRO – Tiny (graphene) membrane key to safe drinking water for billions of people around the World

Sydney’s iconic harbour has played a starring role in the development of new CSIRO technology that could save lives around the world.

Using their own specially designed form of graphene, ‘Graphair’, CSIRO scientists have supercharged water purification, making it simpler, more effective and quicker.

The new filtering technique is so effective, water samples from Sydney Harbour were safe to drink after passing through the filter.

The breakthrough research was published today in Nature Communications.

“Almost a third of the world’s population, some 2.1 billion people, don’t have clean and safe drinking water,” the paper’s lead author, CSIRO scientist Dr Dong Han Seo said. 

“As a result, millions — mostly children — die from diseases associated with inadequate water supply, sanitation and hygiene every year.

“In Graphair we’ve found a perfect filter for water purification. It can replace the complex, time consuming and multi-stage processes currently needed with a single step.”

While graphene is the world’s strongest material and can be just a single carbon atom thin, it is usually water repellent.

Using their Graphair process, CSIRO researchers were able to create a film with microscopic nano-channels that let water pass through, but stop pollutants.

As an added advantage Graphair is simpler, cheaper, faster and more environmentally friendly than graphene to make.

It consists of renewable soybean oil, more commonly found in vegetable oil.

Looking for a challenge, Dr Seo and his colleagues took water samples from Sydney Harbour and ran it through a commercially available water filter, coated with Graphair.

Researchers from QUT, the University of Sydney, UTS, and Victoria University then tested and analysed its water purification qualities.

The breakthrough potentially solves one of the great problems with current water filtering methods: fouling.

Over time chemical and oil based pollutants coat and impede water filters, meaning contaminants have to be removed before filtering can begin. Tests showed Graphair continued to work even when coated with pollutants.

Without Graphair, the membrane’s filtration rate halved in 72 hours.

When the Graphair was added, the membrane filtered even more contaminants (99 per cent removal) faster.

“This technology can create clean drinking water, regardless of how dirty it is, in a single step,” Dr Seo said.

“All that’s needed is heat, our graphene, a membrane filter and a small water pump. We’re hoping to commence field trials in a developing world community next year.”

CSIRO is looking for industry partners to scale up the technology so it can be used to filter a home or even town’s water supply.

It’s also investigating other applications such as the treatment of seawater and industrial effluents.

 

---

Story Source:

Materials provided by CSIRO Australia. Note: Content may be edited for style and length.

---

Journal Reference:

1. Dong Han Seo, Shafique Pineda, Yun Chul Woo, Ming Xie, Adrian T. Murdock, Elisa Y. M. Ang, Yalong Jiao, Myoung Jun Park, Sung Il Lim, Malcolm Lawn, Fabricio Frizera Borghi, Zhao Jun Han, Stephen Gray, Graeme Millar, Aijun Du, Ho Kyong Shon, Teng Yong Ng, Kostya Ostrikov. Anti-fouling graphene-based membranes for effective water desalination. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-018-02871-3

Tuning quantum light sources – Working Toward Quantum Communications … ONE Photon at a Time

Knowing the details of the quantum world—electrons and packets of light called photons—could radically improve computers and sensors. A critical component to making devices that harness the quantum world is a source that emits a regular stream of single photons.

Scientists at the Center for Integrated Nanotechnologies and their colleagues chemically modified tiny tubes of carbon atoms. These tubes are the first material to emit single photons at room temperature and telecom wavelengths. No other material system has been able to meet these two critical operational conditions simultaneously (Nature Photonics, “Tunable room-temperature single-photon emission at telecom wavelengths from sp3 defects in carbon nanotubes”).

The schematic shows the emission of a single photon (red) from a chemically modified carbon nanotube when excited by green light. (Image: Xiaowei He, Center for Integrated Nanotechnologies, Los Alamos)

This critical combination of features makes integrating devices that exploit the quantum world with existing optical networks a very real possibility. That is, the carbon nanotubes that allow for ultra secure data encryption could be used with today’s telecom network. The carbon nanotubes could also be integrated into devices for more sensitive sensors and future quantum computers.

The ability to integrate fiber-based quantum information technology into existing optical networks would be a significant step towards applications in quantum communication. To achieve this, quantum light sources must be able to emit single photons at telecommunication wavelengths and at room temperature.

This combination of features has been elusive until now, despite two decades of research efforts. Some systems (e.g., self-assembled quantum dots) emit at telecommunication wavelengths but require cryogenic cooling. Other systems (for example, diamond nitrogen-vacancy centers) operate at room temperature but can only emit in the visible spectral range.

Scientists at the Center for Integrated Nanotechnologies and their collaborators have produced functionalized carbon nanotubes that have both of these critical features. Carbon nanotubes had been previously identified as a promising quantum light source; however, the unstable photon emissions they generated were problematic.

The answer uncovered by scientists at the Center for Integrated Nanotechnologies was to chemically modify the nanotubes through aryl-diazonium reactions. This introduced defects to the nanotubes that allowed for controllable single-photon emission at both room temperature and telecommunication wavelengths. The team also demonstrated that the emission wavelength was tunable. Just as the tension and length of a violin string can be adjusted to achieve different frequencies, the diameter of the functionalized carbon nanotubes can be varied to generate different emission wavelengths.

Not only do these results have significance for basic science, including functionalization chemistry and quantum metrology, but they also open the door to exciting developments in quantum technologies.

Source: U.S. Department of Energy, Office of Science

UTA researcher to develop nanomaterials to treat antibiotic-resistant infections

IMAGE: THIS IS HE DONG, THE UTA ASSOCIATE PROFESSOR OF CHEMISTRY AND BIOCHEMISTRY AND JOINT ASSOCIATE PROFESSOR OF BIOENGINEERING WHO RECEIVED THE GRANT. view more 

A researcher at The University of Texas at Arlington has been awarded a prestigious National Science Foundation Faculty Early Career Development, or CAREER, grant to develop new synthetic antimicrobial nanomaterials to treat antibiotic-resistant infections in hospitals and military facilities.

Bacterial resistance to conventional antibiotics is a major threat to public health, and antibiotic-resistant infections are associated with close to $20 billion in direct medical costs each year, according to the Alliance for the Prudent Use of Antibiotics. Overuse of existing antibiotics has worsened the problem, resulting in an urgent need to develop new types of antimicrobial agents to combat the ever-increasing emergence of multidrug-resistant bacterial infections.

“We are developing synthetic antimicrobial materials that only target toxic bacteria and are biocompatible with healthy mammalian cells,” said He Dong, the UTA associate professor of chemistry and biochemistry and joint associate professor of bioengineering who received the grant. “These new molecules show great promise to treat infections not only on external surfaces or the skin like traditional antimicrobial peptides do, but also internally through oral or intravenous treatments, as they do not attack healthy human cells.”

The earlier discovery of new antimicrobials based on small proteins or peptides had shown tremendous promise, but their widespread use and translation into clinical application was hampered by their toxicity toward a range of healthy human cells.

“Dong and her colleagues have taken this idea one step further by developing synthetic peptides that self-assemble into nanostructured fibers that can punch holes in the bacterial membrane, killing the pathogen,” said Frederick MacDonnell, the chair of UTA’s Department of Chemistry and Biochemistry. “These synthetic self-assembling antimicrobial nanofibers, or SAANs, are the nucleus of a new therapeutic platform that could have a transformative impact on the multi-billion-dollar research industry around conventional antibiotics.”

This new grant builds on work done over the last three years by Dong around nanomaterials that can mimic nature and self-assemble into larger groups of molecules that have antimicrobial effects without hurting other healthy cells. The $456,985 grant is aimed at furthering the understanding of how SAANs are so effective against bacteria without harming healthy mammalian cells.

“The multidisciplinary nature of this research, involving chemistry, microbiology, engineering, nanoscience and pharmaceutical sciences will also provide opportunities to train students at all levels,” Dong added. “We plan to collaborate closely with Dr. Liping Tang in UTA’s bioengineering department to develop intelligent SAANs technologies that will permit highly effective and accurate disease-specific diagnoses and therapies in the future.”

Dong will soon be transferring to UTA’s new 229,000-square-foot Science & Engineering Innovation & Research or SEIR building, a world-class research and teaching facility focused on health science research that is scheduled to open in July 2018. This facility will advance research at UTA by utilizing the modern concept of research lab neighborhoods to drive cross-disciplinary collaboration like Dong’s research. Each of the 12 research lab neighborhoods will accommodate multiple teams in a wide range of fields, including biology, bioengineering, computational research, nursing and kinesiology.

Dong came to UTA from Clarkson University, where she was an assistant professor of chemistry and biomolecular science. She earned her bachelor and master degrees in chemistry from Tsinghua University in Beijing, China, and her doctorate in chemistry from Rice University in Houston. She did her first post-doctoral fellowship in the Department of Surgery at Emory University in Atlanta, and her second in materials science and engineering at the University of California, Berkeley.

“Dr. Dong’s research exemplifies UTA’s interdisciplinary approach to research, especially in the area of health and the human condition, one of four themes of the University’s strategic plan,” added MacDonnell. “This early CAREER grant recognizes the potential of her research focus to make a real impact on the field.”

Step Towards Better ‘Beyond Lithium’ Batteries: University of Bath

A step towards new “beyond lithium” rechargeable batteries with superior performance has been made by researchers at the University of Bath.

We increasingly rely on rechargeable batteries for a host of essential uses; from mobile phones and electric cars to electrical grid storage. At present this demand is taken up by lithium-ion batteries. As we continue to transition from fossil fuels to low emission energy sources, new battery technologies will be needed for new applications and more efficient energy storage.

One approach to develop batteries that store more energy is to use “multivalent” metals instead of lithium. In lithium-ion batteries, charging and discharging transfers lithium ions inside the battery. For every lithium ion transferred, one electron is also transferred, producing electric current. In multivalent batteries, lithium would be replaced by a different metal that transfers more than one electron per ion. For batteries of equal size, this would give multivalent batteries better energy storage capacity and performance.

The team showed that titanium dioxide can be modified to allow it to be used as an electrode in multivalent batteries, providing a valuable proof of concept in their development.

The scientists, an international team from the University of Bath, France, Germany, Holland, and the USA, deliberately introduced defects in titanium dioxide to form high concentrations of microscopic holes, and showed these can be reversibly occupied by magnesium and aluminium; which carry more than one electron per ion.

The team also describes a new chemical strategy for designing materials that can be used in future multivalent batteries.

The research is published in the journal Nature Materials.

Dr Benjamin Morgan, from the Department of Chemistry at the University of Bath, said: “Multivalent batteries are a really exciting direction for battery technology, potentially offering higher charge densities and better performance. New battery technologies are going to be more and more important as we wean ourselves off fossil fuels and adopt greener energy sources.

“There are quite a few technical hurdles to overcome, including finding materials that are good electrodes for multivalent ions. We’ve shown a way to modify titanium dioxide to turn it into a multivalent electrode.

“In the long term, this proof of concept is a possible step towards “beyond lithium” batteries with superior performance.”