Category Archives: energy

Smart windows need anti-aging treatments

I’ve long been interested in electrochromic windows and this is the first I’ve heard of a problem with limited lifespans. Here’s more from an Oct. 1, 2015 news item on Nanowerk (Note: A link has been removed),

Electrochromic windows, so-called ‘smart windows’, share a well-known problem with rechargeable batteries – their limited lifespan. Researchers at Uppsala University [Sweden] have now worked out an entirely new way to rejuvenate smart windows which have started to show signs of age. The study, published in Nature Materials (“Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films”), may open the way to other areas of application.

An Oct. 1, 2015 Uppsala University press release (also on EurekAlert), which originated the new item, describes previous work on electrochromic windows to provide context for the current research,

The electrochromic smart windows are controlled electrically. This kind of window is the result of research carried out at Uppsala University. Commercial production has recently been started by the company ChromoGenics AB.

The electrochromic smart window is made up of a series of thin layers on top of each other. The most important of these are two layers of tungsten oxide and nickel oxide, both about a third of a micrometer thick. They are separated by an electrolyte layer. The window’s opacity to visible light and solar energy varies when an electrical current flows between the oxide layers.

“The principle is the same as for an electric battery. Here the tungsten-oxide is the cathode and the nickel-oxide the anode. Opacity depends on how much the ‘battery’ is charged,” says Rui-Tao Wen, a doctoral student who carried out the study as part of his thesis.

The lifespan of both electric batteries and electrochromic smart windows is a well-known problem. They need to work after being charged and discharged many times if they are to be really profitable.

In the study, the researchers show that an electrochromic tungsten oxide layer which has been charged and discharged many times and has started to lose its capacity can be restored to its former high capacity. This is achieved by running a weak electric current through it while it is in light mode. This takes about an hour. In this way, the electric charge which has ‘fastened’ in the material is removed and the tungsten oxide layer is like new again.

“This is a new way to rejuvenate smart windows so that they last much longer. And the same principle might perhaps be used for electric batteries,” says Claes-Göran Granqvist, senior professor at the Ångström Laboratory, Uppsala University and one of the authors of the study.

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

Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films by Rui-Tao Wen, Claes G. Granqvist, & Gunnar A. Niklasson. Nature Materials 14, 996–1001 (2015) doi:10.1038/nmat4368 Published online 10 August 2015

This paper is behind a paywall.

Cellulose nanocrystals and supercapacitors at McMaster University (Canada)

Photos: Xuan Yang and Kevin Yager.

Photos: Xuan Yang and Kevin Yager. Courtesy McMaster University

I love that featherlike structure holding up a tiny block of something while balanced on what appears to be a series of medallions. What it has to do with supercapacitors (energy storage) and cellulose nanocrystals is a mystery but that’s one of the images you’ll find illustrating an Oct. 7, 2015 news item on Nanotechnology Now featuring research at McMaster University,

McMaster Engineering researchers Emily Cranston and Igor Zhitomirsky are turning trees into energy storage devices capable of powering everything from a smart watch to a hybrid car.

The scientists are using cellulose, an organic compound found in plants, bacteria, algae and trees, to build more efficient and longer-lasting energy storage devices or supercapacitors. This development paves the way toward the production of lightweight, flexible, and high-power electronics, such as wearable devices, portable power supplies and hybrid and electric vehicles.

A Sept. 10, 2015 McMaster University news release, which originated the news item, describes the research in more detail,

Cellulose offers the advantages of high strength and flexibility for many advanced applications; of particular interest are nanocellulose-based materials. The work by Cranston, an assistant chemical engineering professor, and Zhitomirsky, a materials science and engineering professor, demonstrates an improved three-dimensional energy storage device constructed by trapping functional nanoparticles within the walls of a nanocellulose foam.

The foam is made in a simplified and fast one-step process. The type of nanocellulose used is called cellulose nanocrystals and looks like uncooked long-grain rice but with nanometer-dimensions. In these new devices, the ‘rice grains’ have been glued together at random points forming a mesh-like structure with lots of open space, hence the extremely lightweight nature of the material. This can be used to produce more sustainable capacitor devices with higher power density and faster charging abilities compared to rechargeable batteries.

Lightweight and high-power density capacitors are of particular interest for the development of hybrid and electric vehicles. The fast-charging devices allow for significant energy saving, because they can accumulate energy during braking and release it during acceleration.

For anyone interested in a more detailed description of supercapacitors, there’s my favourite one which involves Captain America’s shield along with some serious science in my April 28, 2014 posting.

Getting back to the research at McMaster, here’s a link to and a citation for the paper,

Cellulose Nanocrystal Aerogels as Universal 3D Lightweight Substrates for Supercapacitor Materials by Xuan Yang, Kaiyuan Shi, Igor Zhitomirsky, and Emily D. Cranston. Advanced Materials DOI: 10.1002/adma.201502284View/save citation First published online 2 September 2015

This paper is behind a paywall.

One final bit, cellulose nanocrystals (CNC) are sometimes referred to as nanocrystalline cellulose (NCC).

Commercializing nanotechnology: Peter Thiel’s Breakout Labs and Argonne National Laboratories

Breakout Labs

I last wrote about entrepreneur Peter Thiel’s Breakout Labs project in an Oct. 26, 2011 posting announcing its inception. An Oct. 6, 2015 Breakout Labs news release (received in my email) highlights a funding announcement for four startups of which at least three are nanotechnology-enabled,

Breakout Labs, a program of Peter Thiel’s philanthropic organization, the Thiel Foundation, announced today that four new companies advancing scientific discoveries in biomedical, chemical engineering, and nanotechnology have been selected for funding.

“We’re always hearing about bold new scientific research that promises to transform the world, but far too often the latest discoveries are left withering in a lab,” said Lindy Fishburne, Executive Director of Breakout Labs. “Our mission is to help a new type of scientist-entrepreneur navigate the startup ecosystem and build lasting companies that can make audacious scientific discoveries meaningful to everyday life. The four new companies joining the Breakout Labs portfolio – nanoGriptech, Maxterial, C2Sense, and CyteGen – embody that spirit and we’re excited to be working with them to help make their vision a reality.”

The future of adhesives: inspired by geckos

Inspired by the gecko’s ability to scuttle up walls and across ceilings due to their millions of micro/nano foot-hairs,nanoGriptech (, based in Pittsburgh, Pa., is developing a new kind of microfiber adhesive material that is strong, lightweight, and reusable without requiring glues or producing harmful residues. Currently being tested by the U.S. military, NASA, and top global brands, nanoGriptech’s flagship product Setex™ is the first adhesive product of its kind that is not only strong and durable, but can also be manufactured at low cost, and at scale.

“We envision a future filled with no-leak biohazard enclosures, ergonomic and inexpensive car seats, extremely durable aerospace adhesives, comfortable prosthetic liners, high performance athletic wear, and widely available nanotechnology-enabled products manufactured less expensively — all thanks to the grippy little gecko,” said Roi Ben-Itzhak, CFO and VP of Business Development for nanoGriptech.

A sense of smell for the digital world

Despite the U.S. Department of Agriculture’s recent goals to drastically reduce food waste, most consumers don’t realize the global problem created by 1.3 billion metric tons of food wasted each year — clogging landfills and releasing unsustainable levels of methane gas into the atmosphere. Using technology developed at MIT’s Swager lab, Cambridge, Ma.-based C2Sense( is developing inexpensive, lightweight hand-held sensors based on carbon nanotubes which can detect fruit ripeness and meat, fish and poultry freshness. Smaller than a half of a business card, these sensors can be developed at very low cost, require very little power to operate, and can be easily integrated into most agricultural supply chains, including food storage packaging, to ensure that food is picked, stored, shipped, and sold at optimal freshness.

“Our mission is to bring a sense of smell to the digital world. With our technology, that package of steaks in your refrigerator will tell you when it’s about to go bad, recommend some recipe options and help build out your shopping list,” said Jan Schnorr, Chief Technology Officer of C2Sense.

Amazing metals that completely repel water

MaxterialTM, Inc. develops amazing materials that resist a variety of detrimental environmental effects through technology that emulates similar strategies found in nature, such as the self-cleaning lotus leaf and antifouling properties of crabs. By modifying the surface shape or texture of a metal, through a method that is very affordable and easy to introduce into the existing manufacturing process, Maxterial introduces a microlayer of air pockets that reduce contact surface area. The underlying material can be chemically the same as ever, retaining inherent properties like thermal and electrical conductivity. But through Maxterial’s technology, the metallic surface also becomes inherently water repellant. This property introduces the superhydrophobic maxterial as a potential solution to a myriad of problems, such as corrosion, biofouling, and ice formation. Maxterial is currently focused on developing durable hygienic and eco-friendly anti-corrosion coatings for metallic surfaces.

“Our process has the potential to create metallic objects that retain their amazing properties for the lifetime of the object – this isn’t an aftermarket coating that can wear or chip off,” said Mehdi Kargar, Co-founder and CEO of Maxterial, Inc. “We are working towards a day when shipping equipment can withstand harsh arctic environments, offshore structures can resist corrosion, and electronics can be fully submersible and continue working as good as new.”

New approaches to combat aging

CyteGen ( wants to dramatically increase the human healthspan, tackle neurodegenerative diseases, and reverse age-related decline. What makes this possible now is new discovery tools backed by the dream team of interdisciplinary experts the company has assembled. CyteGen’s approach is unusually collaborative, tapping into the resources and expertise of world-renowned researchers across eight major universities to focus different strengths and perspectives to achieve the company’s goals. By approaching aging from a holistic, systematic point of view, rather than focusing solely on discrete definitions of disease, they have developed a new way to think about aging, and to develop treatments that can help people live longer, healthier lives.

“There is an assumption that aging necessarily brings the kind of physical and mental decline that results in Parkinson’s, Alzheimer’s, and other diseases. Evidence indicates otherwise, which is what spurred us to launch CyteGen,” said George Ugras, Co-Founder and President of CyteGen.

To date, Breakout Labs has invested in more than two dozen companies at the forefront of science, helping radical technologies get beyond common hurdles faced by early stage companies, and advance research and development to market much more quickly. Portfolio companies have raised more than six times the amount of capital invested in the program by the Thiel Foundation, and represent six Series A valuations ranging from $10 million to $60 million as well as one acquisition.

You can see the original Oct. 6, 2015 Breakout Labs news release here or in this Oct. 7, 2015 news item on Azonano.

Argonne National Labs and Nano Design Works (NDW) and the Argonne Collaborative Center for Energy Storage Science (ACCESS)

The US Department of Energy’s Argonne National Laboratory’s Oct. 6, 2015 press release by Greg Cunningham announced two initiatives meant to speed commercialization of nanotechnology-enabled products for the energy storage and other sectors,

Few technologies hold more potential to positively transform our society than energy storage and nanotechnology. Advances in energy storage research will revolutionize the way the world generates and stores energy, democratizing the delivery of electricity. Grid-level storage can help reduce carbon emissions through the increased adoption of renewable energy and use of electric vehicles while helping bring electricity to developing parts of the world. Nanotechnology has already transformed the electronics industry and is bringing a new set of powerful tools and materials to developers who are changing everything from the way energy is generated, stored and transported to how medicines are delivered and the way chemicals are produced through novel catalytic nanomaterials.

Recognizing the power of these technologies and seeking to accelerate their impact, the U.S. Department of Energy’s Argonne National Laboratory has created two new collaborative centers that provide an innovative pathway for business and industry to access Argonne’s unparalleled scientific resources to address the nation’s energy and national security needs. These centers will help speed discoveries to market to ensure U.S. industry maintains a lead in this global technology race.

“This is an exciting time for us, because we believe this new approach to interacting with business can be a real game changer in two areas of research that are of great importance to Argonne and the world,” said Argonne Director Peter B. Littlewood. “We recognize that delivering to market our breakthrough science in energy storage and nanotechnology can help ensure our work brings the maximum benefit to society.”

Nano Design Works (NDW) and the Argonne Collaborative Center for Energy Storage Science (ACCESS) will provide central points of contact for companies — ranging from large industrial entities to smaller businesses and startups, as well as government agencies — to benefit from Argonne’s world-class expertise, scientific tools and facilities.

NDW and ACCESS represent a new way to collaborate at Argonne, providing a single point of contact for businesses to assemble tailored interdisciplinary teams to address their most challenging R&D questions. The centers will also provide a pathway to Argonne’s fundamental research that is poised for development into practical products. The chance to build on existing scientific discovery is a unique opportunity for businesses in the nano and energy storage fields.

The center directors, Andreas Roelofs of NDW and Jeff Chamberlain of ACCESS, have both created startups in their careers and understand the value that collaboration with a national laboratory can bring to a company trying to innovate in technologically challenging fields of science. While the new centers will work with all sizes of companies, a strong emphasis will be placed on helping small businesses and startups, which are drivers of job creation and receive a large portion of the risk capital in this country.

“For a startup like mine to have the ability to tap the resources of a place like Argonne would have been immensely helpful,” said Roelofs. “We”ve seen the power of that sort of access, and we want to make it available to the companies that need it to drive truly transformative technologies to market.”

Chamberlain said his experience as an energy storage researcher and entrepreneur led him to look for innovative approaches to leveraging the best aspects of private industry and public science. The national laboratory system has a long history of breakthrough science that has worked its way to market, but shortening that journey from basic research to product has become a growing point of emphasis for the national laboratories over the past couple of decades. The idea behind ACCESS and NDW is to make that collaboration even easier and more powerful.

“Where ACCESS and NDW will differ from the conventional approach is through creating an efficient way for a business to build a customized, multi-disciplinary team that can address anything from small technical questions to broad challenges that require massive resources,” Chamberlain said. “That might mean assembling a team with chemists, physicists, computer scientists, materials engineers, imaging experts, or mechanical and electrical engineers; the list goes on and on. It’s that ability to tap the full spectrum of cross-cutting expertise at Argonne that will really make the difference.”

Chamberlain is deeply familiar with the potential of energy storage as a transformational technology, having led the formation of Argonne’s Joint Center for Energy Storage Research (JCESR). The center’s years-long quest to discover technologies beyond lithium-ion batteries has solidified the laboratory’s reputation as one of the key global players in battery research. ACCESS will tap Argonne’s full battery expertise, which extends well beyond JCESR and is dedicated to fulfilling the promise of energy storage.

Energy storage research has profound implications for energy security and national security. Chamberlain points out that approximately 1.3 billion people across the globe do not have access to electricity, with another billion having only sporadic access. Energy storage, coupled with renewable generation like solar, could solve that problem and eliminate the need to build out massive power grids. Batteries also have the potential to create a more secure, stable grid for countries with existing power systems and help fight global climate disruption through adoption of renewable energy and electric vehicles.

Argonne researchers are pursuing hundreds of projects in nanoscience, but some of the more notable include research into targeted drugs that affect only cancerous cells; magnetic nanofibers that can be used to create more powerful and efficient electric motors and generators; and highly efficient water filtration systems that can dramatically reduce the energy requirements for desalination or cleanup of oil spills. Other researchers are working with nanoparticles that create a super-lubricated state and other very-low friction coatings.

“When you think that 30 percent of a car engine’s power is sacrificed to frictional loss, you start to get an idea of the potential of these technologies,” Roelofs said. “But it’s not just about the ideas already at Argonne that can be brought to market, it’s also about the challenges for businesses that need Argonne-level resources. I”m convinced there are many startups out there working on transformational ideas that can greatly benefit from the help of a place Argonne to bring those ideas to fruition. That is what has me excited about ACCESS and NDW.”

For more information on ACCESS, see:

For more information on NDW, see:

You can read more about the announcement in an Oct. 6, 2015 article by Greg Watry for R&D magazine featuring an interview with Andreas Roelofs.

Anyone have a spare portabella (also known as, portobello) mushroom? I need for my phone

Scientists as the University of California at Riverside (UCR) have developed a type of lithium-ion battery with portabella mushrooms, from a Sept. 29, 2015 news item on ScienceDaily,

Can portabella mushrooms stop cell phone batteries from degrading over time?

Researchers at the University of California, Riverside Bourns College of Engineering think so.

They have created a new type of lithium-ion battery anode using portabella mushrooms, which are inexpensive, environmentally friendly and easy to produce. The current industry standard for rechargeable lithium-ion battery anodes is synthetic graphite, which comes with a high cost of manufacturing because it requires tedious purification and preparation processes that are also harmful to the environment.

A Sept. 29, 2015 UCR news release (also on EurekAlert) by Sean Nealon, which originated the news item, expands on the theme,

With the anticipated increase in batteries needed for electric vehicles and electronics, a cheaper and sustainable source to replace graphite is needed. Using biomass, a biological material from living or recently living organisms, as a replacement for graphite, has drawn recent attention because of its high carbon content, low cost and environmental friendliness.

UC Riverside engineers were drawn to using mushrooms as a form of biomass because past research has established they are highly porous, meaning they have a lot of small spaces for liquid or air to pass through. That porosity is important for batteries because it creates more space for the storage and transfer of energy, a critical component to improving battery performance.

In addition, the high potassium salt concentration in mushrooms allows for increased electrolyte-active material over time by activating more pores, gradually increasing its capacity.

A conventional anode allows lithium to fully access most of the material during the first few cycles and capacity fades from electrode damage occurs from that point on. The mushroom carbon anode technology could, with optimization, replace graphite anodes. It also provides a binderless and current-collector free approach to anode fabrication.

“With battery materials like this, future cell phones may see an increase in run time after many uses, rather than a decrease, due to apparent activation of blind pores within the carbon architectures as the cell charges and discharges over time,” said Brennan Campbell, a graduate student in the Materials Science and Engineering program at UC Riverside.

Nanocarbon architectures derived from biological materials such as mushrooms can be considered a green and sustainable alternative to graphite-based anodes, said Cengiz Ozkan, a professor of mechanical engineering and materials science and engineering.

The nano-ribbon-like architectures transform upon heat treatment into an interconnected porous network architecture which is important for battery electrodes because such architectures possess a very large surface area for the storage of energy, a critical component to improving battery performance.

One of the problems with conventional carbons, such as graphite, is that they are typically prepared with chemicals such as acids and activated by bases that are not environmentally friendly, said Mihri Ozkan, a professor of electrical and computer engineering. Therefore, the UC Riverside team is focused on naturally-derived carbons, such as the skin of the caps of portabella mushrooms, for making batteries.

It is expected that nearly 900,000 tons of natural raw graphite would be needed for anode fabrication for nearly six million electric vehicle forecast to be built by 2020. This requires that the graphite be treated with harsh chemicals, including hydrofluoric and sulfuric acids, a process that creates large quantities of hazardous waste. The European Union projects this process will be unsustainable in the future.

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

Hierarchically Porous Carbon Anodes for Li-ion Batteries by Brennan Campbell, Robert Ionescu, Zachary Favors, Cengiz S. Ozkan, & Mihrimah Ozkan. [Nature] Scientific Reports 5, Article number: 14575 (2015)  doi:10.1038/srep14575 Published online: 29 September 2015

This is an open access paper

Enzymatic fuel cells with ultrasmall gold nanocluster

Scientists at the US Department of Energy’s Los Alamos National Laboratory have developed a DNA-templated gold nanocluster (AuNC) for more efficient biofuel cell design (Note: A link has been removed). From a Sept. 24, 2015 news item on ScienceDaily,

With fossil-fuel sources dwindling, better biofuel cell design is a strong candidate in the energy field. In research published in the Journal of the American Chemical Society (“A Hybrid DNA-Templated Gold Nanocluster For Enhanced Enzymatic Reduction of Oxygen”), Los Alamos researchers and external collaborators synthesized and characterized a new DNA-templated gold nanocluster (AuNC) that could resolve a critical methodological barrier for efficient biofuel cell design.

Here’s an image illustrating the DNA-templated gold nanoclusters,

Caption: Gold nanoclusters (~1 nm) are efficient mediators of electron transfer between co-self-assembled enzymes and carbon nanotubes in an enzyme fuel cell. The efficient electron transfer from this quantized nano material minimizes the energy waste and improves the kinetics of the oxygen reduction reaction, toward a more efficient fuel cell cycle. Credit: Los Alamos National Laboratory

Caption: Gold nanoclusters (~1 nm) are efficient mediators of electron transfer between co-self-assembled enzymes and carbon nanotubes in an enzyme fuel cell. The efficient electron transfer from this quantized nano material minimizes the energy waste and improves the kinetics of the oxygen reduction reaction, toward a more efficient fuel cell cycle.
Credit: Los Alamos National Laboratory

A Sept. 24, 2015 Los Alamos National Laboratory news release, which originated the news item, provides more details,

“Enzymatic fuel cells and nanomaterials show great promise and as they can operate under environmentally benign neutral pH conditions, they are a greener alternative to existing alkaline or acidic fuel cells, making them the subject of worldwide research endeavors,” said Saumen Chakraborty, a scientist on the project. “Our work seeks to boost electron transfer efficiency, creating a potential candidate for the development of cathodes in enzymatic fuel cells.”

Ligands, molecules that bind to a central metal atom, are necessary to form stable nanoclusters. For this study, the researchers chose single-stranded DNA as the ligand, as DNA is a natural nanoscale material having high affinity for metal cations and can be used to assembly the cluster to other nanoscale material such as carbon nanotubes.

In enzymatic fuel cells, fuel is oxidized on the anode, while oxygen reduction reactions take place on the cathode, often using multi copper oxidases. Enzymatic fuel cell performance depends critically on how effectively the enzyme active sites can accept and donate electrons from the electrode by direct electron transfer (ET). However, the lack of effective ET between the enzyme active sites, which are usually buried ~10Å from their surface, and the electrode is a major barrier to their development. Therefore, effective mediators of this electron transfer are needed.

The team developed a new DNA-templated gold nanocluster (AuNC) that enhanced electron transfer. This novel role of the AuNC as enhancer of electron transfer at the enzyme-electrode interface could be effective for cathodes in enzymatic fuel cells, thus removing a critical methodological barrier for efficient biofuel cell design.

Possessing many unique properties due to their discrete electron state distributions, metal nanoclusters (<1.5 nm diameter; ~2-144 atoms of gold, silver, platinum, or copper) show application in many fields.

Hypothesizing that due to the ultra-small size (the clusters are ~7 atoms, ~0.9 nm in diameter), and unique electrochemical properties, the AuNC can facilitate electron transfer to an oxygen-reduction reaction enzyme-active site and therefore, lower the overpotential of the oxygen reaction. Overpotential is the extra amount of energy required to drive an electrochemical reaction.

Ideally, it is desirable that all electrochemical reactions have minimal to no overpotential, but in reality they all have some. Therefore, to design an efficient electrocatalyst (for reduction or oxidation) we want to design it so that the reaction can proceed with a minimal amount of extra, applied energy.

When self assembled with bilirubin oxidase and carbon nanotubes, the AuNC acts to enhance the electron transfer, and it lowers the overpotential of oxygen reduction by a significant ~15 mV (as opposed to ~1-2 mV observed using other types of mediators) compared to the enzyme alone. The AuNC also causes significant enhancement of electrocatalytic current densities. Proteins are electronically insulating (they are complex, greasy and large), so the use of carbon nanotubes helps the enzyme stick to the electrode as well as to facilitate electron transfer.

Although gold nanoclusters have been used in chemical catalysis, this is the first time that we demonstrate they can also act as electron relaying agents to enzymatic oxygen reduction reaction monitored by electrochemistry.

Finally, the presence of AuNC does not perturb the mechanism of enzymatic O2 reduction. Such unique application of AuNC as facilitator of ET by improving thermodynamics and kinetics of O2 reduction is unprecedented.

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

A Hybrid DNA-Templated Gold Nanocluster For Enhanced Enzymatic Reduction of Oxygen by Saumen Chakraborty, Sofia Babanova, Reginaldo C. Rocha, Anil Desireddy, Kateryna Artyushkova, Amy E. Boncella, Plamen Atanassov, and Jennifer S. Martinez. J. Am. Chem. Soc., 2015, 137 (36), pp 11678–11687 DOI: 10.1021/jacs.5b05338 Publication Date (Web): August 19, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

A new ink for energy storage devices from the Hong Kong Polytechnic University

Energy storage is not the first thought that leaps to mind when ink is mentioned. Live and learn, eh? A Sept. 23, 2015 news item on Nanowerk describes the connection (Note: A link has been removed),

 The Department of Applied Physics of The Hong Kong Polytechnic University (PolyU) has developed a simple approach to synthesize novel environmentally friendly manganese dioxide ink by using glucose (“Aqueous Manganese Dioxide Ink for Paper-Based Capacitive Energy Storage Devices”).

The MnO2 ink could be used for the production of light, thin, flexible and high performance energy storage devices via ordinary printing or even home-used printers. The capacity of the MnO2 ink supercapacitor is more than 30 times higher than that of a commercial capacitor of the same weight of active material (e.g. carbon powder), demonstrating the great potential of MnO2 ink in significantly enhancing the performances of energy storage devices, whereas its production cost amounts to less than HK$1.

A Sept. 23, 2015 PolyU media release, which originated the news item, expands on the theme,

MnO2 is a kind of environmentally-friendly material and it is degradable. Given the environmental compatibility and high potential capacity of MnO2, it has always been regarded as an ideal candidate for the electrode materials of energy storage devices. The conventional MnO2 electrode preparation methods suffer from high cost, complicated processes and could result in agglomeration of the MnO2 ink during the coating process, leading to the reduction of electrical conductivity. The PolyU research team has developed a simple approach to synthesize aqueous MnO2 ink. Firstly, highly crystalline carbon particles were prepared by microwave hydrothermal method, followed by a morphology transmission mechanism at room temperature. The MnO2 ink can be coated on various substrates, such as conductive paper, plastic and glass. Its thickness and weight can also be controlled for the production of light, thin, transparent and flexible energy storage devices. Substrates coated by MnO2 ink can easily be erased if required, facilitating the fabrication of electronic devices.

PolyU researchers coated the MnO2 ink on conductive A4 paper and fabricated a capacitive energy storage device with maximum energy density and power density amounting to 4 mWh•cm-3 and 13 W•cm-3 respectively. The capacity of the MnO2 ink capacitor is more than 30 times higher than that of a commercial capacitor of the same weight of active material (e.g. carbon powder), demonstrating the great potential of MnO2 ink in significantly enhancing the performances of energy storage devices. Given the small size, light, thin, flexible and high energy capacity properties of the MnO2 ink energy storage device, it shows a potential in wide applications. For instance, in wearable devices and radio-frequency identification systems, the MnO2 ink supercapacitor could be used as the power sources for the flexible and “bendable” display panels, smart textile, smart checkout tags, sensors, luggage tracking tags, etc., thereby contributing to the further development of these two areas.

The related paper has been recently published on Angewandte Chemie International Edition, a leading journal in Chemistry. The research team will work to further improve the performance of the MnO2 ink energy storage device in the coming two years, with special focus on increasing the voltage, optimizing the structure and synthesis process of the device. In addition, further tests will be conducted to integrate the MnO2 ink energy storage device with other energy collection systems.

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

Aqueous Manganese Dioxide Ink for Paper-Based Capacitive Energy Storage Devices by Jiasheng Qian, Huanyu Jin, Dr. Bolei Chen, Mei Lin, Dr. Wei Lu, Dr. Wing Man Tang, Dr. Wei Xiong, Prof. Lai Wa Helen Chan, Prof. Shu Ping Lau, and Dr. Jikang Yuan. Angewandte Chemie International Edition Volume 54, Issue 23, pages 6800–6803, June 1, 2015 DOI: 10.1002/anie.201501261 Article first published online: 17 APR 2015

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

This paper is behind a paywall.

Brushing your way to nanofibres

The scientists are using what looks like a hairbrush to create nanofibres ,

Figure 2: Brush-spinning of nanofibers. (Reprinted with permission by Wiley-VCH Verlag)) [downloaded from]

Figure 2: Brush-spinning of nanofibers. (Reprinted with permission by Wiley-VCH Verlag)) [downloaded from]

A Sept. 23, 2015 Nanowerk Spotlight article by Michael Berger provides an in depth look at this technique (developed by a joint research team of scientists from the University of Georgia, Princeton University, and Oxford University) which could make producing nanofibers for use in scaffolds (tissue engineering and other applications) more easily and cheaply,

Polymer nanofibers are used in a wide range of applications such as the design of new composite materials, the fabrication of nanostructured biomimetic scaffolds for artificial bones and organs, biosensors, fuel cells or water purification systems.

“The simplest method of nanofiber fabrication is direct drawing from a polymer solution using a glass micropipette,” Alexander Tokarev, Ph.D., a Research Associate in the Nanostructured Materials Laboratory at the University of Georgia, tells Nanowerk. “This method however does not scale up and thus did not find practical applications. In our new work, we introduce a scalable method of nanofiber spinning named touch-spinning.”

James Cook in a Sept. 23, 2015 article for Materials Views provides a description of the technology,

A glass rod is glued to a rotating stage, whose diameter can be chosen over a wide range of a few centimeters to more than 1 m. A polymer solution is supplied, for example, from a needle of a syringe pump that faces the glass rod. The distance between the droplet of polymer solution and the tip of the glass rod is adjusted so that the glass rod contacts the polymer droplet as it rotates.

Following the initial “touch”, the polymer droplet forms a liquid bridge. As the stage rotates the bridge stretches and fiber length increases, with the diameter decreasing due to mass conservation. It was shown that the diameter of the fiber can be precisely controlled down to 40 nm by the speed of the stage rotation.

The method can be easily scaled-up by using a round hairbrush composed of 600 filaments.

When the rotating brush touches the surface of a polymer solution, the brush filaments draw many fibers simultaneously producing hundred kilometers of fibers in minutes.

The drawn fibers are uniform since the fiber diameter depends on only two parameters: polymer concentration and speed of drawing.

Returning to Berger’s Spotlight article, there is an important benefit with this technique,

As the team points out, one important aspect of the method is the drawing of single filament fibers.

These single filament fibers can be easily wound onto spools of different shapes and dimensions so that well aligned one-directional, orthogonal or randomly oriented fiber meshes with a well-controlled average mesh size can be fabricated using this very simple method.

“Owing to simplicity of the method, our set-up could be used in any biomedical lab and facility,” notes Tokarev. “For example, a customized scaffold by size, dimensions and othermorphologic characteristics can be fabricated using donor biomaterials.”

Berger’s and Cook’s articles offer more illustrations and details.

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

Touch- and Brush-Spinning of Nanofibers by Alexander Tokarev, Darya Asheghal, Ian M. Griffiths, Oleksandr Trotsenko, Alexey Gruzd, Xin Lin, Howard A. Stone, and Sergiy Minko. Advanced Materials DOI: 10.1002/adma.201502768ViewFirst published: 23 September 2015

This paper is behind a paywall.

Kavli Foundation roundtable on artificial synthesis as a means to produce clean fuel

A Sept. 9, 2015 news item on Azonano features a recent roundtable discussion about artificial photosynthesis and clean fuel held by the Kavli Foundation,

Imagine creating artificial plants that make gasoline and natural gas using only sunlight. And imagine using those fuels to heat our homes or run our cars without adding any greenhouse gases to the atmosphere. By combining nanoscience and biology, researchers led by scientists at University of California, Berkeley, have taken a big step in that direction.

Peidong Yang, a professor of chemistry at Berkeley and co-director of the school’s Kavli Energy NanoSciences Institute, leads a team that has created an artificial leaf that produces methane, the primary component of natural gas, using a combination of semiconducting nanowires and bacteria. The research, detailed in the online edition of Proceedings of the National Academy of Sciences in August, builds on a similar hybrid system, also recently devised by Yang and his colleagues, that yielded butanol, a component in gasoline, and a variety of biochemical building blocks.

The research is a major advance toward synthetic photosynthesis, a type of solar power based on the ability of plants to transform sunlight, carbon dioxide and water into sugars. Instead of sugars, however, synthetic photosynthesis seeks to produce liquid fuels that can be stored for months or years and distributed through existing energy infrastructure.

In a [Kavli Foundation] roundtable discussion on his recent breakthroughs and the future of synthetic photosynthesis, Yang said his hybrid inorganic/biological systems give researchers new tools to study photosynthesis — and learn its secrets.

There is a list of the participants and an edited transcript of the roundtable, which took place sometime during summer 2015, on the Kavli Foundation’s Fueling up: How nanoscience is creating a new type of solar power webpage (Note: Links have been removed),

The participants were:

PEIDONG YANG – is professor of chemistry and Chan Distinguished Professor of Energy at University of California, Berkeley, and co-director of the Kavli Energy NanoScience Institute at Berkeley National Laboratory and UC Berkeley. He serves as director of the California Research Alliance by BASF, and was a founding member of the U.S. Department of Energy (DOE) Joint Center for Artificial Photosynthesis (JCAP).
THOMAS MOORE – is Regents’ Professor of Chemistry and Biochemistry and past director of the Center for Bioenergy & Photosynthesis at Arizona State University. He is a past president of the American Society for Photobiology, and a team leader at the Center for Bio-Inspired Solar Fuel Production.
TED SARGENT – is a University Professor of Electrical and Computer Engineering at the University of Toronto where he is vice-dean for research for the Faculty of Applied Science and Engineering. He holds the Canada Research Chair in Nanotechnology and is a founder of two companies, InVisage Technologies and Xagenic.

THE KAVLI FOUNDATION (TKF): Solar cells do a good job of converting sunlight into electricity. Converting light into fuel seems far more complicated. Why go through the bother?

THOMAS MOORE: That’s a good question. In order to create sustainable, solar-driven societies, we need a way to store solar energy. With solar cells, we can make electricity efficiently, but we cannot conveniently store that electricity to use when it is cloudy or at night. If we want to stockpile large quantities of energy, we have to store it as chemical energy, the way it is locked up in coal, oil, natural gas, hydrogen and biomass.

PEIDONG YANG: I agree. Perhaps, one day, researchers will come up with an effective battery to store photoelectric energy produced by solar cells. But photosynthesis can solve the energy conversion and storage problem in one step. It converts and stores solar energy in the chemical bonds of organic molecules.

TED SARGENT: Much of the globe’s power infrastructure, from automobiles, trucks and planes to gas-fired electrical generators, is built upon carbon-based fossil fuels. So creating a new technology that can generate liquid fuels that can use this infrastructure is a very powerful competitive advantage for a renewable energy technology.

For someone who’s interested in solar energy and fuel issues, this discussion provide a good introduction to some of what’s driving the research and, happily, none of these scientists are proselytizing.

One final comment. Ted Sargent has been mentioned here several times in connection with his work on solar cells and/or quantum dots.

Windows as solar panels

Thanks to Dexter Johnson’s Aug. 27, 2015 posting, I’ve found another type of ‘smart’ window (I have written many postings about nanotechnology-enabled windows, especially self-cleaning ones); this window is a solar panel (Note: Links have been removed),

In joint research between the Department of Energy’s Los Alamos National Laboratory (LANL) and the University of Milan-Bicocca (UNIMIB) in Italy, researchers have spent the last 16 months perfecting a technique that makes it possible to embed quantum dots into windows so that the window itself becomes a solar panel.

Of course, this is not the first time someone thought that it would be a good idea to make windows into solar collectors. But this latest iteration marks a significant development in the evolution of the technology. Previous technologies used organic emitters that limited the size of the concentrators to just a few centimeters.

The energy conversion efficiency the researchers were able to acheive with the solar windows was around 3.2 percent, which stands up pretty well when compared with state-of-the-art quantum dot-based solar cells that have reached 9 percent conversion efficiency.

An August 24, 2015 US Los Alamos National Laboratory news release, which inspired Dexter’s posting, describes the research and the US-Italian collaboration in more detail,

A luminescent solar concentrator [LSC] is an emerging sunlight harvesting technology that has the potential to disrupt the way we think about energy; It could turn any window into a daytime power source.

“In these devices, a fraction of light transmitted through the window is absorbed by nanosized particles (semiconductor quantum dots) dispersed in a glass window, re-emitted at the infrared wavelength invisible to the human eye, and wave-guided to a solar cell at the edge of the window,” said Victor Klimov, lead researcher on the project at the Department of Energy’s Los Alamos National Laboratory. “Using this design, a nearly transparent window becomes an electrical generator, one that can power your room’s air conditioner on a hot day or a heater on a cold one.”

… The work was performed by researchers at the Center for Advanced Solar Photophysics (CASP) of Los Alamos, led by Klimov and the research team coordinated by Sergio Brovelli and Francesco Meinardi of the Department of Materials Science of the University of Milan-Bicocca (UNIMIB) in Italy.

The news release goes on to describe the precursor work which made this latest step forward possible,

In April 2014, using special composite quantum dots, the American-Italian collaboration demonstrated the first example of large-area luminescent solar concentrators free from reabsorption losses of the guided light by the nanoparticles. This represented a fundamental advancement with respect to the earlier technology, which was based on organic emitters that allowed for the realization of concentrators of only a few centimeters in size.

However, the quantum dots used in previous proof-of-principle devices were still unsuitable for real-world applications, as they were based on the toxic heavy metal cadmium and were capable of absorbing only a small portion of the solar light. This resulted in limited light-harvesting efficiency and strong yellow/red coloring of the concentrators, which complicated their application in residential environments.

Here’s how they solved the problem (from the news release),

Klimov, CASP’s director, explained how the updated approach solves the coloring problem: “Our new devices use quantum dots of a complex composition which includes copper (Cu), indium (In), selenium (Se) and sulfur (S). This composition is often abbreviated as CISeS. Importantly, these particles do not contain any toxic metals that are typically present in previously demonstrated LSCs.”

“Furthermore,” Klimov noted, “the CISeS quantum dots provide a uniform coverage of the solar spectrum, thus adding only a neutral tint to a window without introducing any distortion to perceived colors. In addition, their near-infrared emission is invisible to a human eye, but at the same time is ideally suited for most common solar cells based on silicon.”

Francesco Meinardi, professor of Physics at UNIMIB, described the emerging work, noting, “In order for this technology to leave the research laboratories and reach its full potential in sustainable architecture, it is necessary to realize non-toxic concentrators capable of harvesting the whole solar spectrum.”

“We must still preserve the key ability to transmit the guided luminescence without reabsorption losses, though, so as to complement high photovoltaic efficiency with dimensions compatible with real windows. The aesthetic factor is also of critical importance for the desirability of an emerging technology,” Meinardi said. [emphasis mine]

I couldn’t agree more with Professor Meinardi. You’re much more likely to adopt something that’s good for you and the planet if you like the look. Following on that thought, you’re much more likely to adopt solar panel windows if they’re aesthetically pleasing.

However, there is still a problem to be solved,

Hunter McDaniel, formerly a Los Alamos CASP postdoctoral fellow and presently a quantum dot entrepreneur (UbiQD founder and president), added, “with a new class of low-cost, low-hazard quantum dots composed of CISeS, we have overcome some of the biggest roadblocks to commercial deployment of this technology.”

“One of the remaining problems to tackle is reducing cost, but already this material is significantly less expensive to manufacture than alternative quantum dots used in previous LSC demonstrations,” McDaniel said.

Nonetheless, they have high hopes the technology can be commercialized (although as Dexter notes, it’s probably not going to be in the near future), from the news release,

A key element of this work is a procedure comparable to the cell casting industrial method used for fabricating high optical quality polymer windows. It involves a new UNIMIB protocol for encapsulating quantum dots into a high-optical quality transparent polymer matrix. The polymer used in this study is a cross-linked polylaurylmethacrylate, which belongs to the family of acrylate polymers. Its long side-chains prevent agglomeration of the quantum dots and provide them with the “friendly” local environment, which is similar to that of the original colloidal suspension. This allows one to preserve light emission properties of the quantum dots upon encapsulation into the polymer.

Sergio Brovelli, the lead researcher on the Italian team, concluded: “Quantum dot solar window technology, of which we had demonstrated the feasibility just one year ago, now becomes a reality that can be transferred to the industry in the short to medium term, allowing us to convert not only rooftops, as we do now, but the whole body of urban buildings, including windows, into solar energy generators.”

“This is especially important in densely populated urban area where the rooftop surfaces are too small for collecting all the energy required for the building operations,” he said. He proposes that the team’s estimations indicate that by replacing the passive glazing of a skyscraper such as the One World Trade Center in NYC (72,000 square meters divided into 12,000 windows) with our technology, it would be possible to generate the equivalent of the energy need of over 350 apartments.

“Add to these remarkable figures, the energy that would be saved by the reduced need for air conditioning thanks to the filtering effect by the LSC, which lowers the heating of indoor spaces by sunlight, and you have a potentially game-changing technology towards “net-zero” energy cities,” Brovelli said.

For anyone interested in this latest work on energy harvesting and windows, here’s a link to and a citation for the paper,

Highly efficient large-area colourless luminescent solar concentrators using heavy-metal-free colloidal quantum dots by Francesco Meinardi, Hunter McDaniel, Francesco Carulli, Annalisa Colombo, Kirill A. Velizhanin, Nikolay S. Makarov, Roberto Simonutti, Victor I. Klimov, & Sergio Brovelli. Nature Nanotechnology (2015) doi:10.1038/nnano.2015.178 Published online 24 August 2015

This paper is behind a paywall.

Hector Barron Escobar and his virtual nanomaterial atomic models for the oil, mining, and energy industries

I think there’s some machine translation at work in the Aug. 27, 2015 news item about Hector Barron Escobar on Azonano,

By using supercomputers the team creates virtual atomic models that interact under different conditions before being taken to the real world, allowing savings in time and money.

With the goal of potentiate the oil, mining and energy industries, as well as counteract the emission of greenhouse gases, the nanotechnologist Hector Barron Escobar, designs more efficient and profitable nanomaterials.

The Mexican who lives in Australia studies the physical and chemical properties of platinum and palladium, metal with excellent catalytic properties that improve processes in petrochemistry, solar cells and fuel cells, which because of their scarcity have a high and unprofitable price, hence the need to analyze their properties and make them long lasting.

Structured materials that the specialist in nanotechnology designs can be implemented in the petrochemical and automotive industries. In the first, they accelerate reactions in the production of hydrocarbons, and in the second, nanomaterials are placed in catalytic converters of vehicles to transform the pollutants emitted by combustion into less harmful waste.

An August 26, 2015 Investigación y Desarrollo press release on Alpha Galileo, which originated the news item, continues Barron Escobar’s profile,

PhD Barron Escobar, who majored in physics at the National University of Mexico (UNAM), says that this are created by using virtual supercomputers to interact with atomic models under different conditions before being taken to the real world.

Barron recounts how he came to Australia with an invitation of his doctoral advisor, Amanda Partner with whom he analyzed the electronic properties of gold in the United States.

He explains that using computer models in the Virtual Nanoscience Laboratory (VNLab) in Australia, he creates nanoparticles that interact in different environmental conditions such as temperature and pressure. He also analyzes their mechanical and electronic properties, which provide specific information about behavior and gives the best working conditions. Together, these data serve to establish appropriate patterns or trends in a particular application.

The work of the research team serves as a guide for experts from the University of New South Wales in Australia, with which they cooperate, to build nanoparticles with specific functions. “This way we perform virtual experiments, saving time, money and offer the type of material conditions and ideal size for a specific catalytic reaction, which by the traditional way would cost a lot of money trying to find what is the right substance” Barron Escobar comments.

Currently he designs nanomaterials for the mining company Orica, because in this industry explosives need to be controlled in order to avoid damaging the minerals or the environment.

Research is also immersed in the creation of fuel cells, with the use of the catalysts designed by Barron is possible to produce more electricity without polluting.

Additionally, they enhance the effectiveness of catalytic converters in petrochemistry, where these materials help accelerate oxidation processes of hydrogen and carbon, which are present in all chemical reactions when fuel and gasoline are created. “We can identify the ideal particles for improving this type of reactions.”

The nanotechnology specialist also seeks to analyze the catalytic properties of bimetallic materials like titanium, ruthenium and gold, as their reaction according to size, shape and its components.

Escobar Barron chose to study nanomaterials because it is interesting to see how matter at the nano level completely changes its properties: at large scale it has a definite color, but keep another at a nanoscale, besides many applications can be obtained with these metals.

For anyone interested in Orica, there’s more here on their website; as for Dr. Hector Barron Escobar, there’s this webpage on  Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) website.