Tag Archives: nanocrystals

Similarities between biological molecules and synthetic nanocrystals extend beyond size

Researchers at the University of Illinois at Urbana-Champaign have determined that there are more similarities between biological molecules and synthetic nanocrystals than formerly believed, according to a Dec. 17, 2013 news item on Nanowerk (Note: A link has been removed),

Researchers have long thought that biological molecules and synthetic nanocrystals were similar only in size. Now, University of Illinois at Urbana-Champaign chemists have found that they can add reactivity to the list of shared traits. Atoms in a nanocrystal can cooperate with each other to facilitate binding or switching, a phenomenon widely found in biological molecules.

The finding could catalyze manufacturing of nanocrystals for smart sensors, solar cells, tiny transistors for optical computers, and medical imaging. Led by chemistry professor Prashant Jain, the team published its findings in the journal Nature Communications (“Co-operativity in a nanocrystalline solid-state transition”).

A Dec. 16, 2013 University of Illinois at Urbana-Champaign news release, which originated the news item, explains why the scientists are so interested and how they went about their investigation,

“In geological, industrial and domestic environments, the nanoscale grains of any material undergo chemical transitions when they are put under reactive conditions,” Jain said. “Iron rusting over time and diamond forming from carbon are examples of two commonly occurring transitions. Understanding how these transitions occur on the scale of the tiniest grains of the material is a major motivation of our work.”

Scientists can exploit such transitions to make nanocrystals that conform to a particular structure. They can make a nanocrystal of one material and transform it into another material, essentially using the original nanocrystal framework as a template for creating a nanocrystal of the new material with the same size and shape. This lets researchers create nanocrystals of new materials in shapes and structures they may not be able to otherwise.

In the new study, the researchers transformed tiny crystals of the material cadmium selenide to crystals of copper selenide. Copper selenide nanocrystals have a number of interesting properties that can be used for solar energy harvesting, optical computing and laser surgery. Transformation from cadmium selenide creates nanocrystals with a purity difficult to attain from other methods.

The researchers, including graduate student Sarah White, used advanced microscopy and spectroscopy techniques to determine the dynamics of the atoms within the crystals during the transformation and found that the transformation occurs not as a slow diffusion process, but as a rapid switching thanks to co-operativity.

The researchers saw that once the cadmium-selenide nanocrystal has taken up a few initial copper “seed” impurities, atoms in the rest of the lattice can cooperate to rapidly swap out the rest of the cadmium for copper. Jain compares the crystals to hemoglobin, the molecule in red blood cells that carries oxygen. Once one oxygen molecule has bound to hemoglobin, other binding sites within hemoglobin slightly change conformation to more easily pick up more oxygen. He posits that similarly, copper impurities might cause a structural change in the nanocrystal, making it easier for more copper ions to infiltrate the nanocrystal in a rapid cascade.

The researchers reproduced the experiment with silver, in addition to copper, and saw similar, though slightly less speedy, cooperative behavior.

Now, Jain’s team is using its advanced imaging to watch transitions happen in single nanocrystals, in real time.

“We have a sophisticated optical microscope in our lab, which has now allowed us to catch a single nanocrystal in the act of making a transition,” Jain said. “This is allowing us to learn hidden details about how the transition actually proceeds. We are also learning how one nanocrystal behaves differently from another.”

Next, the researchers plan to explore biomolecule-like cooperative phenomena in other solid-state materials and processes. For example, co-operativity in catalytic processes could have major implications for solar energy or manufacturing of expensive specialty chemicals.

“In the long term, we are interested in exploiting the co-operative behavior to design artificial smart materials that respond in a switch-like manner like hemoglobin in our body does,” Jain said.

Here’s an image of the various forms of cadmium selenide used in research,

Nanocrystals of cadmium selenide, known for their brilliant luminescence, display intriguing chemical behavior resulting from positive cooperation between atoms, a behavior akin to that found in biomolecules.  Photo courtesy Prashant Jain

Nanocrystals of cadmium selenide, known for their brilliant luminescence, display intriguing chemical behavior resulting from positive cooperation between atoms, a behavior akin to that found in biomolecules. Photo courtesy
Prashant Jain

For the curious, here’s a link to and a citation for the paper,

Co-operativity in a nanocrystalline solid-state transition by Sarah L. White, Jeremy G. Smith, Mayank Behl, & Prashant K. Jain Nature Communications 4, Article number: 2933 doi:10.1038/ncomms3933 Published 12 December 2013

This article is behind a paywall.

Sea sponges inspire body armour of the future

A Mar. 15, 2013 news item on ScienceDaily features research inspired by sea sponges,

Scientists at Johannes Gutenberg University Mainz (JGU) and the Max Planck Institute for Polymer Research (MPI-P) in Germany have created a new synthetic hybrid material with a mineral content of almost 90 percent, yet extremely flexible. They imitated the structural elements found in most sea sponges and recreated the sponge spicules using the natural mineral calcium carbonate and a protein of the sponge. Natural minerals are usually very hard and prickly, as fragile as porcelain.

Amazingly, the synthetic spicules are superior to their natural counterparts in terms of flexibility, exhibiting a rubber-like flexibility. The synthetic spicules can, for example, easily be U-shaped without breaking or showing any signs of fracture. …

Spicules are structural elements found in most sea sponges. They provide structural support and deter predators. They are very hard, prickly, and even quite difficult to cut with a knife. The spicules of sponges thus offer a perfect example of a lightweight, tough, and impenetrable defense system, which may inspire engineers to create body armors of the future.

I found an image of a sea sponge (this may not be exactly the same type of sponge that inspired the latest work but I think there are enough similarities to the description the researchers give to  include it here) and more information in a Nov. 13, 2008 post by Ed Grabianows on IO9.com,

Downloaded from: http://io9.com/5085064/giant-deep-sea-sponges-evolved-fiber-optic-exoskeletons

Downloaded from: http://io9.com/5085064/giant-deep-sea-sponges-evolved-fiber-optic-exoskeletons

This gigantic sea sponge has an exoskeleton made of glass rods, and each rod can grow up to a meter in length. In the deep sea, these massive sponges contain a menagerie of other tiny lifeforms, all dependent on their sea sponge hosts for something in short supply far under the water. They need light – and some sponges have a [sic] evolved a way to provide it using fiber optics.Sea sponges are among the most primitive animals on Earth. …

Here’s more about the research (from the ScienceDaily news item),

 The researchers led by Wolfgang Tremel, Professor at Johannes Gutenberg University Mainz, and Hans-Jürgen Butt, Director at the Max Planck Institute for Polymer Research in Mainz, used these natural sponge spicules as a model to cultivate them in the lab. The synthetic spicules were made from calcite (CaCO3) and silicatein-α. The latter is a protein from siliceous sponges that, in nature, catalyzes the formation of silica, which forms the natural silica spicules of sponges. Silicatein-α was used in the lab setting to control the self-organization of the calcite spicules. The synthetic material was self-assembled from an amorphous calcium carbonate intermediate and silicatein and subsequently aged to the final crystalline material. After six months, the synthetic spicules consisted of calcite nanocrystals aligned in a brick wall fashion with the protein embedded like cement in the boundaries between the calcite nanocrystals. The spicules were of 10 to 300 micrometers in length with a diameter of 5 to 10 micrometers.

… the synthetic spicules have yet another special characteristic, i.e., they are able to transmit light waves even when they are bent.

The researchers have created a video animation to illustrate their work,

For those who would like to find out more about the research, there’s a citation for and a link to the researchers’ paper here.

Stanford team adds new energy (with graphene and carbon nanotubes) to 100 year old battery design

A nickel-iron battery designed to be recharged 100 years ago by Thomas Edison for use in electric vehicles has been revived with the addition of graphene. From the June 26, 2012 news item by Mark Schwartz on EurekAlert,

Designed in the early 1900s to power electric vehicles, the Edison battery largely went out of favor in the mid-1970s. Today only a handful of companies manufacture nickel-iron batteries, primarily to store surplus electricity from solar panels and wind turbines.

“The Edison battery is very durable, but it has a number of drawbacks,” said Hongjie Dai, a professor of chemistry at Stanford. “A typical battery can take hours to charge, and the rate of discharge is also very slow.”

Now, Dai and his Stanford colleagues have dramatically improved the performance of this century-old technology. The Stanford team has created an ultrafast nickel-iron battery that can be fully charged in about 2 minutes and discharged in less than 30 seconds. The results are published in the June 26 [2012] issue of the journal Nature Communications.

Here’s how the battery worked originally and what they’ve done to improve it,

Edison, an early advocate of all-electric vehicles, began marketing the nickel-iron battery around 1900. It was used in electric cars until about 1920. The battery’s long life and reliability made it a popular backup power source for railroads, mines and other industries until the mid-20th century.

Edison created the nickel-iron battery as an inexpensive alternative to corrosive lead-acid batteries. Its basic design consists of two electrodes – a cathode made of nickel and an anode made of iron – bathed in an alkaline solution. “Importantly, both nickel and iron are abundant elements on Earth and relatively nontoxic,” Dai noted.

Carbon has long been used to enhance electrical conductivity in electrodes. To improve the Edison battery’s performance, the Stanford team used graphene – nanosized sheets of carbon that are only one-atom thick – and multi-walled carbon nanotubes, each consisting of about 10 concentric graphene sheets rolled together.

“In conventional electrodes, people randomly mix iron and nickel materials with conductive carbon,” Wang explained. “Instead, we grew nanocrystals of iron oxide onto graphene, and nanocrystals of nickel hydroxide onto carbon nanotubes.”

This technique produced strong chemical bonding between the metal particles and the carbon nanomaterials, which had a dramatic effect on performance. “Coupling the nickel and iron particles to the carbon substrate allows electrical charges to move quickly between the electrodes and the outside circuit,” Dai said. “The result is an ultrafast version of the nickel-iron battery that’s capable of charging and discharging in seconds.”

The Stanford researchers created a 1-volt ‘graphene-enhanced’ nickel-iron prototype battery for experimentation in the lab. This battery can power a flashlight but the researchers are hoping to scale up so that the battery could be used for the electrical grid or transportation.

The lead author for the study is Hailiang Wang, a Stanford graduate student. Other co-authors of the study are postdoctoral scholars Yongye Liang and Yanguang Li, graduate student Ming Gong, and undergraduates Wesley Chang and Tyler Mefford also of Stanford; Jigang Zhou, Jian Wang and Tom Regier of Canadian Light Source, Inc.; and Fei Wei of Tsinghua University.

ETA: June 27, 2012: Here, by the way, is an electric vehicle powered by Edison’s battery circa 1910, downloaded from the Stanford University site (http://news.stanford.edu/news/2012/june/ultrafast-edison-battery-062612.html) and courtesy of the US National Park  Service.

To demonstrate the reliability of the Edison nickel-iron battery, drivers rode a battery-powered Bailey in a 1,000-mile endurance run in 1910. Courtesy: US National Park Service

Dem bones at McGill; innovation from the Canadian business community?; the archiving frontier; linking and copyright

I have a number of bits today amongst them, Canadian nanotechnology, Canadian business innovation, digital archiving, and copyrights and linking.

A Quebec biotech company, Enobia Pharma is working with Dr. Marc McKee on treatments for genetic bone diseases. From the news item on Nanowerk,

The field is known as biomineralization and it involves cutting-edge, nanotech investigation into the proteins, enzymes and other molecules that control the coupling of mineral ions (calcium and phosphate) to form nano-crystals within the bone structure. The treatment, enzyme replacement therapy to treat hypophosphatasia, is currently undergoing clinical testing in several countries including Canada. Hypophosphatasia is a rare and severe disorder resulting in poor bone mineralization. In infants, symptoms include respiratory insufficiency, failure to thrive and rickets.

This research in biomineralization (coupling of mineral ions to form nano-crystals) could lead to better treatments for other conditions such as cardiovascular diseases, arthritis, and kidney stones.

McKee’s research is being funded in part by the Canadian Institutes of Health Research  From the Nanowerk news item,

McKee’s research program is a concrete example of how university researchers are working with private sector partners as an integral part of Canada’s innovative knowledge economy, and the positive outcomes their collaborations can offer.

I don’t think that businesses partnering with academic institutions in research collaborations is precisely what they mean when they talk about business innovation (research and development). From a March 2, 2010 article about innovation by Preston Manning in the Globe & Mail,

Government competition policy and support for science, technology, and innovation (STI) can complement business leadership on the innovation front, but it is not a substitute for such leadership. Action to increase innovation in the economy is first and foremost a business responsibility.

Manning goes on to describe what he’s done on this matter and asks for suggestions on how to encourage Canadian business to be more innovative. (Thanks to Pasco Phronesis for pointing me to Manning’s article.) I guess the problem is that what we’ve been doing has worked well enough and so there’s no great incentive to change.

I’ve been on an archiving kick lately and so here’s some more. The British Library recently (Feb.25.10) announced public access to their UK Web Archive, a project where they have been saving online materials. From the news release,

British Library Chief Executive, Dame Lynne Brindley said:

“Since 2004 the British Library has led the UK Web Archive in its mission to archive a record of the major cultural and social issues being discussed online. Throughout the project the Library has worked directly with copyright holders to capture and preserve over 6,000 carefully selected websites, helping to avoid the creation of a ‘digital black hole’ in the nation’s memory.

“Limited by the existing legal position, at the current rate it will be feasible to collect just 1% of all free UK websites by 2011. We hope the current DCMS consultation will enact the 2003 Legal Deposit Libraries Act and extend the provision of legal deposit through regulationto cover freely available UK websites, providingregular snapshots ofthe free UK web domain for the benefit of future research.”

Mike Masnick at Techdirt notes (here) that the British Library has to get permission (the legal position Dame Brindley refers to) to archive these materials and this would seem to be an instance where ‘fair use’ should be made to apply.

On the subject of losing data, I read an article by Mike Roberts for the Vancouver Province, January 22, 2006, p. B5 (digital copy here) that posed this question, What if the world lost its memory? It was essentially an interview with Luciana Duranti (chair of the Master of Archival Studies programme and professor at the School of Library, Archival and Information Studies at the University of British Columbia, Canada) where she commented about the memories we had already lost. From the article,

Alas, she says, every day something else is irretrievably lost.

The research records of the U.S. Marines for the past 25 years? Gone.

East German land-survey records vital to the reunification of Germany? Toast.

A piece of digital interactive music recorded by Canadian composer Keith Hamel just eight years ago?

“Inaccessible, over, finito,” says Duranti, educated in her native Italy and a UBC prof since 1987.

Duranti, director of InterPARES (International Research on Permanent Authentic Records in Electronic Systems), an international cyber-preservation project comprising 20 countries and 60 global archivists, says original documentation is a thing of the past.

I was shocked by how much ‘important’ information had been lost and I assume still is. (Getting back to the UK Web Archives, if they can only save 1% of the UK’s online material then a lot has got to be missing.)

For anyone curious about InterPARES, I got my link for the Roberts article from this page on the InterPARES 1 website.

Back to Techdirt and Mike Masnick who has educated me as to a practice I had noted but not realized is ‘the way things are done amongst journalists’. If you spend enough time on the web, you’ll notice stories that make their way to newspapers without any acknowledgment of  their web or writerly origins and I’m not talking about news releases which are designed for immediate placement in the media or rewritten/reworked before placement. From the post on Techdirt,

We recently wrote about how the NY Post was caught taking a blogger’s story and rewriting it for itself — noting the hypocrisy of a News Corp. newspaper copying from someone else, after Rupert Murdoch and his top execs have been going around decrying various news aggregators (and Google especially) for “stealing” from News Corp. newspapers. It’s even more ridiculous when you think about it — because the “stealing” that Rupert is upset about is Google linking to the original story — a step that his NY Post writer couldn’t even be bothered to do.

Of course, as a few people pointed out in the comments, this sort of “re-reporting” is quite common in the traditional news business. You see it all the time in newspapers, magazines and broadcast TV. They take a story that was found somewhere else and just “re-report” it, so that they have their own version of it.

That’s right, it’s ‘re-reporting’ without attributions or links. Masnick’s post (he’s bringing in Felix Salmon’s comments) attributes this to a ‘print’ mentality where reporters are accustomed to claiming first place and see acknowledgments and links as failure while ‘digital natives’ acknowledge and link regularly since they view these as signs of respect. I’m not going to disagree but I would like to point out that citing sources is pretty standard for academics or anyone trained in that field. I imagine most reporters have one university or college degree, surely they learned the importance of citing one’s sources. So does training as a journalist erode that understanding?

And, getting back to this morning’s archival subtheme, at the end of Clark Hoyt’s (blogger for NY Times) commentary about the plagiarism he had this to say,

Finally, The Times owes readers a full accounting. I asked [Philip] Corbett [standards editor] for the examples of Kouwe’s plagiarism and suggested that editors’ notes be appended to those articles on the Web site and in The Times’s electronic archives. Corbett would not provide the examples and said the paper was not inclined to flag them, partly because there were some clear-cut cases and others that were less clear. “Where do you draw the line?” he asked.

I’d draw it at those he regards as clear. To do otherwise is to leave a corrupted record within the archives of The Times. It is not the way to close the case.

One last thing, Heather Haley is one of the guests appearing tonight in Rock Against Prisons.

Tuesday, March 9, 2010

7:00pm – 11:55pm

Little Mountain Gallery

195 east 26th Ave [Vancouver, Canada]

More details from my previous announcement about this event here.