Technology Trends

Researchers from the Lawrence Berkeley Lab are using nanotechnology to learn how to clean up environmental contaminants like nuclear waste. They are also using supercomputers and state-of-the-art imaging to predict how quickly pollutants react with minerals in soils and aquifers. This article from the Daily Californian says they are studying kinetics, or rates, of reactions which occur at the earth’s surface using a nanoscale approach. They started to look at the reactions that take place at the pore scale and plan to expand their scope from nanometers to meters in the months to come. This research has implications for transport of contaminants, especially of radioactive materials, but also for oil or ore recovery. Read more…

Here is the introduction of the Daily Californian article.

Nanotechnology, normally used for work with the crystal structures of silicone chips and pure oxides, is being used for something a little more dirty at the Lawrence Berkeley Lab, like learning how to clean up environmental contaminants like nuclear waste.

Researchers Glenn Waychunas and Carl Steefel are using techniques that allow them to study the environment at the nanoscale as part of the new Center for Environmental Kinetics Analysis (CEKA) program, based at Pennsylvania State University.

The goal of the program is to gain insight into the kinetics, or rates, of reactions that occur at the earth’s surface using a nanoscale approach that better models what happens in the real world as opposed to in the lab.

The CEKA program uses a multidisciplinary approach and includes chemists, geochemists, biochemists, soil scientists and engineers.

[For their part,] Waychunas and Steefel are working on the reactions that take place on the pore scale, like the flow of water through the minerals in an aquifer.

“What has been left out is determining rates at the pore scale, we’re measuring rates at different scales to see how biogeochemical and microbial reactions scale up,” Steefel said.

What will be the impact of this program, which has received $6.7 million from the NSF?

This can have implications for transport of contaminants, especially of radioactive materials. Researchers seek to determine reaction rates to determine how long it would take for a plume of pollutant to spread through different mineral substrates.

The next scale is supercomputer modeling, according to Waychunas. “This will model chemical reactions and integrate fluid flow through pore structures, using more complicated fluids and soils. Then we’ll apply them to real systems, like the Yucca Mountains, natural aquifers, oil recovery, ore recovery, and natural gas,” Waychunas said.

For more information, you can read “Taking a Peek At Our Environmental Future,” published by Berkeley Lab View, and from which I extracted the above photograph. Here are more details about Steefel’s work.

Steefel, also a geochemist in the Earth Sciences Division, will also start small and then try to go big. First, he wants to gain a mechanistic understanding of the processes that control biogeochemical reaction rates in porous material by focusing on a single pore. In a common scenario, there may be a reactive mineral on one side of a pore and biofilm on the other side. How do they communicate? To answer this question, Steefel and several other scientists will conduct reactive flow experiments using single-pore microfluidic devices. They’ll also monitor how fluid reacts with porous samples using imaging technology with a spatial resolution of about 30 nanometers, such as the Advanced Light Source’s scanning transmission x-ray microscope (STXM). They will probably begin with a calcium carbonate mineral that has been studied extensively — but never at the pore scale — and observe the rate at which a slightly acidic solution reacts with the mineral as it flows through.

Next, this pore-by-pore data will be used to develop supercomputer-derived models that depict the rates of these reactions in a much larger sample of porous material.

Here is his conclusion.

“The idea of scaling kinetics is a frontier issue, but that’s what this project is about,” says Steefel. “If we develop a mechanistic understanding of reactive transport at several scales, then we can devise predictive models for bioremediation, chemical weathering, and carbon sequestration. And only through the convergence of modeling, supercomputers, synchrotron techniques, and advanced microfluidic reactors is this possible.”

Sources: Francesca Hopkins, The Daily Californian, January 19, 2005; Dan Krotz, Berkeley Lab View, November 12, 2004; and various websites

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Once again, I’m amazed by the creativity of scientists. Researchers at Cornell University have made a brilliant and environmentally friendly discovery: plastics made from orange peel and a greenhouse gas. By adding a zinc catalyst to a mix of citrus fruits, such as oranges, and carbon dioxide, they found a way to make a new polymer called polylimonene carbonate, very similar to polystyrene, a petroleum-based plastic. This is a double whammy: it will reduce existing carbon dioxide, almost certainly responsible for the global warming effect, while reducing future emissions. Of course, time will pass between this discovery and its practical applications. But ultimately, this will greatly beneficial to all of us. Read more…

A Cornell University research group has made a sweet and environmentally beneficial discovery — how to make plastics from citrus fruits, such as oranges, [which contain limonene oxide ]and carbon dioxide.

Limonene is a carbon-based compound produced in more than 300 plant species. In oranges it makes up about 95 percent of the oil in the peel.

In industry, explains Geoffrey Coates, a Cornell professor of chemistry and chemical biology, the orange peel oil is extracted for various uses, such as giving household cleaners their citrus scent. The oil can be oxidized to create limonene oxide. This is the reactive compound that Coates and his collaborators used as a building block.

The other building block they used was carbon dioxide (CO₂), an atmospheric gas that has been rising steadily over the past century and a half — due largely to the combustion of fossil fuels — becoming an environmentally harmful greenhouse gas.

By using their catalyst to combine the limonene oxide and CO₂, the Coates group produced a novel polymer — called polylimonene carbonate — that has many of the characteristics of polystyrene, a petroleum-based plastic currently used to make many disposable plastic products.

The above diagram shows the very simple process of making polymers by adding a catalyst to a mix of limonene oxide and carbon dioxide (Credit: Cornell University)

And here is Coates’s conclusion.

“Almost every plastic out there, from the polyester in clothing to the plastics used for food packaging and electronics, goes back to the use of petroleum as a building block,” Coates observes. “If you can get away from using oil and instead use readily abundant, renewable and cheap resources, then that’s something we need to investigate. What’s exciting about this work is that from completely renewable resources, we were able to make a plastic with very nice qualities.”

The research work has been published by the Journal of the American Chemical Society (Vol. 126, No. 37, September 22, 2004, Pages 11404-11405, Link).

Here is a direct link to the abstract of this paper called “Alternating Copolymerization of Limonene Oxide and Carbon Dioxide.”

For more information, you can check these pages about Geoffrey Coates and his research group.

Here is what Coates says about his research on polymers created from renewable resources, and more specifically about the copolymerization of CO₂ and epoxides.

Carbon dioxide is an ideal synthetic feedstock since it is abundant, inexpensive, nontoxic, and nonflammable. Although it is estimated that Nature uses CO₂ to make over 200 billion tons of glucose by photosynthesis each year, synthetic chemists have had embarrassing little success in developing efficient catalytic processes that exploit this attractive raw material. There has been considerable recent interest in the development of catalysts for the alternating copolymerization of carbon dioxide with epoxides to produce aliphatic polycarbonates. Due to the low cost and accessibility of the monomers and the attractive properties of polycarbonates, the development of new, efficient initiators for this polymerization process is a significant scientific goal. We have recently discovered a new class of well-defined, highly active zinc-based catalysts that copolymerize carbon dioxide and epoxides under exceptionally mild conditions. These catalysts are remarkable since they are several orders of magnitude more active than the current commercial catalysts.

Let’s hope that this discovery quickly leaves the lab…

Sources: Sarah Davidson, Cornell University news release, January 17, 2005; and various websites

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Even if the Morse code usage has almost disappeared, it was a very efficient communication protocol. Now, researchers from several universities and drug companies in the U.K. have discovered that our cells are also using Morse-like signals to switch genes on and off. In this news release, the Biotechnology and Biological Sciences Research Council (BBSRC) writes that this discovery may have major implications for the pharmaceutical industry. Better and more efficient drugs would only deliver the signals to our cells that will activate a desired behavior. Sounds like science fiction? Read more…

This research is featured as the cover story of the January 2005 issue of Business, the quarterly magazine of the BBSRC. Here is a link to this full issue (PDF format, 32 pages, 1.08 MB). The article about “A Morse code in cells?” appears on pages 16 and 17.

Below is a picture and its legend as they appear in the magazine (Credit: BBSRC)

Composite picture showing a series of timelapse images of a neuroblastoma cell (SK-N-AS) stimulated with TNFalpha continuously for 360 minutes. The images show that in the cell, fluorescent RelA (an NF-kappaB protein) moves into and out of the nucleus three times. Individual pictures of the cell were superimposed over a graph (subsequently removed) that quantified the extent to which the fluorescent protein is localised in the nucleus versus the cytoplasm at different times after stimulation.

Now, let’s move to the essential details of the BBSRC news release.

Morse code is a simple, effective and clear method of communication and now scientists believe that cells in our body may also be using patterns of signals to switch genes on and off. The discovery may have major implications for the pharmaceutical industry as the signalling molecules that are targeted by drugs may have more than one purpose. The number of ‘dots and dashes’ being used by each signal could have different purposes, all of which could be modified by a drug.

The researchers, funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and working at the Universities of Liverpool and Manchester and the Royal Liverpool Children’s Hospital, in collaboration with scientists at AstraZeneca and Pfizer, have studied transcription factors, the signalling molecules inside cells that activate or deactivate genes. They found that the strength of the signal is less important than the dynamic frequency pattern that is used.

The researchers focused on the response of a transcription factor involved in controlling the crucial processes of cell division and cell death. They found that the dynamics of the signalling molecule resemble the changes in calcium levels that encode other messages in cells. The results suggest how common signalling molecules could convey different messages through different frequencies.

Below is a series of pictures showing the results of an experiment which lasted several hours (Credit: BBSRC)

Neuroblastoma (SK-N-AS) cells, expressing EGFP (green) and RelA-Ds-Red (red), showing repeated movements of RelA-DsRed (RelA/p65 is an NF-êB subunit) between the cytoplasm and nucleus following treatment of the cells with TNFá (Time = minutes)

And here is the conclusion of Professor Julia Goodfellow, BBSRC Chief Executive.

This research is an example of a multi-disciplinary approach producing vitally important results. By combining expertise in cell biology, chemistry, mathematical modelling and bio-imaging the research team have discovered this coded signal that is going to inform the development of better, more effective drugs.

Sources: BBSRC news release, January 10, 2005; BBSRC website

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Australian and U.S. researchers have found a new way to exploit the old technology of spinning wool. This CSIRO news release, “Futuristic ’smart’ yarns on the horizon,” tells us that spinning of carbon nanotubes could lead to ’smart’ yarns which could be knitted together to make artificial muscles for robot soldiers or even bandages that send a signal after you’re hurt. However, this news release is short on facts, and in “Knitting in nanometres,” ABC Science Online wrote something more substantial. You’ll discover that the scientists “created the yarn by growing a mat of fibres on a substrate, called a nanotube forest.” And with this spinning process, this ‘forest’ can grow as long as you want, like several kilometers long. If it is proven, this is truly amazing, and practical military or medical applications could be ready within five years. Read more…

Before going further, let’s look at some very interesting pictures.

Now, here are the two first paragraphs of the CSIRO news release.

In a collaborative effort, scientists at CSIRO Textile and Fibre Technology (CTFT) have achieved a major technological breakthrough that should soon lead to the production of futuristic strong, light and flexible ’smart’ clothing materials.

In partnership with the world-renowned NanoTech Institute at the University of Texas at Dallas, CTFT has adapted textile technologies used to spin wool and other fibres to produce yarns made solely from carbon nanotubes (CNTs).

As you can notice, there is not much ‘meat’ there. So let’s switch to ABC Science Online for more technical details.

Ken Atkinson from CSIRO Textile & Fibre Technology said the nanotubes’ structure was similar to a square of hexagonal wire coiled up to form a cylinder.

The researchers created the yarn by growing a mat of fibres on a substrate, called a nanotube forest. A sharp, pointed instrument then pulled at the fibres along the plane of the substrate.

Atkinson said the tubes then formed into a “conga line” and were twisted and wrapped around each other as they were pulled. “As long as there are fibres in the forest, you can make a yarn as long as you want. You get a very even strand,” he said.

And Atkinson is pretty vocal about this spinning process — read carefully this quote.

“People say how can you spin something that is one-third of a millimetre long, but it is the length-to-diameter ratio that matters. We use fibres with a 10 nanometre diameter and put in a lot of wraps.”

Atkinson said nanotubes were usually grown to about 300 micrometres. And scientists couldn’t make nanotube yarn with continuous lengths without blending the fibres with other materials. With spinning you can get pure nanotube yarn as long you want, Atkinson said.

What can we expect of this ’spinning wool’ process adapted to nanotechnology?

Here is what CSIRO says.

Initial research into the potential uses of the new material is focussed on the production of vests and ’soft’ body armour to provide protection from bullets and other small ballistic missiles.

“Small ballistic missiles?” Wow! I don’t think I need protection against this. ABC gives us more realistic expectations.

The team says its unusually long fibres could also be used to make bandages that help injured limbs move again, tighten to stem bleeding or send a signal to say someone was hurt.

For more information, the research work has been published by the journal Science under the title “Multifunctional Carbon Nanotube Yarns by Downsizing an Ancient Technology.” Here are two links to the abstract and to some supporting online material to the article (PDF format, 3 pages). The above illustration was extracted from this document.

Sources: CSIRO news release, November 19, 2004; Heather Catchpole, ABC Science Online, November 19, 2004; Science, Vol. 306, Issue 5700, Pages 1358-1361, November 19, 2004

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Researchers at the University of California, Riverside (UCR), have discovered the world’s strongest acid, according to Nature. It’s a million times stronger than concentrated sulfuric acid and about a billion times stronger than the acids found in your stomach. But surprisingly, it’s also one of the least corrosive. So you might soon find one of these new carborane acids, or superacids, in vitamins bought at your local drugstore. Even if this is not appealing to you, these researchers have other projects. They want to have fun by building molecules that have never been made before. Read more…

This new superacid is even better described in this UCR news release. Let’s start with the introduction.

Researchers at the University of California, Riverside have discovered the world’s strongest acid. Remarkably it is also the gentlest acid. This non-toxic and non-corrosive acid may have a role in processes such as improving the quality of gasoline, developing polymers and synthesizing pharmaceuticals.

The most important characteristic of these carborane acids is that they have anextraordinary chemical stability.

They have an icosahedral arrangement of eleven boron atoms plus one carbon atom, which is probably the most chemically stable cluster of atoms in all of chemistry, according to Christopher Reed, UC Riverside Distinguished Professor of Chemistry. This means that the carborane part of the acid cannot participate in the chemistry of corrosion and decomposition that fluoride and nitrate show in hydrofluoric acid and nitric acid.

Now, how strong are these superacids?

The strongest one is at least a million times stronger than concentrated sulfuric acid (H₂SO₄) and hundreds of times stronger than the previous record holder, fluorosulfuric acid (HFSO₃). Concentrated sulfuric acid is already more than a billion times (10¹²) stronger than dilute swimming pool acid or the acid in one’s stomach.

Fine, but how can we use these enormously strong acids? They could be used for example in hydrocarbon cracking, a process which raises the octane levels of gasoline.This could be useful, but Nature points to other possible usages.

They allow the production of ‘acidified’ organic molecules. These are compounds that have had a hydrogen ion added to them, as in the case of many vitamins in over-the-counter supplements.

Acidified compounds occur fleetingly in the digestion of food, petroleum refinement and drug manufacture, says Reed. Carborane acids could be used to study these elusive chemicals more closely, or even help chemical industries to run their reactions more efficiently.

But even more importantly, these researchers want more to have fun than to make money.

But the researchers’ immediate goal would be less of a money-spinner. They want to use carborane acids to acidify atoms of the inert gas xenon, simply because, they say, “it’s never been done before”.

And in the UCR news release, Reed adds the following.

Our research is driven by making molecules that have never been made before. Carborane acids are allowing us to do this. That is the true value of this research. Science gets advanced, and at the same time, students are experiencing the thrill of discovery as they become scientists.

I don’t know for you, but the idea of taking vitamins containing such strong acids disturbs me a little.

Anyway, if you want more information before taking your next dietary supplement, the research paper has been published by Angewandte Chemie under the ramarkably simple titlee “The Strongest Isolable Acid.” Here are the links to the abstract and to the full paper (PDF format, 4 pages). The diagram of the carborane ions was extracted from this paper.

Sources: Michael Hopkin, Nature, November 16, 2004; University of California, Riverside news release, November 15, 2004; Angewandte Chemie International Edition, Volume 43, Issue 40 , Pages 5352 - 5355, October 5, 2004

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