Tag Archives: Berkeley Labs

Kavli nanoscience and microbiomes

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It’s been a while since I’ve mentioned the Kavli Foundation, which is dedicated to “advancing basic science for humanity.” On this occasion,  there’s a Feb. 12, 2015 news item on Nanowerk featuring a Kavli Foundation discussion about nanoscience and microbiomes,

Microbiomes, communities of one-celled organisms, are everywhere in nature. They play important roles in health and agriculture, yet we know surprisingly little about them. Nanoscience might help.

In a far-ranging discussion, two top researchers spoke with the Kavli Foundation about how nanoscience can help us understand and manipulate natural microbiomes.

Microbiomes are communities of bacteria, fungi, protozoa, algae, other one-celled microbes, and viruses that interact with one another in complex ways. These ecosystems are enormously complex. A few grams of soil or marine sediment might contain as many as several hundred thousand different species of microbes.

“There are all these amazing chemistries that microbes perform that can do really wonderful things for humanity, like providing new antibiotics and nutrients for crops. It’s pretty much an unlimited resource of novelty and chemistry—if we can develop improved tools to tap into it,” said Eoin Brodie, a staff scientist in Lawrence Berkeley National Laboratory’s Ecology Department.

In the past, researchers have sought to understand these communities by growing different microbes in cultures and observing their behaviors. Yet only a small fraction of these microorganisms grow in pure cultures.

Nanoscience could provide new ways to unravel these complex ecosystems, according to Jack Gilbert, a principle investigator at Argonne National Laboratory’s Biosciences Division.

…

You can continue reading either on Nanowerk or here on the Kavli website where you’ll find the Kavli Foundation is having a series of conversations about microbiomes, which you may want to check out. This conversation with Brodie and Gilbert seems to be in aid of an upcoming Google Hangout,

Spotlight Live: Thinking Smaller – How Nanoscience Can Help Us Understand Nature’s Many Microbiomes
Wednesday, March 4 – 11:00 am PST

Join us here on March 4 for a live Google Hangout with Eoin Brodie and Jack A. Gilbert. Questions can be submitted by email or via Twitter with the hashtag: #KavliLive. For updates, follow The Kavli Foundation on Twitter and Facebook.

Using a culinary technique to change fluid drops into exotic shapes

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I always enjoy a culinary reference (h/t Nanowerk) such as the one in Lynne Yarris’ Dec. 2, 2013 science short for the Lawrence Berkeley National Laboratory (California, US),

Oil and water don’t mix, as any chemist or cook knows. Tom Russell, a polymer scientist from the University of Massachusetts who now holds a Visiting Faculty appointment with Berkeley Lab’s Materials Sciences Division, is using that chemical and culinary truth to change the natural spherical shape of liquid drops into ellipsoids, tubes and even fibrous structures similar in appearance to glass wool. Through the combination of water, oil and nanoparticle surfactants plus an external field, Russell is able to stabilize water drops into non-equilibrium shapes that could find valuable uses as therapeutic delivery systems, biosensors, microfluidic lab-on-a-chip devices, or possibly as the basis for an all-liquid electrical battery.

More technical details follow,

n a study he carried out at UMass with Mengmeng Cui and Todd Emrick, a drop of water was suspended in silicone oil and carboxylated nanoparticles were added to the water. The nanoparticles self-assembled at the oil/water interface to form a sphere-shaped surfactant drop – like a soap bubble. Applying an electric field to the drop overcame the equilibrium energy that stabilizes its spherical shape and deformed the sphere into an ellipsoid.

Since an ellipsoid has a greater surface area than a sphere of the same volume, a great many more nanoparticles can attach themselves to it. When the electric field was removed, the nanoparticle drop tried to return to the spherical shape of its equilibrium energy. However, the swollen number of nanoparticles jammed together at the oil/water interface, essentially “gridlocking” the drop into a stable ellipsoid shape.

“You can think of it like traffic getting jammed at an exit ramp or particles of sand getting jammed in an hourglass,” Russell says. “We start out by deforming a drop shaped like a basketball into a drop shaped like a football. The jamming effect locks in the football shape. If we continue the deforming and jamming process, we can create a wide assortment of shapes that are stable even though far removed from equilibrium.”

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

Stabilizing Liquid Drops in Nonequilibrium Shapes by the Interfacial Jamming of Nanoparticles by Mengmeng Cui, Todd Emrick, & Thomas P. Russell. Science 25 October 2013: Vol. 342 no. 6157 pp. 460-463 DOI: 10.1126/science.1242852

The paper is behind a paywall but there is a transcript of a recent (Oct. 25, 2013) Science podcast interview with Russell. Go here and scroll down for access to the transcript (he’s the 2nd interviewee).

Insomniac iron oxide (rust) electrons and environmentally friendly semiconductors

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The Sept. 7, 2012 news item by Lynn Yarris for physorg.com highlights some research on rust being conducted (pun intended) at Lawrence Berkeley National Laboratory (Berkeley Labs).

Rust – iron oxide – is a poor conductor of electricity, which is why an electronic device with a rusted battery usually won’t work. Despite this poor conductivity, an electron transferred to a particle of rust will use thermal energy to continually move or “hop” from one atom of iron to the next. Electron mobility in iron oxide can hold huge significance for a broad range of environment- and energy-related reactions, including reactions pertaining to uranium in groundwater and reactions pertaining to low-cost solar energy devices.  …

“We believe this work is the starting point for a new area of time-resolved geochemistry that seeks to understand chemical reaction mechanisms by making various kinds of movies that depict in real time how atoms and electrons move during reactions,” says Benjamin Gilbert, a geochemist with Berkeley Lab’s Earth Sciences Division and a co-founder of the Berkeley Nanogeoscience Center who led this research. “Using ultrafast pump-probe X-ray spectroscopy, we were able to measure the rates at which electrons are transported through spontaneous iron-to-iron hops in redox-active iron oxides. Our results showed that the rates depend on the structure of the iron oxide and confirmed that certain aspects of the current model of electron hopping in iron oxides are correct.”

The news item provides a wealth of detail about electron hopping and iron oxide but I was most intrigued by future applications,

Katz [Jordan Katz, the lead author, now with Denison University]  is excited about the application of these results to finding ways to use iron oxide for solar energy collection and conversion.

“Iron oxide is a semiconductor that is abundant, stable and environmentally friendly, and its properties are optimal for absorption of sunlight,” he says. “To use iron oxide for solar energy collection and conversion, however, it is critical to understand how electrons are transferred within the material, which when used in a conventional design is not highly conductive. Experiments such as this will help us to design new systems with novel nanostructured architectures that promote desired redox reactions, and suppress deleterious reactions in order to increase the efficiency of our device.”

I find rust quite attractive although, admittedly, very irritating at times. I have never before considered the possibility it might prove useful nor had I realized that it never rests (sleeps).