Materials Update: Nano Glass, Conductive Nanofibers, The Silicene Silly Season, Plus Bonus Ketchup
By Mark Devlin
May 24, 2012
I Can See Clearly Now, the Rain Is Gone
Thanks to new ‘multifunctional’ glass developed by MIT, there may come a day when glass exhibits no glare and, thus, no reflections—‘and whose surface causes water droplets to bounce right off, like tiny rubber balls,’ according to this article at MIT (via PopSci).
Nanotextured silica surfaces produce the conical features shown above.
We’ve seen similar nano-magic before, granted. This one stands out since the researchers ‘hope’ that the glass can be made inexpensively for eventual use on smartphones, televisions, car windshields, and even windows in buildings. (I’m mostly with ‘em so far, but televisions? I don’t know about you, but I’ve never once thought, “Darn, the TVs all fogged up again!”) One would also hope that eyeglasses (Yes, some people still wear them. You know, people like I who think that having a laser cut slits in their eyes could turn out horribly wrong.)
Probably the most interesting app presented in the MIT piece is solar panels…
Photovoltaic panels, [MIT mechanical engineering grad student Kyoo-Chul] Park explains, can lose as much as 40 percent of their efficiency within six months as dust and dirt accumulate on their surfaces. But a solar panel protected by the new self-cleaning glass, he says, would have much less of a problem. In addition, the panel would be more efficient because more light would be transmitted through its surface, instead of being reflected away — especially when the sun’s rays are inclined at a sharp angle to the panel. At such times, such as early mornings and late afternoons, conventional glass might reflect away more than 50 percent of the light, whereas an anti-reflection surface would reduce the reflection to a negligible level.
Here’s a short vid…
The new glass is said to be better than hydrophobic coatings, staying cleaner longer (since droplets rolling off of the glass take dust with them) while preventing reflection.
For more, here’s the link to the related technical paper.
Plastic Nanofibers, Assemble Thy Selves!
Move over UV curing; light’s about to be signed up to do even crazier things.
According to this piece at Gizmag, researchers at the Centre National de la Recherche Scientifique (CNRS) have produced highly conductive plastic fibers—each less than a few nanometers in thickness—that could become a ‘cheaper, easier-to-handle alternative to carbon nanotubes.’ Why would such a thing be important? It could enable faster, cheaper development—and, also, ‘bottom-up’ manufacturing to potentially make processing faster, easier, and cheaper—of nanoscale electronic components that, presumably, would eventually be used in a variety of fields from ‘electronics to architecture.’
The juicy tidbit of this one? The fibers self-assemble when exposed to a flash of light.
It all goes back to Xerox, as have so many amazing engineering feats over the decades…
Back in 2010, [lead researchers] Giuseppone and Doudin succeeded in obtaining nanowires by chemically modifying “triarylamines,” which are synthetic molecules that Xerox used for decades in its photocopying processes. They observed that in light and in solution the new molecules formed miniature fibers by stacking up spontaneously in a regular manner.
For more, see CNRS and Nature Chemistry.
Graphene This, Graphene That. Meh. How About Silicene?
Graphene’s been the fair-haired heir to the Wonderful Material throne for a few years now, but there’s an upstart* called silicene: silicon that’s been turned into a sheet just one atom thick. With properties similar to graphene, according to this article at NewScientist, silicene ‘ought to be more compatible with silicon-based electronic devices.’
Here’s a snippet from NewScientist (link intact)…
Patrick Vogt of Berlin's Technical University in Germany, and colleagues at Aix-Marseille University in France created silicene by condensing silicon vapour onto a silver plate to form a single layer of atoms. They then measured the optical, chemical and electronic properties of the layer, showing it closely matched those predicted by theory (Physical Review Letters, DOI: 10.1103/PhysRevLett.108.155501).
Another potential silicene benefit? Cheaper devices, since it’s expected to be easier to integrate into silicon production lines.
* “A man doesn’t live who can call a Firefly an upstart!” Duck Soup, Marx Brothers, 1933
‘Impossible’ Material to Stretch When Compressed
This one wasn’t originally setup for today’s materials line-up, but it’s too cool to queue.
Also from New Scientist…
Imagine cushions that lift up instead of shrinking when you sit on them. Impossible? Not according to a blueprint for new materials with "negative compressibility": the materials compress when they are pulled and expand when they are pushed.
Their theoretical design involves a row of four "particles" – each made of groups of molecules – that attract each other to varying degrees. The force attracting the two inner particles is weak, so that pulling on the material breaks that bond. "As soon as that happens, the outer particles attract each other more," says [Adilson] Motter [of Northwestern University], so overall the material compresses. If this material is squeezed, though, the two inner particles are brought close enough together to reform the weak bond – and the material can expand.
C’mon. Have some faith in this guy. After all, Motter’s previously worked on invisibility cloaks. “The next phase,” he says, “has to be materials that do completely different things.”
Have even more fun with impossible materials here at Nature Materials.
Why Hasn’t Someone Done This Before?
Titanium dioxide is pretty amazing stuff; I didn’t realize how much so ‘til I glanced through this (seemingly well referenced) Wikipedia article.
So, here’s the deal. Alcoa thinks it’s pretty amazing too, so they patented a technology to apply a titanium dioxide coating (called EcoClean) to the pre-painted aluminum surface of the company’s Reynobond architectural panels. Why? Good question.
The coating works with natural sunlight, acting as a catalyst to break down organic pollutants on its surface and in the air around it into harmless matter which is then washed away by rainwater. Ten thousand square feet of EcoClean has the smog removal power of approximately 80 trees, equivalent to offsetting the nitrogen oxide created by the pollution output of four cars per day.
…according to the source article at Alcoa (via Gizmag).
Reynobond with EcoClean has been around since last year. The big news here is that the new ‘smog-eating’ technology is being installed at a new Electronics Recyclers International, Inc. facility in Badin, NC.
Next up: air-purifying car exhaust and rainmaking droughts.
Would You Like Ketchup With Your Impossible Material?
I spotted this one at the last moment before wrapping up this piece; I couldn’t resist including it. Check this out…
What makes the ketchup pour so easily? A ‘heavily patented coating on the inside of the bottle is "kind of a structured liquid--it's rigid like a solid, but it's lubricated like a liquid."’
For more, see this brief at PopSci.
Have a great weekend, and enjoy your many, already-miraculous materials…