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April 02, 2008

Of nanoworms and bird's nests

nanoworms
Inspired by the highly interlocked structures of bird nests, vanadia-based structures which form a more highly entangled worm-like nanostructure were made. Photo via Chemical Science.
By mimicking the interlocking structure of a bird's nest -- but on a much smaller scale, using nanoparticles -- Missouri S&T's Nicholas Leventis and his colleagues have come up with a way to make a certain class of aerogels less fragile. A recent edition of the journal Chemical Science reports:
Aerogels are typically made from pearl necklace-like strings of silica nanoparticles, and can be strengthened with a polymer coating, so that the strands form crosslinks wherever they meet. But inspired by the highly interlocked structures of bird nests, Leventis switched to vanadia-based structures, which form a more highly entangled worm-like nanostructure.

'Both crosslinked silica and vanadia are very strong materials. But crosslinked vanadia aerogels never fail under compression, and can absorb at least four times the kinetic energy of the silicon carbide ceramics used for armour,' said Leventis. 'Killer applications will be in areas where we can take advantage of the multifunctional character of these materials - strength in combination with acoustic and thermal insulation - such as lightweight structural materials for buildings, and the automotive and airplane industries.'

This is not the first time Leventis has gained notice for his work with nanomaterials. Last June, the chemistry professor made Nanotech Briefs' Nano 50 list of top researchers in the field. Leventis made the list for his previous work with aerogels.

June 15, 2007

'Lightweight, close to nothingness'

nano_50_2.jpgThat's how UMR chemist Nicholas Leventis describes his invention: cross-linked aerogels. The extremely lightweight and sturdy composite material is four to five times stronger than material currently used in military armor. This week he was named to Nanotech Briefs list of Nano 50 for his work.

Aerogels are nothing new. They've been around since the 1930s, but they were highly brittle and of little practical use. By chemically bonding -- or cross-linking -- strings of tiny glass particles with polymers like polystyrene, polyurethane and epoxy, Leventis created aerogels that are 100 times more resistant to breakage and totally resistant to moisture.

Leventis sees possible uses in military armor, lightweight thermal insulation, fuel transport systems, tiny, but sturdy, drug-delivery vehicles and lighter, more efficient aircraft and spacecraft frames.

Want to see something cool? These videos show the difference between conventional armor-grade material and a cross-linked areogel when they're hit with an impact that is eight times that of a .45 mm bullet. It's pretty impressive.

First, the conventional material:

Now, here's the aerogel:

November 27, 2006

Thinking small for microsurgery

Three-time UMR graduate James Friend has a big idea about a very small surgical device.

As reported today by Australian newspaper The Age, in Melbourne, Friend and his colleagues at Monash University are "developing micro-robots they hope will be able to swim through the human body and perform medical tasks." Friend hopes "to build a tiny machine no wider than two human hairs side by side to do the job."

Friend leads the Micro/Nanophysics Research Laboratory at Monash. He learned the art of designing minuscule motors at UMR, where he earned a bachelor's degree in aerospace engineering from UMR in 1992, then stayed on to earn his master's and Ph.D., both in mechanical engineering, in 1994 and 1998.

November 07, 2006

Small but mighty

Seuss_f.jpgIf I learned anything from reading Horton Hears a Who to my kids, it's that things as small as a speck of dust can be very important. Yangchaun "Chad" Xing's research proves it.

Xing has been working to develop an efficient polymer electrolyte membrane (or PEM) fuel cell using a new material called carbon nanotubes, which is more durable than carbon black (the traditional material used). Xing, assistant professor of chemical and biological engineering, along with Guoqiang Ren, a Ph.D. student at UMR, have developed a new, "fast evaporation" technique for depositing metal nanoparticles on carbon nanotubes. Their findings are in the November issue of the Institute of Physics Publishing journal, Nanotechnology.

Continue reading "Small but mighty" »

June 21, 2006

Nano nuggets

National Geographic magazine takes a look at nanotechnology's big future this month. The magazine uses several comparisons to help put the size of the research into perspective. My favorite?


To put it another way, a nanometer is the amount a man's beard grows in the time it takes him to lift a razor to his face.

Via Sciencedude (here).

April 27, 2006

Connecting the quantum dots, UMR style

QuantumUMR2.jpgUMR physicists have developed a process to embed tiny particles of semiconducting materials into an ultra-lightweight material, called an aerogel. That in itself is pretty cool. But what's even cooler is that these quantum dots -- semiconducting specks only a few nanometers in diameter -- also emit and absorb light. At the same time.

Massimo Bertino, an associate professor of physics at UMR, is leading the team of researchers developing this method of embedding quantum dots into aerogel surfaces. Recently, Bertino demonstrated the method by embedding a miniature version of the UMR wordmark into an aerogel surface. The photo, taken by UMR graphic designer/photographer Ian Nance, shows how the dots emit light.

Continue reading "Connecting the quantum dots, UMR style" »

July 15, 2005

Expert Insight -- Good drug, bad drug

An international authority in the field of nano-materials, Jay Switzer has always been intrigued by experimentation and discovery. Even his title at UMR – he is the Donald L. Castleman/Foundation for Chemical Research Professor of Discovery – reflects his passion for the quest into the unknown. His specialty involves electrodeposition, a method of “growing" minuscule ceramic materials, layer by thin layer, on a base surface. It’s a process that mimics the way stalagmites grow from mineral deposits in caves.

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Student View -- Chuck Williams

Chuck Williams is always seeking attention.

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Team Watch -- A bright idea

UMR students are part of a team of researchers turning heads with a new technique to create tiny semiconducting materials, known as quantum dots.

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Faculty View -- A big future for nano

Jee-Ching Wang thinks small.

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A Quick Look -- Small stuff

UMR researchers are creating microchannels to study how particles behave.Shrinking science

Chemical and biological engineers are taking their cue from the microchip industry by helping to develop tiny medical devices, like microneedles. Using tiny glass spheres and self-crafted microchannels, one UMR researcher is studying how the irregularly shaped, cohesive particles behave during delivery. Her work will provide more insight into how cells interact and why they break apart.

Eye on Research -- Clearing the air

Umit Koylu is serious about soot.

For the past five years Koylu, an associate professor of mechanical and aerospace engineering at UMR, and his students have been investigating how the microscopic particles form during combustion.

Continue reading "Eye on Research -- Clearing the air" »

Kidz View -- It's a small world afterall

More than 50 years ago, Dr. Seuss introduced the idea of small-scale worlds to his young audience with the classic Horton Hears a Who. Today UMR researchers continue to stretch our imaginations with MEMS, tiny machines whose gears are the size of a grain of pollen.

Continue reading "Kidz View -- It's a small world afterall" »