- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
|“There’s a delicate balance you have to strike,” said Argonne physicist Byeongdu Lee, who led the characterization of the supraparticles using high-energy X-rays provided by Argonne’s Advanced Photon Source. “If the attractive Van der Waals force is too strong, all the nanoparticles will smash together at once, and you’ll end up with an ugly, disordered glass. But if the repulsive Coulomb force is too strong, they’ll never come together in the first place.”|
Image courtesy of Argonne National Laboratory
Controlling the behavior of nanoparticles can be just as difficult trying to wrangle a group of teenagers. However, a new study involving the U.S. Department of Energy's Argonne National Laboratory has given scientists insight into how tweaking a nanoparticle's attractive electronic qualities can lead to the creation of ordered uniform "supraparticles."
"There's a delicate balance you have to strike," said Argonne physicist Byeongdu Lee, who led the characterization of the supraparticles using high-energy X-rays provided by Argonne's Advanced Photon Source. "If the attractive Van der Waals force is too strong, all the nanoparticles will smash together at once, and you'll end up with an ugly, disordered glass. But if the repulsive Coulomb force is too strong, they'll never come together in the first place."
Researchers from the University of Michigan and China also collaborated on the study.
This problem of trying to achieve the right kind of balance has underpinned an entire field of colloidal research, according to Lee. But even if the right equilibrium is struck to promote the slow, steady growth of a supraparticle, up until now researchers have still had very little way of controlling the size of the particle that would grow. "If you were able to make the attractive force just a little stronger than the repulsive force, you'd see the growth of a crystal—but you wouldn't be able to dictate how big it grew," he said.
The Argonne research focused on finding a way for a supraparticle to automatically stop its own growth. Such a condition could only occur if the net attractive force of the nanoparticles toward the inside of the supraparticle was greater than that of the net attractive force of the nanoparticles that formed the edge of the supraparticle—a so-called "core-shell morphology."
Although core-shell morphologies had been observed in previous research, those earlier studies had concentrated on the types of supraparticles created by "monodisperse" nanoparticles—those that, like marbles, would share a common size and shape. "It's easier to make individuals cluster into larger groups if they have characteristics in common than if they don't," Lee said. "It is just like high school in that way."
Instead of sticking with monodispersity, however, the Argonne research focused instead on "polydisperse" nanoparticles—those with a wide variety of sizes, masses, and configurations. "The advantage with our technique is that there's no longer a need for monodispersity. You can mix two different components—like a metal and a semiconductor—and still see the same kind of controlled self-limiting assembly."
Although the research into supraparticles born from polydisperse collections of nanoparticles is still in its infancy, Lee and his colleagues believe that the methodology could find its way into a number of different applications, perhaps ranging from optics to drug delivery to photovoltaics. "When you work in nanotechnology, we have to ask ‘can we do this?' before we really know what our discovery will be useful for," explained Lee. "We hope that further investigation will open up new lines of discovery that we have not even conceived of yet."
An article based on the research appears in the September 2011 issue of Nature Nanotechnology. The research was funded by the Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science, the U.S. Department of Defense, and the National Science Foundation, among others.
By Jared Sagoff
About Argonne National Laboratory
rgonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.
For more information, please click here
Copyright © Argonne National LaboratoryIf you have a comment, please Contact us.
Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
|Related News Press|
News and information
Animal study shows flexible, dissolvable silicon device promising for brain monitoring: Other applications include post-operative observation for vascular, cardiac, and orthopaedic procedures, finds Penn study May 5th, 2016
Exploring phosphorene, a promising new material April 29th, 2016
Superfast light source made from artificial atom April 28th, 2016
The light stuff: A brand-new way to produce electron spin currents - Colorado State University physicists are the first to demonstrate using non-polarized light to produce a spin voltage in a metal April 26th, 2016
The intermediates in a chemical reaction photographed 'red-handed' Researchers at the UPV/EHU-University of the Basque Country have for the first time succeeded in imaging all the steps in a complex organic reaction and have resolved the mechanisms that explain it May 4th, 2016
Cooling graphene-based film close to pilot-scale production April 30th, 2016