Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Self-Assembling Structures Open Door To New Class Of Materials

Researchers led by Founder Professor of Engineering Steve Granick, right, have developed tiny spheres that attract water to form "supermolecule" structures. Team members, from left, Qian Chen, doctoral student in materials science and engineering; Sung Chul Bae, research scientist; and Jonathan Whitmer, doctoral student in physics.  Photo by L. Brian Stauffer
Researchers led by Founder Professor of Engineering Steve Granick, right, have developed tiny spheres that attract water to form "supermolecule" structures. Team members, from left, Qian Chen, doctoral student in materials science and engineering; Sung Chul Bae, research scientist; and Jonathan Whitmer, doctoral student in physics. Photo by L. Brian Stauffer

Abstract:
Researchers at the University of Illinois and Northwestern University have demonstrated bio-inspired structures that self-assemble from simple building blocks: spheres.

Self-Assembling Structures Open Door To New Class Of Materials

Champaign, IL | Posted on January 13th, 2011

The helical "supermolecules" are made of tiny colloid balls instead of atoms or molecules. Similar methods could be used to make new materials with the functionality of complex colloidal molecules. The team will publish its findings in the Jan. 14 issue of the journal Science.

"We can now make a whole new class of smart materials, which opens the door to new functionality that we couldn't imagine before," said Steve Granick, Founder Professor of Engineering at the University of Illinois and a professor of materials science and engineering, chemistry, and physics.

Granick's team developed tiny latex spheres, dubbed "Janus spheres," which attract each other in water on one side, but repel each other on the other side. The dual nature is what gives the spheres their ability to form unusual structures, in a similar way to atoms and molecules.

In pure water, the particles disperse completely because their charged sides repel one another. However, when salt is added to the solution, the salt ions soften the repulsion so the spheres can approach sufficiently closely for their hydrophobic ends to attract.

The attraction between those ends draws the spheres together into clusters.

At low salt concentrations, small clusters of only a few particles form. At higher levels, larger clusters form, eventually self-assembling into chains with an intricate helical structure.

"Just like atoms growing into molecules, these particles can grow into supracolloids," Granick said. "Such pathways would be very conventional if we were talking about atoms and molecules reacting with each other chemically, but people haven't realized that particles can behave in this way also."

The team designed spheres with just the right amount of attraction between their hydrophobic halves so that they would stick to one another but still be dynamic enough to allow for motion, rearrangement, and cluster growth.

"The amount of stickiness really does matter a lot. You can end up with something that's disordered, just small clusters, or if the spheres are too sticky, you end up with a globular mess instead of these beautiful structures," said graduate student Jonathan Whitmer, a co-author of the paper.

One of the advantages of the team's supermolecules is that they are large enough to observe in real time using a microscope. The researchers were able to watch the Janus spheres come together and the clusters grow - whether one sphere at a time or by merging with other small clusters - and rearrange into different structural configurations the team calls isomers.

"We design these smart materials to fall into useful shapes that nature wouldn't choose," Granick said.

Surprisingly, theoretical calculations and computer simulations by Erik Luijten, Northwestern University professor of materials science and engineering and of engineering sciences and applied mathematics, and Whitmer, a student in his group, showed that the most common helical structures are not the most energetically favorable. Rather, the spheres come together in a way that is the most kinetically favorable - that is, the first good fit that they encounter.

Next, the researchers hope to continue to explore the colloid properties with a view toward engineering more unnatural structures. Janus particles of differing sizes or shapes could open the door to building other supermolecules and to greater control over their formation.

"These particular particles have preferred structures, but now that we realize the general mechanism, we can apply it to other systems - smaller particles, different interactions - and try to engineer clusters that switch in shape," Granick said.

The team also included University of Illinois graduate students Qian Chen and Shan Jiang and research scientist Sung Chul Bae. The U.S. Department of Energy and the National Science Foundation supported this work.

####

For more information, please click here

Contacts:
Liz Ahlberg
Physical Sciences Editor
217-244-1073

Copyright © University of Illinois at Urbana-Champaign

If 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.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Efficiency of Nanodrug Containing Antibiotics in Treatment of Infectious Diseases Evaluated August 31st, 2015

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Possible Futures

Sediment dwelling creatures at risk from nanoparticles in common household products August 13th, 2015

Harris & Harris Group Reports Financial Statements as of June 30, 2015, and Announces a Stock Repurchase Program August 10th, 2015

Molecular trick alters rules of attraction for non-magnetic metals August 5th, 2015

Global Carbon Nanotubes Industry 2015: Acute Market Reports August 4th, 2015

Academic/Education

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Kwansei Gakuin University in Hyogo, Japan, uses Raman microscopy to study crystallographic defects in silicon carbide wafers August 25th, 2015

JPK reports on the use of a NanoWizard® AFM-SECM system at the Université Paris Diderot looking at nanoscale biostructures August 18th, 2015

Rice, Penn State open center for 2-D coatings: National Science Foundation selects universities to develop atom-thin materials with industry partners August 13th, 2015

Self Assembly

Louisiana Tech University researchers discover synthesis of a new nanomaterial: Interdisciplinary team creates biocomposite for first time using physiological conditions August 24th, 2015

Novel nanostructures for efficient long-range energy transport August 21st, 2015

Biophysics: Formation of swarms in nanosystems August 18th, 2015

Self-assembling, biomimetic membranes may aid water filtration August 1st, 2015

Materials/Metamaterials

Draw out of the predicted interatomic force August 30th, 2015

Nanocatalysts improve processes for the petrochemical industry August 28th, 2015

Successful boron-doping of graphene nanoribbon August 27th, 2015

Developing Component Scale Composites Using Nanocarbons August 26th, 2015

Announcements

Efficiency of Nanodrug Containing Antibiotics in Treatment of Infectious Diseases Evaluated August 31st, 2015

Seeing quantum motion August 30th, 2015

Artificial leaf harnesses sunlight for efficient fuel production August 30th, 2015

Researchers use DNA 'clews' to shuttle CRISPR-Cas9 gene-editing tool into cells August 30th, 2015

Research partnerships

Nanocatalysts improve processes for the petrochemical industry August 28th, 2015

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Researchers combine disciplines, computational programs to determine atomic structure August 26th, 2015

Developing Component Scale Composites Using Nanocarbons August 26th, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic