Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Berkeley Lab researchers create nanoparticle thin films that self-assemble in 1 minute

Upon solvent annealing, supramolecules made from gold nanoparticles and block copolymers will self-assemble into highly ordered thin films in one minute.
Upon solvent annealing, supramolecules made from gold nanoparticles and block copolymers will self-assemble into highly ordered thin films in one minute.

Abstract:
The days of self-assembling nanoparticles taking hours to form a film over a microscopic-sized wafer are over. Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have devised a technique whereby self-assembling nanoparticle arrays can form a highly ordered thin film over macroscopic distances in one minute.

Berkeley Lab researchers create nanoparticle thin films that self-assemble in 1 minute

Berkeley, CA | Posted on June 9th, 2014

Ting Xu, a polymer scientist with Berkeley Lab's Materials Sciences Division, led a study in which supramolecules based on block copolymers were combined with gold nanoparticles to create nanocomposites that under solvent annealing quickly self-assembled into hierarchically-structured thin films spanning an area of several square centimeters. The technique is compatible with current nanomanufacturing processes and has the potential to generate new families of optical coatings for applications in a wide number of areas including solar energy, nanoelectronics and computer memory storage. This technique could even open new avenues to the fabrication of metamaterials, artificial nanoconstructs that possess remarkable optical properties.

"Our technique can rapidly generate amazing nanoparticle assemblies over areas as large as a silicon wafer," says Xu, who also holds a joint appointment with the University of California (UC) Berkeley's Departments of Materials Sciences and Engineering, and Chemistry. "You can think of it as pancake batter that you can spread over a griddle, wait one minute and you have a pancake ready to eat."

Xu is the corresponding author of a paper describing this research in Nature Communications titled "Rapid fabrication of hierarchically structured supramolecular nanocomposite thin films in one minute." Co-authors are Joseph Kao, Kari Thorkelsson, Peter Bai, Zhen Zhang and Cheng Sun.

Nanoparticles function as artificial atoms with unique optical, electrical and mechanical properties. If nanoparticles can be induced to self-assemble into complex structures and hierarchical patterns, similar to what nature does with proteins, it would enable mass-production of devices a thousand times smaller those used in today's microtechnology.

Xu and her research group have been steadily advancing towards this ultimate goal. Most recently their focus has been on the use of block copolymer-based supramolecular solutions to direct the self-assembly of nanoparticle arrays. A supramolecule is a group of molecules that act as a single molecule able to perform a specific set of functions. Block copolymers are long sequences or "blocks" of one type of monomer bound to blocks of another type of monomer that have an innate ability to self-assemble into well-defined arrays of nano-sized structures over macroscopic distances.

"Block copolymer-based supramolecules self-assemble and form a wide range of morphologies that feature microdomains typically a few to tens of nanometers in size," Xu says. "As their size is comparable to that of nanoparticles, the microdomains of supramolecules provide an ideal structural framework for the self-assembly of nanoparticle arrays."

In the supramolecular technique devised by Xu and her colleagues, arrays of gold nanoparticles were incorporated into solutions of supramolecules to form films that were about 200 nanometers thick. Through solvent annealing, using chloroform as the solvent, the nanoparticle arrays organized into three-dimensional cylindrical microdomains that were packed into distorted hexagonal lattices in parallel orientation with the surface. This display of hierarchical structural control in nanoparticle self-assembly was impressive but was only half the game.

"To be compatible with nanomanufacturing processes, the self-assembly fabrication process must also be completed within a few minutes to minimize any degradation of nanoparticle properties caused by exposure to the processing environment," Xu says.

She and her group systematically analyzed the thermodynamics and kinetics of self-assembly in their supramolecular nanocomposite thin films upon exposure to solvent vapor. They found that by optimizing a single parameter, the amount of solvent, assembly kinetics could be precisely tailored to produce hierarchically structured thin films in a single minute.

"By constructing our block copolymer-based supramolecules from small molecules non-covalently attached to polymer side chains, we changed the energy landscape so that solvent content became the most important factor," Xu says. "This enabled us to achieve fast-ordering of the nanoparticle arrays with the addition of only a very small amount of solvent, about 30-percent of the fraction of a 200 nanometer thick film."

The optical properties of nanocomposite thin films depend on the properties of individual nanoparticles and on well-defined inter-particle distances along different directions. Given that the dimensions of the gold nanoparticle arrays are at least one order of magnitude smaller than the wavelengths of visible light, the supramolecular technique of Xu and her colleagues has strong potential to be used for making metamaterials. These artificial materials have garnered a lot of attention in recent years because their electromagnetic properties are unattainable in natural materials. For example, a metamaterial can have a negative index of refraction, the ability to bend light backwards, unlike all materials found in nature, which bend light forward.

"Our gold nanocomposite thin films exhibit strong wavelength- dependent optical anisotropy that can be tailored simply by varying the solvent treatment," Xu says. "This presents a viable alternative to lithography for making metamaterials."

While Xu and her colleagues used gold nanoparticles in their films, the supramolecular approach is compatible with nanoparticles of other chemical compositions as well.

"We should be able to create a library of nanoparticle assemblies engineered for light manipulation and other properties," Xu says, "using a technique that is compatible with today's most widely used nanomanufacturing processes, including blade coating, ink-jet printing and dynamic zone annealing."

This research was funded by the DOE Office of Science and made use of the Advanced Photon Source at Argonne National Laboratory, a DOE Office of Science user facility.

####

About DOE/Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

For more information, please click here

Contacts:
Lynn Yarris

510-486-5375

Copyright © DOE/Lawrence Berkeley National Laboratory

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 Links

Download article:

For more information on the research of Ting Xu go here:

Related News Press

Imaging

New NPZ100-403 Piezo Stage from nPoint Inc. September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Advanced Light Source Sets Microscopy Record| Berkeley Lab Researchers Achieve Highest Resolution Ever with X-ray Microscopy September 11th, 2014

News and information

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Laboratories

Elusive Quantum Transformations Found Near Absolute Zero: Brookhaven Lab and Stony Brook University researchers measured the quantum fluctuations behind a novel magnetic material's ultra-cold ferromagnetic phase transition September 15th, 2014

'Squid skin' metamaterials project yields vivid color display: Rice lab creates RGB color display technology with aluminum nanorods September 15th, 2014

Berkeley Lab Licenses Boron Nitride Nanotube Technology: New material has unique mechanical and electronic properties September 13th, 2014

Thin films

Beneq launches nFOG™ wet coating technology September 3rd, 2014

Picosun joins forces with IMEC for novel, industrial ALD applications August 25th, 2014

An Inkjet-Printed Field-Effect Transistor for Label-Free Biosensing August 11th, 2014

Advanced thin-film technique could deliver long-lasting medication: Nanoscale, biodegradable drug-delivery method could provide a year or more of steady doses August 6th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Nanoribbon film keeps glass ice-free: Rice University lab refines deicing film that allows radio frequencies to pass September 16th, 2014

Self Assembly

Rice rolls 'neat' nanotube fibers: Rice University researchers' acid-free approach leads to strong conductive carbon threads September 15th, 2014

Molecular self-assembly controls graphene-edge configuration September 10th, 2014

Rice chemist wins rare NSF Special Creativity Award: Grant extension will bolster Zubarev's effort to produce gold nanorods September 8th, 2014

Magnetic nanocubes self-assemble into helical superstructures September 4th, 2014

Discoveries

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Announcements

New NPZ100-403 Piezo Stage from nPoint Inc. September 17th, 2014

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

New non-invasive technique could revolutionize the imaging of metastatic cancer September 17th, 2014

Toward making lithium-sulfur batteries a commercial reality for a bigger energy punch September 17th, 2014

Recruiting bacteria to be technology innovation partners: September 17th, 2014

Tools

New NPZ100-403 Piezo Stage from nPoint Inc. September 17th, 2014

Advanced Light Source Sets Microscopy Record| Berkeley Lab Researchers Achieve Highest Resolution Ever with X-ray Microscopy September 11th, 2014

Researchers Create World’s Largest DNA Origami September 11th, 2014

Development of Algorithm for Accurate Calculation of Average Distance Travelled by Low-Speed Electrons without Energy Loss that Are Sensitive to Surface Structure September 11th, 2014

Photonics/Optics/Lasers

'Squid skin' metamaterials project yields vivid color display: Rice lab creates RGB color display technology with aluminum nanorods September 15th, 2014

Fonon at Cutting-Edge of 3D Military Printing: Live-Combat Scenarios Could See a Decisive Advantage with 3D Printing September 15th, 2014

Simple, Cost-Effective Method Proposed for Synthesizing Zinc Oxide Nanopigments September 15th, 2014

First Colloid and Polymer Science Lecture awarded to Orlin D. Velev: Chemical engineer honored for outstanding research in colloid science September 12th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE