Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Plasmonic chains act like polymers: Rice University researchers find repeating patterns dictate optical properties of nanoparticle arrays

How far a wavelength of light can be transmitted along a gold nanoparticle chain to where it dies down (the “extinction” point) depends on the configuration of the repeat units – the nanoparticles themselves – according to Rice University researchers. Their study was intended to draw parallels between nanoparticle arrays and polymers that also depend on chemical repeat units for their characteristics. (Credit: Liane Slaughter/Rice University)
How far a wavelength of light can be transmitted along a gold nanoparticle chain to where it dies down (the “extinction” point) depends on the configuration of the repeat units – the nanoparticles themselves – according to Rice University researchers. Their study was intended to draw parallels between nanoparticle arrays and polymers that also depend on chemical repeat units for their characteristics. (Credit: Liane Slaughter/Rice University)

Abstract:
New research at Rice University that seeks to establish points of reference between plasmonic particles and polymers might lead to smaller computer chips, better antennae and improvements in optical computing.

Plasmonic chains act like polymers: Rice University researchers find repeating patterns dictate optical properties of nanoparticle arrays

Houston, TX | Posted on July 12th, 2012

Materials scientists take advantage of strong interactions between chemicals to form polymers that self-assemble into patterns and are the basis of things people use every day. Anything made of plastic is a good example.

Now, Rice scientists have detailed similar patterns in the way that surface plasmons - charged "quasiparticles" that flow within metallic particles when excited by light - influence each other in chains of gold nanoparticles.

The results of work by the Rice lab of Stephan Link, an assistant professor of chemistry and electrical and computer engineering, appear online in the American Chemical Society journal Nano Letters.

Interactions between small things have been very much in the news lately with the discovery of signs of the Higgs boson and extensive discussion about how the most elemental particles interact to give the universe its form. The Rice team studies nanoparticles that are orders of magnitude larger - though still so small that they can only be seen with an electron microscope - with the goal of understanding how the more elemental electromagnetic particles within behave.

This is important to electronics engineers perpetually looking for ways to shrink the size of computer chips and other devices through ever-smaller components like waveguides. The ability of nanoparticles to pass waves that can be interpreted as signals may open the door to new methods for optical computing. The work may also contribute to more finely tuned antennae and sensors.

Specifically, the researchers looked for the ways plasmons influence each other across tiny gaps - as small as one nanometer - between gold nanoparticles. Lead author Liane Slaughter, a Rice graduate student, and her colleagues engineered chains of 50-nanometer particles in single and double rows that mimicked the repeating molecular patterns of polymers. They then looked into the standing super-radiant and subradiant signals collectively sustained by the individual assemblies of nanoparticles. The composition of the chain in terms of nanoparticle sizes, shapes and positions determines the frequencies of light they can characteristically interact with.

"In plasmonics, we use individual nanoparticles as building blocks to make higher-order structures," Link said. "Here, we're taking concepts known to polymer scientists to analyze the structures of longer chains of nanoparticles that we think resemble polymers."

"The fundamental definition of a polymer is that it's a long molecule whose properties depend on the repeat unit," Slaughter said. "If you change the atoms that repeat in the chain, then you change the properties of the polymer."

"What we changed in our assembly structures was the repeat unit - a single particle row versus a dimer (in the double row) - and we found that this fit the analogy with chemical polymers because that change very clearly alters the interactions along the chain," Link added.

This basic structure change from a single row to a double row led to pronounced differences demonstrated by additional subradiant modes and a lower energy super-radiant mode.

Two additional interesting effects seemed to be universal among the team's plasmonic polymers. One was that the energy of the super-radiant mode, which results from the interaction over the most repeat units, would characteristically decrease with the addition of nanoparticles along the length, up to about 10 particles, and then level off. "Once you have 10 repeat units, you basically see an optical spectrum that will not change very much if you make a chain with 20 or 50 repeat units," Link said.

The other was that disorder among the repeat units - the nanoparticles - only seems to matter at the small scale. "With chemically prepared nanoparticles, there's always a distribution of sizes and perhaps shapes," Link said. "As you bring them close together, they couple really strongly, and that's a big advantage. But at the same time, we can never make structures that are perfect.

"So we wanted to understand the effect of disorder, and what we found was pretty amazing: As the system grows in size, the effect of disorder is less and less important on the optical properties. That also has a strong analogy in polymers, in which disorder can be seen as chemical defects," he said.

"If the plasmonic interactions over the chain tolerate disorder, it gives promise to designing functional structures more economically and maybe with higher throughput," Slaughter said. "With a whole bunch of small building blocks, even if they're not all perfectly alike, you can make a great variety of shapes and structures with broad tunability."

Co-authors of the paper are graduate student Britain Willingham, Rice postdoctoral fellow Wei-Shung Chang and undergraduates Maximilian Chester and Nathan Ogden.

The Robert A. Welch Foundation, the Office of Naval Research, the National Science Foundation, the American Chemical Society Petroleum Research Fund and a 3M Nontenured Faculty Grant supported the research.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is known for its “unconventional wisdom.” With 3,708 undergraduates and 2,374 graduate students, Rice’s undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 4 for “best value” among private universities by Kiplinger’s Personal Finance. To read “What they’re saying about Rice,” go to www.rice.edu/nationalmedia/Rice.pdf.

For more information, please click here

Contacts:
Jeff Falk
713-348-6775


Mike Williams
713-348-6728

Copyright © Rice University

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

Read the abstract at:

Link Lab:

Related News Press

News and information

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Renishaw receives Queen's Award for spectroscopy developments November 25th, 2014

JPK reports on the use of AFM and the CellHesion module to study plant cells at the University of Queensland November 25th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Chemistry

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Renishaw receives Queen's Award for spectroscopy developments November 25th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Chip Technology

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Nanometrics Announces Upcoming Investor Events November 19th, 2014

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

Self Assembly

Live Images from the Nano-cosmos: Researchers watch layers of football molecules grow November 5th, 2014

Outsmarting Thermodynamics in Self-assembly of Nanostructures: Berkeley Lab reports method for symmetry-breaking in feedback-driven self-assembly of optical metamaterials November 4th, 2014

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Optical computing/ Photonic computing

Penn engineers efficiently 'mix' light at the nanoscale November 17th, 2014

Nanoparticles Break the Symmetry of Light October 6th, 2014

Speed at its limits September 30th, 2014

'Pixel' engineered electronics have growth potential: Rice, Oak Ridge, Vanderbilt, Penn scientists lead creation of atom-scale semiconducting composites September 29th, 2014

Discoveries

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Materials/Metamaterials

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

Lawrence Livermore researchers develop efficient method to produce nanoporous metals November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Aromatic food chemistry to the making of copper nanowires November 24th, 2014

Announcements

'Giant' charge density disturbances discovered in nanomaterials: Juelich researchers amplify Friedel oscillations in thin metallic films November 26th, 2014

JPK reports on the use of AFM and the CellHesion module to study plant cells at the University of Queensland November 25th, 2014

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Military

NRL Scientists Discover Novel Metamaterial Properties within Hexagonal Boron Nitride November 20th, 2014

Two sensors in one: Nanoparticles that enable both MRI and fluorescent imaging could monitor cancer, other diseases November 18th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

Penn engineers efficiently 'mix' light at the nanoscale November 17th, 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