Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

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

Nanoparticles Increase Durability of Concrete Decorations in Cold Areas January 26th, 2015

Iranian Researchers Boost Solar Cells Efficiency Using Anti-Aggregates January 26th, 2015

Detection of Heavy Metals in Samples with Naked Eye January 26th, 2015

Engineering self-assembling amyloid fibers January 26th, 2015

Chemistry

Anti-microbial coatings with a long-term effect for surfaces – presentation at nano tech 2015 in Japan January 21st, 2015

Hydrogels deliver on blood-vessel growth: Rice researchers introduce improved injectable scaffold to promote healing January 20th, 2015

Graphene enables all-electrical control of energy flow from light emitters: First signatures of graphene plasmons at telecommunications wavelength revealed January 20th, 2015

Nanotechnology Used to Produce Ceramic Membrane with High Thermal Stability January 19th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Nanoshuttle wear and tear: It's the mileage, not the age January 26th, 2015

Visualizing interacting electrons in a molecule: Scientists at Aalto University and the University of Zurich have succeeded in directly imaging how electrons interact within a single molecule January 26th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

Scientists 'bend' elastic waves with new metamaterials that could have commercial applications: Materials could benefit imaging and military enhancements such as elastic cloaking January 23rd, 2015

Chip Technology

Electronic circuits with reconfigurable pathways closer to reality January 26th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

New method to generate arbitrary optical pulses January 21st, 2015

New signal amplification process set to transform communications, imaging, computing: UC San Diego researchers discover a mechanism to amplify signals in optoelectronic systems that is far more efficient than standard processes January 21st, 2015

Self Assembly

Engineering self-assembling amyloid fibers January 26th, 2015

Revealed: How bacteria drill into our cells and kill them December 2nd, 2014

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

Optical computing/ Photonic computing

New signal amplification process set to transform communications, imaging, computing: UC San Diego researchers discover a mechanism to amplify signals in optoelectronic systems that is far more efficient than standard processes January 21st, 2015

Rice's Naomi Halas to direct Smalley Institute: Optics pioneer will lead Rice's multidisciplinary science institute January 15th, 2015

Graphene plasmons go ballistic: Graphene combined with the insulting power of boron nitride enables light control in tiny circuits with dramatically reduced energy loss January 12th, 2015

High photosensitivity 2D-few-layered molybdenum diselenide phototransistors December 8th, 2014

Discoveries

Visualizing interacting electrons in a molecule: Scientists at Aalto University and the University of Zurich have succeeded in directly imaging how electrons interact within a single molecule January 26th, 2015

Electronic circuits with reconfigurable pathways closer to reality January 26th, 2015

Nanoparticles Increase Durability of Concrete Decorations in Cold Areas January 26th, 2015

Iranian Researchers Boost Solar Cells Efficiency Using Anti-Aggregates January 26th, 2015

Materials/Metamaterials

Chromium-centered cycloparaphenylene rings for making functionalized nanocarbons January 26th, 2015

Engineering self-assembling amyloid fibers January 26th, 2015

Toyocolor to Launch New Carbon Nanotube Materials at nano tech 2015 January 24th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

Announcements

Nanoparticles Increase Durability of Concrete Decorations in Cold Areas January 26th, 2015

Iranian Researchers Boost Solar Cells Efficiency Using Anti-Aggregates January 26th, 2015

Detection of Heavy Metals in Samples with Naked Eye January 26th, 2015

Engineering self-assembling amyloid fibers January 26th, 2015

Military

Detection of Heavy Metals in Samples with Naked Eye January 26th, 2015

The latest fashion: Graphene edges can be tailor-made: Rice University theory shows it should be possible to tune material's properties January 24th, 2015

Scientists 'bend' elastic waves with new metamaterials that could have commercial applications: Materials could benefit imaging and military enhancements such as elastic cloaking January 23rd, 2015

Laser-generated surface structures create extremely water-repellent metals: Super-hydrophobic properties could lead to applications in solar panels, sanitation and as rust-free metals January 20th, 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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE