Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Wavelength-Dependent Shapeshifting: Plasmon-Mediated Growth Control

Abstract:
Methods which allow predictable and reproducible control over the shape and defect structures of nanoparticles are a sought-after ideal in research on nanoparticle synthesis. Realising this ideal for silver nanoparticles is one step closer with the discovery that the localised surface plasmon resonance feature observed for nanoscale metals - the collective oscillation of their electrons caused by incident light - can be used to predictably direct the growth of silver nanocrystals.

Wavelength-Dependent Shapeshifting: Plasmon-Mediated Growth Control

Germany | Posted on January 10th, 2013

Such plasmon-mediated growth allows control over the size and shape of the crystals by controlling the wavelength of light incident on the sample. The underlying mechanism is based on silver redox chemistry: excitation of the plasmon in an aqueous citrate solution catalyses the reduction of silver ions, the speed of which influences the dominant facets (and hence the shape) of the growing crystals. In this way, longer excitation wavelengths can be applied to produce longer edge lengths. The corresponding oxidation of seed particles causes their dissolution, increasing the bulk concentration of silver ions.

Mirkin and co-workers have refined this technique to generate twinned silver nanocrystals by controlling the defects within the crystal structure. They discovered that irradiation at higher energies increases the number of twin boundaries during growth. By adjusting the wavelength from 400 to 500 nm, bipyramids or cubes with different types of twin boundaries could be selectively produced.

More specifically, longer excitation wavelengths (500 nm) reduce silver ions more slowly, producing monodisperse planar-twinned nanostructures (right bipyramids); shorter excitation wavelengths (400 nm) increase the silver ion reduction rate, increasing the growth speed and hence producing crystals with a higher number of defects, leading to twinned structures. Using the intermediate wavelength of 450 nm, silver nanocubes with multiple twin boundaries could be selectively generated.

This plasmon-mediated shape control could also be extended to longer wavelengths, which were tuned to produce silver nanorods with controllable aspect ratios.

The challenge is now to develop this method for other nanoscale species with plasmon resonances.

####

For more information, please click here

Copyright © Wiley-VCH Materials Science Journals

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

Link to the original paper on Wiley Online Library:

Related News Press

News and information

Quantum teleportation on a chip: A significant step towards ultra-high speed quantum computers April 1st, 2015

So, near and yet so far: Stable HGNs for Raman April 1st, 2015

Two-dimensional dirac materials: Structure, properties, and rarity April 1st, 2015

3-D neural structure guided with biocompatible nanofiber scaffolds and hydrogels April 1st, 2015

Chemistry

Tokyo Institute of Technology research: Catalyst redefines rate limitations in ammonia production March 30th, 2015

Chemists make new silicon-based nanomaterials March 27th, 2015

First proof of isolated attosecond pulse generation at the carbon K-edge March 20th, 2015

Click! That's how modern chemistry bonds nanoparticles to a substrate March 19th, 2015

Discoveries

Quantum teleportation on a chip: A significant step towards ultra-high speed quantum computers April 1st, 2015

Two-dimensional dirac materials: Structure, properties, and rarity April 1st, 2015

3-D neural structure guided with biocompatible nanofiber scaffolds and hydrogels April 1st, 2015

Light-powered gyroscope is world's smallest: Promises a powerful spin on navigation April 1st, 2015

Materials/Metamaterials

Wrapping carbon nanotubes in polymers enhances their performance: Scientists at Japan's Kyushu University say polymer-wrapped carbon nanotubes hold much promise in biotechnology and energy applications March 30th, 2015

DFG to Establish One Clinical Research Unit and Five Research Units: New Projects to Investigate Complications in Pregnancy, Particle Physics, Nanoparticles, Implants and Transport Planning / Approximately 13 Million Euros in Funding for an Initial Three-Year Period March 28th, 2015

Chemists make new silicon-based nanomaterials March 27th, 2015

UT Dallas engineers twist nanofibers to create structures tougher than bulletproof vests March 27th, 2015

Announcements

Quantum teleportation on a chip: A significant step towards ultra-high speed quantum computers April 1st, 2015

So, near and yet so far: Stable HGNs for Raman April 1st, 2015

Two-dimensional dirac materials: Structure, properties, and rarity April 1st, 2015

3-D neural structure guided with biocompatible nanofiber scaffolds and hydrogels April 1st, 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