Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

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

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

PETA science consortium to present hazard testing strategy at nanotoxicology meeting: High tech field ripe for use of sophisticated non-animal testing strategies April 22nd, 2014

Harris & Harris Group Notes the Receipt of Proceeds From the Sale of Molecular Imprints' Semiconductor Business to Canon April 22nd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 2014

Chemistry

Thinnest feasible membrane produced April 17th, 2014

Targeting cancer with a triple threat: MIT chemists design nanoparticles that can deliver three cancer drugs at a time April 15th, 2014

Scientists Succeed in Simultaneous Determination of Acetaminophen, Codeine in Drug Samples April 9th, 2014

Good vibrations: Using light-heated water to deliver drugs - Researchers use near-infrared light to warm water-infused polymeric particles April 1st, 2014

Discoveries

Like a hall of mirrors, nanostructures trap photons inside ultrathin solar cells April 22nd, 2014

Nanomaterial Outsmarts Ions April 22nd, 2014

Vacuum Ultraviolet Lamp of the Future Created in Japan: First Solid-State Vacuum UV Phosphor, Described in APL-Materials, Promises Smaller, Safer, Longer Lasting, Low Power Lamps for Industrial Applications April 22nd, 2014

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

Materials/Metamaterials

Nanomaterial Outsmarts Ions April 22nd, 2014

Thinnest feasible membrane produced April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Engineers develop new materials for hydrogen storage April 15th, 2014

Announcements

Berkeley Lab Researchers Demonstrate First Size-based Chromatography Technique for the Study of Living Cells April 22nd, 2014

PETA science consortium to present hazard testing strategy at nanotoxicology meeting: High tech field ripe for use of sophisticated non-animal testing strategies April 22nd, 2014

Harris & Harris Group Notes the Receipt of Proceeds From the Sale of Molecular Imprints' Semiconductor Business to Canon April 22nd, 2014

National Space Society Congratulates SpaceX on the Success of CRS-3 and the First Flight of the Falcon 9R April 22nd, 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