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

Measuring the Smallest Magnets July 28th, 2014

WITec to host the 11th Confocal Raman Imaging Symposium from September 29th - October 1st in Ulm, Germany July 28th, 2014

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Chemistry

Oregon chemists eye improved thin films with metal substitution: Solution-based inorganic process could drive more efficient electronics and solar devices July 21st, 2014

Fundamental Chemistry Findings Could Help Extend Moore’s Law: A Berkeley Lab-Intel collaboration outlines the chemistry of photoresist, enabling smaller features for future generations of microprocessors July 15th, 2014

Researchers discover boron 'buckyball' July 14th, 2014

Highlights for 2014 national meeting of world’s largest scientific society July 8th, 2014

Discoveries

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties July 28th, 2014

Measuring the Smallest Magnets July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 2014

Stanford team achieves 'holy grail' of battery design: A stable lithium anode - Engineers use carbon nanospheres to protect lithium from the reactive and expansive problems that have restricted its use as an anode July 27th, 2014

Materials/Metamaterials

Seeing is bead-lieving: Rice University scientists create model 'bead-spring' chains with tunable properties July 28th, 2014

Silicene Labs Announces the Launch of 2D Materials Briefing Book™ and 2D Materials Road-Heat Map™: Contributors Include One of the World's Foremost 2D Materials Scientists July 25th, 2014

Silicene Labs Announces the Launch of Patent-Pending, 2D Materials Composite Index™ : The Initial 2D Materials Composite Index™ for Q2 2014 Is: 857.3; Founders Include World-Renowned Physicist and Seasoned Business and IP Professionals July 24th, 2014

Iranian Scientists Produce Transparent Nanocomposite Coatings with Longer Lifetime July 24th, 2014

Announcements

Measuring the Smallest Magnets July 28th, 2014

WITec to host the 11th Confocal Raman Imaging Symposium from September 29th - October 1st in Ulm, Germany July 28th, 2014

FEI adds Phase Plate Technology and Titan Halo TEM to its Structural Biology Product Portfolio: New solutions provide the high-quality imaging and contrast necessary to analyze the 3D structure of molecules and molecular complexes July 28th, 2014

Production of Toxic Gas Sensor Based on Nanorods July 28th, 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