Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Nanojewels made easy: Coaxing colors from nanoscale particles broadens horizons for optical technologies

Abstract:
Butterfly wings, peacock feathers, opals and pearls are some of nature's jewels that use nanostructures to dazzle us with color. It's accomplished through the way light reaches our eyes after passing through the submicroscopic mazes within these materials.

The seemingly effortless way that nature creates this effect is now rivaled by a rapid and simple method developed through a collaboration of researchers from North Carolina State University (NCSU), Arizona State University (ASU) and the Universidad Complutense de Madrid (UCM).

Nanojewels made easy: Coaxing colors from nanoscale particles broadens horizons for optical technologies

Tempe, AZ | Posted on July 30th, 2008

Professor Orlin Velev and graduate student researcher Vinayak Rastogi in the Department of Chemical Engineering at NCSU have shown how colloid chemistry methods originally used to form particle aggregates from nanoparticles can be used to quickly make particles with dazzling colors simply by letting a suspension of nanoparticles dry on a superhydrophobic surface.

Superhydrophobicity is a property of a material that repels water like ducks' feathers or lotus leaves. It has been used commercially in textiles, coatings and building materials.

The basic idea behind the process is akin to stacking round fruits or vegetables in a supermarket produce bin in high, neat rows to keep the produce from falling to the floor as customers pick them out. Doing this with nanoscale particles of different sizes leads to opalescence, since some colors of light are reflected differently depending on the size of the holes between the nanoparticles and the angle from which they are viewed.

Normally, carefully arranging the nanoparticles in neat rows requires a complex series of steps with oily solvents and water mixtures requiring extensive washing afterwards to remove the solvents.

Now, with the help of researchers at ASU, this process has been made as simple as placing a drop on a superhydrophobic surface and letting it dry for one to two hours.

The researchers call these one- to two-millimeter particles "nanojewels."

Velev and Rastogi of NCSU developed the method with help of several colleagues, including: Manuel Marquez, an adjunct professor in the Harrington Department of Bioengineering in ASU's Ira A. School of Engineering, and Antonio Garcia, a professor in the bioengineering department and director of the Laboratory for Personalized Molecule Measurement; and professors Sonia Melle and Oscar Calderon in the School of Optics at UCM.

Rastogi's presentation at the 82nd American Chemical Society Colloid & Surface Science Symposium on June 18, 2008 titled "Synthesis of Light-Diffracting Colloidal Crystal Assemblies from Microspheres and Nanoparticles in Droplets on a Superhydrophobic Surface" and a paper just published in the journal Advanced Materials (published Online: July 28, 2008), authored by these researchers, describes how for the first time superhydrophobic surfaces are shown to play an important role in making new materials.

In the paper, they describe how different nanoparticles of various sizes can produce "nanojewels" of various colors that display different optical properties.

"These nanojewels can potentially find application in photonics, drug delivery, special coatings, sensors and microfluidics," Velev explains.

Indeed, many researchers around the world are working on ways to make similar two-dimensional and three-dimensional photonic crystals to fabricate light-emitting diodes, optical fibers for communications, submicroscopic lasers, ultrawhite pigments, antennas and reflectors, and optical integrated circuits.

The biggest stumbling blocks in making these materials is finding ways of making photonic crystals with uniform properties in very large quantities and in minimizing imperfections in structure that reduce the quality of the final product.

This new process is certainly easy to replicate to make large quantities, and superhydrophobic surfaces lead to structures that naturally form ordered structures.

Superhydrophobic surfaces allow nanojewels to be created from a single drop of water containing nanoparticles, because of several effects.

First, the drop stays in the shape of a ball because water does not spread on it while the nanoparticles are held in the drop due to the surface tension of water.

Compared to drying the drop in air, which is a fast evaporation process that causes the water in the drop to distort and flow, the drop gently dries on the superhydrophobic surface. This lets the nanoparticles get as close to each other as possible, swirling in a slow circular motion until all of the water evaporates.

When nanoparticles of two different sizes are used in the same drop, the smaller ones move to the surface of the drop while the bigger ones stay in the middle. This is because the smaller ones have more Brownian motion and are elevated to the surface with the water molecules that are subsequently evaporating at the surface, leaving all of the nanoparticles behind to form the nanojewels.

"Besides the dazzling look of these nanojewels, the most exciting thing about this work is that it opens up many interesting possibilities in quickly and inexpensively making new materials with nanoparticles", Marquez says.

"By understanding how different particle sizes determine the colors produced, these nanojewels can be designed for applications in optical communication systems," Melle adds.

As more nanoparticles and nanostructures come into the marketplace, technologies that can quickly assemble the structures so that their unique size and properties can be employed in new devices will be important to the growth of nanotechnology and related industries.

Referenced Article

"Synthesis of Light-Diffracting Assemblies from Microspheres and Nanoparticles in Droplets on a Superhydrophobic Surface", Vinayak Rastogi, Osca G. Calderon, Antonio A. Garcia, Manuel Marquez, and Orlin Velev, Advanced Materials, (Early View) Published Online 28 Jul 2008 (DOI 10.1002/adma.200703008).

####

For more information, please click here

Contacts:
Joe Kullman

480-965-8122

SOURCE:
Antonio Garcia,
Professor, Harrington Department of Bioengineering
Arizona State University
(480) 965-8798

MEDIA CONTACT:
Ira A. Fulton School of Engineering
Arizona State University
Tempe, Arizona USA
www.fulton.asu.edu/fulton/

Copyright © Arizona State 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 News Press

News and information

Feynman Prize Winners Announced! April 26th, 2015

New ASTM Standards Will Help Educate Present and Future Nanotechnology Workforces April 26th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

QD Vision Wins 2015 Bronze Edison Award for Color IQ™ Quantum Dot Technology April 26th, 2015

Chemistry

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

New class of 3D-printed aerogels improve energy storage April 22nd, 2015

Expanding the reach of metallic glass April 22nd, 2015

Protein Building Blocks for Nanosystems: Scientists develop method for producing bio-based materials with new properties April 17th, 2015

Microfluidics/Nanofluidics

Light in a spin: Researchers demonstrate angular accelerating light April 15th, 2015

Device extracts rare tumor cells using sound: Microfluidic chip developed by CMU President Suresh and collaborators uses acoustic waves to separate circulating tumor cells from blood cells April 7th, 2015

Square ice filling for a graphene sandwich March 26th, 2015

Dolomite’s microfluidics technology ideal for B cell encapsulation March 24th, 2015

Nanomedicine

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Nanotech-enabled moisturizer speeds healing of diabetic skin wounds: Spherical nucleic acids silence gene that interferes with wound healing April 24th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

A silver lining: UCSB researchers cradle silver nanoclusters inside synthetic DNA to create a programmed, tunable fluorescent array April 23rd, 2015

Sensors

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

New class of 3D-printed aerogels improve energy storage April 22nd, 2015

‘Oxford Instruments Young Nanoscientist India Award 2015’ to Prof. Arindam Ghosh April 20th, 2015

Optical resonance-based biosensors designed for medical applications April 18th, 2015

Discoveries

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

SEFCU, SUNY Poly CNSE Announce Winning Student-Led Teams in the 6th Annual $500,000 New York Business Plan Competition April 25th, 2015

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

Materials/Metamaterials

Electron spin brings order to high entropy alloys April 23rd, 2015

Scientists Use Nanoscale Building Blocks and DNA 'Glue' to Shape 3D Superlattices: New approach to designing ordered composite materials for possible energy applications April 23rd, 2015

Surface matters: Huge reduction of heat conduction observed in flat silicon channels April 23rd, 2015

Nanoparticles Used to Improve Mechanical, Thermal Properties of Cellulose Fibers April 23rd, 2015

Announcements

Feynman Prize Winners Announced! April 26th, 2015

New ASTM Standards Will Help Educate Present and Future Nanotechnology Workforces April 26th, 2015

Heat makes electrons’ spin in magnetic superconductors April 26th, 2015

QD Vision Wins 2015 Bronze Edison Award for Color IQ™ Quantum Dot Technology April 26th, 2015

Photonics/Optics/Lasers

Northwestern scientists develop first liquid nanolaser: Technology could lead to new way of doing 'lab on a chip' medical diagnostics April 25th, 2015

Fast and accurate 3-D imaging technique to track optically trapped particles April 24th, 2015

ORNL reports method that takes quantum sensing to new level April 23rd, 2015

Quantum 'paparazzi' film photons in the act of pairing up April 22nd, 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