Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > A Simple Magnet Can Control the Color of a Liquid, Making New Technologies Possible, UCR Nanotechnologists Report

Image shows the solution of iron oxide in water changing color under a magnetic field, with increasing strength of the field from left to right. Photo credit: Yin laboratory, UCR.
Image shows the solution of iron oxide in water changing color under a magnetic field, with increasing strength of the field from left to right. Photo credit: Yin laboratory, UCR.

Abstract:
Research by Yadong Yin and colleagues will be featured on the inside cover of Angewandte Chemie, a top science journal

A Simple Magnet Can Control the Color of a Liquid, Making New Technologies Possible, UCR Nanotechnologists Report

Riverside, CA | Posted on July 3rd, 2007

University of California, Riverside nanotechnologists have succeeded in controlling the color of very small particles of iron oxide suspended in water simply by applying an external magnetic field to the solution. The discovery has potential to greatly improve the quality and size of electronic display screens and to enable the manufacture of products such as erasable and rewritable electronic paper and ink that can change color electromagnetically.

In their experiments, the researchers found that by changing the strength of the magnetic field they were able to change the color of the iron oxide solution - similar to adjusting the color of a television screen image.

When the strength of the magnetic field is changed, it alters the arrangement of the spherical iron oxide particles in solution, thereby modifying how light falling on the particles passes through or is deflected by the solution.

Study results appear in Angewandte Chemie International Edition's online edition today. The research paper is scheduled to appear in print in issue 34 of the journal. Identified by Angewandte Chemie as a "very important paper," the research will be featured on the inside cover of the print issue.

"The key is to design the structure of iron oxide nanoparticles through chemical synthesis so that these nanoparticles self-assemble into three-dimensionally ordered colloidal crystals in a magnetic field," said Yadong Yin, an assistant professor of chemistry who led the research.

A nanoparticle is a microscopic particle whose size is measured in nanometers, a nanometer being a billionth of a meter. (A pin head is 1 million nanometers wide.)

A colloid is a substance comprised of small particles uniformly distributed in another substance. Milk, paint and blood are examples of colloids.

"By reflecting light, these crystals - also called photonic crystals - show brilliant colors," Yin said. "Ours is the first report of a photonic crystal that is fully tunable in the visible range of the electromagnetic spectrum, from violet light to red light."

A photonic crystal controls the flow of light (photons) and works like a semiconductor for light. The nanoparticles' spacing dictates the wavelength of light that a photonic crystal reflects.

Iron oxide (formula: Fe3O4) nanoparticles are "superparamagnetic," meaning that they turn magnetic only in the presence of an external magnetic field. In contrast, "ferromagnetic" materials become magnetized in a magnetic field and retain their magnetism when the field is removed.

The researchers used the superparamagnetic property of iron oxide particles to tune the spacing between nanoparticles, and therefore the wavelength of the light reflection - or the color of the colloidal crystals - by changing the strength of the external magnetic field.

"Other reported photonic crystals can only reflect light with a fixed wavelength," Yin said. "Our crystals, on the other hand, show a rapid, wide and fully reversible optical response to the external magnetic field."

Photonic materials such as those used by Yin and his team could help in the fabrication of new optical microelectromechanical systems and reflective color display units. They also have applications in telecommunication (fiber optics), sensors and lasers.

"This is an elegant method that allows researchers in the field to assemble photonic crystals and control their spacing by using a magnetic field," said Orlin Velev, an associate professor of chemical and biomolecular engineering at North Carolina State University, Raleigh, N.C., who was not involved in the research. "A simple magnet can be used to change the color of a suspension throughout the whole visible spectra. This has potential to result in usable precursors for various photonic devices."

"What should make the technology commercially attractive is that iron oxide is cheap, non-toxic and available in plenty," Yin said.

Yin explained that the new technology can be used to make an inexpensive color display by forming millions of small pixels using the photonic crystals. "A different color for each pixel can be assigned using a magnetic field," he said. "The advantage is that you need just one material - for example, photonic crystals like iron oxide - for all the pixels. Moreover, you don't need to generate light in each pixel. You would be using reflected light to create the images - a form of recycling."

Yin was joined in the research by UC Riverside's Jianping Ge, a postdoctoral researcher, and Yongxing Hu, a first-year graduate student in the Department of Chemistry.

The UCR Office of Technology Commercialization has filed a patent application on the technology.

####

About University of California, Riverside
The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 17,000 is projected to grow to 21,000 students by 2010. The campus is planning a medical school and already has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. With an annual statewide economic impact of nearly $1 billion, UCR is actively shaping the region's future. To learn more, visit http://www.ucr.edu or call (951) UCR-NEWS.

For more information, please click here

Contacts:
Iqbal Pittalwala
951.827.6050

Copyright © University of California, Riverside

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

Display technology/LEDs/SS Lighting/OLEDs

Research opens door to smaller, cheaper, more agile communications tech February 16th, 2017

Dual-function nanorod LEDs could make multifunctional displays February 11th, 2017

1,000 times more efficient nano-LED opens door to faster microchips February 5th, 2017

Leti Presents First Results in LED Pixelization & Record Resolution for Micro-Displays at Photonics West February 3rd, 2017

MEMS

Engineers shrink microscope to dime-sized device February 17th, 2017

Leti Coordinating Project to Adapt Obstacle-Detection Technology Used in Autonomous Cars for Portable and Wearable Systems: INSPEX to Combine Knowhow of Nine European Organizations to Create Portable and Wearable Spatial-Exploration Systems February 2nd, 2017

Manufacturing platform makes intricate biocompatible micromachines January 7th, 2017

STMicroelectronics Peps Up Booming Social-Fitness Scene with Smart Motion Sensors for Better Accuracy, Longer Battery Life, and Faster Time to Market January 2nd, 2017

Self Assembly

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

In-cell molecular sieve from protein crystal February 14th, 2017

Synthetic nanoparticles achieve the complexity of protein molecules: Study published in Science reveals the structure of the largest gold nanoparticles to-date and the self-assembly mechanisms behind their formation January 25th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Sensors

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

Liquid metal nano printing set to revolutionize electronics: Creating integrated circuits just atoms thick February 18th, 2017

Research opens door to smaller, cheaper, more agile communications tech February 16th, 2017

Metamaterial: Mail armor inspires physicists: KIT researchers reverse hall coefficient -- medieval mail armor inspired development of metamaterial with novel properties February 15th, 2017

Discoveries

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Molecular phenomenon discovered by advanced NMR facility: Cutting edge technology has shown a molecule self-assembling into different forms when passing between solution state to solid state, and back again - a curious phenomenon in science - says research by the University of Wa February 22nd, 2017

Tiny nanoclusters could solve big problems for lithium-ion batteries February 21st, 2017

Breakthrough with a chain of gold atoms: In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport February 20th, 2017

Announcements

Atomic force imaging used to study nematodes: KFU bionanotechnology lab (head - Dr. Rawil Fakhrullin) has obtained 3-D images of nematodes' cuticles February 23rd, 2017

Particle Works creates range of high performance quantum dots February 23rd, 2017

GLOBALFOUNDRIES Announces Availability of 45nm RF SOI to Advance 5G Mobile Communications: Optimized RF features deliver high-performance solutions for mmWave beam forming applications in 5G smartphones and base stations February 22nd, 2017

EmTech Asia breaks new barriers with potential applications of space exploration with NASA and MIT February 22nd, 2017

Photonics/Optics/Lasers

'Lossless' metamaterial could boost efficiency of lasers and other light-based devices February 20th, 2017

Liquid metal nano printing set to revolutionize electronics: Creating integrated circuits just atoms thick February 18th, 2017

Research opens door to smaller, cheaper, more agile communications tech February 16th, 2017

1,000 times more efficient nano-LED opens door to faster microchips February 5th, 2017

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