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

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Missing atoms in a forgotten crystal bring luminescence October 10th, 2017

The power of perovskite: OIST researchers improve perovskite-based technology in the entire energy cycle, from solar cells harnessing power to LED diodes to light the screens of future electronic devices and other lighting applications August 18th, 2017

Nanocrystalline LEDs: Red, green, yellow, blue ... August 7th, 2017

MEMS

First Capacitive Transducer with 13nm Gap July 27th, 2017

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Smart multi-layered magnetic material acts as an electric switch: New study reveals characteristic of islands of magnetic metals between vacuum gaps, displaying tunnelling electric current March 1st, 2017

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

Self Assembly

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

Nanotubes that build themselves April 14th, 2017

Nanocages for gold particles: what is happening inside? March 16th, 2017

Sensors

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Single ‘solitons’ promising for optical technologies October 9th, 2017

Two dimensional materials: Advanced molybdenum selenide near infrared phototransistors September 27th, 2017

Enhancing the sensing capabilities of diamonds with quantum properties: A simple method can give diamonds the special properties needed for quantum applications such as sensing magnetic fields September 24th, 2017

Discoveries

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Announcements

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Spin current detection in quantum materials unlocks potential for alternative electronics October 15th, 2017

Quantum manipulation power for quantum information processing gets a boost: Improving the efficiency of quantum heat engines involves reducing the number of photons in a cavity, ultimately impacting quantum manipulation power October 14th, 2017

The secret to improving liquid crystal's mechanical performance: Better lubricating properties of lamellar liquid crystals could stem from changing the mobility of their structural dislocations by adding nanoparticles October 13th, 2017

Photonics/Optics/Lasers

Rice U. study: Vibrating nanoparticles interact: Placing nanodisks in groups can change their vibrational frequencies October 16th, 2017

Injecting electrons jolts 2-D structure into new atomic pattern: Berkeley Lab study is first to show potential of energy-efficient next-gen electronic memory October 13th, 2017

Single ‘solitons’ promising for optical technologies October 9th, 2017

A dash of gold improves microlasers: The precious metal provides a 'nano' solution for improving disease detection, defense and cybersecurity applications October 9th, 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