Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > New Fabricated Material Changes Color Instantly In Response to External Magnetic Field

Yadong Yin is an assistant professor of chemistry at UC Riverside. Photo credit: Yin lab, UC Riverside.
Yadong Yin is an assistant professor of chemistry at UC Riverside. Photo credit: Yin lab, UC Riverside.

Abstract:
New mechanism for inducing color change in materials paves way for manufacturing rewritable color display units, environmentally friendly color paints

New Fabricated Material Changes Color Instantly In Response to External Magnetic Field

Riverside, CA | Posted on June 16th, 2009

A research team led by a chemist at the University of California, Riverside has fabricated microscopic polymer beads that change color instantly and reversibly when external magnetic fields acting upon the microspheres change orientation.

The beads or "magnetochromatic microspheres" have excellent structural stability. They also are highly compatible with various types of dispersion media such as water, alcohol, hexane and even polymer solutions, allowing them to retain magnetically tunable colors in a variety of chemical environments.

"Unlike many conventional approaches, the instantaneous color change occurs with no change in the structure or intrinsic properties of the microspheres themselves," said Yadong Yin, an assistant professor of chemistry who led the study that brought together chemists at UCR and engineers at Seoul National University, South Korea. "What changes instead are the magnetic fields acting externally on the orientation of these microspheres, these photonic crystals. Our work provides a new mechanism for inducing color change in materials. Now, for the first time, stable photonic materials with tunable colors can be fabricated on a large scale."

Applications of the new material include display type units such as rewritable or reusable signage, posters, papers and labels, and other magnetically activated security features. The new material also can be used to make environmentally friendly pigments for paints and cosmetics, as well as ink materials for color printing.

"Within a certain range, it is possible also to tune the color of the material by simply rotating the microspheres," Yin said.

Study results appeared June 15 in the online issue of the Journal of the American Chemical Society.

"The new technology has a great potential for a wide range of photonic applications because the on/off switching of the diffraction color by the rotating photonic sphere is fast, greatly simplifying the pixel structures," said Seoul National University's Sunghoon Kwon, a leading expert in biophotonics and nanoengineering, whose lab collaborated with Yin's lab on the research. "Therefore, the new technology is suitable for very large-scale displays, such as active signage."

In their lab experiments, the researchers embedded arrays of spatially ordered magnetic iron oxide nanostructures within each polymer microsphere, enabling its colors to be switched on and off simply by changing the microsphere's orientation - or more precisely the orientation of the array. Furthermore, the new system has the advantage of producing bistable color states, required for making rewritable displays.

Yin explained that the color observed in the new materials is "structural color" because it is caused by interference effects rather than pigments. Such color effects, as seen in colorful feathers of many birds, butterfly wings and beetle shells, are produced when microstructures in these objects are aligned in periodic arrays.

"Conventional methods to produce tunable structural color rely on changing the periodicity of the array or the refractive index of the materials - changes that are difficult to achieve or involve slow processes," he said. "In our method, the color is tuned by changing the relative orientation of the periodic arrays in the microspheres by conveniently using external fields. The use of magnetic fields as external stimuli has the additional benefits of instant action, contactless control and easy integration into electronic devices already in the market."

Said Luke P. Lee, the Lloyd Distinguished Professor of Bioengineering at UC Berkeley, who was not involved in the research, "This is a smart and effective solution to solve the problems of previous works, which could not tune the photonic crystal structures."

To fabricate the microspheres, the researchers first mixed magnetic iron oxide particles into a resin, which is initially in liquid phase but later turns solid on exposure to ultraviolet curable resin. They then dispersed the resin solution in oil (mineral oil or silicon oil), whereupon the resin transformed into spherical droplets in the oil. Next, the researchers applied an external magnetic field to organize the iron oxide particles into periodically ordered structures. These structures display a reflective color if viewed along the direction of the magnetic field. Finally, the research team exposed the liquid system to ultraviolet radiation to polymerize the resin droplets and make them solid microspheres.

Next in the research, Yin and his colleagues plan to work on the specific applications of the magnetochromatic microspheres. "Rewritable energy saving display units such as papers and posters are our main interests," he said. "We will also try to develop similar new material for chemical and biological sensors."

Yin, recently named a Cottrell Scholar by the Research Corporation for Science Advancement, and Kwon were joined in the research by Jianping Ge (first author of the research paper), Le He, Zhenda Lu and James Goebl of UCR; and Howon Lee, Junhoi Kim and Hyoki Kim of Seoul National University.

The four-month study was supported by UC Riverside startup funds and the Petroleum Research Fund administered by the American Chemical Society.

The UCR Office of Technology Commercialization has filed a patent application on the technology and is currently seeking partners in industry interested in developing the technology commercially.

####

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 expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion. To learn more, visit www.ucr.edu or call (951) UCR-NEWS.

For more information, please click here

Contacts:
Iqbal Pittalwala
Tel: (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 Links

Video

Related News Press

News and information

Multi-million pound project to use nanotechnology to improve safety September 4th, 2015

Magnetic wormhole connecting 2 regions of space created for the first time: The device could have applications in medicine, opening up ways to make MRIs more comfortable for patients September 4th, 2015

Tongfang Global and QD Vision Partner to Bring Wide Color Gamut to Global Television Lines: Color IQTM quantum dots help boost company’s focus on superior color reproduction September 3rd, 2015

QEOS and GLOBALFOUNDRIES to Offer Industry’s First CMOS Platform for MillimeterWave Markets: GLOBALSOLUTIONSSM Partnership will enable next-generation wireless technologies for applications in IoT, 5G and automotive September 3rd, 2015

GLOBALFOUNDRIES and Catena Partner to Provide Next-Generation RF Connectivity Solutions for Growing Wireless Markets: Catena Wi-Fi and Bluetooth RF technologies available on GLOBALFOUNDRIES 28nm Super Low Power Process technology September 3rd, 2015

Display technology/LEDs/SS Lighting/OLEDs

Tongfang Global and QD Vision Partner to Bring Wide Color Gamut to Global Television Lines: Color IQTM quantum dots help boost company’s focus on superior color reproduction September 3rd, 2015

Possible Futures

Magnetic wormhole connecting 2 regions of space created for the first time: The device could have applications in medicine, opening up ways to make MRIs more comfortable for patients September 4th, 2015

Silk bio-ink could help advance tissue engineering with 3-D printers September 2nd, 2015

Sediment dwelling creatures at risk from nanoparticles in common household products August 13th, 2015

Harris & Harris Group Reports Financial Statements as of June 30, 2015, and Announces a Stock Repurchase Program August 10th, 2015

Materials/Metamaterials

Magnetic wormhole connecting 2 regions of space created for the first time: The device could have applications in medicine, opening up ways to make MRIs more comfortable for patients September 4th, 2015

Sustainable nanotechnology center September 1st, 2015

Using ultrathin sheets to discover new class of wrapped shapes: UMass Amherst materials researchers describe a new regime of wrapped shapes August 31st, 2015

An engineered surface unsticks sticky water droplets August 31st, 2015

Announcements

Multi-million pound project to use nanotechnology to improve safety September 4th, 2015

Magnetic wormhole connecting 2 regions of space created for the first time: The device could have applications in medicine, opening up ways to make MRIs more comfortable for patients September 4th, 2015

Making nanowires from protein and DNA September 3rd, 2015

Making fuel from light: Argonne research sheds light on photosynthesis and creation of solar fuel September 3rd, 2015

Environment

Reversible Writing with Light: Self-assembling nanoparticles take their cues from their surroundings September 3rd, 2015

RUSNANOPRIZE Directorate Announces New Deadline for Nominations Submission – September 11, 2015 September 1st, 2015

Successful boron-doping of graphene nanoribbon August 27th, 2015

Iranian Scientists Utilize Nanomembranes to Purify Wastewater of Olive Oil Plants August 20th, 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







Car Brands
Buy website traffic