Featured Research

from universities, journals, and other organizations

"Rainbow Metal," Similar To Opal, Suggests Light-Steering Computer Parts And Catalysts

Date:
October 8, 1999
Source:
University Of Delaware
Summary:
Porous, rainbow-colored metal--inspired by opal--may suggest new materials to steer light inside superfast computers, or to more efficiently catalyze chemical reactions, University of Delaware researchers report.

Porous, rainbow-colored metal--inspired by opal--may suggest new materials to steer light inside superfast computers, or to more efficiently catalyze chemical reactions, University of Delaware researchers report Oct. 7 in Nature.

Because it's riddled with regularly spaced holes only slightly wider than the wavelength of light, the UD material acts like a prism, diffracting a spectrum of colors--from gold and blue to red, green and purple.

"It reflects different wavelengths of light, just like opal, only it's much sturdier," explains Research Assistant Prof. Orlin D. Velev, lead author of the Nature paper, with coauthors including graduate student Peter M. Tessier and Prof. Abraham M. Lenhoff.

In fact, tiny holes in the new material are 20,000 times smaller than the pores in an existing metal mesh that can be used to direct radar waves, reports coauthor Eric W. Kaler, the University's Elizabeth Inez Kelley Professor of Chemical Engineering and chairperson of his department.

Consequently, "It should help guide the much shorter light waves, perhaps in photooptic computer components," says Kaler. Such devices will be crucial in next-generation computers, he says, because "fiber optics can't turn sharp corners, and you don't have much room to maneuver in nanoscale devices."

A sister version of the rainbow metal features light-sized pores--20 times smaller than the smallest red blood cell--as well as even smaller pores, all of which are aligned in tightly packed, uniformly spaced rows. This versatile, "meso/macroporous" form of the material may also be photoactive, and could prove useful as a catalyst for, say, cracking hydrocarbon to produce gasoline, or as a filter for rapidly separating molecules of different sizes.

Dots of gold

Creating the material is a low-energy process involving latex beads, much smaller microspheres of gold and "very simple chemistry," Kaler says. The size of the resulting pores can be "tuned" or changed simply by selecting different sizes of latex and gold beads, he adds.

First, the UD researchers pour a watery solution containing the latex particles onto a polycarbonate membrane. Water slips right through the membrane's 50-nanometer pores. But, the 300-nanometer latex beads are trapped on top.

"It's a bit like dumping a bunch of marbles into a bathtub and then pulling the drain plug," Kaler explains. "After the water escapes, you're left with a densely packed layer of these spheres."

After many hundreds of layers of latex are deposited, bits of gold just one-tenth the size of the polymer beads can be slowly filtered onto them, to fill the gaps between neighboring spheres.

As a final step, the researchers either "bake" or "pickle" their sample to remove the latex.

A multicolored metal with pores about 600 nanometers wide--close to the wavelength of light--is created by heating the latex and fusing the gold for 30 minutes at 300 degrees Celsius (572 degrees Fahrenheit). For a sample with both large and small pores, the researchers instead chemically oxidize and dissolve the latex.

"Our system is a very powerful, versatile way to make porous nanostructures in a variety of materials," Kaler says.

In the past, Velev notes, researchers have used ion beams to drill individual holes into metals, one pore at a time. "Obviously," he says, "that's very time-consuming and expensive. We think we've found another way."

And, UD's material manufacturing technique could be applied to any type of material, Velev says, theoretically allowing polymers and carbon to "shine," or reflect light.

The UD research team, working from the University's Center for Molecular and Engineering Thermodynamics, has been at the forefront of the rapidly accelerating effort to develop porous nanostructures by using arrays of particles as templates, field launched by the same group just two years ago. Their earlier work with porous silica--supported by collaborator Raul Lobo, an Assistant Prof. with the UD Center for Catalytic Science and Technology--appeared in the Oct. 2, 1997 issue of Nature (Vol. 389, pp. 447-448). Similar efforts to develop porous metals are under way by teams at Rice University and the University of Minnesota.


Story Source:

The above story is based on materials provided by University Of Delaware. Note: Materials may be edited for content and length.


Cite This Page:

University Of Delaware. ""Rainbow Metal," Similar To Opal, Suggests Light-Steering Computer Parts And Catalysts." ScienceDaily. ScienceDaily, 8 October 1999. <www.sciencedaily.com/releases/1999/10/991008075633.htm>.
University Of Delaware. (1999, October 8). "Rainbow Metal," Similar To Opal, Suggests Light-Steering Computer Parts And Catalysts. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/1999/10/991008075633.htm
University Of Delaware. ""Rainbow Metal," Similar To Opal, Suggests Light-Steering Computer Parts And Catalysts." ScienceDaily. www.sciencedaily.com/releases/1999/10/991008075633.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins