Featured Research

from universities, journals, and other organizations

Purifying Nanorods: Big Success With Tiny Cleanup

Date:
September 25, 2008
Source:
Rice University
Summary:
Chemists have discovered a novel method to produce ultra-pure gold nanorods -- tiny, wand-like nanoparticles that are being studied in dozens of labs worldwide for applications as broad as diagnosing disease and improving electronic viewscreens. The method removes more than 99 percent of impurities from nanorods.

Chemists at Rice University have discovered a novel method to produce ultra-pure gold nanorods -- tiny, wand-like nanoparticles that are being studied in dozens of labs worldwide for applications as broad as diagnosing disease and improving electronic viewscreens.

"The content of high-aspect-ratio gold nanorods produced by today's best synthetic methods is only about 20 percent," said lead researcher Eugene Zubarev, assistant professor of chemistry at Rice. "A nanoparticle's shape plays a crucial role in determining many of its physical and chemical properties, so when four out of five particles in a batch are the wrong shape, it's a tremendous impediment to practical applications and commercialization."

Zubarev and graduate student Bishnu Khanal's new purification method filters more than 99 percent of impurities from gold nanorods. The research is available online and will appear in the Sep. 25 issue of the Journal of the American Chemical Society. It's an example of the sort of processing and synthesis methods that the federal government called for last year in a key report that examined the economic potential of nanotechnology.

Nanotechnology refers to a set of tools and methods that scientists use to see, measure and control matter with exquisite control, sometimes moving just one atom at a time. By building materials from the bottom up, at the molecular level, scientists can tailor particles that interact in precise ways with living cells, light waves, drugs and other chemicals. The word nanotechnology refers to the nanometer, a unit of length equal to one-billionth of a meter.

The nanorods studied by Zubarev and Khanal are about 25 nanometers in diameter and about 250 nanometers long. In comparison, a single gold atom is only about one third of a nanometer in diameter. Thus, the cross-section of each nanorod is made of just a few thousand gold atoms. Because of their long, narrow shape, the nanorods interact with light, electricity and magnetic fields differently than spheres or discs containing the same number of atoms.

Tuning the shape- and size-specific properties of nanoparticles is critically important for the emerging U.S. nanotechnology industry. The U.S. has invested more than $8 billion in nanotechnology research and development since 2000, and the National Science Foundation estimates the global market for nanotechnology products will be about $1 trillion by 2015. In its 2007 strategic plan, the National Nanotechnology Initiative, which oversees U.S. nanotechnology research spending, pointed to the critical need for synthesis and processing techniques that yield high-quality, pure nanomaterials.

Nanorods are produced by mixing several chemicals in a precise, multi-step process. The method also produces gold nanoparticles of other shapes, including spheres and flattened sheets called platelets. Researchers had previously found a way to remove the spheres; the nanorods and platelets were allowed to gradually sink to the bottom of the mixture, and the spheres were siphoned away.

While conducting research on a different project, Zubarev and Khanal noticed that the nanorods and platelets in the remaining solution shrank when a solution of gold ions was added. They found that the platelets shrank much faster than the nanorods, and by tuning the process they discovered they could filter out the platelets and produce nanorod solutions that were more than 99 percent pure.

The research was funded by the National Science Foundation and the Welch Foundation.


Story Source:

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


Cite This Page:

Rice University. "Purifying Nanorods: Big Success With Tiny Cleanup." ScienceDaily. ScienceDaily, 25 September 2008. <www.sciencedaily.com/releases/2008/09/080922135223.htm>.
Rice University. (2008, September 25). Purifying Nanorods: Big Success With Tiny Cleanup. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2008/09/080922135223.htm
Rice University. "Purifying Nanorods: Big Success With Tiny Cleanup." ScienceDaily. www.sciencedaily.com/releases/2008/09/080922135223.htm (accessed September 23, 2014).

Share This



More Matter & Energy News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Company Copies Keys From Photos

Company Copies Keys From Photos

Newsy (Sep. 22, 2014) A new company allows customers to make copies of keys by simply uploading a couple of photos. But could it also be great for thieves? Video provided by Newsy
Powered by NewsLook.com
Rockefeller Oil Heirs Switching To Clean Energy

Rockefeller Oil Heirs Switching To Clean Energy

Newsy (Sep. 22, 2014) The Rockefellers — heirs to an oil fortune that made the family name a symbol of American wealth — are switching from fossil fuels to clean energy. Video provided by Newsy
Powered by NewsLook.com
Raw: SpaceX Rocket Carries 3-D Printer to Space

Raw: SpaceX Rocket Carries 3-D Printer to Space

AP (Sep. 22, 2014) A SpaceX Rocket launched from Cape Canaveral, carrying a custom-built 3-D printer into space. NASA envisions astronauts one day using the printer to make their own spare parts. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Inside London's Massive Sewer Tunnel Project

Inside London's Massive Sewer Tunnel Project

AP (Sep. 22, 2014) Billions of dollars are being spent on a massive super sewer to take away London's vast output of waste, which is endangering the River Thames. (Sept. 22) Video provided by AP
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