Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > All Smoothed Out

Gold service: The asperities on a polished gold surface are quickly dissolved by the OH. radicals of Fentons reagent. The dissolution of Au is rapid at the beginning of the reaction and is negligible when the asperities have been dissolved. Although the OH. radicals also oxidize the smooth parts of the Au surface, they do not dissolve them, but form a stable oxide monolayer.
Gold service: The asperities on a polished gold surface are quickly dissolved by the OH. radicals of Fentons reagent. The dissolution of Au is rapid at the beginning of the reaction and is negligible when the asperities have been dissolved. Although the OH. radicals also oxidize the smooth parts of the Au surface, they do not dissolve them, but form a stable oxide monolayer.

Abstract:
Hydroxyl radicals remove nanoscopic irregularities on polished gold surfaces

All Smoothed Out

Weinheim, Germany | Posted on January 14th, 2010

The precious metal gold is the material of choice for many technical applications because it does not corrode - and because it also has interesting electrical, magnetic, and optical properties. Gold is thus one of the most important metals in the electronics industry, miniaturized optical components, and electrochemical processes. In these applications, it is extremely important that the surface of the gold be completely clean and smooth. However, conventional processes not only "polish" away the undesirable irregularities, but also attack the gold surface. Fritz Scholz and a team from the Universities of Greifswald (Germany) and Warsaw (Poland) have now discovered a technique that can differentiate between the two. As the scientists report in the journal Angewandte Chemie, hydroxyl radicals (OH radicals) rapidly remove all tiny protrusions on mechanically polished gold surfaces, leaving behind an extremely smooth surface.

The researchers treated gold surfaces with Fenton's reagent, which is a mixture of hydrogen peroxide and iron(II) salts that releases OH radicals. It is also used to degrade organic impurities in the purification of waste water. "Actually, it was not expected that the radicals would attack a polished pure gold surface," says Scholz, "because gold is notoriously difficult to oxidize." The experiments demonstrated that the hydroxyl radicals oxidize gold very well, though measurable dissolution continues only as long as there are still bumps on the gold surface. Though these results seem contradictory at first glance, the researchers explain that the reaction of the radicals with the highly ordered gold atoms of the completely smooth surface produces a stable layer of gold oxide, which can be reduced back to elemental gold without a significant loss of material. In the protrusions, however, the gold atoms are less ordered and very reactive. During the oxidation, they detach themselves from the atomic structure.

"Because the protrusions are selectively removed, our method is very interesting for polishing gold surfaces for industrial applications," says Scholz. The process may also find a use in medical technology: gold is used to replace teeth, in tissues for reconstructive surgery, and in electrode implants, such as those used for implanted hearing aids. These release tiny amounts of gold, which enters into the surrounding tissue. This apparently occurs because of an immune reaction that results in the formation of OH radicals or similar species. Pre-treatment of gold implants with Fenton's reagent could inhibit this release of gold into the body.

Author: Fritz Scholz, Universität Greifswald (Germany),

www.chemie.uni-greifswald.de/~analytik/

Title: Hydroxyl Radicals Attack Metallic Gold

Angewandte Chemie International Edition, Permalink: dx.doi.org/10.1002/anie.200906358

####

About Wiley InterScience
Wiley InterScience (www.interscience.wiley.com) provides access to over 3 million articles across nearly 1500 journals and 7000 Online Books and major reference works. It also holds industry leading databases such as The Cochrane Library, chemistry databases and the acclaimed Current Protocols laboratory manuals.

Wiley InterScience is one of the world's premiere resources for study, teaching and advanced research.

For more information, please click here

Contacts:
Editorial office


Amy Molnar (US)


Jennifer Beal (UK)


Alina Boey (Asia)

Copyright © Wiley InterScience

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

News and information

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

Chemistry

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

Nanosorbent Produced in Iran to Adsorb Tiny Amounts of Aromatic Hydrocarbon from Seawater May 18th, 2015

Possible Futures

Simulations predict flat liquid May 21st, 2015

Nature inspires first artificial molecular pump: Simple design mimics pumping mechanism of life-sustaining proteins found in living cells May 19th, 2015

NNCO and Museum of Science Fiction to Collaborate on Nanotechnology and 3D Printing Panels at Awesome Con May 19th, 2015

Quantum 'gruyères' for spintronics of the future: Topological insulators become a little less 'elusive' May 12th, 2015

Chip Technology

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

Nanometrics Announces Live Webcast of Upcoming Investor and Analyst Day May 20th, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Defects can 'Hulk-up' materials: Berkeley lab study shows properly managed damage can boost material thermoelectric performances May 20th, 2015

Nanomedicine

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

New Antibacterial Wound Dressing in Iran Can Display Replacement Time May 22nd, 2015

Researchers develop new way to manufacture nanofibers May 21st, 2015

Discoveries

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Announcements

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 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