High-Intensity Ultrasound Creates Hollow Nanospheres And Nanocrystals

NANO TECH

Using high-intensity ultrasound, chemistry professor Ken Suslick has created hollow nanospheres and the first hollow nanocrystals. The nanospheres could be used in microelectronics, drug delivery and as catalysts for making environmentally friendly fuels.

Champaign IL (SPX) Feb 23, 2005
Using high-intensity ultrasound, researchers at the University of Illinois at Urbana-Champaign have created hollow nanospheres and the first hollow nanocrystals. The nanospheres could be used in microelectronics, drug delivery and as catalysts for making environmentally friendly fuels.

"We use high-intensity ultrasound to generate nanoparticles of molybdenum disulfide or molybdenum oxide, which bind to the surface of tiny silica spheres that are much smaller than red blood cells," said Ken Suslick, the Marvin T. Schmidt Professor of Chemistry at Illinois and a researcher at the Beckman Institute for Advanced Science and Technology.

"After heating the spheres to produce uniform coatings, we use hydrofluoric acid to etch away the silica, leaving hollow shells of the desired material."

Suslick and former postdoctoral research associate Arul Dhas describe their work in a paper that has been accepted for publication in the Journal of the American Chemical Society, and posted on its Web site. Funding was provided by the National Science Foundation.

Hollow nanospheres crafted from molybdenum disulfide could serve as a superior catalyst for removing sulfur-containing compounds from gasoline and other fossil fuels.

"Molybdenum-disulfide is a layered material, but its catalytic activity occurs at its edges," Suslick said. "By distorting and breaking up the layers, hollow nanospheres offer increased edge-surface area, as well as access to both inner and outer shell surfaces."

Further processing of hollow spheres made of molybdenum oxide, however, results in the unusual formation of hollow crystals that resemble truncated cubes. Upon heating a second time � referred to as thermal annealing � the hollow molybdenum oxide spheres are transformed into single-crystal boxes with spherical hollow voids.

The sonochemical procedure could be easily applied to other material systems to create additional types of hollow, nanostructured particles, Suslick said.

Sonochemistry arises from acoustic cavitation � the formation, growth and implosion of small gas bubbles in a liquid blasted with sound. The collapse of these bubbles generates intense local heating, forming a hot spot in the cold liquid with a transient temperature of about 9,000 degrees Fahrenheit, the pressure of about 1,000 atmospheres and the duration of about 1 billionth of a second.

For a rough comparison, these values correspond to the temperature of the surface of the sun, the pressure at the bottom of the ocean, and the lifetime of a lightning strike.

Ultrasound consists of sound waves above 18,000 cycles per second, too high-pitched to be audible to human ears.

NANO TECH

Purdue Proves Concept Of Using Nano-Materials For Drug Discovery

West Lafayette IN (SPX) Feb 18, 2005
Researchers at Purdue University have built and demonstrated a prototype for a new class of miniature devices to study synthetic cell membranes in an effort to speed the discovery of new drugs for a variety of diseases, including cancer.

Thanks for being here; We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain. With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords. Our news coverage takes time and effort to publish 365 days a year. If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor $5 Billed Once credit card or paypal		SpaceDaily Monthly Supporter $5 Billed Monthly paypal only

The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.