Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New type of nanotube made of gold or silver created at the Weizmann Institute

27.01.2004


Weizmann Institute scientists have created a new type of nanotube built of gold, silver and other nanoparticles. The tubes exhibit unique electrical, optical and other properties, depending on their components, and as such, may form the basis for future nanosensors, catalysts and chemistry-on-a-chip systems.



The study, published in Angewandte Chemie, was performed by Prof. Israel Rubinstein, Dr. Alexander Vaskevich, postdoctoral associate Dr. Michal Lahav and doctoral student Tali Sehayek, all of the Institute’s Department of Materials and Interfaces.

Nanotubes are tiny cylinder-shaped structures (a nanometer is one millionth of a millimeter). Discovered in 1991, the first nanotubes were made of carbon and captured the attention of scientists worldwide when they proved to be the strongest material ever made (100 times stronger than steel), as well as being excellent conductors of electricity and heat.


The new nanotube created at the WIS lacks the mechanical strength of carbon nanotubes. Its advantages lie instead in its use of nanoparticles as building blocks, which makes it possible to tailor the tube’s properties for diverse applications. The properties can be altered by choosing different types of nanoparticles or even a mixture, thus creating composite tubes. Moreover, the nanoparticle building blocks can serve as a scaffold for various add-ons, such as metallic, semiconducting or polymeric materials – thus further expanding the available properties.

The tubes are produced at room temperature – a first-time achievement – in a three-step process. The scientists start out with a nanoporous aluminum oxide template that they modify chemically to make it bind readily to gold or silver nanoparticles. When a solution containing the nanoparticles (each only 14 nanometers in diameter) is poured through, they bind both to the aluminum oxide membrane and to themselves, creating multi-layered nanotubes in the membrane pores. In step three, the aluminum oxide membrane is dissolved, leaving an assembly of free-standing, solid nanotubes.

"We were amazed when we discovered the beautifully formed tubes," says Rubinstein. "The construction of nanotubes out of nanoparticles is unprecedented. We expected the nanoparticles to bind to the aluminum oxide template – that had been done before; but we did not expect them to bind to each other, creating the tubes."

The discovery process held other surprises for the Institute team. They had set out to accomplish something else entirely – to create a nanoporous template for studying the passage of biological molecules through different membranes. Likewise, having employed annealing – a process that uses heat to bind structures – they found that annealing actually prevented tube formation. "Everything interesting, in fact, happened at room temperature," says Rubinstein. "This exceptional process, of spontaneous room-temperature binding of nanoparticles to form tubes, is not yet fully understood and is currently being studied."

The resulting tube is porous and has a high surface area, distinct optical properties and electrical conductivity. Collectively, the tube’s unusual properties may enable the design of future sensors and catalysts (both requiring high surface area), as well as microfluidic, chemistry-on- a-chip systems applied in biotechnology, such as DNA chips (used to detect genetic mutations and evaluate drug performance).

Applying their approach, the team has succeeded in creating various metal and composite nanotubes, including gold, silver, gold/palladium and copper-coated gold tubes. Yeda, the Institute’s technology transfer arm, has filed a patent application for the new tubes.


Prof. Israel Rubinstein’s research is supported by the Clore Center for Biological Physics, The Philip M. Klutznick Fund for Research, the Fritz Haber Center for Physical Chemistry, the Minerva Stiftung Gesellschaft fuer die Forschung m.b.H., and the Angel Faivovich Foundation for Ecological Studies.

The Weizmann Institute of Science in Rehovot, Israel is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,500 scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.

Alex Smith | EurekAlert!
Further information:
http://www.weizmann.ac.il/

More articles from Materials Sciences:

nachricht Molecular switch detects metals in the environment
15.08.2018 | Université de Genève

nachricht Breakthrough in nanoresearch - Quantum chains in graphene nanoribbons
09.08.2018 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Early opaque universe linked to galaxy scarcity

15.08.2018 | Physics and Astronomy

Molecular switch detects metals in the environment

15.08.2018 | Materials Sciences

Seeing on the Quick: New Insights into Active Vision in the Brain

15.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>