Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Small is different

18.02.2005


A computer simulation shows a jet of propane just six nanometers wide exiting a nozzle.


Computer sims vital tools in exploring nanoworld

Years ago, when Uzi Landman and his colleagues set out to uncover some of the rules that govern why a non-reactive metal like gold acts as a catalyst when it is in nanoclusters only a few atoms in size, they didn’t sit down in a lab with the precious metal. Instead, they ran computer simulations and discovered that gold is a very effective catalyst when it is in clusters of eight to two dozen atoms. They also found that electrical charging of gold is crucial to its catalytic capabilities. Six years later, the team has verified their earlier predictions experimentally, and they stand ready to further explore environmental effects on catalysis.

This practice of partnering computer simulations with real-world experiments is becoming more vital as scientists delve deeper into realms where the actors are measured on the nanoscale, Landman told a group of scientists Thursday, February 17 at the annual meeting of the American Association for the Advancement of Science (AAAS). "Small is different," said Landman, director of the Center for Computational Materials Science and professor of physics at the Georgia Institute of Technology. "We cannot use the way physical systems behave on the large scale to predict what will happen when we go to levels only a few atoms in size. In this size regime, electrons transport electricity in a different way, crystallites have different mechanical properties and gold nanowires have strength twenty times larger than a big bar of gold, and inert metals may exhibit remarkable catalytic activity. But we know the rules of physics, and we can use them to create model environments in which we can discover new phenomena through high-level computer-based simulations."



Computers are constantly becoming more powerful and capable of conducting more detailed explorations at the same time scientists across the globe are increasing their interest in the science of the small. The intersection of these two trends, said Landman, is allowing scientists to investigate realms that are too small for today’s technology to explore experimentally.

It’s not just a matter of making faster calculations, he said. "Experimentally, we can’t always go down to the resolution we need to see, explain and predict things, but with computer simulations we can go to any resolution we need," said Landman. "Therefore, you can ask questions, deeper questions, on how materials behave on the small scale, even if you can’t get to that fine resolution experimentally." This doesn’t mean that experiments aren’t necessary, said Landman. "It’s a supplementary and complimentary approach. The pillars of scientific methodology are composed now of experimentation, analytical theory and computer simulation."

In addition to their work on nanocatalysis, Landman and colleagues have used simulations to explore other phenomena, such as the possibility of producing and maintaining a stable flow of liquid on the nanoscale. Their models predicted that it is possible to produce liquid jets only six nanometers wide. To date, in collaboration with Landman’s theory group, there are teams of engineers building nozzles that can produce jets in the 100 nanometer range. Within one year, said Landman, they expect to produce "nanojets" in the 10 nanometer range.

"The opportunity to make new discoveries in ways that weren’t possible before is an incredible gift and it has come about only because we can now simulate environments on the computer that are either not yet possible, too expensive or too dangerous to do in the lab," said Landman. "We are now at a point in history where the science of the small holds the promise of producing a windfall of scientific discoveries. Computers serve tools for discovery in this exciting adventure."

David Terraso | EurekAlert!
Further information:
http://www.icpa.gatech.edu

More articles from Physics and Astronomy:

nachricht SwRI-led team discovers lull in Mars' giant impact history
26.04.2017 | Southwest Research Institute

nachricht New survey hints at exotic origin for the Cold Spot
26.04.2017 | Royal Astronomical Society

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>