Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Peering into the never before seen

17.06.2010
Scientists can now peer into the inner workings of catalyst nanoparticles 3,000 times smaller than a human hair within nanoseconds.

The findings point the way toward future work that could greatly improve catalyst efficiency in a variety of processes that are crucial to the world’s energy security, such as petroleum catalysis and catalyst-based nanomaterial growth for next-generation rechargeable batteries. The work was performed in a collaborative effort by Lawrence Livermore National Laboratory and the University of California at Davis.

Using a new imaging technique on Lawrence Livermore’s Dynamic Transmission Electron Microscope (DTEM), researchers have achieved unprecedented spatial and temporal resolution in single-shot images of nanoparticulate catalysts.

The DTEM uses a laser-driven photocathode to produce short pulses of electrons capable of recording electron micrographs with 15-nanosecond (one billionth of a second) exposure time. The recent addition of an annular dark field (ADF) aperture to the instrument has greatly improved its ability to time-resolve images of nanoparticles as small as 30 nanometers in diameter.

“Nanoparticles in this size range are of crucial importance to a wide variety of catalytic process of keen interest to energy and nanotechnology researchers,” said UC Davis’ Dan Masiel, formerly of LLNL and lead author of a paper appearing in the journal, ChemPhysChem. “Time-resolved imaging of such materials will allow for unprecedented insight into the dynamics of their behavior.”

Previously, particles smaller than 50 nanometers could not be resolved in the 15-nanosecond exposure because of the limited signal and low contrast without ADF aperature. But by using DTEM’s ADF, almost every 50-nanometer particle and many 30-nanometer ones became clearly visible because of the fast time resolution and high contrast.

“The stark difference between these two images clearly demonstrates the efficacy of annual dark field imaging when imaging samples with feature sizes near the resolution limit of DTEM,” Masiel said.

The new technique makes it easier to discern significant features when compared to bright field pulsed imaging. It allows for vastly improved contrast for smaller particles, widening the range of catalyst systems that can be studied using DTEM.

DTEM can record images with six orders of magnitude higher temporal resolution than conventional TEM and can provide important insights into processes such as phase transformations, chemical reactions and nanowire and nanotube growth.

Co-authors include LLNL’s Bryan Reed, Thomas LaGrange, Geoffrey Campbell, Ting Guo and Nigel Browning. The work was funded by the Department of Energy’s Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division.

The article appears in the May 27 online edition of ChemPhys Chem.

Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.

Anne Stark | EurekAlert!
Further information:
http://www.llnl.gov

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>