Navigation Links
Nanoparticles seen as artificial atoms
Date:5/25/2012

In the growth of crystals, do nanoparticles act as "artificial atoms" forming molecular-type building blocks that can assemble into complex structures? This is the contention of a major but controversial theory to explain nanocrystal growth. A study by researchers at the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) may resolve the controversy and point the way to energy devices of the future.

Led by Haimei Zheng, a staff scientist in Berkeley Lab's Materials Sciences Division, the researchers used a combination of transmission electron microscopy and advanced liquid cell handling techniques to carry out real-time observations of the growth of nanorods from nanoparticles of platinum and iron. Their observations support the theory of nanoparticles acting like artificial atoms during crystal growth.

"We observed that as nanoparticles become attached they initially form winding polycrystalline chains," Zheng says. "These chains eventually align and attach end-to-end to form nanowires that straighten and stretch into single crystal nanorods with length-to-thickness ratios up to 40:1. This nanocrystal growth process, whereby nanoparticle chains as well as nanoparticles serve as the fundamental building blocks for nanorods, is both smart and efficient."

Zheng is the corresponding author of a paper describing this research in the journal Science. The paper is titled "Real-Time Imaging of Pt3Fe Nanorod Growth in Solution." Co-authors are Hong-Gang Liao, Likun Cui and Stephen Whitelam.

If the near limitless potential of nanotechnology is to even be approached, scientists will need a much better understanding of how nano-sized particles can assemble into hierarchical structures of ever-increasing organization and complexity. Such understanding comes from tracking nanoparticle growth trajectories and determining the forces that guide these trajectories.

Through the use of transmission electron microscopy and liquid observation cells, scientists at Berkeley Lab and elsewhere have made significant progress in observing nanoparticle growth trajectories, including the oriented attachment of nanoparticles - the chemical phenomenon that starts the growth of nanocrystals in solution. However, these observations have typically been limited to the first few minutes of crystal growth. In their study, Zheng and her colleagues were able to extend the time of observation from minutes to hours.

"The key to studying the growth of colloidal nanocrystals with different shapes and architectures is to maintain the liquid in the viewing window long enough to allow complete reactions," Zheng says. "We dissolved molecular precursors of platinum and iron in an organic solvent and used capillary pressure to draw the growth solution into a silicon-nitride liquid cell that we sealed with epoxy. The sealing of the cell was especially important as it helped keep the liquid from turning viscous over time. Previously, we'd often see the liquids become viscous and this would prevent the nanoparticle interactions that drive crystal growth from taking place."

Zheng and her colleagues chose to study the growth of platinum iron nanorods because of the electrocatalytic material's promising potential for use in next generation energy conversion and storage devices. They were able to observe these nanoparticles assemble into nanorod crystals using powerful transmission electron microscopes at Berkeley Lab's National Center for Electron Microscopy, including TEAM 0.5 (Transmission Electron Aberration-corrected Microscope), which can produce images with half angstrom resolution less than the diameter of a single hydrogen atom.

"From what we observed only single nanoparticles exist at the beginning of crystal growth, but, as growth proceeds, small chains of nanoparticles become dominant until, ultimately, only long chains of nanoparticles can be seen," Zheng says. "Our observations provide a link between the world of single molecules and hierarchical nanostructures, paving the way for the rational design of nanomaterials with controlled properties."


'/>"/>

Contact: Lynn Yarris
lcyarris@lbl.gov
510-486-5375
DOE/Lawrence Berkeley National Laboratory
Source:Eurekalert  

Related biology technology :

1. Light touch keeps a grip on delicate nanoparticles
2. New measuring techniques can improve efficiency, safety of nanoparticles
3. Metal nanoparticles shine with customizable color
4. Marshall study shows nanoparticles used as additives in diesel fuels can travel from lungs to liver
5. How to count nanoparticles
6. Nanoparticles seek and destroy glioblastoma in mice
7. Hydrogen released to fuel cell more quickly when stored in metal nanoparticles
8. Rice University lab develops technique to control light from nanoparticles
9. New technique maps twin faces of smallest Janus nanoparticles
10. TU Delft: cheap and efficient solar cell made possible by linked nanoparticles
11. Artificial nanoparticles influence the heart rate
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Nanoparticles seen as artificial atoms
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial ... Cary 5000 and the 6000i models are higher end machines that use the more ... the spectrophotometer’s light beam from the bottom of the cuvette holder. , FireflySci ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... release of its second eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering ... retention in this eBook by providing practical tips, tools, and strategies for clinical ...
(Date:6/23/2016)... CAMBRIDGE, Mass. , June 23, 2016 /PRNewswire/ ... the development of novel compounds designed to target ... compound, napabucasin, has been granted Orphan Drug Designation ... in the treatment of gastric cancer, including gastroesophageal ... cancer stemness inhibitor designed to inhibit cancer stemness ...
(Date:6/23/2016)... SILVER SPRING, Md. , June 23, 2016 ... evidence collected from the crime scene to track the criminal ... sick, and the U.S. Food and Drug Administration (FDA) uses ... Sound far-fetched? It,s not. ... whole genome sequencing to support investigations of foodborne illnesses. Put ...
Breaking Biology Technology:
(Date:6/9/2016)... , June 9, 2016 ... Police deploy Teleste,s video security solution to ensure the safety ... France during the major tournament Teleste, ... communications systems and services, announced today that its video security ... to back up public safety across the country. ...
(Date:6/2/2016)... June 2, 2016 Perimeter Surveillance ... Unmanned Systems, Physical Infrastructure, Support & Other Service  ... visiongain offers comprehensive analysis of the global ... will generate revenues of $17.98 billion in 2016. ... Inc, a leader in software and hardware technologies for ...
(Date:5/12/2016)... , May 12, 2016 WearablesResearch.com , ... published the overview results from the Q1 wave of ... recent wave was consumers, receptivity to a program where ... with a health insurance company. "We were ... share," says Michael LaColla , CEO of Troubadour ...
Breaking Biology News(10 mins):