Featured Research

from universities, journals, and other organizations

First direct observation of oriented attachment in nanocrystal growth

Date:
May 24, 2012
Source:
DOE/Lawrence Berkeley National Laboratory
Summary:
Researchers have reported the first direct observation of nanoparticles undergoing oriented attachment, the critical step in biomineralization and the growth of nanocrystals. A better understanding of oriented attachment in nanoparticles is a key to synthesizing new materials with remarkable structural properties.

Berkeley Lab researchers at the Molecular Foundry have elucidated important mechanisms behind oriented attachment, the phenomenon that drives biomineralization and the growth of nanocrystals.
Credit: Image courtesy of Jim DeYorero

Through biomineralization, nature is able to produce such engineering marvels as mother of pearl, or nacre, the inner lining of abalone shells renowned for both its iridescent beauty and amazing toughness. Key to biomineralization is the phenomenon known as "oriented attachment," whereby adjacent nanoparticles connect with one another in a common crystallographic orientation. While the importance of oriented attachment to biomineral properties long has been recognized, the mechanism by which it occurs has remained a mystery. With a better understanding of oriented attachment it should be possible to synthesize new materials with remarkable structural properties.

To that end, a team of researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have reported the first direct observation of what they have termed "jump-to-contact," the critical step in oriented attachment.

"The direct observation of the translational and rotational accelerations associated with the jump-to-contact between nanoparticles enabled us to calculate the forces that drive oriented attachment," said Jim DeYoreo, a scientist with the Molecular Foundry, a DOE nanoscience center at Berkeley Lab where this research took place. "This gives us a basis for testing models and simulations that could open the door to using oriented attachment in the synthesis of unique new materials."

DeYoreo is the corresponding author of a paper in the journal Science that describes this research titled "Direction-specific interactions control crystal growth by oriented attachment." Co-authoring this paper were Dongsheng Li, Michael Nielsen, Jonathan Lee, Cathrine Frandsen and Jillian Banfield.

Ever since a study in 2000 led by co-author Banfield revealed the existence of nanoparticle oriented attachment, it has become widely recognized that the phenomenon is an important mechanism of crystal growth in many natural and biomimetic materials, as well as in the synthesis of nanowires.

"Such nanocrystal systems often exhibit complex forms ranging from quasi-one dimensional chains to three-dimensional hierarchical superstructures, but typically diffract as a single crystal, implying that the primary particles underwent alignment during growth," says Li, first author of the Science paper and member of DeYoreo's research group. "When particle alignment is accompanied by coalescence, this growth is characterized as oriented attachment, however, the pathway by which nanoparticles become aligned and attached has been poorly understood."

To learn more about the interactions and forces that drive oriented attachment, the Berkeley researchers studied the early crystal growth of iron oxide nanoparticles. Iron oxides are abundant in Earth's crust and play an important role in the biogeochemical processes that shape near-surface environments. Using a silicon liquid cell mounted within a high-resolution transmission electron microscope at the Molecular Foundry, the research team recorded images with sufficient resolution to track nanoparticle orientations throughout the growth of the crystals.

"We observed the particles undergoing continuous rotation and interaction until they found a perfect lattice match at which point a sudden jump-to-contact occurred over a distance of less than one nanometer," DeYoreo says. "This jump-to-contact is followed by lateral atom-by-atom additions initiated at the contact point. The measured translational and rotational accelerations show that strong, highly-direction-specific interactions drive crystal growth via oriented attachment."

The information gained from this investigation into the oriented attachment of iron oxide nanoparticles should be applicable not only to the future synthesis of biomimetic materials, but also to environmental restoration efforts. Scientists now know that mineralization in natural environments often proceeds through particle-particle attachment events and plays an important part in the sequestration of contaminants. Understanding the forces behind oriented attachment should also advance the development of branched or tree-like semiconductor nanowires, structures in which one or more secondary nanowires grow radially from a primary nanowire.

"Branched semiconductor nanowires are being pursued for applications in photocatalysis, photovoltaics and nanoelectronics because of their large surface areas, small diameters, and ability to form natural junctions," DeYoreo says. "An understanding of the underlying mechanisms that control nanowire branching should help materials scientists develop more effective strategies for producing these materials."

This research was primarily supported by the DOE Office of Science.


Story Source:

The above story is based on materials provided by DOE/Lawrence Berkeley National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Li, M. H. Nielsen, J. R. I. Lee, C. Frandsen, J. F. Banfield, J. J. De Yoreo. Direction-Specific Interactions Control Crystal Growth by Oriented Attachment. Science, 2012; 336 (6084): 1014 DOI: 10.1126/science.1219643

Cite This Page:

DOE/Lawrence Berkeley National Laboratory. "First direct observation of oriented attachment in nanocrystal growth." ScienceDaily. ScienceDaily, 24 May 2012. <www.sciencedaily.com/releases/2012/05/120524143456.htm>.
DOE/Lawrence Berkeley National Laboratory. (2012, May 24). First direct observation of oriented attachment in nanocrystal growth. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2012/05/120524143456.htm
DOE/Lawrence Berkeley National Laboratory. "First direct observation of oriented attachment in nanocrystal growth." ScienceDaily. www.sciencedaily.com/releases/2012/05/120524143456.htm (accessed April 17, 2014).

Share This



More Matter & Energy News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
Powered by NewsLook.com
German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
Powered by NewsLook.com
Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

TheStreet (Apr. 16, 2014) The Porsche Spyder 918 proves that, in an automotive world obsessed with fuel efficiency, the supercar is not dead. Porsche North America CEO Detlev von Platen attributes the brand's consistent sales growth -- 21% in 2013 -- with an investment in new technology and expanded performance dynamics. The hybrid Spyder 918 has 887 horsepower and 944 lb-ft of torque, but it can run 18 miles on just an electric charge. The $845,000 vehicle is not a consumer-targeted vehicle but a brand statement. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins