Featured Research

from universities, journals, and other organizations

Important mechanism behind nanoparticle reactivity discovered

Date:
November 3, 2013
Source:
University of York
Summary:
An international team of researchers has used pioneering electron microscopy techniques to discover an important mechanism behind the reaction of metallic nanoparticles with the environment.

An international team of researchers has used pioneering electron microscopy techniques to discover an important mechanism behind the reaction of metallic nanoparticles with the environment.

Related Articles


Crucially, the research led by the University of York and reported in Nature Materials, shows that oxidation of metals -- the process that describes, for example, how iron reacts with oxygen, in the presence of water, to form rust -- proceeds much more rapidly in nanoparticles than at the macroscopic scale. This is due to the large amount of strain introduced in the nanoparticles due to their size which is over a thousand times smaller than the width of a human hair.

Improving the understanding of metallic nanoparticles -- particularly those of iron and silver -- is of key importance to scientists because of their many potential applications. For example, iron and iron oxide nanoparticles are considered important in fields ranging from clean fuel technologies, high density data storage and catalysis, to water treatment, soil remediation, targeted drug delivery and cancer therapy.

The research team, which also included scientists from the University of Leicester, the National Institute for Materials Science, Japan and the University of Illinois at Urbana-Champaign, USA, used the unprecedented resolution attainable with aberration-corrected scanning transmission electron microscopy to study the oxidisation of cuboid iron nanoparticles and performed strain analysis at the atomic level.

Lead investigator Dr Roland Krφger, from the University of York's Department of Physics, said: "Using an approach developed at York and Leicester for producing and analysing very well-defined nanoparticles, we were able to study the reaction of metallic nanoparticles with the environment at the atomic level and to obtain information on strain associated with the oxide shell on an iron core.

"We found that the oxide film grows much faster on a nanoparticle than on a bulk single crystal of iron -- in fact many orders of magnitude quicker. Analysis showed there was an astonishing amount of strain and bending in nanoparticles which would lead to defects in bulk material."

The scientists used a method known as Z-contrast imaging to examine the oxide layer that forms around a nanoparticle after exposure to the atmosphere, and found that within two years the particles were completely oxidised.

Corresponding author Dr Andrew Pratt, from York's Department of Physics and Japan's National Institute for Materials Science, said: "Oxidation can drastically alter a nanomaterial's properties -- for better or worse -- and so understanding this process at the nanoscale is of critical importance. This work will therefore help those seeking to use metallic nanoparticles in environmental and technological applications as it provides a deeper insight into the changes that may occur over their desired functional lifetime."

The experimental work was carried out at the York JEOL Nanocentre and the Department of Physics at the University of York, the Department of Physics and Astronomy at the University of Leicester and the Frederick-Seitz Institute for Materials Research at the University of Illinois at Urbana-Champaign.

The scientists obtained images over a period of two years. After this time, the iron nanoparticles, which were originally cube-shaped, had become almost spherical and were completely oxidised.

Professor Chris Binns, from the University of Leicester, said: "For many years at Leicester we have been developing synthesis techniques to produce very well-defined nanoparticles and it is great to combine this technology with the excellent facilities and expertise at York to do such penetrating science. This work is just the beginning and we intend to capitalise on our complementary abilities to initiate a wider collaborative programme."

The research was supported by a Max-Kade Foundation Visiting Professorship stipend to Dr Krφger and financial support from the World Universities Network (WUN). The Engineering and Physical Sciences Research Council (EPSRC) funded the initial stages of the project (EP/D034604/1).


Story Source:

The above story is based on materials provided by University of York. Note: Materials may be edited for content and length.


Journal Reference:

  1. Andrew Pratt, Leonardo Lari, Ondrej Hovorka, Amish Shah, Charles Woffinden, Steve P Tear, Chris Binns and Roland Krφger. Enhanced Oxidation of Nanoparticles through Strain-Mediated Ionic Transport. Nature Materials, 2013

Cite This Page:

University of York. "Important mechanism behind nanoparticle reactivity discovered." ScienceDaily. ScienceDaily, 3 November 2013. <www.sciencedaily.com/releases/2013/11/131103140257.htm>.
University of York. (2013, November 3). Important mechanism behind nanoparticle reactivity discovered. ScienceDaily. Retrieved February 28, 2015 from www.sciencedaily.com/releases/2013/11/131103140257.htm
University of York. "Important mechanism behind nanoparticle reactivity discovered." ScienceDaily. www.sciencedaily.com/releases/2013/11/131103140257.htm (accessed February 28, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Saturday, February 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Elon Musk's Hyperloop Moves Forward

Elon Musk's Hyperloop Moves Forward

Buzz60 (Feb. 27, 2015) — Zipping around at 800-miles an hour is coming closer to reality in California. An entire town is being built around Elon Musk&apos;s Hyperloop concept and it wants you to stop in for a ride when it&apos;s ready. Brett Larson is on board. Video provided by Buzz60
Powered by NewsLook.com
Vibrating Bicycle Senses Traffic

Vibrating Bicycle Senses Traffic

Reuters - Innovations Video Online (Feb. 26, 2015) — Dutch scientists have developed a smart bicycle that uses sensors, wireless technology and video to warn riders of traffic dangers. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
In Japan, Robot Dogs Are for Life -- And Death

In Japan, Robot Dogs Are for Life -- And Death

AFP (Feb. 25, 2015) — Robot dogs are the perfect pet for some in Japan who go to repairmen-turned-vets when their pooch breaks down - while a full Buddhist funeral ceremony awaits those who don&apos;t make it. Duration: 02:40 Video provided by AFP
Powered by NewsLook.com
London Show Dissects History of Forensic Science

London Show Dissects History of Forensic Science

AFP (Feb. 25, 2015) — Forensic science, which has fascinated generations with its unravelling of gruesome crime mysteries, is being put under the microscope in an exhibition of real criminal investigations in London. Duration: 00:53 Video provided by AFP
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:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

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