Featured Research

from universities, journals, and other organizations

Magnetic Nanoparticles Assembled Into Long Chains

Date:
October 23, 2005
Source:
National Institute of Standards and Technology
Summary:
Chains of 1 million magnetic nanoparticles have been assembled and disassembled in a solution of suspended particles in a controlled way, scientists at the National Institute of Standards and Technology (NIST) report. Such particles and structures, once their properties are more fully understood and can be manipulated reliably, may be useful in applications such as medical imaging and information storage.

Colorized transmission electron micrograph showing chains of cobalt nanoparticles.
Credit: Image credit: G. Cheng, A.R. Hight Walker/NIST

Chains of 1 million magnetic nanoparticles have been assembled and disassembled in a solution of suspended particles in a controlled way, scientists at the National Institute of Standards and Technology (NIST) report. Such particles and structures, once their properties are more fully understood and can be manipulated reliably, may be useful in applications such as medical imaging and information storage.

The NIST work, scheduled to be featured on the cover of an upcoming issue of Langmuir* (an American Chemical Society journal), is the first to demonstrate the formation and control of centimeter-long chains of magnetic nanoparticles of a consistent size and quality in a solution. The researchers spent several years learning how to make cobalt particles with controllable size and shape, and they hope to use this knowledge to eventually "build" useful structures.

The researchers induce the nanoparticles to form linear chains by subjecting them to a weak magnetic field--about the same strength as a refrigerator magnet. The particles line up because the nanoparticles act like tiny bar magnets, all facing the same direction as the applied field. Once this alignment occurs, the attraction between particles is so strong that reversing the direction of the applied magnetic field causes the whole chain to rotate 180 degrees. When the magnetic field is turned off, the chains fold into three-dimensional coils. When the solution is lightly shaken, the chains fall apart into small rings. NIST scientists used optical and transmission electron microscopes to characterize these structures.

Magnetic particles have already been used in medical imaging and information storage, and nano-sized particles may offer unique or improved properties. For example, magnetic nanoparticle dyes may improve contrast between healthy and diseased tissue in magnetic resonance imaging (MRI), a possibility under study by a different NIST research group. The authors of the Langmuir paper are now developing methods to improve the biocompatibility of these magnetic nanoparticles.

###

*G. Cheng, D. Romero, G.T. Fraser, and A.R. Hight Walker. 2005. Magnetic-field-induced assemblies of cobalt nanoparticles. Langmuir. December. Posted online Oct. 12.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology. Note: Materials may be edited for content and length.


Cite This Page:

National Institute of Standards and Technology. "Magnetic Nanoparticles Assembled Into Long Chains." ScienceDaily. ScienceDaily, 23 October 2005. <www.sciencedaily.com/releases/2005/10/051023122633.htm>.
National Institute of Standards and Technology. (2005, October 23). Magnetic Nanoparticles Assembled Into Long Chains. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2005/10/051023122633.htm
National Institute of Standards and Technology. "Magnetic Nanoparticles Assembled Into Long Chains." ScienceDaily. www.sciencedaily.com/releases/2005/10/051023122633.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) — British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
7 Ways to Use Toothpaste: Howdini Hacks

7 Ways to Use Toothpaste: Howdini Hacks

Howdini (July 30, 2014) — Fresh breath and clean teeth are great, but have you ever thought, "my toothpaste could be doing more". Well, it can! Lots of things! Howdini has 7 new uses for this household staple. Video provided by Howdini
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) — A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) — Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
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