Peanut-shaped nanostructures

February 22, 2007

This release is also available in German.

Tiny acorns that fuse together in pairs to form miniature peanuts - Japanese researchers have succeeded in producing peanut-shaped nanoparticles comprised of two different sulfur-containing substances. The ends of the "peanuts" are made of palladium sulfide and the center of cobalt sulfide, report scientists working with Toshiharu Teranishi in the journal Angewandte Chemie.

Unlike "normal-sized" granules, the structural characteristics - such as shape and size - of nanoscale inorganic particles have a significant effect on the physical and chemical properties of these tiny structures. Therefore, there is great interest in the discovery of processes for the controlled production of such particles.

Things get especially interesting when the nanoparticles are made of two different substances to give two different functionalities in one particle, such as luminescence and magnetism. Previous synthetic methods resulted in either a random, unordered mixture or defined core-shell structures in which one substance grows onto the surface of a particle of another. However, a few years ago, a team led by Teranishi was able to synthesize particles with an unequal distribution of two substances, palladium sulfide and cobalt sulfide. In this process, the tiny granules of noncrystalline palladium sulfide, which measure only a few nanometers, act as crystallization nuclei for crystalline cobalt sulfide. Once a few tiny cobalt sulfide particles have settled onto the nucleus, this becomes the preferred site for further crystal growth, and the cobalt sulfide crystal grows exclusively onto one side of the palladium sulfide granule. This results in acorn-shaped structures with palladium sulfide at one end and cobalt sulfide at the other.

The Japanese team has now gone a step further: under the right conditions, the tiny "acorns" can be induced to aggregate into pairs. The crystalline cobalt sulfide sides of the two acorns grow together into a continuous crystal lattice. This forms oblong particles with something of a "waist" - a shape reminiscent of a peanut.
-end-
Author: Toshiharu Teranishi, University of Tsukuba (Japan), http://www.chem.tsukuba.ac.jp/teranisi/member-e.html

Title: Anisotropically Phase-Segregated Pd-Co-Pd Sulfide Nanoparticles Formed by Fusing Two Co-Pd Sulfide Nanoparticles

Angewandte Chemie International Edition 2007, 46, No. 10, 1713-1715, doi: 10.1002/anie.200603865

Wiley

Related Nanoparticles Articles from Brightsurf:

An ionic forcefield for nanoparticles
Nanoparticles are promising drug delivery tools but they struggle to get past the immune system's first line of defense: proteins in the blood serum that tag potential invaders.

Phytoplankton disturbed by nanoparticles
Products derived from nanotechnology are efficient and highly sought-after, yet their effects on the environment are still poorly understood.

How to get more cancer-fighting nanoparticles to where they are needed
University of Toronto Engineering researchers have discovered a dose threshold that greatly increases the delivery of cancer-fighting drugs into a tumour.

Nanoparticles: Acidic alert
Researchers of Ludwig-Maximilians-Universitaet (LMU) in Munich have synthesized nanoparticles that can be induced by a change in pH to release a deadly dose of ionized iron within cells.

3D reconstructions of individual nanoparticles
Want to find out how to design and build materials atom by atom?

Directing nanoparticles straight to tumors
Modern anticancer therapies aim to attack tumor cells while sparing healthy tissue.

Sweet nanoparticles trick kidney
Researchers engineer tiny particles with sugar molecules to prevent side effect in cancer therapy.

A megalibrary of nanoparticles
Using straightforward chemistry and a mix-and-match, modular strategy, researchers have developed a simple approach that could produce over 65,000 different types of complex nanoparticles.

Dialing up the heat on nanoparticles
Rapid progress in the field of metallic nanotechnology is sparking a science revolution that is likely to impact all areas of society, according to professor of physics Ventsislav Valev and his team at the University of Bath in the UK.

Illuminating the world of nanoparticles
Scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) have developed a light-based device that can act as a biosensor, detecting biological substances in materials; for example, harmful pathogens in food samples.

Read More: Nanoparticles News and Nanoparticles Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.