Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists learn to build curved structures with nanoscale building blocks

16.01.2004


The natural world is full of curves and three dimensions, but the ability to deliberately and rationally construct such complex structures using nanoscale building blocks has eluded nanotechnologists who are eager to add curved structures to their toolbox.



Now a team of Northwestern University chemists report they have discovered ways to construct nanoscale building blocks that assemble into flat or curved structures with a high level of predictability, depending on the architecture and composition of the building blocks. The results will be published in the Jan. 16 issue of the journal Science.

Using hybrid nanorods consisting of segments of gold and conducting polymers as their building blocks, the researchers created a number of unusual structures, including bundles, sheets and tubes of varying diameters. The extraordinary control that they were able to demonstrate over the process holds promise for building new and powerful drug delivery systems, electronic circuits, catalysts and light-harvesting materials.


"We are trying to mimic life itself," said Chad A. Mirkin, director of Northwestern’s Institute for Nanotechnology, who led the research team. "Much like proteins which must fold into complex structures in order to function properly, we have designed new materials that also form complex structures through the process of self-assembly."

Mirkin and his team made the different structures by varying the diameter of the gold-polymer rods or adjusting the ratio of polymer segment to gold segment in the rods. Both methods should enable researchers to design structures with interesting electronic and optical properties.

"We also discovered that the alumina template we used to build the rods initially is essential in guiding the assembly process," said Mirkin, also George B. Rathmann Professor of Chemistry. "Without the orientation the template provides, the rods do not form bundles, sheets or tubes."

The nanorods were made by the sequential deposition of gold and conducting polymer into the pores of an aluminum template. After the gold-polymer rods were synthesized, the template was dissolved, leaving the rods parallel to one another, gold end to gold end and polymer end to polymer end. The strong interactions between the polymer ends built stress, causing curves to form.

In a subsequent experiment, the researchers observed that self-assembly did not take place when the rods were randomly dispersed in solution.

"The research clearly shows that some unnatural building blocks, such as the gold-polymer rods, need assistance in order to form higher-ordered structures," said Mirkin. "This means that when we work with building blocks that are larger than molecules but smaller than macroscopic objects, we should consider building materials in a completely new way -- by using templates to help guide the assembly process and reduce the large number of assembly pathways potentially available to the building blocks."


In addition to Mirkin, other authors on the Science paper are Sungho Park (lead author), Jung-Hyurk Lim and Sung-Wook Chung, all from Northwestern University. The research was supported by the National Science Foundation and the U.S. Air Force Office of Scientific Research.

Megan Fellman | EurekAlert!
Further information:
http://www.nwu.edu/

More articles from Life Sciences:

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

nachricht Topological Quantum Chemistry
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

Scientists announce the quest for high-index materials

24.07.2017 | Materials Sciences

ADIR Project: Lasers Recover Valuable Materials

24.07.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>