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 New application for acoustics helps estimate marine life populations
16.01.2018 | University of California - San Diego

nachricht Unexpected environmental source of methane discovered
16.01.2018 | University of Washington Health Sciences/UW Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Gran Chaco: Biodiversity at High Risk

17.01.2018 | Ecology, The Environment and Conservation

Only an atom thick: Physicists succeed in measuring mechanical properties of 2D monolayer materials

17.01.2018 | Physics and Astronomy

Fraunhofer HHI receives AIS Technology Innovation Award 2018 for 3D Human Body Reconstruction

17.01.2018 | Awards Funding

VideoLinks
B2B-VideoLinks
More VideoLinks >>>