Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chains of Gold and Palladium

24.02.2014
Copolymerization of metal nanoparticles for the production of colloidal plasmonic copolymers

Molecules can copolymerize to form longer composite chains; it turns out that nanoparticles called colloidal particles can also copolymerize to make hybrid nanostructures. The fact that these reactions occur in a very similar manner is not obvious, but this could be used to carry out fundamental studies of copolymerization reactions. However, colloidal polymers are primarily useful for the development of highly complex nanosystems. In the journal Angewandte Chemie, a team of Chinese, Canadian, and American researchers has presented a report about the copolymerization of gold nanorods of various sizes as well as gold and palladium nanorods.


Polymers made of metal nanoparticles are particularly interesting because of their plasmons – quantized charge carrier density oscillations resulting from the collective excitation of free electrons to plasma oscillations. Long chains of metal nanoparticles known as plasmonic polymers display strong interactions between the plasmons of the individual building blocks.

Their optical properties can be controlled by means of factors like the degree of polymerization, the size of the nanoparticles, or the distance between particles. Copolymer chains made from nanoparticles with different sizes, shapes and compositions are even more interesting as they offer another degree of freedom in tuning the properties (and potentially, leading to new properties) of plasmonic polymers. Potential applications could include smaller computer chips, improved nanoantennas and sensors, and improved optical data processing.

The researchers from Jilin University (China), the University of Toronto (Canada), and the University of North Carolina (USA) have now developed methods for applying strategies from molecular copolymerization (the polymerization of different monomers together) to the co-assembly of nanorods of varying sizes and composition. Led by Kun Liu and Eugenia Kumacheva, the team uses gold nanorods with polystyrene chains on the ends as building blocks.

Addition of water to the organic solvent containing a suspension of the nanorods causes the polystyrene ends, which are only poorly soluble in water, to bond tightly together, connecting the nanorods into long polymer chains. This approach was extended to the co-assembly of random and block copolymers of gold nanorods of different length as well as random copolymers of gold and palladium nanorods. (Random copolymers contain different monomers in a random order; in a block copolymer the polymer chain contains larger domains of either one or the other monomer.)

The researchers were able to establish a model for the reactions that confirmed and extended established kinetic theories for molecular stepwise copolymerization reactions. The colloidal polymers obtained also provide an excellent model system for the fundamental investigation of plasmonic properties such as special modes resulting from the asymmetry of nanostructures with irregularly distributed components.

About the Author

Dr. Eugenia Kumacheva is a University Professor at the University of Toronto with a major appointment in the Department of Chemistry and cross-appointments in the Department of Chemical Engineering and the Institute of Biomaterials and Biomedical Engineering (IBBME). Her main specialty is the chemistry, physics, and materials science of soft matter, with the focus on polymers, nanoscience, and microfluidics. She is Fellow of the Royal Society of Canada, and recipient of a Humboldt Research Award and a Fellowship from the Killam Foundation. In 2009 she was awarded the L'Oreal-Unesco "Women in Science" Award given to five women in the world, one from each continent.

Author: Eugenia Kumacheva, University of Toronto (Canada), http://www.chem.utoronto.ca/staff/EK/index.htm

Title: Copolymerization of Metal Nanoparticles: A Route to Colloidal Plasmonic Copolymers

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201309718

Dr. Eugenia Kumacheva | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

Further reports about: Palladium chains of Gold polymerization

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

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...

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

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>