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 Nonstop Tranport of Cargo in Nanomachines
20.11.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Researchers find social cultures in chimpanzees
20.11.2018 | Universität Leipzig

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>