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 No chance for house dust mites
06.05.2015 | Hohenstein Institute

nachricht Expedition Genomics Lab: the mobile revolution in genetic analysis
06.05.2015 | MUSE Museo delle Scienze

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Spray drying the precision particle under the virtual magnifying glass

Spray drying is a common manufacturing process, used in the production of ceramic granulate for technical components or dental prostheses as well as dissolvable medicinal substances, food additives and in the processing of milk into powder. Using computer simulation methodology developed by scientists at the Fraunhofer Institute for Mechanics of Materials IWM, a more comprehensible understanding can now be gained of the behavior of particles in solvent during the spray drying process. This allows powder and granulate manufacturers to specifically adjust the properties of their products while reducing waste.

Previously, it was unusual for granule and powder producers to use granulation simulations to improve their products. For new product development or process...

Im Focus: The random raman laser: A new light source for the microcosmos

Texas A&M University researchers demonstrate how a narrow-band strobe light source for speckle-free imaging has the potential to reveal microscopic forms of life

In modern microscope imaging techniques, lasers are used as light sources because they can deliver fast pulsed and extremely high-intensity radiation to a...

Im Focus: Pulsar with widest orbit ever detected

Discovered by high school research team

A team of highly determined high school students discovered a never-before-seen pulsar by painstakingly analyzing data from the National Science Foundation's...

Im Focus: Erosion, landslides and monsoon across the Himalaya

Scientists from Nepal, Switzerland and Germany was now able to show how erosion processes caused by the monsoon are mirrored in the sediment load of a river crossing the Himalaya.

In these days, it was again tragically demonstrated that the Himalayas are one of the most active geodynamic regions of the world. Landslides belong to the...

Im Focus: Through the galaxy by taxi - The Dream Chaser Space Utility Vehicle

A world-class prime systems integrator and electronic systems provider known for its rapid, innovative, and agile technology solutions, Sierra Nevada Corporation (SNC) is currently developing a new space transportation system called the Dream Chaser.

The ultimate aim is to construct a multi-mission-capable space utility vehicle, while accelerating the overall development process for this critical capability...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Green Summit 2015: the summit of the essential

05.05.2015 | Event News

HHL Energy Conference on May 11/12, 2015: Students Discuss about Decentralized Energy

23.04.2015 | Event News

“Developing our cities, preserving our planet”: Nobel Laureates gather for the first time in Asia

23.04.2015 | Event News

 
Latest News

Expedition Genomics Lab: the mobile revolution in genetic analysis

06.05.2015 | Life Sciences

How noise changes the way the brain gets information

06.05.2015 | Life Sciences

A model approach for sustainable phosphorus recovery from wastewater

06.05.2015 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>