Carbon-based nanomaterials have unique properties that make them useful for many technical applications, including lightweight construction, electronics, energy generation, environmental technology, and medicine.
In the journal Angewandte Chemie, an international team of researchers has now introduced a new process for the production of especially fine carbon nanowires from carbon in the diamond configuration. In this process, molecules with a diamond-like structure are linked together inside a carbon nanotube.
On the occasion of the 125th anniversary of Angewandte Chemie, a one-day symposium is held on March 12 with several Nobel laureates. Learn more and join the webcast at chemistryviews.org/angewandtechemie125.
Carbon occurs in several configurations. Graphite and diamond have long been known. While graphite consists of two-dimensional, honeycomb-like sheets of carbon, diamonds are three- dimensional, cage-like structures consisting of puckered six-carbon rings. A variety of new nanoconfigurations have also been discovered: fullerenes, carbon nanotubes, graphene (graphite monolayers), nanodiamonds, and diamondoids. Diamondoids are actually cycloalkane molecules with a skeleton of carbon configured in "cages", like diamond. They can be viewed as miniature diamonds with hydrogen atoms bound to their outer surfaces.Nanowires are needed for many nanoscale applications. Various types of nanowire have been produced, including some with diameters ranging from about 50 to 100 nm, made of carbon in the diamond configuration. A team of researchers from Japan, China, Germany, and the USA wanted to reduce the dimensions of nanowires further into the sub-nanometer range. Such tiny wires could be of use in the tips of scanning tunneling microscopes, which are devices that can be used to scan the topology of a surface to produce extremely high-resolution images.
Researchers led by Hisanori Shinohara at Nagoya University (Japan) came up with the idea of fusing diamondoids into longer, superfine wires.
To make this work they had to resort to a trick: carbon nanotube "molds". For their starting material, the scientists chose diadamantane, a diamondoid made of two diamond-like cages. They attached a carbonic acid group at each end of these molecules. The molecules are transferred to the gas phase for the synthetic procedure. They are sucked into the tiny carbon nanotubes by capillary action. The best nanotube molds were found to be those with an inner diameter of about 1.3 nm.Within the nanotubes, the diamondoids line up like a string of pearls. Heating these to about 600 °C under a hydrogen atomsphere causes a polymerization/fusion reaction in which the individual diamondoid molecules link up through their carbonic acid groups to form a long "wire" with a diameter of about 0.78 nm. The cage-like structure is maintained.
By using theoretical calculations and various analytical techniques, the scientists were able to demonstrate that the carbon in the wires is indeed in a diamond-like structure.
Currently, the scientists are elaborating an ultrasonication extraction technique for releasing the nanowires from the surrounding carbon nanotubes.About the Author
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201209192
Hisanori Shinohara | Angewandte Chemie
A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)
CWRU researchers find a chemical solution to shrink digital data storage
22.06.2017 | Case Western Reserve University
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.
New Manufacturing Technologies for New Products
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
22.06.2017 | Life Sciences
22.06.2017 | Materials Sciences
22.06.2017 | Materials Sciences