An international research team’s theoretical simulation of the synthesis of single-walled carbon nanotubes has revealed important details of the mechanisms at play. This could lead to better ways to control the production of carbon nanotubes.
The synthesis of carbon nanotubes (CNTs), with a view to their industrial-scale production, is attracting heavy scientific interest. Their unique chemical properties promise a wide variety of groundbreaking uses in acoustic, biomedical, electronic, environmental, optical and structural technologies.
Led by Professor Stephan Irle of the Institute of Transformative Bio-Molecules at Nagoya University, a team of researchers in Japan, the United States and China conducted computer simulations that show similar molecular mechanisms at work in the growth of carbon nanotubes and the combustion of hydrocarbons to form soot. This discovery challenges a previously accepted view that metal carbides are needed to create nanotubes, through a process called chemical vapour deposition.
The team’s own models suggest that alternative chemical processes such as hydrogen- bstraction/acetylene addition – a mechanism often observed in combustion processes – could also be used to grow carbon nanotubes. “This finding is very intriguing in the sense that these processes were long considered to proceed by completely different mechanisms,” says Professor Irle.
In 2014, the team reported the first growth simulations of single-walled carbon nanotube synthesis, using acetylene as a feedstock. Their simulation model used acetylene due to the relatively low temperatures needed to catalyse chemical vapour deposition, and because even small amounts speed up reactions significantly. According to the researchers, their modelling suggests that acetylene’s potential role needs further study, as does the currently accepted model for carbon nanotube production.
Since publishing their results, the researchers have started modelling the synthesis of graphene – a one atomthick layer of pure carbon – using nickel and copper with a methane catalyst. They hope to publicly release the new simulation model – based on a direct version of a kinetic Monte Carlo simulation where reaction channels are predicted automatically on the fly as the growth process proceeds – in 2015.
DID YOU KNOW?
Carbon nanotubes are nanocylinders consisting of one atom-thick sheets of carbon (or graphene). They are currently used as additives to strengthen various structural materials, and may also be used for energy storage as well as in the next generation of nanoelectronics and biomedical devices. CNTs are often synthesised via chemical vapour deposition, in which hydrocarbon vapour is deposited on metal catalysts under a flow of non-reactive gas at high temperatures. However, quality control is a challenge since this method usually results in the production of CNTs with variable diameters and different sidewall structures.
For further information contact:
Professor Stephan Irle
Institute of Transformative Bio-Molecules
World Premier International Research Center Initiative
Nagoya University, Japan
Institute of Transformative Bio-Molecules (ITbM), Nagoya University
*This article also appears in Asia Research News 2015 (P.61).
Ayako Miyazaki | ResearchSEA
Superresolution live-cell imaging provides unexpected insights into the dynamic structure of mitochondria
18.02.2020 | Heinrich-Heine-Universität Düsseldorf
Blood and sweat: Wearable medical sensors will get major sensitivity boost
18.02.2020 | Moscow Institute of Physics and Technology
Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.
Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...
Investigation of the temperature dependence of the skyrmion Hall effect reveals further insights into possible new data storage devices
The joint research project of Johannes Gutenberg University Mainz (JGU) and the Massachusetts Institute of Technology (MIT) that had previously demonstrated...
Researchers at Chalmers University of Technology, Sweden, recently completed a 5-year research project looking at how to make fibre optic communications systems more energy efficient. Among their proposals are smart, error-correcting data chip circuits, which they refined to be 10 times less energy consumptive. The project has yielded several scientific articles, in publications including Nature Communications.
Streaming films and music, scrolling through social media, and using cloud-based storage services are everyday activities now.
After helping develop a new approach for organic synthesis -- carbon-hydrogen functionalization -- scientists at Emory University are now showing how this approach may apply to drug discovery. Nature Catalysis published their most recent work -- a streamlined process for making a three-dimensional scaffold of keen interest to the pharmaceutical industry.
"Our tools open up whole new chemical space for potential drug targets," says Huw Davies, Emory professor of organic chemistry and senior author of the paper.
Superconductivity approaching room temperature may be possible in hydrogen-rich compounds at much lower pressures than previously expected
Reaching room-temperature superconductivity is one of the biggest dreams in physics. Its discovery would bring a technological revolution by providing...
12.02.2020 | Event News
16.01.2020 | Event News
15.01.2020 | Event News
18.02.2020 | Power and Electrical Engineering
18.02.2020 | Information Technology
18.02.2020 | Physics and Astronomy