‘Because we’re using an airbrush, this technique could easily be incorporated into large-scale, high-throughput manufacturing processes,’ said Dr. Anatoli Melechko, an adjunct associate professor of materials science and engineering at North Carolina State University and co-author of a paper describing the work. ‘In principle, you could cover an entire building with it.’
‘It’s common to use nickel nanoparticles as catalysts to grow carbon nanofibres, and we were able to coat metal substrates with nickel nanoparticles using an airbrush,’ said Dr. Joseph Tracy, an associate professor of materials science and engineering at NC State and senior author of the paper. ‘Airbrushing gives us a fairly uniform coating of the substrate and it can be applied to a large area at room temperature in a short period of time.’
According to NC State, after applying the nickel nanoparticles, the researchers airbrushed the substrate with a layer of silicon powder and heated the coated substrate to 600 degrees Celsius in a reactor filled with acetylene and ammonia gas.
In the reactor, carbon nanofibres formed under the nickel nanoparticles and were held upright by a silicon-enriched coating. The finished product resembles a forest of nanofibres running perpendicular to the substrate. The researchers tested this technique successfully on aluminium, copper and titanium substrates.
‘Growing carbon nanofibres on a metal substrate means the interface between the two materials is highly conductive, which makes the product more useful as an electrode material for use in a range of potential applications,’ said Mehmet Sarac, a Ph.D. student at NC State and lead author of the paper.
The paper, ‘Airbrushed Nickel Nanoparticles for Large-Area Growth of Vertically Aligned Carbon Nanofibres on Metal (Al, Cu, Ti) Surfaces,’ has been published online in ACS Applied Materials & Interfaces.
The work was supported by the US National Science Foundation, the Defense Threat Reduction Agency, the US Department of Energy and the Republic of Turkey’s Ministry of National Education.