Ambient air manufacture for vertical carbon nanofibres

VACNFs hold promise for use in gene-delivery tools, sensors, batteries and other technologies.

Conventional techniques for creating VACNFs rely on the use of ammonia gas, which is toxic.

‘This discovery makes VACNF manufacture safer and cheaper, because you don’t need to account for the risks and costs associated with ammonia gas,’ said Dr Anatoli Melechko, an adjunct associate professor of materials science and engineering at NC State and senior author of a paper on the work. ‘This also raises the possibility of growing VACNFs on a much larger scale.’

In the most common method for VACNF manufacture, a substrate coated with nickel nanoparticles is placed in a vacuum chamber and heated to 700 degrees Celsius.

The chamber is then filled with ammonia gas and either acetylene or acetone gas, which contain carbon.

When a voltage is applied to the substrate and a corresponding anode in the chamber, the gas is ionized. This creates plasma that directs the nanofibre growth.