German researchers have developed a new path to produce carbon nanomembranes that can be used to filter toxins from the air.
A team from Bielefield University led by Professor Armin Gölzhäuser has designed and tested a method that allows creating a variety of nanomembranes that are much thinner than conventional ones.
In fact, the material-separating tissues consists of just one layer of molecules. The method has been described in an article that will be published in an upcoming issue of the ACS Nano journal.
"Up until now, we have produced small samples of a size of a few square centimetres," said Professor Gölzhäuser. "However, with this process it is possible to make nanomembranes that are as big as square metres."
The method uses carbon material in the form of powder that is dissolved in pure alcohol. In this solution, very thin metal layers are being immersed, creating a one-molecule-thick coating on the metal’s surface.
Afterwards, the material is exposed to electron irradiation, which turns the monolayer into a cross-linked nanomembrane. The supporting metal is than disintegrated, leaving only the super-thin nanomembrane.
“Every starting material has a different property, from thickness or transparency to elasticity. By using our process, these characteristics are transferred onto the nanomembrane,” Professor Gölzhäuser explained. “In this way, carbon nanomembranes can be produced to address many different needs, which has not been possible until now,” said Gölzhäuser.
Researchers believe the technique could be used also to manufacture graphene – a wonder material believed to bring about another technological revolution in the future.
According to Gölzhäuser, all it takes to use the method for graphene production is heating the membranes in a vacuum at the temperature of about 700 °C.
The University of Bielefield team cooperates on the project with the Ulm University, Frankfurt University and the Max Planck Institute for Polymer Research.