Scientists used carbon nanotubes to toughen graphene and increase its stretchability, according to a report published on August 2, 2018.
This study was conducted by the researchers at the Rice University. As per the study, fracture-resistant rebar graphene was found to be twice more tough as pristine graphene. Graphene is a one-atom-thick sheet of carbon, which is stronger than steel on a two-dimensional scale. However, it is subjected to ripping and tearing, as graphene is very thin.
A nanoscale analog of rebar (reinforcement bars) in concrete is called as rebar graphene, in which embedded steel bars enhance the strength and durability of the material. Carbon nanotubes were used in rebar graphene for reinforcement. When stress-test was conducted on rebar graphene, researchers found that nanotube rebar aided in diverting and bridging cracks, which would otherwise propagate in unreinforced graphene.
From the experiments, it was clear that nanotubes improved stretchability of graphene and reduced the effects of cracks. This property could be beneficial for its use in flexible electronics and electrically active wearables or other devices which requires stress tolerance, flexibility, transparency, and mechanical stability.
Graphene has good conductivity, which makes it suitable for devices, however, brittle nature is a drawback about graphene. Similar tests were carried out on rebar graphene that were made by spin-coating single-walled nanotubes onto a copper substrate and growing graphene atop them via chemical vapor deposition. The graphene was pulled into pieces to carry out stress-test of rebar graphene. After pulling it into pieces, the force that was applied was measured. A method was developed by the researchers to cut microscopic pieces of the material through trial and error and further observed it under the microscopes. Jun Lou, graduate student said, “We hope this opens a direction people can pursue to engineer 2D material features for applications.”