Computational Studies of Defects in Nanoscale Carbon Materials
Extended defects in carbon nanotubes and graphene
We have studied experimentally the influence of defects on the physical properties on two carbon based nanostructures: carbon nanotubes and graphene. In carbon nanotubes Young's modulus measurements show that with nanotube diameter the number of extended defects strongly increases weakening the structure of the tube. We believe that this is due to instabilities in the catalysis of hydrocarbons in CVD grown nanotubes.
In the case of graphene we report the results of the characterization of graphene oxide and reduced graphene oxide flakes, putting a great emphasis on the latter ones, since they represent the starting material for future applications. Our ESR data bring information on the defect density in these flakes. The electrical resistivity studies through the charge transport mechanism give a further insight into the influence of defects on the extended electronic states.
Acknowledgments. All the collaborators in these topics are gratefully acknowledged. The work in Lausanne is supported by the Swiss NSF and a European network "IMPRESS".