We find that the Raman G band for individual double wall carbon nanotubes is split when the two walls are closely spaced or strongly coupled. We show that agglomeration of tubes into bundles leads to line broadening and overlapping of the G bands from the inner and outer tubes. This demonstrates that the observed broadening is not due to defects in the tube walls. We identify the tube helicity of an individual double wall tube. The consequence of our finding is that mapping of the Raman G band allows us to access the dispersion state of carbon nanotubes in a composite matrix.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2010: Advanced Materials, CNTs, Particles, Films and Composites
Published: June 21, 2010
Pages: 172 - 175
Industry sector: Advanced Materials & Manufacturing
Topic: Carbon Nano Structures & Devices