Confocal microRaman Spectroscopy

Single-walled carbon nanotubes have large resonant Raman scattering cross sections. When the polarization direction of a laser beam coincides with the long axis of a SWNT, the scattered intensity is maximized. Polarized microscopy is therefore quite useful to identify the presence and alignment of SWNT in composites.

A modified Renishaw 1000 spectrometer utilizing two excitation wavelengths (785 nm, 633 nm), X-Y-Z translation stage, and additional X-Y-Rotation stage are used to measure alignment and dispersion of SWNT in polymer composites, as well as estimate the purity of SWNT produced by laser vaporization and CVD. The instrument has been modified for confocal operation (to collect light only from a small volume of a transparent sample).

Back to