Alignments of Carbon Nanotubes in Polymer Matrix: A Raman Perspective

Carbon nanotubes are highly anisotropic due to their high aspect ratio, therefore it is very important to align them in CNT/polymer composites. The extent of alignment can be easily studied by Raman spectroscopy. Carbon nanotubes are aligned perpendicular and parallel to the polymer film by application of an external magnetic field in polyvinyl butyral (PVB). FT-IR spectra of these films suggest that there is no chemical reaction between CNT and polyvinyl butyral, but the decrease in the G band intensity of carbon nanotubes in Raman spectra suggests that the tangential site of carbon nanotubes faces the surface of the polymer film, indicating the alignment of the carbon nanotubes in a CNT/polymer composite.