Characterization of single walled carbon nanotube: Polyvinylene difluoride composites

Composites of polyvinylene difluoride (PVdF) and single walled carbon nanotubes (SWNTs) produced by evaporation of suspensions of PVdF and SWNTs in acetone while being subjected to sonication are characterized. Raman measurements of the PVdF/SWNT composites showed sizable shifts of the radial breathing and tangential mode frequencies of the SWNT compared with the values in pristine SWNTs indicative of interaction between the PVdF and the SWNT. Changes of the frequencies and intensities of the CH stretching modes of PVdF were also observed. Variable temperature F-19 NMR measurements show differences in the line widths of the PVdF/SWNT composite compared to the pristine polymer but no differences were observed in the spin-lattice relaxation time. Composites containing 6.7% SWNTs by weight showed a 30% increase in hardness and a resistivity of 3.38 Omega cm. Ferromagnetic resonance and magnetization measurements indicated the composites were ferromagnetic due to presence of iron nanoparticles used as catalysts in the synthesis of the carbon nanotubes. (c) 2005 Elsevier Ltd. All rights reserved.