Aligned carbon nanotube-polymer composites: Investigating their electrical and physical characteristics

Single wall carbon nanotube (SWNT)-polymer composites aligned by an AC electric field were characterized using Raman spectroscopy and electrical conductivity measurements to assess the resulting alignment. The Polarized Raman spectra was recorded at several angles between the SWNT axis and the incident polarization ranging from 0degrees to 180degrees. Inspection of the spectra revealed that maximum intensity is obtained when the polarization of incident radiation is parallel to the SWNT axis (alpha(i) = 0degrees and alpha(i) = 180degrees), while the smallest intensity is obtained when the polarization of incident radiation is perpendicular to the SWNT axis (alpha(i) = 90degrees). The electrical measurements were made in three directions; parallel to the aligned SWNTs and perpendicular to the aligned SWNTs. Based on the electrical conductivity and polarized Raman spectroscopy measurements, it can be concluded that the SWNTs in the polymer matrix were preferentially aligned by applying an AC electric field of 43.5 V/mm at a frequency of 1 Hz, 10 Hz, 10 KHz and 100 KHz.