Magnetic field alignment and electrical properties of solution cast PET-carbon nanotube composite films

Single-wall carbon nanotubes (SWNTs) were dispersed in a polyethylene terephthalate (PET) matrix by solution blending and then cast onto a glass substrate to create flexible films. Various SWNT loading concentrations were implemented (0.5, 1.0, and 3.0 wt%), and the processing method was repeated to produce films in the presence of magnetic fields (3.0 and 9.4 T). Alignment of the SWNTs in the PET matrix was characterized by Raman spectroscopy. Impedance spectroscopy was utilized to study the electrical behavior of the nanocomposites. It was concluded that SWNT concentration and dispersion are the key variables for improving electrical conductivity, while alignment plays a secondary role. Interestingly, it appears that a magnetic field may prove to be a novel method for improving the dispersion of unmodified SWNTs by disrupting van der Waals interactions.