(119y) Preparation and Testing of Carbon Nanotube Composites by Various Methods

Multi-walled carbon nanotubes (MWCNTs) were deagglomerated by various methods to be incorporated into a polymer matrix in order to make a high performance composite. Deagglomeration methods studied in this work include ultrasound, rapid expansion of supercritical suspensions (RESS), and the functionalization of MWCNTs. Following deagglomeration, MWCNTs were stabilized in solution using the anionic surfactant, sodium dodecyl sulfate (SDS), in order to keep a highly dispersed homogenous suspension. Polyethylene oxide (PEO), a water soluble polymer, was used as the polymer component in this work. Thin composite films were achieved using the solvent casting method and hot-pressed into uniform sized films. Electrical conductivity of the PEO/MWCNT films was tested to determine the extent to which the MWCNT were deagglomerated and the level of dispersion within the polymer matrix. Highly deagglomerated MWCNTs will disperse easily throughout a polymer matrix and in turn yield a composite film with a high conductivity. The deagglomeration methods were compared and it was found that a combination of RESS and ultrasound yield the most promising results. In addition, RESS was also explored in depth as a method to deagglomerate CNT using image analysis. It was found that RESS effectively de-agglomerates tight bundles of CNT into loose meshes.