Soft-Bake Purification Of Single-Walled Carbon Nanotubes Produced By Pulsed Laser Vaporizationt

Metal impurities within as-produced single-walled carbon nanotubes (SWCNTs) are generally coated with thick shells of graphitic carbon, which prevent the. acid treatments commonly used in SWCNT purification from attacking the metals. The purpose of this study was to determine a more effective and efficient means for the removal of metal impurities from SWCNTs produced by pulsed laser vaporization (PLV). The method investigated was a modified version of a soft-bake purification procedure developed at Rice University, and in the current work, the soft-bake temperature suitable for PLV-produced SWCNTs was determined, and several samples were purified. The quality of material was determined using the standard protocol developed at NASA Johnson Space Center (JSC), and data was collected for several samples in order to determine the consistency and reproducibility of the purification yield and purity. The properties and quality of soft-bake purified material were compared with those of several equivalent materials purified by the JSC standard purification method. It is found that this modified procedure resulted in better purity of SWCNTs, while reducing the purification time by two-thirds.