Purification of surface-modified arc-discharge single-walled carbon nanotubes by centrifugation processes

Talk delivered at GDR-I GNT2013 conference, held at Guidel-Plages (France), from 8th-12th April 2013.Arc-discharge single-walled carbon nanotubes (SWCNTs) demonstrate well-defined spectroscopic responses and a high structural quality. In addition, the arc-discharge technique allows the synthesis of relatively large amounts of material, and the product is available at moderate prices. However, pristine arc-discharge SWCNTs contain large amounts of impurities, including catalyst metals, graphitic particles, and amorphous carbon. Well-purified commercial samples are expensive since current purification processes are time consuming and have low yields. Liquid media, which are necessary for the purification, change the physical aggregation of the SWCNTs or modify its chemical reactivity. Therefore, chemical studies on high-purity arc-discharge SWCNTs are limited. In this communication, we present our results on SWCNT purification by centrifugation or ultracentrifugation in aqueous media. More specifically, we study the influence of surface chemistry on the separation of arc-discharge SWCNTs from their impurities during the centrifugation. The results of processing chemically modified materials are analyzed in terms of graphitic and amorphous carbon impurities, residual metal content, and SWCNT spectral characteristics.Peer reviewe