title: Purification of single-walled carbon nanotubes.
abstract: The discovery of carbon nanotubes (CNTs) created much excitement and stimulated extensive research into the properties of nanometer-scale cylindrical networks. From then on, various methods for the synthesis and characterization of aligned CNTs-both single-walled (SWCNTs) and multi-walled (MWCNTs) by different methods have been hotly pursued. Unfortunately, most methods currently in use produce raw multi component solid products, only a small fraction of which contains carbon nanotubes. The balance of the material is composed of residual catalyst particles (some of which are encased in concentric graphitic shells), fullerenes, other graphitic materials and amorphous carbon. These impurities cause a serious impediment for their detailed characterization and applications. If the carbon nanotube is ever to fulfill its promise as an engineering material, large, high quality aliquots will be required. A number of purification methods involving elimination processes such as physical separation, gas phase and liquid phase oxidation in combination with chemical treatments have been developed for nanotube materials. Though the quantitative determination of purity remains controversial, reported yields are best regarded with an appropriate level of skepticism on the method of assay. In this article, a review is given on the past and recent advances in purification of SWCNTs.
authors.affiliation: National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, 1-Meiring Naude Road, Brummeria, PO. Box 395, Pretoria 0001, Republic of South Africa.
authors.forename: Sreejarani K
authors.initials: SK
authors.lastname: Pillai
authors.forename: Suprakas Sinha
authors.initials: SS
authors.lastname: Ray
authors.forename: Mathew
authors.initials: M
authors.lastname: Moodley
mesh_terms: D002244:Carbon / Q000737:chemistry; D003198:Computer Simulation; D037741:Fullerenes / Q000737:chemistry; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013059:Spectrum Analysis, Raman; D013696:Temperature
chemical_list: D037741:Fullerenes; D037742:Nanotubes, Carbon; D002244:Carbon