title: Comparative dispersion studies of single-walled carbon nanotubes in aqueous solution.
abstract: Single-walled carbon nanotubes (SWCNT) produced by various methods are commercially available but systematic characterization of their dispersion behavior in aqueous solution is rare. Here, we compare the properties of various SWCNT after their dispersion in aqueous solution assisted by DNA oligo. UV-vis-NIR absorbance measurement and atomic force microscopy (AFM) imaging showed marked differences among SWCNT produced from arc-discharge (AD) method, chemical vapor deposition (CVD), and high-pressure carbon monoxide process (HiPCO). To our surprise, the SWCNT produced from AD method showed the highest nanotube purity and the cleanest AFM image, better than HiPCO SWCNT that has been used extensively for biological applications. We also report our systematic studies on optimizing dispersing conditions to maximize SWCNT solubility and remove insoluble materials. We recommend a low power and short time of sonication to disperse SWCNT to preserve their average lengths. These results altogether serve as a future guide for the usage of commercial SWCNT in water-based applications.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Byumseok
authors.initials: B
authors.lastname: Koh
authors.forename: Jong Bae
authors.initials: JB
authors.lastname: Park
authors.forename: Ximiao
authors.initials: X
authors.lastname: Hou
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
mesh_terms: D018625:Microscopy, Atomic Force; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D017942:Nitric Acid / Q000737:chemistry; D010084:Oxidation-Reduction; D010316:Particle Size; D011071:Poly T / Q000737:chemistry; D012995:Solubility; D013010:Sonication / Q000379:methods; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013464:Sulfuric Acids / Q000737:chemistry; D014461:Ultracentrifugation / Q000379:methods; D014867:Water / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; D013464:Sulfuric Acids; D014867:Water; D011071:Poly T; D017942:Nitric Acid; C033158:sulfuric acid