Browsing by Author "Ziegler, Kirk J."

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    Bulk cutting of carbon nanotubes using electron beam irradiation
    (2013-09-24) Ziegler, Kirk J.; Rauwald, Urs; Hauge, Robert H.; Schmidt, Howard K.; Smalley, Richard E.; Kittrell, Carter W.; Gu, Zhenning; Rice University; United States Patent and Trademark Office
    According to some embodiments, the present invention provides a method for attaining short carbon nanotubes utilizing electron beam irradiation, for example, of a carbon nanotube sample. The sample may be pretreated, for example by oxonation. The pretreatment may introduce defects to the sidewalls of the nanotubes. The method is shown to produces nanotubes with a distribution of lengths, with the majority of lengths shorter than 100 tun. Further, the median length of the nanotubes is between about 20 nm and about 100 nm.
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    Length-based liquid-liquid extraction of carbon nanotubes using a phase transfer catalyst
    (2009-08-25) Ziegler, Kirk J.; Schmidt, Daniel J.; Hauge, Robert H.; Smalley, Richard E.; Marek, Irene Morin; Rice University; United States Patent and Trademark Office
    The present invention is generally directed to new liquid-liquid extraction methods for the length-based separation of carbon nanotubes (CNTs) and other 1-dimensional nanostructures. In some embodiments, such methods are directed to separating SWNTs on the basis of their length, wherein such methods comprise the steps of: (a) functionalizing SWNTs to form functionalized SWNTs with ionizable functional moieties; (b) dissolving said functionalized SWNTs in a polar solvent to form a polar phase; (c) dissolving a substoichiometric (relative to the amount of ionizable functional moieties present on the SWNTs) amount of a phase transfer agent in a non-polar solvent to form a non-polar phase; (d) combining the polar and non-polar phases to form a bi-phase mixture; (e) adding a cationic donor species to the bi-phase mixture; and (f) agitating the bi-phase mixture to effect the preferential transport of short SWNTs into the non-polar phase such that the non-polar phase is enriched in short SWNTs and the polar phase is enriched in longer SWNTs. In other embodiments, analogous methods are used for the length-based separation of any type of CNT, and more generally, for any type of 1-dimensional nanostructure.
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    Ozonation of carbon nanotubes in fluorocarbons
    (2008-12-30) Ziegler, Kirk J.; Shaver, Jonah; Hauge, Robert H.; Marek, Irene Morin; Rice University; United States Patent and Trademark Office
    The present invention is generally directed to methods of ozonating CNTs in fluorinated solvents (fluoro-solvents), wherein such methods provide a less dangerous alternative to existing ozonolysis methods. In some embodiments, such methods comprise the steps of: (a) dispersing carbon nanotubes in a fluoro-solvent to form a dispersion; and (b) reacting ozone with the carbon nanotubes in the dispersion to functionalize the sidewalls of the carbon nanotubes and yield functionalized carbon nanotubes with oxygen-containing functional moieties. In some such embodiments, the fluoro-solvent is a fluorocarbon solvent, such as a perfluorinated polyether.