Browsing by Author "Billups, Edward W."

Now showing 1 - 7 of 7
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    Amplification of carbon nanotubes via seeded-growth methods
    (2013-10-22) Smalley, Richard E.; Hauge, Robert H.; Barron, Andrew R.; Tour, James M.; Schmidt, Howard K.; Billups, Edward W.; Dyke, Christopher A.; Moore, Valerie C.; Whitsitt, Elizabeth Anne; Anderson, Robin E.; Colorado Jr., Ramon; Stewart, Michael P.; Ogrin, Douglas C.; Rice University; United States Patent and Trademark Office
    The present invention is directed towards methods (processes) of providing large quantities of carbon nanotubes (CNTs) of defined diameter and chirality (i.e., precise populations). In such processes, CNT seeds of a pre-selected diameter and chirality are grown to many (e.g., hundreds) times their original length. This is optionally followed by cycling some of the newly grown material back as seed material for regrowth. Thus, the present invention provides for the large-scale production of precise populations of CNTs, the precise composition of such populations capable of being optimized for a particular application (e.g., hydrogen storage). The present invention is also directed to complexes of CNTs and transition metal catalyst precurors, such complexes typically being formed en route to forming CNT seeds.
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    Cytotoxicity and variant cellular internalization behavior of water-soluble sulfonated nanographene sheets in liver cancer cells
    (Springer, 2013) Corr, Stuart J.; Raoof, Mustafa; Cisneros, Brandon T.; Kuznetsov, Oleksandr; Massey, Katheryn; Kaluarachchi, Warna D.; Cheney, Matthew A.; Billups, Edward W.; Wilson, Lon J.; Curley, Steven A.; Richard E. Smalley Institute for Nanoscale Science and Technology
    Highly exfoliated sulfonated graphene sheets (SGSs), an alternative to graphene oxide and graphene derivatives, were synthesized, characterized, and applied to liver cancer cells in vitro. Cytotoxicity profiles were obtained using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, WST-1[2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, and lactate dehydrogenase release colorimetric assays. These particles were found to be non-toxic across the concentration range of 0.1 to 10 μg/ml. Internalization of SGSs was also studied by means of optical and electron microscopy. Although not conclusive, high-resolution transmission and scanning electron microscopy revealed variant internalization behaviors where some of the SGS became folded and compartmentalized into tight bundles within cellular organelles. The ability for liver cancer cells to internalize, fold, and compartmentalize graphene structures is a phenomenon not previously documented for graphene cell biology and should be further investigated.
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    Method for functionalizating carbon naontubes utilizing peroxides
    (2011-07-12) Khabashesku, Valery N.; Peng, Haiqing; Margrave, John L.; Margrave, Mary Lou; Billups, Edward W.; Ying, Yunming; Rice University; United States Patent and Trademark Office
    A method for functionalizing the wall of single-wall or multi-wall carbon nanotubes involves the use of acyl peroxides to generate carbon-centered free radicals. The method allows for the chemical attachment of a variety of functional groups to the wall or end cap of carbon nanotubes through covalent carbon bonds without destroying the wall or endcap structure of the nanotube. Carbon-centered radicals generated from acyl peroxides can have terminal functional groups that provide sites for further reaction with other compounds. Organic groups with terminal carboxylic acid functionality can be converted to an acyl chloride and further reacted with an amine to form an amide or with a diamine to form an amide with terminal amine. The reactive functional groups attached to the nanotubes provide improved solvent dispersibility and provide reaction sites for monomers for incorporation in polymer structures. The nanotubes can also be functionalized by generating free radicals from organic sulfoxides.
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    Method for functionalizing carbon nanotubes utilizing peroxides
    (2006-10-24) Khabashesku, Valery N.; Peng, Haiqing; Margrave, Mary Lou; Billups, Edward W.; Ying, Yunming; Rice University; United States Patent and Trademark Office
    A method for functionalizing the wall of single-wall or multi-wall carbon nanotubes involves the use of acyl peroxides to generate carbon-centered free radicals. The method allows for the chemical attachment of a variety of functional groups to the wall or end cap of carbon nanotubes through covalent carbon bonds without destroying the wall or endcap structure of the nanotube. Carbon-centered radicals generated from acyl peroxides can have terminal functional groups that provide sites for further reaction with other compounds. Organic groups with terminal carboxylic acid functionality can be converted to an acyl chloride and further reacted with an amine to form an amide or with a diamine to form an amide with terminal amine. The reactive functional groups attached to the nanotubes provide improved solvent dispersibility and provide reaction sites for monomers for incorporation in polymer structures. The nanotubes can also be functionalized by generating free radicals from organic sulfoxides.
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    Method for functionalizing carbon nanotubes utilizing peroxides
    (2010-06-22) Khabashesku, Valery N.; Peng, Haiqing; Margrave, John L.; Margrave, Mary Lou; Billups, Edward W.; Ying, Yunming; Rice University; United States Patent and Trademark Office
    A method for functionalizing the wall of single-wall or multi-wall carbon nanotubes involves the use of acyl peroxides to generate carbon-centered free radicals. The method allows for the chemical attachment of a variety of functional groups to the wall or end cap of carbon nanotubes through covalent carbon bonds without destroying the wall or endcap structure of the nanotube. Carbon-centered radicals generated from acyl peroxides can have terminal functional groups that provide sites for further reaction with other compounds. Organic groups with terminal carboxylic acid functionality can be converted to an acyl chloride and further reacted with an amine to form an amide or with a diamine to form an amide with terminal amine. The reactive functional groups attached to the nanotubes provide improved solvent dispersibility and provide reaction sites for monomers for incorporation in polymer structures. The nanotubes can also be functionalized by generating free radicals from organic sulfoxides.
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    Polyamide composites having flexible spacers
    (2014-08-26) Moniruzzaman, Mohammad; Winey, Karen I.; Chattopadhyay, Jayanta; Billups, Edward W.; Trustees of the University of Pennsylvania; Rice University; United States Patent and Trademark Office
    Provided are polyamide nanocomposites incorporating carbon nanotubes and other filler species. Also provided are related methods.
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    Reductive functionalization of carbon nanotubes
    (2010-07-20) Billups, Edward W.; Sadana, Anil K.; Liang, Feng; Hauge, Robert H.; Rice University; United States Patent and Trademark Office
    The present invention is directed to novel processes for the functionalization (derivatization) of carbon nanotubes and, as an extension, to fullerenes and other carbon surfaces. Generally, such processes involve reductive pathways. In some embodiments, carbon nanotubes are reacted with alkali metal and organic halides in anhydrous liquid ammonia. In other embodiments, polymers are grown from carbon nanotube sidewalls by reacting carbon nanotubes with alkali metal and monomer species in anhydrous liquid ammonia.