Browsing by Author "Kosynkin, Dmitry V."

Now showing 1 - 8 of 8
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    Dissolution of graphite, graphite and graphene nanoribbons in superacid solutions and manipulation thereof
    (2017-01-03) Tour, James M.; Pasquali, Matteo; Behabtu, Natnael; Lomeda, Jay R.; Kosynkin, Dmitry V.; Duque, Amanda; Green, Micah J.; Parra-vasquez, A. Nicholas; Young, Colin; Rice University; United States Patent and Trademark Office
    Methods for dissolving carbon materials such as, for example, graphite, graphite oxide, oxidized graphene nanoribbons and reduced graphene nanoribbons in a solvent containing at least one superacid are described herein. Both isotropic and liquid crystalline solutions can be produced, depending on the concentration of the carbon material The superacid solutions can be formed into articles such as, for example, fibers and films, mixed with other materials such as, for example, polymers, or used for functionalization of the carbon material. The superacid results in exfoliation of the carbon material to produce individual particles of the carbon material. In some embodiments, graphite or graphite oxide is dissolved in a solvent containing at least one superacid to form graphene or graphene oxide, which can be subsequently isolated. In some embodiments, liquid crystalline solutions of oxidized graphene nanoribbons in water are also described.
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    Graphene compositions and drilling fluids derived therefrom
    (2012-05-22) Tour, James M.; Schmidt, Howard K.; Lomeda, Jay R.; Kosynkin, Dmitry V.; Doyle, Condell D.; Rice University; United States Patent and Trademark Office
    Drilling fluids comprising graphenes and nanoplatelet additives and methods for production thereof are disclosed. Graphene includes graphite oxide, graphene oxide, chemically-converted graphene, and functionalized chemically-converted graphene. Derivatized graphenes and methods for production thereof are disclosed. The derivatized graphenes are prepared from a chemically-converted graphene through derivatization with a plurality of functional groups. Derivatization can be accomplished, for example, by reaction of a chemically-converted graphene with a diazonium species. Methods for preparation of graphite oxide are also disclosed.
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    Graphene compositions and methods for production thereof
    (2013-01-29) Tour, James M.; Schmidt, Howard K.; Doyle, Condell D.; Kosynkin, Dmitry V.; Lomeda, Jay R.; Rice University; United States Patent and Trademark Office
    Drilling fluids comprising graphenes and nanoplatelet additives and methods for production thereof are disclosed. Graphene includes graphite oxide, graphene oxide, chemically-converted graphene, and functionalized chemically-converted graphene. Derivatized graphenes and methods for production thereof are disclosed. The derivatized graphenes are prepared from a chemically-converted graphene through derivatization with a plurality of functional groups. Derivatization can be accomplished, for example, by reaction of a chemically-converted graphene with a diazonium species. Methods for preparation of graphite oxide are also disclosed.
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    Graphene nanoribbons prepared from carbon nanotubes via alkali metal exposure
    (2015-03-31) Tour, James M.; Kosynkin, Dmitry V.; Rice University; United States Patent and Trademark Office
    In various embodiments, the present disclosure describes processes for preparing functionalized graphene nanoribbons from carbon nanotubes. In general, the processes include exposing a plurality of carbon nanotubes to an alkali metal source in the absence of a solvent and thereafter adding an electrophile to form functionalized graphene nanoribbons. Exposing the carbon nanotubes to an alkali metal source in the absence of a solvent, generally while being heated, results in opening of the carbon nanotubes substantially parallel to their longitudinal axis, which may occur in a spiralwise manner in an embodiment. The graphene nanoribbons of the present disclosure are functionalized on at least their edges and are substantially defect free. As a result, the functionalized graphene nanoribbons described herein display a very high electrical conductivity that is comparable to that of mechanically exfoliated graphene.
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    Highly oxidized graphene oxide and methods for production thereof
    (2016-08-30) Tour, James M.; Kosynkin, Dmitry V.; Rice University; United States Patent and Trademark Office
    A highly oxidized form of graphene oxide and methods for production thereof are described in various embodiments of the present disclosure. In general, the methods include mixing a graphite source with a solution containing at least one oxidant and at least one protecting agent and then oxidizing the graphite source with the at least one oxidant in the presence of the at least one protecting agent to form the graphene oxide. Graphene oxide synthesized by the presently described methods is of a high structural quality that is more oxidized and maintains a higher proportion of aromatic rings and aromatic domains than does graphene oxide prepared in the absence of at least one protecting agent. Methods for reduction of graphene oxide into chemically converted graphene are also disclosed herein. The chemically converted graphene of the present disclosure is significantly more electrically conductive than is chemically converted graphene prepared from other sources of graphene oxide.
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    Layer-by-layer removal of graphene
    (2015-04-14) Tour, James M.; Dimiev, Ayrat M.; Kosynkin, Dmitry V.; Rice University; United States Patent and Trademark Office
    The present invention provides methods of selectively removing one or more graphene layers from a graphene material by: (1) applying a metal to a surface of the graphene material; and (2) applying a hydrogen containing solution to the surface of the graphene material that is associated with the metal. The hydrogen containing solution dissolves the metal along with one or more layers of graphene associated with the metal, thereby removing the layer(s) of graphene from the graphene material. In some embodiments, the hydrogen containing solution is an acidic solution, such as hydrochloric acid. In some embodiments, the metal is zinc. In some embodiments, the methods of the present invention are utilized to selectively remove one or more layers of graphene from one or more targeted sites on the surface of a graphene material.
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    Methods for preparation of graphene nanoribbons from carbon nanotubes and compositions- thin films and devices derived therefrom
    (2014-04-22) Tour, James M.; Kosynkin, Dmitry V.; Higginbotham, Amanda; Price, Brandi Katherine; Rice University; United States Patent and Trademark Office
    Methods for producing macroscopic quantities of oxidized graphene nanoribbons are disclosed herein. The methods include providing a plurality of carbon nanotubes and reacting the plurality of carbon nanotubes with at least one oxidant to form oxidized graphene nanoribbons. The at least one oxidant is operable to longitudinally open the carbon nanotubes. In some embodiments, the reacting step takes place in the presence of at least one acid. In some embodiments, the reacting step takes place in the presence of at least one protective agent. Various embodiments of the present disclosure also include methods for producing reduced graphene nanoribbons by reacting oxidized graphene nanoribbons with at least one reducing agent. Oxidized graphene nanoribbons, reduced graphene nanoribbons and compositions and articles derived therefrom are also disclosed herein.
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    Water-soluble carbon nanotube compositions for drug delivery and medicinal applications
    (2014-07-22) Tour, James M.; Lucente-schultz, Rebecca; Leonard, Ashley; Kosynkin, Dmitry V.; Price, Brandi Katherine; Hudson, Jared L.; Conyers, Jodie L., Jr.; Moore, Valerie C.; Casscells, Ward S.; Myers, Jeffrey N.; Milas, Zvonimir L.; Mason, Kathy A.; Milas, Luka; Rice University; Board of Regents of the University of Texas System; United States Patent and Trademark Office
    Compositions comprising a plurality of functionalized carbon nanotubes and at least one type of payload molecule are provided herein. The compositions are soluble in water and PBS in some embodiments. In certain embodiments, the payload molecules are insoluble in water. Methods are described for making the compositions and administering the compositions. An extended release formulation for paclitaxel utilizing functionalized carbon nanotubes is also described.