Browsing by Author "Kittrell, Carter W."
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Item 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 OfficeAccording 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.Item Carbon nanotube diameter selection by pretreatment of metal catalysts on surfaces(2012-02-28) Hauge, Robert H.; Xu, Ya-Qiong; Shan, Hongwei; Nicholas, Nolan Walker; Kim, Myung Jong; Schmidt, Howard K.; Kittrell, Carter W.; Rice University; United States Patent and Trademark OfficeA new and useful nanotube growth substrate conditioning processes is herein disclosed that allows the growth of vertical arrays of carbon nanotubes where the average diameter of the nanotubes can be selected and/or controlled as compared to the prior art.Item Carbon nanotube substrates and catalyzed hot stamp for polishing and patterning the substrates(2009-09-08) Wang, Yuhuang; Hauge, Robert H.; Schmidt, Howard K.; Kim, Myung Jong; Kittrell, Carter W.; Rice University; United States Patent and Trademark OfficeThe present invention is generally directed to catalyzed hot stamp methods for polishing and/or patterning carbon nanotube-containing substrates. In some embodiments, the substrate, as a carbon nanotube fiber end, is brought into contact with a hot stamp (typically at 200-800° C.), and is kept in contact with the hot stamp until the morphology/patterns on the hot stamp have been transferred to the substrate. In some embodiments, the hot stamp is made of material comprising one or more transition metals (Fe, Ni, Co, Pt, Ag, Au, etc.), which can catalyze the etching reaction of carbon with H2, CO2, H2O, and/or O2. Such methods can (1) polish the carbon nanotube-containing substrate with a microscopically smooth finish, and/or (2) transfer pre-defined patterns from the hot stamp to the substrate. Such polished or patterned carbon nanotube substrates can find application as carbon nanotube electrodes, field emitters, and field emitter arrays for displays and electron sources.Item Electrical device fabrication from nanotube formations(2013-03-12) Nicholas, Nolan Walker; Kittrell, Carter W.; Kim, Myung Jong; Schmidt, Howard K.; Rice University; United States Patent and Trademark OfficeA method for forming nanotube electrical devices, arrays of nanotube electrical devices, and device structures and arrays of device structures formed by the methods. Various methods of the present invention allow creation of semiconducting and/or conducting devices from readily grown SWNT carpets rather than requiring the preparation of a patterned growth channel and takes advantage of the self-controlling nature of these carpet heights to ensure a known and controlled channel length for reliable electronic properties as compared to the prior methods.Item Embedded arrays of vertically aligned carbon nanotube carpets and methods for making them(2015-06-30) Kim, Myung Jong; Nicholas, Nolan Walker; Kittrell, Carter W.; Schmidt, Howard K.; Rice University; United States Patent and Trademark OfficeAccording to some embodiments, the present invention provides a system and method for supporting a carbon nanotube array that involve an entangled carbon nanotube mat integral with the array, where the mat is embedded in an embedding material. The embedding material may be depositable on a carbon nanotube. A depositable material may be metallic or nonmetallic. The embedding material may be an adhesive material. The adhesive material may optionally be mixed with a metal powder. The embedding material may be supported by a substrate or self-supportive. The embedding material may be conductive or nonconductive. The system and method provide superior mechanical and, when applicable, electrical, contact between the carbon nanotubes in the array and the embedding material. The optional use of a conductive material for the embedding material provides a mechanism useful for integration of carbon nanotube arrays into electronic devices.Item Fibers comprised of epitaxially grown single-wall carbon nanotubes- and a method for added catalyst and continuous growth at the tip(2010-06-01) Kittrell, Carter W.; Wang, Yuhuang; Kim, Myung Jong; Hauge, Robert H.; Smalley, Richard E.; Marek, Irene Morin; Rice University; United States Patent and Trademark OfficeThe present invention is directed to fibers of epitaxially grown single-wall carbon nanotubes (SWNTs) and methods of making same. Such methods generally comprise the steps of: (a) providing a spun SWNT fiber; (b) cutting the fiber substantially perpendicular to the fiber axis to yield a cut fiber; (c) etching the cut fiber at its end with a plasma to yield an etched cut fiber; (d) depositing metal catalyst on the etched cut fiber end to form a continuous SWNT fiber precursor; and (e) introducing feedstock gases under SWNT growth conditions to grow the continuous SWNT fiber precursor into a continuous SWNT fiber.Item Gas-phase process for purifying single-wall carbon nanotubes and compositions thereof(2006-08-15) Smalley, Richard E.; Hauge, Robert H.; Chiang, Wan-Ting; Yang, Yuemei; Smith, Kenneth A.; Kittrell, Carter W.; Gu, Zhenning; Rice University; United States Patent and Trademark OfficeThe present invention relates to an all gas-phase process for the purification of single-wall carbon nanotubes and the purified single-wall carbon nanotube material. Known methods of single-wall carbon nanotube production result in a single-wall carbon nanotube product that contains single-wall carbon nanotubes in addition to impurities including residual metal catalyst particles and amounts of small amorphous carbon sheets that surround the catalyst particles and appear on the sides of the single-wall carbon nanotubes and “ropes” of single-wall carbon nanotubes. The purification process removes the extraneous carbon as well as metal-containing residual catalyst particles. The process comprises oxidation of the single-wall carbon nanotube material, reduction and reaction of a halogen-containing gas with the metal-containing species. The oxidation step may be done dry or in the presence of water vapor. The present invention provides a scalable means for producing high-purity single-wall carbon nanotube material.Item Method for separating single-wall carbon nanotubes and compositions thereof(2006-07-11) Smalley, Richard E.; Hauge, Robert H.; Kittrell, Carter W.; Sivarajan, Ramesh; Strano, Michael S.; Bachilo, Sergei M.; Weisman, R. Bruce; Rice University; United States Patent and Trademark OfficeThe invention relates to a process for sorting and separating a mixture of (n, m) type single-wall carbon nanotubes according to (n, m) type. A mixture of (n, m) type single-wall carbon nanotubes is suspended such that the single-wall carbon nanotubes are individually dispersed. The nanotube suspension can be done in a surfactant-water solution and the surfactant surrounding the nanotubes keeps the nanotube isolated and from aggregating with other nanotubes. The nanotube suspension is acidified to protonate a fraction of the nanotubes. An electric field is applied and the protonated nanotubes migrate in the electric fields at different rates dependent on their (n, m) type. Fractions of nanotubes are collected at different fractionation times. The process of protonation, applying an electric field, and fractionation is repeated at increasingly higher pH to separated the (n, m) nanotube mixture into individual (n, m) nanotube fractions. The separation enables new electronic devices requiring selected (n, m) nanotube types.Item Methods for selective functionalization and separation of carbon nanotubes(2011-02-15) Strano, Michael S.; Usrey, Monica; Barone, Paul; Dyke, Christopher A.; Tour, James M.; Kittrell, Carter W.; Hauge, Robert H.; Smalley, Richard E.; Marek, Irene Morin; Rice University; United States Patent and Trademark OfficeThe present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.Item Process utilizing pre-formed cluster catalysts for making single-wall carbon nanotubes(2005-07-05) Smalley, Richard E.; Hauge, Robert H.; Willis, Peter Athol; Kittrell, Carter W.; Rice University; United States Patent and Trademark OfficeA gas-phase method for producing high yields of single-wall carbon nanotubes with high purity and homogeneity is disclosed. The method involves using preformed metal catalyst clusters to initiate and grow single-wall carbon nanotubes. In one embodiment, multi-metallic catalyst precursors are used to facilitate the metal catalyst cluster formation. The catalyst clusters are grown to the desired size before mixing with a carbon-containing feedstock at a temperature and pressure sufficient to initiate and form single-wall carbon nanotubes. The method also involves using small fullerenes and preformed sections of single-wall carbon nanotubes, either derivatized or underivatized, as seed molecules for expediting the growth and increasing the yield of single-wall carbon nanotubes. The multi-metallic catalyst precursors and the seed molecules may be introduced into the reactor by means of a supercritical fluid. In addition the seed molecules may be introduced into the reactor via an aerosol or smoke.Item Process utilizing seeds for making single-wall carbon nanotubes(2006-05-30) Smalley, Richard E.; Hauge, Robert H.; Willis, Peter Athol; Kittrell, Carter W.; Rice University; United States Patent and Trademark OfficeA gas-phase method for producing high yields of single-wall carbon nanotubes with high purity and homogeneity is disclosed. The method involves using preformed metal catalyst clusters to initiate and grow single-wall carbon nanotubes. In one embodiment, multi-metallic catalyst precursors are used to facilitate the metal catalyst cluster formation. The catalyst clusters are grown to the desired size before mixing with a carbon-containing feedstock at a temperature and pressure sufficient to initiate and form single-wall carbon nanotubes. The method also involves using small fullerenes and preformed sections of single-wall carbon nanotubes, either derivatized or underivatized, as seed molecules for expediting the growth and increasing the yield of single-wall carbon nanotubes. The multi-metallic catalyst precursors and the seed molecules may be introduced into the reactor by means of a supercritical fluid. In addition the seed molecules may be introduced into the reactor via an aerosol or smoke.Item Pulsed-multiline excitation for color-blind fluorescence detection(2006-02-07) Scott, Graham B. I.; Kittrell, Carter W.; Curl, Robert F.; Metzker, Michael L.; Rice University; Baylor College of Medicine; United States Patent and Trademark OfficeThe present invention provides a technology called Pulse-Multiline Excitation or PME. This technology provides a novel approach to fluorescence detection with application for high-throughput identification of informative SNPs, which could lead to more accurate diagnosis of inherited disease, better prognosis of risk susceptibilities, or identification of sporadic mutations. The PME technology has two main advantages that significantly increase fluorescence sensitivity: (1) optimal excitation of all fluorophores in the genomic assay and (2) “color-blind” detection, which collects considerably more light than standard wavelength resolved detection. Successful implementation of the PME technology will have broad application for routine usage in clinical diagnostics, forensics, and general sequencing methodologies and will have the capability, flexibility, and portability of targeted sequence variation assays for a large majority of the population.Item Pulsed-multiline excitation for color-blind fluorescence detection(2009-03-31) Scott, Graham B. I.; Kittrell, Carter W.; Curl, Robert F.; Metzker, Michael L.; Baylor College of Medicine; Rice University; United States Patent and Trademark OfficeThe present invention provides a technology called Pulse-Multiline Excitation or PME. This technology provides a novel approach to fluorescence detection with application for high-throughput identification of informative SNPs, which could lead to more accurate diagnosis of inherited disease, better prognosis of risk susceptibilities, or identification of sporadic mutations. The PME technology has two main advantages that significantly increase fluorescence sensitivity: (1) optimal excitation of all fluorophores in the genomic assay and (2) “color-blind” detection, which collects considerably more light than standard wavelength resolved detection. This technology differs significantly from the current state-of-the-art DNA sequencing instrumentation, which features single source excitation and color dispersion for DNA sequence identification. Successful implementation of the PME technology will have broad application for routine usage in clinical diagnostics, forensics, and general sequencing methodologies and will have the capability, flexibility, and portability of targeted sequence variation assays for a large majority of the population.Item Pulsed-multiline excitation for color-blind fluorescence detection(2012-01-03) Scott, Graham B. I.; Kittrell, Carter W.; Curl, Robert F.; Metzker, Michael L.; Baylor College of Medicine; Rice University; United States Patent and Trademark OfficeThe present invention provides a technology called Pulse-Multiline Excitation or PME. This technology provides a novel approach to fluorescence detection with application for high-throughput identification of informative SNPs, which could lead to more accurate diagnosis of inherited disease, better prognosis of risk susceptibilities, or identification of sporadic mutations. The PME technology has two main advantages that significantly increase fluorescence sensitivity: (1) optimal excitation of all fluorophores in the genomic assay and (2) “color-blind” detection, which collects considerably more light than standard wavelength resolved detection. Successful implementation of the PME technology will have broad application for routine usage in clinical diagnostics, forensics, and general sequencing methodologies and will have the capability, flexibility, and portability of targeted sequence variation assays for a large majority of the population.Item Selective functionalization of carbon nanotubes(2009-08-11) Strano, Michael S.; Usrey, Monica; Barone, Paul; Dyke, Christopher A.; Tour, James M.; Kittrell, Carter W.; Hauge, Robert H.; Smalley, Richard E.; Rice University; United States Patent and Trademark OfficeThe present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.Item Strongly bound carbon nanotube arrays directly grown on substrates and methods for production thereof(2014-04-29) Hauge, Robert H.; Pint, Cary; Alvarez, Noe; Kittrell, Carter W.; Rice University; United States Patent and Trademark OfficeThe present disclosure describes carbon nanotube arrays having carbon nanotubes grown directly on a substrate and methods for making such carbon nanotube arrays. In various embodiments, the carbon nanotubes may be covalently bonded to the substrate by nanotube carbon-substrate covalent bonds. The present carbon nanotube arrays may be grown on substrates that are not typically conducive to carbon nanotube growth by conventional carbon nanotube growth methods. For example, the carbon nanotube arrays of the present disclosure may be grown on carbon substrates including carbon foil, carbon fibers and diamond. Methods for growing carbon nanotubes include a) providing a substrate, b) depositing a catalyst layer on the substrate, c) depositing an insulating layer on the catalyst layer, and d) growing carbon nanotubes on the substrate. Various uses for the carbon nanotube arrays are contemplated herein including, for example, electronic device and polymer composite applications.