Abstract:
This invention relates generally to a single-wall carbon nanotube (SWNT) purification process and more particularly to a purification process that comprises heating the SWNT-containing felt under oxidizing conditions to remove the amorphous carbon deposits and other contaminating materials. In a preferred mode of this purification procedure, the felt is heated in an aqueous solution of an inorganic oxidant, such as nitric acid, a mixture of hydrogen peroxide and sulfuric acid, or a potassium permanganate. Preferably, SWNT-containing felts are refluxed in an aqueous solution of an oxidizing acid at a concentration high enough to etch away amorphous carbon deposits within a practical time frame, but not so high that the single-wall carbon nanotube material will be etched to a significant degree. When material having a high proportion of SWNT is purified, the preparation produced will be enriched in single-wall nanotubes, so that the SWNT are substantially free of other material.
Abstract:
This invention relates generally to a method for producing composites of single-wall carbon nanotubes (SWNTs) and compositions thereof. In one embodiment, the present invention involves a method of producing a composite material that includes a matrix and a carbon nanotube material embedded within said matrix. In another embodiment, a method of producing a composite material containing carbon nanotube material is disclosed. This method includes the steps of preparing an assembly of a fibrous material; adding the carbon nanotube material to the fibrous material; and adding a matrix material precursor to the carbon nanotube material and the fibrous material.
Abstract:
This invention relates generally to carbon fiber produced from single-wall carbon nanotube (SWNT) molecular arrays. In one embodiment, the carbon fiber which comprises an aggregation of substantially parallel carbon nanotubes comprises more than one molecular array. Another embodiment of this invention is a large cable-like structure with enhanced tensile properties comprising a number of smaller separate arrays. In another embodiment, a composite structure is disclosed in which a central core array of metallic SWNTs is surrounded by a series of smaller circular non-metallic SWNT arrays.
Abstract:
Macroscopically manipulable nanoscale devices made from nanotube assemblies are disclosed. The article of manufacture comprises a macroscopic mounting element capable of being manipulated or observed in a macroscale environment, and a nanoscale nanotube assembly attached to the mounting element. The article permits macroscale information to be provided to or obtained from a nanoscale environment. A method for making a macroscopically manipulable nanoscale devices comprises the steps of (1) providing a nanotube-containing material; (2) preparing a nanotube assembly device having at least one carbon nanotube for attachment; and (3) attaching said nanotube assembly to a surface of a mounting element.
Abstract:
This invention relates generally to cutting single-wall carbon nanotubes (SWNT). In one embodiment, the present invention provides for preparation of homogeneous populations of short carbon nanotube molecules by cutting and annealing (reclosing) the nanotube pieces followed by fractionation. The cutting and annealing processes may be carried out on a purified nanotube bucky paper, on felts prior to purification of nanotubes or on any material that contains single-wall nanotubes. In one embodiment, oxidative etching with concentrated nitric acid is employed to cut SWNTs into shorter lengths. The annealed nanotubes may be disbursed in an aqueous detergent solution or an organic solvent for the fractionation. Closed tubes can also be derivatized to facilitate fractionation, for example, by adding solubilizing moieties to the end caps.
Abstract:
This invention relates generally to a method for growing carbon fiber from single-wall carbon nanotube (SWNT) molecular arrays. The carbon fiber which comprises an aggregation of substantially parallel carbon nanotubes may be produced by growth (elongation) of a suitable seed molecular array. The first step is to open the growth end of the SWNTs in the molecular array. Next, a transition metal catalyst is added to the open-ended seed array. In the next step, the SWNT molecular array with catalyst deposited on the open tube ends is subjected to tube growth (extension) conditions. The carbon supply necessary to grow the SWNT molecular array into a continuous fiber is supplied to the SWNT molecular array tip heated to a temperature sufficient to cause growth to any desired length. The continuous carbon fiber can also be grown from more than one separately prepared molecular arrays or templates.
Abstract:
This invention is directed to making chemical derivatives of carbon nanotubes and to uses for the derivatized nanotubes, including making arrays as a basis for synthesis of carbon fibers. In one embodiment, this invention also provides a method for preparing single wall carbon nanotubes having substituents attached to the side wall of the nanotube by reacting single wall carbon nanotubes with fluorine gas and recovering fluorine derivatized carbon nanotubes, then reacting fluorine derivatized carbon nanotubes with a nucleophile. Some of the fluorine substituents are replaced by nucleophilic substitution. If desired, the remaining fluorine can be completely or partially eliminated to produce single wall carbon nanotubes having substituents attached to the side wall of the nanotube. The substituents will, of course, be dependent on the nucleophile, and preferred nucleophiles include alkyl lithium species such as methyl lithium. Alternatively, fluorine may be fully or partially removed from fluorine derivatized carbon nanotubes by reacting the fluorine derivatized carbon nanotubes with various amounts of hydrazine, substituted hydrazine or alkyl amine. The present invention also provides seed materials for growth of single wall carbon nanotubes comprising a plurality of single wall carbon nanotubes or short tubular molecules having a catalyst precursor moiety covalently bound or physisorbed on the outer surface of the sidewall to provide the optimum metal cluster size under conditions that result in migration of the metal moiety to the tube end.
Abstract:
This invention relates generally to forming a patterned array of fullerene nanotubes. In one embodiment, a nanoscale array of microwells is provided on a substrate; a metal catalyst is deposited in each microwells; and a stream of hydrocarbon or CO feedstock gas is directed at the substrate under conditions that effect growth of fullerene nanotubes from each microwell.
Abstract:
This invention relates generally to forming a patterned array of fullerene nanotubes. In one embodiment, a nanoscale array of microwells is provided on a substrate; a metal catalyst is deposited in each microwells; and a stream of hydrocarbon or CO feedstock gas is directed at the substrate under conditions that effect growth of fullerene nanotubes from each microwell.
Abstract:
This invention relates generally to a fullerene nanotube composition. The fullerene nanotubes may be in the form of a felt, such as a bucky paper. Optionally, the fullerene nanotubes may be derivatized with one or more functional groups. Devices employing the fullerene nanotubes of this invention are also disclosed.