Abstract: This invention is directed to the fluorination (or derivatization with alternative chemical species) of fullerene carbon nanocages as an efficient way to (a) facilitate synthesis of endohedral complexes by a significant reduction or elimination of the barriers for the entry of guest-ions, -atoms or molecules, and (b) to preserve the chemical stability of final product.

Abstract: This invention relates generally to membranes comprising an array of single-wall carbon nanotubes (SWNT) wherein the membrane is nanoporous. In one embodiment, the membrane comprises a substantially two-dimensional array of a homogeneous population of single-walled nanotubes aggregated in substantially parallel orientation to form a monolayer extending in directions substantially perpendicular to the orientation of the individual nanotubes. Using single-wall carbon nanotubes of the same type and structure provides a homogeneous array. By using different single-wall carbon nanotubes, either a random or ordered heterogeneous structure can be produced by employing successive reactions after removal of previously masked areas of a substrate.

Abstract: The present invention discloses the process of supplying high pressure (e.g., 30 atmospheres) CO that has been preheated (e.g., to about 1000° C.) and a catalyst precursor gas (e.g., Fe(CO)5) in CO that is kept below the catalyst precursor decomposition temperature to a mixing zone. In this mixing zone, the catalyst precursor is rapidly heated to a temperature that results in (1) precursor decomposition, (2) formation of active catalyst metal atom clusters of the appropriate size, and (3) favorable growth of SWNTs on the catalyst clusters. Preferably a catalyst cluster nucleation agency is employed to enable rapid reaction of the catalyst precursor gas to form many small, active catalyst particles instead of a few large, inactive ones. Such nucleation agencies can include auxiliary metal precursors that cluster more rapidly than the primary catalyst, or through provision of additional energy inputs (e.g., from a pulsed or CW laser) directed precisely at the region where cluster formation is desired.

Abstract: The present invention concerns a method for growing carbon nanotubes using a catalyst system that preferentially promotes the growth of single- and double-wall carbon nanotubes, rather than larger multi-walled carbon nanotubes. Ropes of the carbon nanotubes are formed that comprise single-wall and/or double-wall carbon nanotubes.

Abstract: The present invention concerns a method for growing carbon nanotubes using a catalyst system that preferentially promotes the growth of single- and double-wall carbon nanotubes, rather than larger multi-walled carbon nanotubes. Ropes of the carbon nanotubes are formed that comprise single-wall and/or double-wall carbon nanotubes.

Abstract: A continuous gas-phase method for producing single-wall carbon nanotubes at high catalyst productivity and high yield is disclosed. The method involves the use of a novel in-situ formed catalyst to initiate and grow single-wall carbon nanotubes using a carbon-containing feedstock in a high temperature and pressure process. The catalyst comprises in-situ-generated transition metal particles in contact with in-situ-generated refractory particles. The population of nucleating sites for single-wall carbon nanotubes is enhanced due to the ease of formation of a population of refractory particles. These, in turn, improve the nucleation and stability of the transition metal particles that grow on them. The larger number of transition metal particles translate into a larger number of sites for single-wall carbon nanotube production. The higher catalyst yields provide a means for obtaining higher purity single-wall carbon nanotubes.

Abstract: The present invention involves fibers of highly aligned single-wall carbon nanotubes and a process for making the same. The present invention provides a method for effectively dispersing single-wall carbon nanotubes. The process for dispersing the single-wall carbon nanotubes comprises mixing single-wall carbon nanotubes with 100% sulfuric acid or a superacid, heating and stirring under an inert, oxygen-free environment. The single-wall carbon nanotube/acid mixture is wet spun into a coagulant to form the single-wall carbon nanotube fibers. The fibers are recovered, washed and dried. The single-wall carbon nanotubes were highly aligned in the fibers, as determined by Raman spectroscopy analysis.

Abstract: Single-walled carbon nanotubes have been synthesized by the catalytic decomposition of both carbon monoxide and ethylene over a supported metal catalyst known to produce larger multi-walled nanotubes. Under certain conditions, there is no termination of nanotube growth, and production appears to be limited only by the diffusion of reactant gas through the product nanotube mat that covers the catalyst. The present invention concerns a catalyst-substrate system which promotes the growth of nanotubes that are predominantly single-walled tubes in a specific size range, rather than the large irregular-sized multi-walled carbon fibrils that are known to grow from supported catalysts.

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 forming a patterned array of single-wall carbon nanotubes (SWNT). 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 single-wall carbon nanotubes from each microwell.

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: The 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.

Abstract: This invention relates generally to a forming an array of single-wall carbon nanotubes (SWNT) in an electric field and compositions thereof. In one embodiment, a purified bucky paper of single-wall carbon nanotubes is used as the starting material. Upon oxidative treatment of the bucky paper surface, many tube and/or rope ends protrude up from the surface of the paper. Disposing the resulting bucky paper in an electric field results in the protruding tubes and or ropes of single-wall carbon nanotubes aligning in a direction substantially perpendicular to the paper surface. These tubes tend to coalesce to form a molecular array. In another embodiment, a molecular array of SWNTs can be made by “combing” the purified bucky paper starting material with a sharp microscopic tip to align the nanotubes.

Abstract: The 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.

Abstract: This invention provides a method of making single-wall carbon nanotubes by laser vaporizing a mixture of carbon and one or more Group VIII transition metals. Single-wall carbon nanotubes preferentially form in the vapor and the one or more Group VIII transition metals catalyzed growth of the single-wall carbon nanotubes. In one embodiment of the invention, one or more single-wall carbon nanotubes are fixed in a high temperature zone so that the one or more Group VIII transition metals catalyze further growth of the single-wall carbon nanotube that is maintained in the high temperature zone. In another embodiment, two separate laser pulses are utilized with the second pulse timed to be absorbed by the vapor created by the first pulse.

Abstract: This invention relates generally to forming an array of single-wall carbon nanotubes (SWNT). In one embodiment, a macroscopic molecular array is provided comprising at least about 106 single-wall carbon nanotubes in generally parallel orientation and having substantially similar lengths in the range of from about 5 to about 500 nanometers.

Abstract: This invention relates generally to forming an array of single-wall carbon nanotubes (SWNT) and compositions thereof. In one embodiment, a homogeneous population of SWNT molecules is used to produce a substantially two-dimensional array made up of single-walled nanotubes aggregated in substantially parallel orientation to form a monolayer extending in directions substantially perpendicular to the orientation of the individual nanotubes. Using SWNT molecules of the same type and structure provides a homogeneous array. By using different SWNT molecules, either a random or ordered heterogeneous structure can be produced by employing successive reactions after removal of previously masked areas of a substrate. Tn one embodiment, SWNT molecules may be linked to a substrate through a linker moiety such as —S—, —S—(CH2)n,-NH-, SiO3(CH2)3NH- or the like.

Abstract: A 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.

Abstract: This invention relates generally to cutting single-wall carbon nanotubes (SWNT). In one embodiment, the present invention provides for preparations of homogemeous 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.