Abstract: Carbon nanotubes grown on nanostructured flake substrates are disclosed. The nanostructured flake substrates include a catalyst support layer and at least one catalyst layer. Carbon nanotubes grown on the nanostructured flake substrates can have very high aspect ratios. Further, the carbon nanotubes can be aligned on the nanostructured flake substrates. Through routine optimization, the nanostructured flake substrates may be used to produce single-wall, double-wall, or multi-wall carbon nanotubes of various lengths and diameters. The nanostructured flake substrates produce very high yields of carbon nanotubes per unit weight of substrate. Methods for making the nanostructured flake substrates and for using the nanostructured flake substrates in carbon nanotube synthesis are disclosed.

Abstract: In some embodiments, the present disclosure pertains to methods of forming a reinforcing material by: (1) depositing a first material onto a catalyst surface; and (2) forming a second material on the catalyst surface, where the second material is derived from and associated with the first material. In some embodiments, the first material includes, without limitation, carbon nanotubes, graphene nanoribbons, boron nitride nanotubes, chalcogenide nanotubes, carbon onions, and combinations thereof. In some embodiments, the formed second material includes, without limitation, graphene, hexagonal boron nitride, chalcogenides, and combinations thereof. In additional embodiments, the methods of the present disclosure also include a step of separating the formed reinforcing material from the catalyst surface, and transferring the separated reinforcing material onto a substrate without the use of polymers.

Abstract: In some embodiments, the present disclosure pertains to methods of forming a reinforcing material by: (1) depositing a first material onto a catalyst surface; and (2) forming a second material on the catalyst surface, where the second material is derived from and associated with the first material. In some embodiments, the first material includes, without limitation, carbon nanotubes, graphene nanoribbons, boron nitride nanotubes, chalcogenide nanotubes, carbon onions, and combinations thereof. In some embodiments, the formed second material includes, without limitation, graphene, hexagonal boron nitride, chalcogenides, and combinations thereof. In additional embodiments, the methods of the present disclosure also include a step of separating the formed reinforcing material from the catalyst surface, and transferring the separated reinforcing material onto a substrate without the use of polymers.

Abstract: A method of forming a nanotube grid includes placing a plurality of catalyst nanoparticles on a grid framework, contacting the catalyst nanoparticles with a gas mixture that includes hydrogen and a carbon source in a reaction chamber, forming an activated gas from the gas mixture, heating the grid framework and activated gas, and controlling a growth time to generate a single-wall carbon nanotube array radially about the grid framework. A filter membrane may be produced by this method.

Abstract: 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.

Abstract: According 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.

Abstract: A hot filament chemical vapor deposition method has been developed to grow at least one vertical single-walled carbon nanotube (SWNT). In general, various embodiments of the present invention disclose novel processes for growing and/or producing enhanced nanotube carpets with decreased diameters as compared to the prior art.

Abstract: Methods for producing carbon films are disclosed herein. The methods include treating a carbon nanostructure with one or more dispersing agents, filtering the solution through a filter membrane to form the carbon film, releasing the carbon film from the filter membrane, and transferring the film onto a desired substrate without the use of sonication. Carbon films formed by said methods are also disclosed herein.

Abstract: A hot filament chemical vapor deposition method has been developed to grow at least one vertical single-walled carbon nanotube (SWNT). In general, various embodiments of the present invention disclose novel processes for growing and/or producing enhanced nanotube carpets with decreased diameters as compared to the prior art.

Abstract: A 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.

Abstract: The 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.

Abstract: The 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.

Abstract: A method of forming a nanotube grid includes placing a plurality of catalyst nanoparticles on a grid framework, contacting the catalyst nanoparticles with a gas mixture that includes hydrogen and a carbon source in a reaction chamber, forming an activated gas from the gas mixture, heating the grid framework and activated gas, and controlling a growth time to generate a single-wall carbon nanotube array radially about the grid framework. A filter membrane may be produced by this method.

Abstract: According 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.

Abstract: 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.

Abstract: A method for separating fractions of single-walled carbon nanotubes includes exposing a solution containing fractions of single-walled carbon nanotubes to a reducing agent and separating the resulting reaction products. An alternate method for separating fractions of single-walled carbon nanotubes includes exposing a solution containing fractions of single-walled carbon nanotubes to an oxidizing agent and separating the resulting reaction products. A third method for separating fractions of single-walled carbon nanotubes includes exposing a solution containing fractions of substantially non-functionalized single-walled carbon nanotubes to a charge transfer complex agent and separating the resulting reaction products. These methods allow the production of single-walled carbon nanotubes of approximately 95 to 99% metallic and semiconducting types.

Abstract: The 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.

Abstract: The present invention relates to processes for the purification of single-wall carbon nanotubes (SWNTs). 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 side of the single-wall carbon nanotubes. The present purification processes remove the extraneous carbon as well as metal-containing residual catalyst particles.

Abstract: Carbon nanotubes grown on nanostructured flake substrates are disclosed. The nanostructured flake substrates include a catalyst support layer and at least one catalyst layer. Carbon nanotubes grown on the nanostructured flake substrates can have very high aspect ratios. Further, the carbon nanotubes can be aligned on the nanostructured flake substrates. Through routine optimization, the nanostructured flake substrates may be used to produce single-wall, double-wall, or multi-wall carbon nanotubes of various lengths and diameters. The nanostructured flake substrates produce very high yields of carbon nanotubes per unit weight of substrate. Methods for making the nanostructured flake substrates and for using the nanostructured flake substrates in carbon nanotube synthesis are disclosed.

Abstract: The 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.