摘要:
The present invention is directed to at least one method and at least one apparatus for determining the length of single-wall carbon nanotubes (SWNTs). The method generally comprises the steps of: dispersing a sample of SWNTs into a suitable dispersing medium to form a solvent-suspension of solvent-suspended SWNTs; determining the mean SWNT diameter of the solvent-suspended SWNTs; introducing the solvent-suspended SWNTs into a viscosity-measuring device; obtaining a specific viscosity for the SWNT solvent-suspension; and determining the length of the SWNTs based upon the specific viscosity by solving, for example, the Kirkwood-Auer equation corrected by Batchelor's formula for the drag on a slender cylinder for “L,” to determine the length of the SWNTs. The apparatus generally comprises: a SWNT sample introduction mechanism; a dispersal chamber; a SWNT radius-determination chamber; and a viscosity determining chamber, wherein the SWNT sample introduction mechanism, the dispersal chamber, the SWNT radius-determination chamber, and the viscosity determination chamber are each operatively connected to at least one of the others.
摘要:
We have discovered that size dependent solubility of large fullerenes in strong acids is dependent on acid strength. This provides a scalable method for separating large fullerenes by size. According to some embodiments, a method for processing a fullerene starting material comprises large fullerenes comprises mixing the starting material with a first concentrated sulfuric acid solution so as to obtain a first dispersion comprising a first portion of the large fullerenes solubilized in the first concentrated sulfuric acid solution.
摘要:
We have discovered that size dependent solubility of large fullerenes in strong acids is dependent on acid strength. This provides a scalable method for separating large fullerenes by size. According to some embodiments, a method for processing a fullerene starting material comprises large fullerenes comprises mixing the starting material with a first concentrated sulfuric acid solution so as to obtain a first dispersion comprising a first portion of the large fullerenes solubilized in the first concentrated sulfuric acid solution.
摘要:
Methods for preparing carbon nanotube layers are disclosed herein. Carbon nanotube layers may be films, ribbons, and sheets. The methods comprise preparing an aligned carbon nanotube array and compressing the array with a roller to create a carbon nanotube layer. Another method disclosed herein comprises preparing a carbon nanotube layer from an aligned carbon nanotube array grown on a grouping of lines of metallic catalyst. A composite material comprising at least one carbon nanotube layer and prepared by the process comprising a) compressing an aligned single-wall carbon nanotube array with a roller, and b) transferring the carbon nanotube layer to a polymer is also disclosed.
摘要:
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.
摘要:
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.
摘要:
The present invention is directed to the creation of macroscopic materials and objects comprising aligned nanotube segments. The invention entails aligning single-wall carbon nanotube (SWNT) segments that are suspended in a fluid medium and then removing the aligned segments from suspension in a way that macroscopic, ordered assemblies of SWNT are formed. The invention is further directed to controlling the natural proclivity of nanotube segments to self assemble into ordered structures by modifying the environment of the nanotubes and the history of that environment prior to and during the process. The materials and objects are “macroscopic” in that they are large enough to be seen without the aid of a microscope or of the dimensions of such objects. These macroscopic, ordered SWNT materials and objects have the remarkable physical, electrical, and chemical properties that SWNT exhibit on the microscopic scale because they are comprised of nanotubes, each of which is aligned in the same direction and in contact with its nearest neighbors. An ordered assembly of closest SWNT also serves as a template for growth of more and larger ordered assemblies. An ordered assembly further serves as a foundation for post processing treatments that modify the assembly internally to specifically enhance selected material properties such as shear strength, tensile strength, compressive strength, toughness, electrical conductivity, and thermal conductivity.
摘要:
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.
摘要:
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.
摘要:
The present invention is directed to methods of purifying carbon nanotubes (CNTs). In general, such methods comprise the following steps: (a) preparing an aqueous slurry of impure CNT material; (b) establishing a source of Fe2+ ions in the slurry to provide a catalytic slurry; (c) adding hydrogen peroxide to the catalytic slurry to provide an oxidative slurry, wherein the Fe2+ ions catalyze the production of hydroxyl radicals; and (d) utilizing the hydroxyl radicals in the oxidative slurry to purify the CNT material and provide purified CNTs.