433results about "Aligned nanotubes" patented technology

A method of forming a periodic array of nano-scale objects using a block copolymer, and nano-scale object arrays formed from the method are provided. The method for forming the arrays generally includes the steps of depositing a block copolymer of at least two blocks on a substrate to form an ordered meso-scale structured array of the polymer materials, forming catalytic metal dots based on the meso-scale structure, and growing nano-scale objects on the catalytic dots to form an ordered array of nano-scale objects.

A carbon nanotube film structure includes at least two overlapped carbon nanotube films, with adjoining films being aligned in different directions. Each carbon nanotube film includes a plurality of successive carbon nanotube bundles aligned in the same direction. The carbon nanotube structure further includes a plurality of micropores formed by/between the adjoining carbon nanotube bundles. A method for fabricating the carbon nanotube film structure includes the steps of: (a) providing an array of carbon nanotubes; (b) pulling out, using a tool, one carbon nanotube film from the array of carbon nanotubes; (c) providing a frame and adhering the carbon nanotube film to the frame; (d) repeating steps (b) and (c), depositing each successive film on a preceding film, thereby achieving at least a two-layer carbon nanotube film; and (e) peeling the carbon nanotube film off the frame to achieve the carbon nanotube structure.

The present invention provides methods for uniform growth of nanostructures such as nanotubes (e.g., carbon nanotubes) on the surface of a substrate, wherein the long axes of the nanostructures may be substantially aligned. The nanostructures may be further processed for use in various applications, such as composite materials. For example, a set of aligned nanostructures may be formed and transferred, either in bulk or to another surface, to another material to enhance the properties of the material. In some cases, the nanostructures may enhance the mechanical properties of a material, for example, providing mechanical reinforcement at an interface between two materials or plies. In some cases, the nanostructures may enhance thermal and/or electronic properties of a material. The present invention also provides systems and methods for growth of nanostructures, including batch processes and continuous processes.

The present invention relates to a method for making a carbon nanotube film. The method includes the steps of: (a) forming an array of carbon nanotubes on a substrate; and (b) press the array of carbon nanotubes using a compressing apparatus, thereby forming a carbon nanotube film.

An aggregate of carbon-based fine structures in which a plurality of carbon-based fine structures are collected, wherein respective carbon-based fine structures are oriented in the same direction. The above aggregate of carbon-based fine structures is an aggregate of a plurality of carbon-based fine structures in a state they are pulled by one another with strong interaction, and has such a length that allows the improvement of the handleability and workability thereof.

A method for directly growing carbon nanotubes, and in particular single-walled carbon nanotubes on a flat substrate, such as a silicon wafer, and subsequently transferring the nanotubes onto the surface of a polymer film, or separately harvesting the carbon nanotubes from the flat substrate.

The present invention provides methods for uniform growth of nanostructures such as nanotubes (e.g., carbon nanotubes) on the surface of a substrate, wherein the long axes of the nanostructures may be substantially aligned. The nanostructures may be further processed for use in various applications, such as composite materials. For example, a set of aligned nanostructures may be formed and transferred, either in bulk or to another surface, to another material to enhance the properties of the material. In some cases, the nanostructures may enhance the mechanical properties of a material, for example, providing mechanical reinforcement at an interface between two materials or plies. In some cases, the nanostructures may enhance thermal and/or electronic properties of a material. The present invention also provides systems and methods for growth of nanostructures, including batch processes and continuous processes.

A process for preparing a patterned layer of aligned carbon nanotubes on a substrate including: applying a pattern of polymeric material to the surface of a substrate capable of supporting nanotube growth using a soft-lithographic technique; subjecting said polymeric material to carbonization to form a patterned layer of carbonized polymer on the surface of the substrate; synthesising a layer of aligned carbon nanotubes on regions of said substrate to which carbonized polymer is not attached to provide a patterned layer of aligned carbon nanotubes on said substrate.

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.

A method of controllably aligning carbon nanotubes to a template structure to fabricate a variety of carbon nanotube containing structures and devices having desired characteristics is provided. The method allows simultaneous, selective growth of both vertically and horizontally controllably aligned nanotubes on the template structure but not on a substrate in a single process step.

A composite structure includes a matrix material and a carbon nanotube (CNT)-infused fiber material that includes a plurality of carbon nanotubes (CNTs) infused to a fiber material. The CNT-infused fiber material is disposed throughout a portion of the matrix material. The composite structure is adapted for application of a current through the CNT-infused fiber material to provide heating of the composite structure. A heating element includes a CNT-infused fiber material includes a plurality of CNTs infused to a fiber material. The CNT-infused fiber material is of sufficient proportions to provide heating to a structure in need thereof.

This invention provides an aligned single-layer carbon nanotube bulk structure, which comprises an assembly of a plurality of aligned single-layer carbon nanotube and has a height of not less than 10 μm, and an aligned single-layer carbon nanotube bulk structure which comprises an assembly of a plurality of aligned single-layer carbon nanotubes and has been patterned in a predetermined form. This structure is produced by chemical vapor deposition (CVD) of carbon nanotubes in the presence of a metal catalyst in a reaction atmosphere with an oxidizing agent, preferably water, added thereto. An aligned single-layer carbon nanotube bulk structure, which has realized high purify and significantly large scaled length or height, its production process and apparatus, and its applied products are provided.

A field emission device having bundles of aligned parallel carbon nanotubes on a substrate. The carbon nanotubes are oriented perpendicular to the substrate. The carbon nanotube bundles may be up to 300 microns tall, for example. The bundles of carbon nanotubes extend only from regions of the substrate patterned with a catalyst material. Preferably, the catalyst material is iron oxide. The substrate is preferably porous silicon, as this produces the highest quality, most well-aligned nanotubes. Smooth, nonporous silicon or quartz can also be used as the substrate. The method of the invention starts with forming a porous layer on a silicon substrate by electrochemical etching. Then, a thin layer of iron is deposited on the porous layer in patterned regions. The iron is then oxidized into iron oxide, and then the substrate is exposed to ethylene gas at elevated temperature. The iron oxide catalyzes the formation of bundles of aligned parallel carbon nanotubes which grow perpendicular to the substrate surface. The height of the nanotube bundles above the substrate is determined by the duration of the catalysis step. The nanotube bundles only grow from the patterned regions.

An array of long carbon nanotubes (i.e. an array where the average length of the nanotubes is greater than 0.5 millimeters) is prepared by exposing a supported catalyst at elevated temperature to a gas mixture of hydrocarbon, inert gas, and a relatively low percentage of hydrogen. Addition of water vapor to the gas mixture may result in an increase in the length of the nanotubes, an increase the rate of growth, and a decrease in contamination of the array by amorphous carbon. The temperature and growth time are also chosen to minimize the amount of amorphous carbon that forms on the array. Fibers spun from the array have a higher tensile strength compared to known CNT fibers.

According to one embodiment, a method of fabricating a nanotube on a substrate is provided. The method can include a step for attaching a catalyst to a substrate. The method can also include a step for heating the catalyst to a predetermined temperature such that a nanotube grows from the catalyst. Further, the method can include a step for directing a feeding gas over the catalyst in a predetermined direction such that the nanotube grows in the predetermined direction.

Thermal interfaces and methods include an array of carbon nanotubes aligned substantively perpendicularly from a substrate. One method includes arranging metal catalyst particles with a particular ligand on a fluid surface of a Langmuir-Blodgett trough. This forms uniformly spaced particles with spacing based on the particular ligand. The uniformly spaced metal catalyst particles are deposited on a substrate and carbon nanotubes are grown on the particles using chemical vapor deposition. A highly efficient thermal interface can be produced with a carbon nanotube packing ratio greater than fifty percent and used in a thermal switch or other device. In some methods, commercially available nanotubes are condensed on a substrate using carbon nanotubes with terminal carboxylic acids in solution and an amine monolayer on the substrate. Pretreatment of the nanotubes in a switch by applying heavy pressure between two surfaces results in good thermal conductivity between those surfaces at smaller operating pressures.

Aligned and open-ended nanotube structures, methods for making the same, and devices including open-ended nanotubes. An aligned and open-ended nanotube structure which is free of catalyst particles at top ends, the aligned and open-ended nanotube structure having an uneven open-end height with local protruding portions. A method of opening an end of a nanotube including a catalyst particle including sputter etching the nanotube to remove an amorphous layer, bend the nanotube to one side, open a hole in the nanotube, and cause detachment of the catalyst particle.

The present invention relates to an ultralong oriented carbon nano tube wire/film and its preparation method. The described carbon nano tube wire/film is made up by using mutually-winded and connected tube bundle end portions of several bundles of carbon nano tubes, their orientations are basically identical, the macrodiameter is above micrometer grade, length is above centrimeter grade, the macrothickness of carbon nano tube film is above several tens nanometers, its width is above several tens micrometers and its length is above centrimeter grade. Its preparation method includes the following steps: utilizing floatation process to make the carbon nano tube array be grown out from base surface, then using tension tool to draw carbon nano tube wire or film from one end of carbon nano tube array, utilizing continuous tension to make the tube bundle of carbon nano tube be formed into oriented carbon nano tube wire/film along the tension direction.

A method for forming a carbon nanotube array using a metal substrate includes the following steps: providing a metal substrate (11); oxidizing the metal substrate to form an oxidized layer (21) thereon; depositing a catalyst layer (31) on the oxidized layer; introducing a carbon source gas; and thus forming a carbon nanotube array (61) extending from the metal substrate. Generally, any metallic material can be used as the metal substrate. Various carbon nanotube arrays formed using various metal substrates can be incorporated into a wide variety of high power electronic device applications such as field emission devices (FEDs), electron guns, and so on. Carbon nanotubes formed using any of a variety of metal substrates are well aligned, and uniformly extend in a direction substantially perpendicular to the metal substrate.

A method for making a carbon nanotube composite structure, the method comprising the steps of: providing a carbon nanotube structure having a plurality of carbon nanotubes; and forming at least one conductive coating on a plurality of the carbon nanotubes in the carbon nanotube structure to achieve a carbon nanotube composite structure, wherein the conductive coating comprises of a conductive layer.

This invention provides ways to fabricate nanotubes and nanobead arrays by utilizing nanopores in anodic aluminum oxide (AAO) membranes. Nanotubes of bismuth and other low melting point metals with controlled diameters and lengths can be fabricated by sintering AAO coated with appropriate metals at temperatures above their melting points. Carbon nanotubes may also be readily formed by carbonizing a polymer on the interior walls of the nanopores in AAO membranes. Palladium nanobead arrays which can be used as ultrafast hydrogen sensors are fabricated by coating the flat surface of AAO membranes with controlled pore-wall ratios.