1407 results about "Nanotube array" patented technology

A method of fabricating a long carbon nanotube yarn includes the following steps: (1) providing a flat and smooth substrate; (2) depositing a catalyst on the substrate; (3) positioning the substrate with the catalyst in a furnace; (4) heating the furnace to a predetermined temperature; (5) supplying a mixture of carbon containing gas and protecting gas into the furnace; (6) controlling a difference between the local temperature of the catalyst and the furnace temperature to be at least 50° C.; (7) controlling the partial pressure of the carbon containing gas to be less than 0.2; (8) growing a number of carbon nanotubes on the substrate such that a carbon nanotube array is formed on the substrate; and (9) drawing out a bundle of carbon nanotubes from the carbon nanotube array such that a carbon nanotube yarn is formed.

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.

A carbon nanotube-based device (40) includes a substrate (10), a number of alloyed, nano-sized catalytic particles (26) formed on the substrate, and an array of aligned carbon nanotubes (15) extending from the alloyed, nano-sized catalytic particles. The nanotube array bends in an arcuate configuation. A method for making the carbon nanotube-based device includes the steps of: providing a substrate; depositing a catalyst layer on the substrate; depositing two different layers of catalyst-doped materials on different areas of the catalyst layer for accelerating or decelerating the rate of synthesis of the aligned carbon nanotube array; annealing the catalyst and the catalyst-doped materials in an oxygen-containing gas at a low temperature; introducing a carbon source gas; and forming an array of aligned carbon nanotubes extending from the alloyed, nano-sized catalytic particles using a chemical vapor deposition method.

A thermal interface material (40) includes a polymer matrix (32) and an array of carbon nanotubes (22) incorporated in the polymer matrix. The polymer matrix has a thermally conductive first face (42) and an opposite thermally conductive second face (44). The carbon nanotubes are substantially parallel to each other, and extend between the first and the second faces. A preferred method for making the thermal interface material includes the steps of: (a) forming the array of carbon nanotubes on a substrate (11); (b) immersing the carbon nanotubes in a liquid prepolymer (31) such that the liquid prepolymer infuses into the array of carbon nanotubes; (c) polymerizing the liquid prepolymer to obtain the polymer matrix having the carbon nanotubes secured therein; and (d) peeling the polymer matrix having the carbon nanotubes off from the substrate to obtain the thermal interface material.

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.

A method of producing polymer/nanotube composites where the density and position of the nanotubes (11) within the composite ca be controlled. Carbon nanotubes (11) are grown from organometallic micropatterns. These periodic nanotube arrays are then incorporated into a polymer matrix (7) by deposing a curable polymer film on the as-grown tubes. This controlled method of producing free-standing nanotube/polymer composite films may be used to form nanosensor (3) which provide information regarding a physical condition of a material (20), such as an airplane chassis or wing, in contact with the nanosensor (3).

Nitrogen-doped titania nanotubes exhibiting catalytic activity on exposure to any one or more of ultraviolet, visible, and/or infrared radiation, or combinations thereof are disclosed. The nanotube arrays may be co-doped with one or more nonmetals and may further include co-catalyst nanoparticles. Also, methods are disclosed for use of nitrogen-doped titania nanotubes in catalytic conversion of carbon dioxide alone or in admixture with hydrogen-containing gases such as water vapor and/or other reactants as may be present or desirable into products such as hydrocarbons and hydrocarbon-containing products, hydrogen and hydrogen-containing products, carbon monoxide and other carbon-containing products, or combinations thereof.

A method for forming a carbon nanotube array on a metal substrate includes the following steps: providing a metal substrate (11); depositing a silicon layer (21) on a surface of the metal substrate; depositing a catalyst layer (31) on the silicon layer; annealing the treated substrate; heating the treated substrate up to a predetermined temperature in flowing protective gas; introducing a carbon source gas for 5-30 minutes; and thus forming a carbon nanotube array (51) extending from the treated 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 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.

Carbon nanotube-based devices made by electrolytic deposition and applications thereof are provided. In a preferred embodiment, the present invention provides a device comprising at least one array of active carbon nanotube junctions deposited on at least one microelectronic substrate. In another preferred embodiment, the present invention provides a device comprising a substrate, at least one pair of electrodes disposed on the substrate, wherein one or more pairs of electrodes are connected to a power source, and a bundle of carbon nanotubes disposed between the at least one pair of electrodes wherein the bundle of carbon nanotubes consist essentially of semiconductive carbon nanotubes. In another preferred embodiment, a semiconducting device formed by electrodeposition of carbon nanotubes between two electrodes is provided. The invention also provides preferred methods of forming a semiconductive device by applying a bias voltage to a carbon nanotube rope. The plurality of metallic single-wall carbon nanotubes are removed (e.g., by application of bias voltage) in an amount sufficient to form the semiconducting device. The devices of the invention include, but not limited to, chemical or biological sensors, carbon nanotube field-effect transistors (CNFETs), tunnel junctions, Schottky junctions, and multi-dimensional nanotube arrays.

A method for forming a carbon nanotube array includes the following steps: providing a smooth substrate (11); depositing a metal catalyst layer (21) on a surface of the substrate; heating the treated substrate to a predetermined temperature in flowing protective gas; and introducing a mixture of carbon source gas and protective gas for 5-30 minutes, thus forming a carbon nanotube array (61) extending from the substrate. When the mixture of carbon source gas and protective gas is introduced, a temperature differential greater than 50° C. between the catalyst and its surrounding environment is created by adjusting a flow rate of the carbon source gas. Further, a partial pressure of the carbon source gas is maintained lower than 20%, by adjusting a ratio of the flow rates of the carbon source gas and the protective gas. The carbon nanotubes formed in the carbon nanotube array are well bundled.

The present invention provides arrays of longitudinally aligned carbon nanotubes having specified positions, nanotube densities and orientations, and corresponding methods of making nanotube arrays using guided growth and guided deposition methods. Also provided are electronic devices and device arrays comprising one or more arrays of longitudinally aligned carbon nanotubes including multilayer nanotube array structures and devices.

A preferred method for making a carbon nanotube-based field emission device in accordance with the invention includes the following steps: providing a substrate (22) with a surface; depositing a catalyst layer (24) on a predetermined area on the surface of the substrate; forming a carbon nanotube array (30) extending from the predetermined area; forming a cathode electrode (40) on top of the carbon nanotube array; and removing the substrate so as to expose the carbon nanotube array.

According to one exemplary embodiment, an optical polarizer positioned before a light source for use in semiconductor wafer lithography includes an array of aligned nanotubes. The array of aligned nanotubes cause light emitted from the light source and incident on the array of aligned nanotubes to be converted into polarized light for use in the semiconductor wafer lithography. The amount of polarization can be controlled by a voltage source coupled to the array of aligned nanotubes. Chromogenic material of a light filtering layer can vary the wavelength of the polarized light transmitted through the array of aligned nanotubes.

The invention provides a process for preparing biocompatible directional carbon nanotube array reinforced composite hydrogel, which utilizes the chemical vapor deposition (CVD) technique, the radial cross linking technique and a freezing and thawing method. By permeating polymer sol into a carbon nanotube prefabricated body, aggregating and tangling problems during a compounding process of the carbon nanotube and polymer are resolved, boundary strength of a reinforcing phase and a basis phase is increased, and excellent performances of the nanotube on mechanics and electricity are played sufficiently. The composite hydrogel prepared by utilizing a physical cross linking process does not contain chemical additives and meets requirements on biocompatibility. The composite hydrogel prepared by the process has controllable length and direction of the reinforcing phase of a nanotube array, has integrated mechanics and electricity performances superior to those of the conventional hydrogel,and is adoptive to be applied to the biomedical field such as artificial articular cartilages, tissues engineering supports, nerve cell carries, biomimetic implanted electrode and the like.

The invention discloses a method for preparing a metal titanium or titanium alloy super-oleophobic surface. The method comprises the following steps of: performing primary anodic oxidation treatment on metal titanium or titanium alloy to obtain a roughened surface with a microstructure; forming a titanium dioxide nanotube array film on the surface with microstructure through secondary anodic oxidation so as to obtain a composite fine structured micro-nanostructure; and modifying with a low-surface-energy substance to obtain the super-oleophobic surface and the super-hydrophobic and super-oleophobic surface. The metal titanium or titanium alloy surface has super-oleophobic and super-hydrophobic characteristics for multiple kinds of organic liquid, the static contact angle is greater than 155 degrees; the rolling angle is less than 10 degrees; meanwhile, the surface also shows superior super-oleophobic and super-hydrophobic characteristics for pure water and aqueous solution of acid, alkali and salt.

The invention provides a method for a preparing TiO2 nanotube array film, relating to a method for preparing a nanotube film. The method solves the problems of the prior art that the prepared nanotube array film features thin film, irregular micro appearance, heterogeneous length of nanotubes, reunion of tube orifice and cracking of the film. The preparation method comprises: 1. a titanium plate is cut into two titanium sheets of the same size, and polishing, ultrasound processing and washing are carried out on the two titanium sheets; 2. electrolyte is prepared; 3. primary anodic oxidation is carried out on the titanium sheets; 4. demoulding is carried out; 5. secondary anodic oxidation is carried out on the titanium sheets; 6. the titanium sheets are dried after ultrasonic processing; and 7. calcination treatment is carried out, thus obtaining the TiO2 nanotube array film. In the invention, twice anodic oxidations are carried out on the titanium sheets, thus producing the TiO2 nanotube array film featuring regular micro appearance, homogeneous, smoothness, thick film layer, reunion-free tube orifice and no cracking. The preparation method of the invention features simple technique and equipment and controllable thickness of the nanotube film.