Template-guided growth of carbon nanotubes using anodized aluminum oxide nanopore templates provides vertically aligned, untangled planarized arrays of multiwall carbon nanotubes with Ohmic back contacts. Growth by catalytic chemical vapor deposition results in multiwall carbon nanotubes with uniform diameters and crystalline quality, but varying lengths. The nanotube lengths can be trimmed to uniform heights above the template surface using ultrasonic cutting, for example. The carbon nanotube site density can be controlled by controlling the catalyst site density. Control of the carbon nanotube site density enables various applications. For example, the highest possible site density is preferred for thermal interface materials, whereas, for field emission, significantly lower site densities are preferable.

A chemical vapor deposition (CVD) system for forming carbon nanotubes from solid or liquid feedstock. The system includes a reactor including a housing that includes an inlet and an outlet. The housing defines an interior for receiving the feedstock, and the interior receives inert gas. The CVD system includes a first stop valve in flow communication with the inlet and a second stop valve in flow communication with the outlet. The first and second stop valves seal the inlet and the outlet such that a static environment is formed in the interior when reacting the feedstock. A heater heats the interior to a temperature such that the feedstock is vaporized, thereby forming vaporized feedstock. The CVD system further includes a controller coupled in communication with the first and second valves and the heater. The controller is configured to selectively actuate the first and second valves and the heater.

A cable includes a conductive core, an insulating layer, a shielding layer, and a sheath. The sheath coats the shielding layer. The shielding layer coats the insulating layer. The insulating layer coats the conductive wire. The conductive core includes a conductive wire and a carbon nanotube film comprising a plurality of carbon nanotubes. The carbon nanotubes coat the conductive core.

A method for making a variable-density carbon nanotube film is provided. A drawn carbon nanotube film, including a number of carbon nanotubes aligned along an aligned direction, is prepared. A number of thin regions are formed in the drawn carbon nanotube film along the aligned direction by reducing density of carbon nanotubes in each of the plurality of thin regions. A variable-density carbon nanotube film is provided and includes a number of thin regions and at least one normal region having a density of carbon nanotubes greater than that of the thin regions. The at least one normal region includes a number of carbon nanotubes substantially aligned along an aligned direction. The thin regions are arranged in the form of at least one row extending along the aligned direction.

Membranes are described that may include aligned carbon nanotubes coated with an inorganic support layer and a polymeric matrix. Methods of membrane fabrication are described that may include coating an aligned carbon nanotube array with an inorganic support layer followed by infiltration with a polymeric solvent or solution. The support carbon nanotube membrane may have improved performance for separations such as desalination, drug delivery, or pharmaceuticals.

A method for making carbon nanotube film includes providing a growth substrate having a first surface and a second surface opposite to the first surface. A catalyst layer is placed on the first surface. The growth substrate and the catalyst layer are placed in a reaction chamber. The carbon source gas and hydrogen are supplied into the reaction chamber at a growth temperature of a plurality of carbon nanotubes. An electric field is applied to the growth substrate, wherein an electric field direction of the electric field is from the first surface to the second surface. After the plurality of carbon nanotubes fly away from the growth substrate, the electric field is stopped applying to the growth substrate, and the carbon source gas and hydrogen are continually supplied into the reaction chamber.

A device used for making a carbon fiber film includes a chamber, a support base, and a power supply. The support base is used for suspending a carbon nanotube film in the chamber and transporting a negative voltage to the carbon nanotube film. The power supply is located outside of the chamber and used for applying the negative voltage.

A method is employed to separate a carbon structure, which is disposed on a seed structure, from the seed structure. In the method, a carbon structure is deposited on the seed structure in a process chamber of a CND reactor. The substrate comprising the seed structure (2) and the carbon structure (1) is heated to a process temperature. At least one etching gas is injected into the process chamber, the etching gas having the chemical formula AO.sub.mX.sub.n, AO.sub.mX.sub.nY.sub.p or A.sub.mX.sub.n, wherein A is selected from a group of elements that includes S, C and N, wherein O is oxygen, wherein X and Y are different halogens, and wherein m, n and p are natural numbers greater than zero. Through a chemical reaction with the etching gas, the seed structure is converted into a gaseous reaction product. A carrier gas flow is used to remove the gaseous reaction product from the process chamber.

The disclosure relates to a method for making a carbon nanotube structure, comprising the following steps of providing a carbon nanotube array formed on a surface of a substrate; drawing a first carbon nanotube film from the carbon nanotube array, wherein the first carbon nanotube film comprises a first end connected to the carbon nanotube array and a second end opposite to the first end; providing an elastic rod and fixing the second end of the first carbon nanotube film to a first portion of the elastic rod, wherein the elastic rod is curved toward the carbon nanotube array; and rotating the elastic rod around a rotational axis which coincides with a center axis of the elastic rod, wherein the elastic rod is curved toward the carbon nanotube array during the rotation of the elastic rod.

The disclosure relates to a method for making a carbon nanotube structure, comprising the following steps of: providing a carbon nanotube array formed on a surface of a substrate; drawing a first carbon nanotube film from the carbon nanotube array, wherein the first carbon nanotube film comprises a first end connected to the carbon nanotube array and a second end opposite to the first end; providing an elastic rod and fixing the second end of the first carbon nanotube film to a first portion of the elastic rod, wherein the elastic rod is curved away from the carbon nanotube array; and rotating the elastic rod around a rotational axis which coincides with a center axis of the elastic rod, wherein the elastic rod is curved away from the carbon nanotube array during rotation the elastic rod.