High-surface area carbon nanotubes having targeted, or selective, oxidation levels and/or content on the interior and exterior of the tube walls are claimed. Such carbon nanotubes can have little to no inner tube surface oxidation, or differing amounts and/or types of oxidation between the tubes' inner and outer surfaces. Additionally, such high-surface area carbon nanotubes may have greater lengths and diameters, creating useful mechanical, electrical, and thermal properties.

The present invention relates to a carbon nanotube composition including entangled-type carbon nanotubes and bundle-type carbon nanotubes, wherein the carbon nanotube composition has a specific surface area of 190 m.sup.2/g to 240 m.sup.2/g and a ratio of specific surface area to bulk density of 0.1 to 5.29.

The present invention relates to a carbon nanotube dispersion including carbon nanotubes, a polymer dispersant containing an amine, a phenolic compound including two or more aromatic rings, and an aqueous solvent, wherein the polymer dispersant and the phenolic compound including two or more aromatic rings are included in a weight ratio of 100:1 to 100:90, and having low viscosity and a small change of viscosity over time.

A carbon nanotube dispersion liquid for nonaqueous electrolyte secondary battery is a carbon nanotube dispersion liquid containing carbon nanotubes, a dispersant and a solvent, and is characterized in satisfying (1) to (3) below: (1) the average outer diameter of the carbon nanotubes ranging from more than 3 nm to 25 nm; (2) the BET surface area of the carbon nanotubes ranging from 150 m.sup.2/g to 800 m.sup.2/g; and (3) the fiber length of the carbon nanotubes in the carbon nanotube dispersion liquid ranging from 0.8 μm to 3.5 μm.

The present disclosure provides a filter for removing contaminants from a liquid or gaseous medium including a woven or nonwoven sheet of entangled carbon nanotubes. The present disclosure also provides a method for reducing the concentration of contaminants in a liquid or gaseous medium by contacting the liquid or gaseous medium with the filter.

The present invention relates to a carbon nanotube dispersion including carbon nanotubes, a polymer dispersant containing an amine, a phenolic compound including two or more aromatic rings, and an aqueous solvent, wherein the polymer dispersant and the phenolic compound including two or more aromatic rings are included in a weight ratio of 100:1 to 100:90, and having low viscosity and a small change of viscosity over time.

A production method for growing a carbon nanotube assembly on a substrate having a catalyst on a surface thereof. In this production method, in each of a formation unit that carries out a formation step of reducing a catalyst on the substrate and a growth unit that carries out a growth step of growing a carbon nanotube assembly, the substrate is continuously being conveyed using conveyance units that convey the substrate by screw rotations. In carrying out the formation step and the growth step, these steps are carried out while the gas environments in these steps are prevented from mixing with each other.

The present disclosure is directed to providing a carbon film having an excellent shield performance against electromagnetic waves. The carbon film of the present disclosure is a carbon film made of a carbon nanotube assembly, wherein a pore distribution curve of the carbon film indicating the relationship between the pore size and the Log differential pore capacity obtained from an adsorption isotherm at 77 K of liquid nitrogen based on the Barrett-Joyner-Halenda method has a peak in which the Log differential pore capacity is maximized within a pore size range of 10 nm or more and 100 nm or less, and the value of the Log differential pore capacity at the peak is 1.2 cm.sup.3/g or more.

The present invention proposes a process for purifying raw carbon nanotubes to obtain an content in metallic impurities comprised between 5 ppm and 200 ppm. The process includes an increase in the bulk density of the raw carbon nanotubes via compacting to produce compacted carbon nanotubes. The process further includes sintering the compacted carbon nanotubes by undergoing thermal treatment under gaseous atmosphere in order to remove at least a portion of the metallic impurities contained in the raw carbon nanotubes, and consequently producing purified carbon nanotubes. These purified carbon nanotubes are directly usable as electronic conductors serving as basis additive to an electrode material without requiring any subsequent purification step. The electrode material can then be used to manufacture an electrode destined to a lithium-ion battery.

Disclosed is a method of producing surface-treated carbon nanostructures which comprises: a depressurization step wherein a carbon nanostructure-containing liquid which comprises carbon nanostructures and a dispersion medium is depressurized; and a surface treatment step wherein an oxidizing agent is added in the carbon nanostructure-containing liquid after or during the depressurization step so that the carbon nanostructures have a surface oxygen atom concentration of 7.0 at % or more. The carbon nanostructures preferably comprise carbon nanotubes.