Abstract: A carbon nanotube production method forms a carbon nanotube aggregate having a high perpendicular orientation characteristic where a plurality of carbon nanotubes are aligned in a direction perpendicular to a surface of a substrate, without using terpineol, which is a viscosity improver. A catalyst solution having a predetermined concentration (from 0.2 M to 0.8 M) of a transition metal salt dissolved therein, and free of terpineol is prepared. Catalyst particles are caused to be present on the surface of the substrate by making the catalyst solution contact with the surface of the substrate. By making a carbon nanotube forming gas contact with the surface of the substrate in a carbon nanotube forming temperature region, the carbon nanotube aggregate is grown on the surface of the substrate where a plurality of carbon nanotubes are aligned in the direction perpendicular to the surface of the substrate.

Abstract: A new carbon nanotube device is provided. The carbon nanotube device has first carbon nanotubes and second carbon nanotubes that are different from each other in property. The carbon nanotube device includes: an object having a first carbon nanotube forming surface and a second carbon nanotube forming surface; first carbon nanotubes formed on the first carbon nanotube forming surface; and second carbon nanotubes formed on the second carbon nanotube forming surface, the second carbon nanotubes being different from the first carbon nanotubes in property.

Abstract: Disclosed are a carbon nanotube composite and a method for making the same advantageous for achieving a higher density of a carbon nanotube assembly. The carbon nanotube composite includes a substrate and a carbon nanotube assembly mounted on the surface of the substrate. The carbon nanotube assembly is composed of multiple carbon nanotubes arranged densely in parallel oriented in the direction upward from the surface of the substrate. The carbon nanotube assembly has a density of 70 mg/cm3 or more in a grown state.

Abstract: A membrane electrode assembly includes an ion conducting membrane; an anode catalyst layer arranged on one side of the ion conducting membrane; a cathode catalyst layer arranged on the other side of the ion conducting membrane; an anode diffusion layer arranged on an outer side of the anode catalyst layer; and a cathode diffusion layer arranged on an outer side of the cathode catalyst layer. Only in the anode catalyst layer, the density of a first catalyst layer portion located close to the anode diffusion layer is smaller than the density of a second catalyst layer portion located close to the ion conducting membrane.

Abstract: Disclosed is a composite carbon having a novel structure. This composite carbon has fibrous carbon which extends in the direction of the long axis, and multiple carbon nanotubes which are formed on the surface of the fibrous carbon and have a smaller diameter than the diameter of the fibrous carbon. The carbon nanotubes are formed as a group of multiple carbon nanotubes, with the lengthwise directions of each of the carbon nanotubes aligned in the same direction.

Abstract: A membrane electrode assembly includes an ion conducting membrane; an anode catalyst layer arranged on one side of the ion conducting membrane; a cathode catalyst layer arranged on the other side of the ion conducting membrane; an anode diffusion layer arranged on an outer side of the anode catalyst layer; and a cathode diffusion layer arranged on an outer side of the cathode catalyst layer. Only in the anode catalyst layer, the density of a first catalyst layer portion located close to the anode diffusion layer is smaller than the density of a second catalyst layer portion located close to the ion conducting membrane.