A magnet module used for producing a carbon nanotube dispersion liquid, comprising: a pipe portion having a first opening connected to a shearing module, and a second opening at both ends; and a magnet disposed in the pipe portion, wherein a medium liquid containing the carbon nanotube defibrated by the shearing module is supplied through the first opening, and after a ferromagnetic impurity attached to the carbon nanotube is attracted to the magnet and removed, the medium liquid is discharged from the second opening.

A magnet module used for producing a carbon nanotube dispersion liquid, comprising: a pipe portion having a first opening connected to a shearing module, and a second opening at both ends; and a magnet disposed in the pipe portion, wherein a medium liquid containing the carbon nanotube defibrated by the shearing module is supplied through the first opening, and after a ferromagnetic impurity attached to the carbon nanotube is attracted to the magnet and removed, the medium liquid is discharged from the second opening.

A method for fabricating a field emission cathode, the field emission cathode including a substrate having a field emission layer engaged therewith, where the field emission layer includes a plurality of purified carbon nanotubes. The carbon nanotubes are purified via a graphitization or annealing process.

The disclosed method includes a separation step wherein composite particles are transferred to a vicinity of an inlet of a fibrous carbon nanostructure path configured to recover fibrous carbon nanostructures by allowing the fibrous carbon nanostructures to pass therethrough, and a fluid flowing toward the inlet of the path and an external force including a component of a direction opposite to the direction in which the fluid flows are applied to the composite particles to separate the fibrous carbon nanostructures and a particulate ceramic support substrate; and a recovery step wherein the separated fibrous carbon nanostructures are transferred to an interior of the path for recovery by a flow of the fluid, with the separated substrate transferred away from the fibrous carbon nanostructure path for recovery, wherein, in the separation step, the external force applied to the substrate is greater than that applied to the fibrous carbon nanostructures.

The disclosed method includes a separation step wherein composite particles are transferred to a vicinity of an inlet of a fibrous carbon nanostructure path configured to recover fibrous carbon nanostructures by allowing the fibrous carbon nanostructures to pass therethrough, and a fluid flowing toward the inlet of the path and an external force including a component of a direction opposite to the direction in which the fluid flows are applied to the composite particles to separate the fibrous carbon nanostructures and a particulate ceramic support substrate; and a recovery step wherein the separated fibrous carbon nanostructures are transferred to an interior of the path for recovery by a flow of the fluid, with the separated substrate transferred away from the fibrous carbon nanostructure path for recovery, wherein, in the separation step, the external force applied to the substrate is greater than that applied to the fibrous carbon nanostructures.

An electrode membrane having high adhesiveness and electrical conductivity can be produced using carbon nanotubes each of which meets the following requirements (1) and (2). (1) A peak appears at a diffraction angle 2=252 in powder X-ray diffraction analysis, and the half value width of the peak is 2 or more and less than 3. (2) The G/D ratio is 1.5 to 5.0, wherein G represents the maximum peak intensity in the range from 1560 to 1600 cm.sup.1 and D represents the maximum peak intensity in the range from 1310 to 1350 cm.sup.1 in Raman spectra.

A carbon purification method (10) and a carbon product are provided. The carbon purification method (10) includes providing (12) a carbon product having a catalyst content and/or impurities, performing (14) a hydrothermal acid digestion operation on the carbon product in an acid to dissolve the catalyst content and/or the impurities, and performing (16) a filtering operation to separate the dissolved catalyst content and/or the dissolved impurities from the carbon product.

A carbon purification method (10) and a carbon product are provided. The carbon purification method (10) includes providing (12) a carbon product having a catalyst content and/or impurities, performing (14) a hydrothermal acid digestion operation on the carbon product in an acid to dissolve the catalyst content and/or the impurities, and performing (16) a filtering operation to separate the dissolved catalyst content and/or the dissolved impurities from the carbon product.

A polymer comprising at least one unit of the formula (1) wherein T.sup.1 is a carbon atom or a nitrogen atom, T.sup.2 is a carbon atom if T.sup.1 is a nitrogen atom, or is a nitrogen atom if T.sup.1 is a carbon atom, r is 1, 2, 3 or 4, s is 1, 2, 3, or 4, M.sup.1 is preferably selected from the group consisting of M.sup.2 is preferably The polymers are prepared by reacting monomers (1a) with monomers (2a) H.sub.2N-[-M.sup.1-]r-NH.sub.2 (1a) OHC-[-M.sup.2-]s-CHO (2a) or the step of reacting monomers (1b) with monomers (2b) OHC-[-M.sup.1-]r-CHO (1b) H.sub.2N-[-M.sup.2-]s-NH.sub.2 (2b). ##STR00001##

A polymer comprising at least one unit of the formula (1) wherein T.sup.1 is a carbon atom or a nitrogen atom, T.sup.2 is a carbon atom if T.sup.1 is a nitrogen atom, or is a nitrogen atom if T.sup.1 is a carbon atom, r is 1, 2, 3 or 4, s is 1, 2, 3, or 4, M.sup.1 is preferably selected from the group consisting of M.sup.2 is preferably The polymers are prepared by reacting monomers (1a) with monomers (2a) H.sub.2N-[-M.sup.1-]r-NH.sub.2 (1a) OHC-[-M.sup.2-]s-CHO (2a) or the step of reacting monomers (1b) with monomers (2b) OHC-[-M.sup.1-]r-CHO (1b) H.sub.2N-[-M.sup.2-]s-NH.sub.2 (2b). ##STR00001##