Method for producing carbon nanohorn aggregate
A method for producing a carbon nanohorn aggregate including a fibrous carbon nanohorn aggregate, comprising continuously irradiating with laser light a surface of a carbon target containing a metal catalyst such as iron, wherein a laser irradiation position is moved at a constant speed so that a power density of the laser light with which the surface of the carbon target is irradiated is generally constant, and irradiation is moved to a region adjacent to a region previously irradiated with the laser light, in a direction different from a moving and traveling direction of the laser irradiation position at an interval equal to or more than a width of a degradation region formed around the region irradiated with the laser light
1. A method for producing a carbon nanohorn aggregate including a fibrous carbon nanohorn aggregate, comprising continuously irradiating with laser light a surface of a carbon target containing a metal catalyst selected from a simple substance of Fe, Ni, or Co or a mixture of two or three thereof, wherein
the carbon target has a bulk density of 1.6 g/cm 3 or less and a thermal conductivity of 15 W/(m·K) or less.
2. A method for producing a carbon nanohorn aggregate including a fibrous carbon nanohorn aggregate, comprising continuously irradiating with laser light a surface of a carbon target containing a metal catalyst selected from a simple substance of Fe, Ni, or Co or a mixture of two or three thereof, wherein
a laser irradiation position is moved at a constant speed so that a power density of the laser light with which the surface of the carbon target is irradiated is approximately constant, and
irradiation is moved to a region adjacent to a region previously irradiated with the laser light, in a direction different from a moving and traveling direction of the laser irradiation position at an interval equal to or more than a width of a degradation region formed around the region irradiated with the laser light.
3. The method for producing a carbon nanohorn aggregate according to claim 2 , wherein a content of the catalyst in the carbon target based on carbon is within the range of 0.5 to 3 at %.
4. The method for producing a carbon nanohorn aggregate according to claim 3 , wherein the catalyst is Fe.
5. The method for producing a carbon nanohorn aggregate according to claim 3 , wherein the carbon target has a bulk density of 1.6 g/cm 3 or less and a thermal conductivity of 15 W/(m·K) or less.
6. The method for a producing carbon nanohorn aggregate according to claim 2 , wherein a moving speed of an irradiation position of the laser light is in the range of 3 cm/min to 50 cm/min.
7. The method for producing a carbon nanohorn aggregate according to claim 6 , wherein an output power of the laser light is in the range of 1.0 kW to 10 kW.
8. The method for producing a carbon nanohorn aggregate according to claim 7 , wherein a content of the catalyst in the carbon target based on carbon is within the range of 0.5 to 3 at %.
9. The method for producing a carbon nanohorn aggregate according to claim 8 , wherein the catalyst is Fe.
10. The method for producing a carbon nanohorn aggregate according to claim 8 , wherein the carbon target has a bulk density of 1.6 g/cm 3 or less and a thermal conductivity of 15 W/(m·K) or less.
11. The method for producing a carbon nanohorn aggregate according to claim 6 , wherein the carbon target is cylindrical, and rotation and movement of the target are performed so that the irradiation position moves in a helical form around the surface of the target.
12. The method for producing a carbon nanohorn aggregate according to claim 11 , wherein a pitch of the helical form is equal to or more than a value obtained by adding the width of the degradation region to an irradiation spot diameter of the laser light.
13. The method for producing a carbon nanohorn aggregate according to claim 11 , wherein a content of the catalyst in the carbon target based on carbon is within the range of 0.5 to 3 at %.
14. The method for producing a carbon nanohorn aggregate according to claim 13 , wherein the catalyst is Fe.
15. The method for producing a carbon nanohorn aggregate according to claim 13 , wherein the carbon target has a bulk density of 1.6 g/cm 3 or less and a thermal conductivity of 15 W/(m·K) or less.
16. The method for producing a carbon nanohorn aggregate according to claim 6 , wherein a content of the catalyst in the carbon target based on carbon is within the range of 0.5 to 3 at %.
17. The method for producing a carbon nanohorn aggregate according to claim 16 , wherein the catalyst is Fe.
18. The method for producing a carbon nanohorn aggregate according to claim 16 , wherein the carbon target has a bulk density of 1.6 g/cm 3 or less and a thermal conductivity of 15 W/(m·K) or less.