ALIGNED CARBON NANOTUBE BULK STRUCTURE HAVING PORTIONS DIFFERENT INDENSITY

• US 20100159222A1
• Filed: 08/25/2009
• Published: 06/24/2010
• Est. Priority Date: 01/06/2006
• Status: Active Grant

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Original Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Inventors: Yumura, Motoo, Iijima, Sumio, Hata, Kenji, Futaba, Don N.
• Granted Patent: US 8,329,135 B2
• Time in Patent Office: Days
• US Class Current: 428/218
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/08 Aligned nanotubes
• CPC Class Codes: C01B 2202/26 Mechanical properties
• CPC Class Codes: C01B 2202/32 Specific surface area
• CPC Class Codes: C01B 2202/34 Length
• CPC Class Codes: C01B 2202/36 Diameter
• CPC Class Codes: C01B 32/162 characterised by catalysts
• CPC Class Codes: C01B 32/168 After-treatment
• CPC Class Codes: C01B 32/176 Cutting
• CPC Class Codes: Y10T 428/24992 Density or compression of components

Abstract

An aligned carbon nanotube bulk structure in which various properties such as density and hardness are controlled depending on the place is provided.

An aligned carbon nanotube bulk structure having different density portions is an aligned carbon nanotube bulk structure provided with a high-density portion applied with a density-increasing treatment and an low-density portion and having a plurality of carbon nanotubes (CNT) aligned in a predetermined direction, in which the structure has 1:3 or more of the degree of anisotropy in the alignment direction and in the direction vertical to the alignment direction and, in the (002) peak of the X-ray diffraction data in the high density region, the intensity of X-ray incident along the orientation direction is higher than that of the X-ray intensity from the direction vertical to the alignment direction, and the degree of alignment is defined by specific conditions.

Claims

1. An aligned carbon nanotube bulk structure having a plurality of carbon nanotubes (CNTs) having a high density portion applied with a density-increasing treatment and a low density portion and having alignment in a predetermined direction in which

a degree of anisotropy between the direction of alignment and the direction vertical to said direction in the structure is 1:

3 or more, and

the intensity by irradiating X-rays along the direction of alignment is higher compared with the intensity by irradiating X-rays from the direction vertical to the direction of alignment at a (002) peak of X-ray diffraction data of the high density portion, and

the degree of alignment is defined by at least one of the conditions;

1) in a case of measuring the X-diffraction intensity by irradiating X-rays from a first direction parallel with the longitudinal direction of the CNT and a second direction vertical to the first direction (θ

-2θ

method), an angle θ and

a reflection azimuth at which the reflection intensity from the second direction is higher than the reflection intensity from the first direction are present, and an angle θ and

a reflection azimuth at which the reflection intensity from the first direction is higher than the reflection intensity from the second direction is present,

2) a diffraction peak pattern exhibiting the presence of anisotropy appears in a case of measuring an X-ray diffraction intensity by a 2-dimensional diffraction pattern image obtained by irradiating X-rays from a direction vertical to the longitudinal direction of CNT (Laue method), and

3) a Herman'"'"'s orientation factor is larger than 0 and smaller than 0.1 when using the X-ray diffraction intensity obtained according to the θ

-2θ

method or the Laue method.

2. An aligned carbon nanotube bulk structure according to claim 1, wherein the alignment directions of the carbon nanotube in the high-density region and the low-density region are different from each other.

3. An aligned carbon nanotube bulk structure according to claim 1, wherein the high-density portion and the low-density portion are disposed regularly.

4. An aligned carbon nanotube bulk structure according to claim 1, further provided with a density region different from the high-density region and the low-density region.

5. An aligned carbon nanotube bulk structure according to claim 4, wherein the region of different density has an intermediate density between the high-density region and the low-density region.

6. An aligned carbon nanotube bulk structure according to claim 1, wherein the density changes continuously from the high-density region to the low-density region.

7. An aligned carbon nanotube bulk structure according to claim 1, wherein the high-density portion has a weight density of 0.2 to 1.5 g/cm³ while the low-density portion has a weight density of 0.001 to 0.2 g/cm³, and the high-density portion has a specific surface area of 600 to 2600 m²/g.