U.S. patent application number 13/185296 was filed with the patent office on 2012-02-23 for carbon nanotube composite hollow structure and method for making the same.
This patent application is currently assigned to HON HAI PRECISION INDUSTRY CO., LTD.. Invention is credited to SHOU-SHAN FAN, YANG WEI.
Application Number | 20120045599 13/185296 |
Document ID | / |
Family ID | 45594295 |
Filed Date | 2012-02-23 |
United States Patent
Application |
20120045599 |
Kind Code |
A1 |
WEI; YANG ; et al. |
February 23, 2012 |
CARBON NANOTUBE COMPOSITE HOLLOW STRUCTURE AND METHOD FOR MAKING
THE SAME
Abstract
A macro-scale carbon nanotube composite hollow structure
includes a plurality of carbon nanotubes and a polymer. The carbon
nanotubes are combined with each other via van der Waals attractive
force. The polymer is at least partly attached to the carbon
nanotubes. A method for making the carbon nanotube composite hollow
structure includes the steps of providing a linear structure and a
carbon nanotube structure including at least one carbon nanotube
film or at least one carbon nanotube wire, wrapping the carbon
nanotube structure around the linear structure to form a first
carbon nanotube composite structure, applying a polymer liquid to
the first carbon nanotube composite structure such that a second
carbon nanotube composite structure is formed, and removing the
linear structure from the second carbon nanotube composite
structure.
Inventors: |
WEI; YANG; (Beijing, CN)
; FAN; SHOU-SHAN; (Beijing, CN) |
Assignee: |
HON HAI PRECISION INDUSTRY CO.,
LTD.
Tu-Cheng
TW
TSINGHUA UNIVERSITY
Beijing
CN
|
Family ID: |
45594295 |
Appl. No.: |
13/185296 |
Filed: |
July 18, 2011 |
Current U.S.
Class: |
428/35.7 ;
156/173; 977/742 |
Current CPC
Class: |
B32B 37/14 20130101;
Y10T 428/1352 20150115; C08K 7/24 20130101 |
Class at
Publication: |
428/35.7 ;
156/173; 977/742 |
International
Class: |
B32B 9/04 20060101
B32B009/04; B29C 53/56 20060101 B29C053/56 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2010 |
CN |
201010259930.0 |
Claims
1. A carbon nanotube composite hollow structure comprising a
plurality of carbon nanotubes combined with each other by van der
Waals attractive force therebetween and a polymer at least partly
attached to the carbon nanotubes.
2. The carbon nanotube composite hollow structure of claim 1,
wherein the carbon nanotubes and the polymer cooperatively form a
carbon nanotube composite layer defining a through hole.
3. The carbon nanotube composite hollow structure of claim 2,
wherein the through hole has a linear axis, and the carbon
nanotubes are arranged around the linear axis.
4. The carbon nanotube composite hollow structure of claim 3,
wherein the carbon nanotubes are entangled with each other or
oriented along more directions.
5. The carbon nanotube composite hollow structure of claim 3,
wherein the carbon nanotubes substantially spirally extend along
the linear axis.
6. The carbon nanotube composite hollow structure of claim 5,
wherein adjacent carbon nanotubes extending along a same direction
are joined end-to-end via van der Waals attractive force
therebetween.
7. The carbon nanotube composite hollow structure of claim 5,
wherein angles defined by extending directions of the carbon
nanotubes and the linear axis is larger than 0 degrees and less
than or equal to 90 degrees.
8. The carbon nanotube composite hollow structure of claim 2,
wherein the carbon nanotube composite layer comprises a carbon
nanotube layer comprising the carbon nanotubes, and a layer of the
polymer is located on an outer surface of the carbon nanotube
layer.
9. The carbon nanotube composite hollow structure of claim 2,
wherein the polymer is dispersed between the carbon nanotubes.
10. The carbon nanotube composite hollow structure of claim 1,
wherein a cross sectional view of an outline of the carbon nanotube
composite hollow structure is rectangular, trapezoid shaped, circle
shaped, or ellipse shaped.
11. A carbon nanotube composite hollow structure, comprising a wall
and a through hole defined by the wall, the wall comprising a
carbon nanotube structure and a polymer at least partly attached to
the carbon nanotube structure, wherein the carbon nanotube
structure comprises a plurality of carbon nanotubes.
12. A method for making a carbon nanotube composite hollow
structure, the method comprising: (a) providing a linear structure
and a carbon nanotube structure comprising at least one carbon
nanotube film or at least one carbon nanotube wire; (b) wrapping
the carbon nanotube structure around the linear structure to form a
first carbon nanotube composite structure; (c) applying a polymer
liquid to the first carbon nanotube composite structure such that a
second carbon nanotube composite structure is formed; and (d)
removing the linear structure from the second carbon nanotube
composite structure.
13. The method of claim 12, wherein a material of the linear
structure is metal, alloy, or plastics.
14. The method of claim 12, wherein step (b) comprises steps of:
(b1) fixing one end of the carbon nanotube structure on the linear
structure; and (b2) winding the carbon nanotube structure around
the linear structure by relatively moving the carbon nanotube
structure to the linear structure.
15. The method of claim 12, wherein providing the linear structure
comprises substeps: providing a supply unit comprising a guiding
shaft; providing the linear structure coiled around a bobbin; and
hanging the bobbin wound around the linear structure on the guiding
shaft.
16. The method of claim 15, wherein if the carbon nanotube
structure is a drawn carbon nanotube film or an untwisted carbon
nanotube wire, providing the carbon nanotube structure comprises
substeps: providing a wrapping unit comprising a hollow rotating
shaft being rotatable and a face plate comprising a support stage,
the face plate being mounted on the hollow rotating shaft;
providing a carbon nanotube array with a growing substrate; fixing
the growing substrate on the support stage; and drawing the carbon
nanotube film or untwisted carbon nanotube wire from the carbon
nanotube array.
17. The method of claim 16, wherein the step (b) comprises
substeps: providing a collecting unit comprising a rotatable
collecting shaft; fixing one end of the linear structure on the
collecting shaft; adhering the drawn carbon nanotube film or the
untwisted carbon nanotube wire to the linear structure; and
rotating the face plate and the collecting shaft such that the
linear structure moves along a fixed direction, thereby drawing
simultaneously the drawn carbon nanotube film or the untwisted
carbon nanotube wire from the carbon nanotube array and winding
around the linear structure to form the carbon nanotube composite
wire structure.
18. The method of claim 17, wherein the polymer liquid comprises
epoxy resin, acrylic resin, polyimides, polyvinyl alcohol,
polyester, silastic, or thermal conductive adhesive.
19. The method of claim 18, wherein in the step (c), the step of
applying the polymer liquid to the first carbon nanotube composite
structure is carried out by dipping the first carbon nanotube
composite wire structure into the polymer liquid, injecting the
polymer liquid into the first carbon nanotube composite wire
structure, or coating the polymer liquid on a surface of the first
carbon nanotube composite wire structure.
20. The method of claim 12, wherein the step of removing the linear
structure is executed by a chemical method or a physical method.
Description
RELATED APPLICATIONS
[0001] This application claims all benefits accruing under 36
U.S.C. .sctn.119 from China Patent Application No. 201010259930.0,
filed on Aug. 23, 2010 in the China Intellectual Property Office,
the disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates to a carbon nanotube
composite hollow structure.
[0004] 2. Discussion of Related Art
[0005] Carbon nanotubes have interesting and potentially useful
electrical and mechanical properties. Due to these and other
properties, carbon nanotubes have become a significant focus of
research and development for use in electron emitting devices,
sensors, transistors, and other devices.
[0006] It is becoming increasingly popular for carbon nanotubes to
be used to make composite materials. Carbon nanotubes can be
composed of a plurality of coaxial cylinders of graphite sheets.
Carbon nanotubes composited with metals, semiconductors, or
polymers result in a composite material with qualities of both
materials. Generally, the composite has a solid linear structure or
a sheet-shaped structure. However, macro-scale carbon nanotube
hollow structures and methods for making the same are not
provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Many aspects of the embodiments can be better understood
with references to the following drawings. The components in the
drawings are not necessarily drawn to scale, the emphasis instead
being placed upon clearly illustrating the principles of the
embodiments. Moreover, in the drawings, like reference numerals
designate corresponding parts throughout the several views.
[0008] FIG. 1 is a schematic side view of one embodiment of a
carbon nanotube composite hollow structure including a carbon
nanotube composite layer.
[0009] FIG. 2 is a cross-sectional view of one embodiment of the
carbon nanotube composite layer shown in FIG. 1.
[0010] FIG. 3 is a cross-sectional view of another embodiment of
the carbon nanotube composite layer shown in FIG. 1.
[0011] FIG. 4 shows a scanning electron microscope (SEM) image of a
pressed carbon nanotube film with the carbon nanotubes therein
arranged along a preferred orientation.
[0012] FIG. 5 shows an SEM image of a flocculated carbon nanotube
film with carbon nanotubes entangled with each other therein.
[0013] FIG. 6 shows an SEM image of a drawn carbon nanotube
film.
[0014] FIG. 7 shows an SEM image of an untwisted carbon nanotube
wire.
[0015] FIG. 8 shows an SEM image of a twisted carbon nanotube
wire.
[0016] FIG. 9 shows a flow chart of one embodiment of a method for
making a carbon nanotube composite hollow structure.
[0017] FIG. 10 is a top view of an apparatus partially cut-away for
making the carbon nanotube composite hollow structure shown in FIG.
1.
[0018] FIG. 11 is a frontal, partially cut-away view of the
apparatus shown in FIG. 10.
DETAILED DESCRIPTION
[0019] The disclosure is illustrated by way of example and not by
way of limitation in the figures of the accompanying drawings. It
should be noted that references to "an" or "one" embodiment in this
disclosure are not necessarily to the same embodiment, and such
references mean at least one.
[0020] Referring to FIG. 1, one embodiment of a carbon nanotube
composite hollow structure 10 is provided. The carbon nanotube
composite hollow structure 10 is a freestanding tube-shaped
structure. The cross-section of the outline of the carbon nanotube
composite hollow structure 10 along a direction substantially
perpendicular to the length of the carbon nanotube composite hollow
structure 10 can be rectangular, trapezoid-shaped, circle-shaped,
or ellipse-shaped. The carbon nanotube composite hollow structure
10 includes a carbon nanotube composite layer 12 and a through hole
14.
[0021] The outline of the through hole 14 can be similar to the
outline of the carbon nanotube composite hollow structure 10. That
is, the inner wall of the carbon nanotube composite hollow
structure 10 can be rectangular, trapezoid-shaped, circle-shaped,
or ellipse-shaped. It can be noted that the shape of the through
hole 14 can be selected as desired. The through hole 14 can be
substantially defined in the center of the carbon nanotube
composite layer 12. The carbon nanotube composite layer 12 and the
through hole 14 have a common linear axis 142. In one embodiment,
an effective diameter of the through hole 14 can be larger than 10
micrometers (.mu.m). In another embodiment, the effective diameter
of the through hole 14 is larger than 18 .mu.m. The thickness of
the carbon nanotube composite layer 12 can be substantially the
same.
[0022] The carbon nanotube composite hollow structure 10 can be a
composite structure including a polymer and at least one carbon
nanotube structure. The carbon nanotube structure can include at
least one carbon nanotube film or at least one carbon nanotube
wire. The carbon nanotube structure includes a plurality of carbon
nanotubes. At least part of the polymer can be directly attached to
the at least one carbon nanotube structure. The carbon nanotubes
surround the through hole 14. Axes of the carbon nanotubes along
the length direction of the carbon nanotubes can be substantially
parallel to an outer surface of the carbon nanotube composite
hollow structure 10.
[0023] Referring to FIG. 2, one embodiment of the carbon nanotube
composite layer 12 is provided. The carbon nanotube composite layer
12 can include a plurality of carbon nanotubes 122 and a polymer
124 dispersed between the carbon nanotubes 122. The plurality of
carbon nanotubes 122 form the at least one carbon nanotube
structure. That is to say, the polymer 124 is dispersed in the at
least one carbon nanotube structure.
[0024] Specifically, the carbon nanotubes 122 define a plurality of
micropores. The polymer 124 is filled in the interspaces and wraps
around the carbon nanotubes 122. The carbon nanotubes 122
surrounding the axis 142 are tightly combined with each other by
van der Waals attractive force therebetween. The carbon nanotubes
122 and the polymer 124 cooperatively form the tube wall of the
carbon nanotube composite hollow structure 10. In one embodiment,
the carbon nanotube composite hollow structure 10 has a tube
structure, and the carbon nanotubes 122 and the polymer 124 are
uniformly dispersed in the carbon nanotube composite hollow
structure.
[0025] The polymer 124 can be epoxy resin, acrylic resin,
polyimides, polyvinyl alcohol, polyester, silastic, thermal
conductive adhesive, or any combinations thereof.
[0026] Referring to FIG. 3, another embodiment of the carbon
nanotube composite layer 12 is also provided. The carbon nanotube
composite layer 12 can include a carbon nanotube layer 121
including at least one carbon nanotube structure including the
carbon nanotubes 122, and a polymer layer 123 located on an outer
surface of the carbon nanotube layer 121. In one embodiment, the
polymer layer 123 is the polymer 124 coated on the outer surface of
the carbon nanotube layer 121.
[0027] Specifically, the carbon nanotube layer 121 and the polymer
layer 123 cooperatively form the wall of the carbon nanotube
composite hollow structure 10. The polymer layer 123 wraps around
the carbon nanotube layer 121. An inner surface of the carbon
nanotube layer 121 surrounds the through hole 14. The polymer layer
123 is an outer layer of the carbon nanotube composite hollow
structure 10 away from the through hole 14.
[0028] The carbon nanotubes 122 in the at least one carbon nanotube
film or at least one carbon nanotube wire can be orderly or
disorderly aligned in the carbon nanotube composite layer 12. The
disorderly aligned carbon nanotubes are carbon nanotubes arranged
along many different directions, such that the number of carbon
nanotubes arranged along each different direction can be almost the
same (e.g. uniformly disordered), and/or entangled with each other.
The orderly aligned carbon nanotubes are carbon nanotubes arranged
in a consistently systematic manner, e.g., most of the carbon
nanotubes are arranged approximately along a same direction or have
two or more sections within each of which the most of the carbon
nanotubes are arranged approximately along a same direction
(different sections can have different directions). The carbon
nanotubes can be single-walled, double-walled, and/or multi-walled
carbon nanotubes. The diameters of the single-walled carbon
nanotubes can range from about 0.5 nanometers (nm) to about 50 nm.
The diameters of the double-walled carbon nanotubes can range from
about 1 nm to about 50 nm. The diameters of the multi-walled carbon
nanotubes can range from about 1.5 nm to about 50 nm.
[0029] The at least one carbon nanotube film and the at least one
carbon nanotube wire can be a freestanding structure. The
freestanding structure may have a planar shape or a linear
shape.
[0030] Referring to FIG. 4, the carbon nanotube film can be a
pressed carbon nanotube film formed by pressing a carbon nanotube
array down on the substrate. The carbon nanotubes in the pressed
carbon nanotube film are arranged along the same direction or along
different directions. The carbon nanotubes in the pressed carbon
nanotube film can rest upon each other. Adjacent carbon nanotubes
are attracted to each other and are combined by van der Waals
attractive force. An angle between a primary alignment direction of
the carbon nanotubes and a surface of the pressed carbon nanotube
film is about 0 degrees to approximately 15 degrees. The greater
the pressure applied, the smaller the angle obtained. If the carbon
nanotubes in the pressed carbon nanotube film are arranged along
different directions, the carbon nanotube structure can be
isotropic. The thickness of the pressed carbon nanotube film can
range from about 0.5 nm to about 1 mm. The length of the carbon
nanotubes can be larger than 50 .mu.m. Clearances can exist in the
carbon nanotube array. Therefore, micropores can exist in the
pressed carbon nanotube film and be defined by the adjacent carbon
nanotubes. Examples of the pressed carbon nanotube film are taught
by US PGPub. 20080299031A1 to Liu et al.
[0031] If the carbon nanotube composite hollow structure 10
includes at least one pressed carbon nanotube film. The at least
one pressed carbon nanotube film can be substantially coiled around
the through hole 14 to form a plurality of coils, with adjacent
coils tightly combined with each other by van der Waals attractive
force therebetween. The polymer can be filled in the micropores
defined by the carbon nanotubes of the at least one pressed carbon
nanotube film to form the carbon nanotube composite layer 12, or
surround a surface of the at least one pressed carbon nanotube film
to form the carbon nanotube composite layer 12. The carbon
nanotubes 122 in the carbon nanotube composite layer 12 can be
uniformly arranged along the linear axis 142, and adjacent carbon
nanotubes 122 are attracted to each other and combined by van der
Waals attractive force. An angle between a primary alignment
direction of the carbon nanotubes and the linear axis 142 can be
about 0 degrees to about 15 degrees.
[0032] Referring to FIG. 5, the carbon nanotube film can also be a
flocculated carbon nanotube film formed by a flocculating method.
The flocculated carbon nanotube film can include a plurality of
long, curved, disordered carbon nanotubes entangled with each
other. A length of the carbon nanotubes can be greater than 10
centimeters. In one embodiment, the length of the carbon nanotubes
is in a range from about 200 .mu.m to about 900 .mu.m. Further, the
flocculated carbon nanotube film can be isotropic. Here,
"isotropic" means the carbon nanotube film has properties identical
in all directions substantially parallel to a surface of the carbon
nanotube film. The carbon nanotubes can be substantially uniformly
distributed in the carbon nanotube film. The adjacent carbon
nanotubes are acted upon by the van der Waals attractive force
therebetween, thereby forming an entangled structure with
micropores defined therein. The thickness of the flocculated carbon
nanotube film can range from about 1 .mu.m to about 1 mm. In one
embodiment, the thickness of the flocculated carbon nanotube film
is about 100 .mu.m.
[0033] If the carbon nanotube composite hollow structure 10
includes at least one flocculated carbon nanotube film, the at
least one flocculated carbon nanotube film can be spirally arranged
around the through hole 14 to form a plurality of coils, with
adjacent coils tightly combined with each other by van der Waals
attractive force therebetween. The polymer can be filled in the
micropores defined by the carbon nanotubes to form the carbon
nanotube composite layer 12, or surround a surface of the at least
one flocculated carbon nanotube film to form the carbon nanotube
composite layer 12. The carbon nanotubes 122 in the carbon nanotube
composite layer 12 can be substantially uniformly arranged around
the linear axis 142 by van der Waals attractive force therebetween.
The carbon nanotubes 122 are substantially entangled with each
other and can be substantially parallel to the outline of the
carbon nanotube composite hollow structure 10.
[0034] Referring to FIG. 6, the carbon nanotube film can also be a
drawn carbon nanotube film formed by drawing a film from a carbon
nanotube array. Examples of the drawn carbon nanotube film are
taught by U.S. Pat. No. 7,045,108 to Jiang et al. The thickness of
the drawn carbon nanotube film can be in a range from about 0.5 nm
to about 100 .mu.m.
[0035] The drawn carbon nanotube film includes a plurality of
carbon nanotubes that are arranged substantially parallel to a
surface of the drawn carbon nanotube film. A large number of the
carbon nanotubes in the drawn carbon nanotube film can be oriented
along a preferred orientation, meaning that a large number of the
carbon nanotubes in the drawn carbon nanotube film are arranged
substantially along the same direction. An end of one carbon
nanotube is joined to another end of an adjacent carbon nanotube
arranged substantially along the same direction by van der Waals
attractive force. A small number of the carbon nanotubes are
randomly arranged in the drawn carbon nanotube film, and has a
small if not negligible effect on the larger number of the carbon
nanotubes in the drawn carbon nanotube film arranged substantially
along the same direction. It can be understood that some variation
can occur in the orientation of the carbon nanotubes in the drawn
carbon nanotube film. Microscopically, the carbon nanotubes
oriented substantially along the same direction may not be
perfectly aligned in a straight line, and some curved portions may
exist. It can be understood that contact between some carbon
nanotubes located substantially side by side and oriented along the
same direction cannot be totally excluded.
[0036] More specifically, the drawn carbon nanotube film can
include a plurality of successively oriented carbon nanotube
segments joined end-to-end by van der Waals attractive force
therebetween. Each carbon nanotube segment includes a plurality of
carbon nanotubes substantially parallel to each other, and joined
by van der Waals attractive force therebetween. The carbon nanotube
segments can vary in width, thickness, uniformity, and shape. The
carbon nanotubes in the drawn carbon nanotube film are also
substantially oriented along a preferred orientation. The width of
the drawn carbon nanotube film relates to the carbon nanotube array
from which the drawn carbon nanotube film is drawn.
[0037] The carbon nanotube structure can include more than one
drawn carbon nanotube film. An angle can exist between the
orientation of carbon nanotubes in adjacent films, stacked, and/or
coplanar. Adjacent carbon nanotube films can be bonded by van der
Waals attractive force therebetween without an additional adhesive.
An angle between the aligned directions of the carbon nanotubes in
two adjacent drawn carbon nanotube films can range from about 0
degrees to about 90 degrees. Spaces are defined between two
adjacent carbon nanotubes in the drawn carbon nanotube film. If the
angle between the aligned directions of the carbon nanotubes in
adjacent drawn carbon nanotube films is larger than 0 degrees, the
micropores can be defined by the crossed carbon nanotubes in
adjacent drawn carbon nanotube films.
[0038] The carbon nanotube wire itself can be untwisted or twisted.
Referring to FIG. 7, treating the drawn carbon nanotube film with a
volatile organic solvent can obtain the untwisted carbon nanotube
wire. In one embodiment, the organic solvent is applied to soak the
entire surface of the drawn carbon nanotube film. During the
soaking, the adjacent substantially parallel carbon nanotubes in
the drawn carbon nanotube film will bundle together due to the
surface tension of the organic solvent as it volatilizes, and thus,
the drawn carbon nanotube film will be shrunken into an untwisted
carbon nanotube wire. The untwisted carbon nanotube wire includes a
plurality of carbon nanotubes substantially oriented along a same
direction (i.e., a direction along the length direction of the
untwisted carbon nanotube wire). The carbon nanotubes are
substantially parallel to the axis of the untwisted carbon nanotube
wire. In one embodiment, the untwisted carbon nanotube wire
includes a plurality of successive carbon nanotubes joined end to
end by the van der Waals force therebetween. A length of the
untwisted carbon nanotube wire can be arbitrarily set as desired. A
diameter of the untwisted carbon nanotube wire can range from about
0.5 nm to about 100 .mu.m. Examples of the untwisted carbon
nanotube wire are taught by US Patent Application Publication US
2007/0166223 to Jiang et al.
[0039] If the carbon nanotube composite hollow structure 10
includes at least one drawn carbon nanotube film, or at least one
untwisted carbon nanotube wire, the at least one drawn carbon
nanotube film or the at least one untwisted carbon nanotube wire
can be spirally arranged around the through hole 14 to form a
plurality of coils, with adjacent coils tightly combined with each
other by van der Waals attractive force therebetween. The polymer
can be filled in the micropores defined by the carbon nanotubes of
the at least one drawn carbon nanotube film or at least one
untwisted carbon nanotube wire to form the carbon nanotube
composite layer 12, or surround a surface of the at least one drawn
carbon nanotube film or at least one untwisted carbon nanotube wire
to form the carbon nanotube composite layer 12.
[0040] Most of the carbon nanotubes 122 in the carbon nanotube
composite layer 12 can be uniformly arranged around the linear axis
142. Most adjacent carbon nanotubes 122 substantially extending
along the same direction are joined end-to-end by van der Waals
attractive force. Furthermore, most of the carbon nanotubes 122 can
substantially spirally extend along the linear axis 142. Namely,
most of the carbon nanotubes 122 can substantially spirally extend
along the inner wall of the carbon nanotube composite hollow
structure 10. An angle is defined between most of the carbon
nanotubes and the linear axis 142. The angle can be larger than 0
degrees and less than or equal to 90 degrees. Carbon nanotubes 122
in each drawn carbon nanotube film or untwisted carbon nanotube
wire can extend along a same direction, such that angles defined
between most of the carbon nanotubes 122 and the linear axis 142
can be substantially equal to each other.
[0041] Referring to FIG. 8, the twisted carbon nanotube wire can be
obtained by twisting a drawn carbon nanotube film using a
mechanical force to turn the two ends of the drawn carbon nanotube
film in opposite directions. The twisted carbon nanotube wire
includes a plurality of carbon nanotubes helically oriented around
an axial direction of the twisted carbon nanotube wire. In one
embodiment, the twisted carbon nanotube wire includes a plurality
of successive carbon nanotubes joined end to end by van der Waals
attractive force therebetween. The length of the carbon nanotube
wire can be set as desired. A diameter of the twisted carbon
nanotube wire can be from about 0.5 nm to about 100 .mu.m.
[0042] The twisted carbon nanotube wire can be treated with a
volatile organic solvent, before or after being twisted. After
being soaked by the organic solvent, the adjacent substantially
parallel carbon nanotubes in the twisted carbon nanotube wire will
bundle together due to the surface tension of the organic solvent
when the organic solvent volatilizes. The specific surface area of
the twisted carbon nanotube wire will decrease. The density and
strength of the twisted carbon nanotube wire will increase.
[0043] If the carbon nanotube composite hollow structure 10
includes at least one twisted carbon nanotube wire, the at least
one twisted carbon nanotube wire can be spirally arranged around
the through hole 14 to form a plurality of coils. Adjacent coils
are tightly combined with each other by van der Waals attractive
force therebetween. The polymer can be dispersed between the carbon
nanotubes of the at least one twisted carbon nanotube wire to form
the carbon nanotube composite layer 12, or surround a surface of
the at least one twisted carbon nanotube wire to form the carbon
nanotube composite layer 12. Most of the carbon nanotubes 122 in
the carbon nanotube composite layer 12 are joined end-to-end and
uniformly located around the linear axis 142 by van der Waals
attractive force therebetween.
[0044] In one embodiment, the carbon nanotube composite hollow
structure 10 has a hollow tube-shaped structure with an inner
diameter of about 25 .mu.m and an outer diameter of about 50 .mu.m.
The shape of the cross-section of the carbon nanotube composite
hollow structure 10 is a ring. The carbon nanotube composite hollow
structure 10 includes a plurality of carbon nanotubes 122 and
silastic. The carbon nanotubes 122 and the silastic cooperatively
form the carbon nanotube composite layer 12. The carbon nanotube
tubes 122 are tightly combined by van der Waals attractive force to
form the carbon nanotube layer 121 in the carbon nanotube composite
layer 12 and define the through hole 14 with the diameter of about
25 .mu.m. Most of the silastic is formed into a silastic layer
located on the carbon nanotube layer 121, and part of the silastic
is infiltrated into the carbon nanotube layer 121.
[0045] Specifically, six drawn carbon nanotube films spiral upwards
to form a carbon nanotube tube structure and define the through
hole 14, the silastic surrounds the carbon nanotube tube structure
and is filled in a part of the micropores in the carbon nanotube
tube structure, thereby forming the carbon nanotube composite
hollow structure 10. Most of the carbon nanotubes 122 oriented
along a same direction are joined end-to-end by van der Waals
attractive force.
[0046] Furthermore, most of the carbon nanotubes 122 substantially
spirally extend along the linear axis 142. The silastic
substantially surrounds the linear axis 142. Angles (not shown)
defined by the carbon nanotubes 122 and the linear axis 142 are
about 45 degrees. Most of the carbon nanotubes 122 in each drawn
carbon nanotube film are substantially oriented along a same
direction such that angles defined by the carbon nanotubes 122 and
the linear axis 142 are substantially the same.
[0047] Referring to FIG. 9, one embodiment of a method for making
the carbon nanotube composite hollow structure 10 is provided. The
method can include the following steps:
[0048] (a), providing a linear structure and a carbon nanotube
structure including at least one carbon nanotube film or at least
one carbon nanotube wire;
[0049] (b), winding the carbon nanotube structure around the linear
structure to form a first carbon nanotube composite wire
structure;
[0050] (c), applying a polymer liquid to the first carbon nanotube
composite wire structure, thereby forming a second carbon nanotube
composite wire structure; and
[0051] (d), removing the linear structure from the second carbon
nanotube composite wire structure.
[0052] In step (a), the linear structure is configured to support
the carbon nanotube structure. Therefore the linear structure
should have a certain strength and toughness. In addition, the
linear structure should be easily removed by a chemical method or a
physical method. The material of the linear structure can be metal,
alloy, or plastics. The cross sectional view of the linear
structure along a direction substantially perpendicular to the
linear structure, can be rectangular, trapezoid shaped, circle
shaped, or ellipse shaped.
[0053] The step (b) can include the following steps: (b1), adhering
one end of the carbon nanotube structure to the linear structure;
and (b2), rotating the linear structure with the carbon nanotube
structure, and simultaneously moving the linear structure or the
carbon nanotube structure along a fixed direction, thereby forming
the carbon nanotube composite wire structure. In step (b1), if the
carbon nanotube structure includes a plurality of carbon nanotube
films or carbon nanotube wires, then step (b1) can be performed by
adhering one end of each carbon nanotube film or carbon nanotube
wire to the linear structure in sequence. The step (b1) can also be
performed by combining the plurality of carbon nanotube films or
carbon nanotube wires first, and then adhering one end of the
combination of the plurality of carbon nanotube films or carbon
nanotube wires.
[0054] In one embodiment, if the carbon nanotube structure is made
from a carbon nanotube array, the step (a) can provide a linear
structure and a carbon nanotube array. The step (b) can include
steps: (b1), drawing a drawn carbon nanotube film or untwisted
carbon nanotube wire from the carbon nanotube array; (b2), adhering
the drawn carbon nanotube film or untwisted carbon nanotube wire to
the linear structure; and (b3), rotating the linear structure with
the carbon nanotube array, and simultaneously moving the linear
structure or the carbon nanotube structure along a fixed direction.
The drawn carbon nanotube film or untwisted carbon nanotube wire
can be continuously drawn from the carbon nanotube array. The first
carbon nanotube composite wire structure can be continuously
produced.
[0055] The step (b) can further include a step of treating the
carbon nanotube composite wire structure using an organic solvent.
Specifically, the carbon nanotube structure is treated by spreading
the organic solvent on the entire surface of the structure wound
around the linear structure, or immersing the linear structure with
the carbon nanotube structure into the organic solvent. The organic
solvent is volatilizable and can be ethanol, methanol, acetone,
dichloroethane, chloroform, or combinations thereof. After being
soaked by the organic solvent, the carbon nanotube structure can be
compacted and decrease the adhesiveness of the carbon nanotube
structure due to the decrease of the surface tension of the carbon
nanotube structure.
[0056] The step (c) can be executed by dipping the first carbon
nanotube composite wire structure into the polymer liquid,
injecting the polymer liquid into the first carbon nanotube
composite wire structure, or coating the polymer liquid on a
surface of the first carbon nanotube composite wire structure. The
polymer liquid can be a polymer solution or melted polymer. The
polymer in the polymer liquid can be epoxy resin, acrylic resin,
polyimides, polyvinyl alcohol, polyester, silastic, thermal
conductive adhesive, or any other organic materials. In one
embodiment, the step (c) includes: dispersing the silastic into
aether to form silastic solution; immersing the first carbon
nanotube composite wire structure into the silastic solution;
adding a little curing agent of epoxy resin into the silastic
solution, and then curing more than two hours to make carbon
nanotubes composite with silastic. The curing agent of epoxy resin
can be substituted with basic curing agent, acid curing agent, or
other curing agent.
[0057] The step (d) can be performed by a chemical method, or a
physical method, such as a mechanical method. In one embodiment, if
the linear structure is made of an active metal or an alloy
composed of active metals, such as iron, aluminum, or an alloy
thereof, the step (d) can include a step of applying the second
carbon nanotube composite wire structure into an acidic liquid to
react the linear structure with the acidic liquid. The acidic
liquid can be nitric acid, sulfuric acid, hydrochloric acid, or
other suitable acidic liquid. If the material of the linear
structure is an inactive metal or an alloy consisting of inactive
metals, such as gold, silver, or an alloy thereof, the step (d) can
include a step of heating the second carbon nanotube composite wire
structure to evaporate the linear structure. If the material of the
linear structure is a polymer material, metal, or an alloy, the
step (d) can include a step of pulling the linear structure out
from the second carbon nanotube composite wire structure using a
stretching device along the axial direction of the linear
structure. Therefore, the figure and the effective diameter of the
linear structure can dictate the figure and effective diameter of
the through hole 14 of the carbon nanotube composite hollow
structure 10. The outline of the carbon nanotube composite hollow
structure 10 can also be decided by the linear structure.
[0058] In one embodiment, the carbon nanotube structure is made of
at least one drawn carbon nanotube film, at least one untwisted
carbon nanotube wire, or a combination thereof. The carbon nanotube
composite hollow structure can be executed by an apparatus 100
shown in FIG. 10 and FIG. 11. The apparatus 100 can include a
supply unit 20, a wrapping unit 30, and a collecting unit 40. The
supply unit 20 supplies a linear structure. The wrapping unit 30
can load at least one carbon nanotube array (not shown) thereon. A
carbon nanotube structure (not shown) can be drawn from the at
least one carbon nanotube array. The carbon nanotube structure can
be at least one drawn carbon nanotube film, at least one untwisted
carbon nanotube wire, or a combination thereof. The wrapping unit
30 wraps the carbon nanotube structure around the linear structure,
thereby forming the carbon nanotube composite wire structure. The
collecting unit 40 can drive the linear structure to move along a
fixed direction and collect the carbon nanotube composite wire
structure.
[0059] The supply unit 20 can include a pedestal 22, a guiding
shaft 28, and a bobbin 24. The pedestal 22 is substantially
perpendicular to the supporter 60 by fixing one end of the pedestal
22 with respect to the supporter 60. One end of the guiding shaft
28 is fixed on the pedestal 22, and the other end is suspended. The
guiding shaft 28 is substantially perpendicular to the pedestal 22.
The bobbin 24 is hung on the guiding shaft 28, and can be freely
moved around the guiding shaft 28. The bobbin 24 winds a linear
structure thereon. The linear structure can be a conductive thread
structure or a non-conductive thread structure. The non-conductive
thread structure can be a carbon fiber, an artificial fiber such as
Kevlar, or a natural fiber. The natural fiber can be spider silk or
silkworm silk. The conductive thread structure can be a metal
thread, an alloy thread, a conductive polymer thread, or a
combination thereof.
[0060] The wrapping unit 30 can be configured to load a carbon
nanotube array with a growing substrate for growing the carbon
nanotube array. The wrapping unit 30 can include a drive mechanism
32, a hollow rotating shaft 34, two bearings 342, two braces 36,
and a face plate 38. The drive mechanism 32 is positioned at one
end of the hollow rotating shaft 34 close to the supply unit 20.
The face plate 38 is located at the other end of the hollow
rotating shaft 34. The two bearings 36 are separately harnessed to
the hollow rotating shaft 34. Each brace 36 couples with a bearing
342 to support the hollow rotating shaft 34.
[0061] The drive mechanism 32 drives the hollow rotating shaft 34
to rotate. The hollow rotating shaft 34 is rotated to allow the
face plate 38 to rotate. The drive mechanism 32 can include a first
motor 322, a first belt pulley 324, a second belt pulley 328, and a
belt 326. The first belt pulley 324 is mounted on the first motor
322. The second belt pulley 328 is separated from the first belt
pulley 324, and mounted on the hollow rotating shaft 34. The belt
326 is harnessed to the first belt pulley 324 and the second belt
pulley 328. The first belt pulley 324 can be rotated under the
first motor 322. The first belt pulley 324 can drive the second
belt pulley 328 to rotate by the belt 328. The second belt pulley
328 drives the hollow rotating shaft 34 to rotate. Therefore, a
speed of the first motor 322 can control a rotating speed of the
hollow rotating shaft 34. The structure of the drive mechanism 32
is not restricted by the above description, provided the drive
mechanism 32 can drive the hollow rotating shaft 34 to rotate.
[0062] The hollow rotating shaft 34 is a tube-shaped structure. The
hollow rotating shaft 34 defines a first axis 344 substantially
overlapping with the linear structure, if the linear structure
passes through the hollow rotating shaft 34. The hollow rotating
shaft 34 can be rotatable clockwise or anti-clockwise around the
first axis 344 by the driving mechanism 32.
[0063] The face plate 38 is harnessed on the hollow rotating shaft
34, such that the face plate 38 can accompany the hollow rotating
shaft 34 to rotate around the first axis 344. The hollow rotating
shaft 34 is driven by the first motor 322 such that the rotating
speed of the face plate 38 is controlled by the speed of the first
motor 322. The shape of the face plate 38 is similar to a frustum
pyramid, such as a triangular frustum pyramid, a quadrangular
frustum pyramid, a pentangular frustum pyramid, a hexangular
frustum pyramid, or a heptangular frustum pyramid. The face plate
38 has a plurality of side faces. A support stage protrudes from
each side face. A plurality of support stages locates the carbon
nanotube array. Each support stage can define an angle with the
first axis of the hollow rotating shaft 34, and faces the
collecting unit 40. A plurality of support stages (not labeled)
uniformly surrounds the hollow rotating shaft 34. In one
embodiment, the shape of the face plate 38 is similar to a
hexangular frustum pyramid.
[0064] Six support stages protrude from the side faces of the
hexangular frustum pyramid. Each support stage can define the angle
of about 45 degrees with the first axis 344 of the hollow rotating
shaft 34.
[0065] The collecting unit 40 can include a second motor 42, and a
collecting shaft 44 fixed on the second motor 42. The collecting
shaft 44 can be substantially perpendicular to the hollow rotating
shaft 34. The collecting shaft 44 can rotate around a second axis
442 of the collecting shaft 44 under the second motor 42. The
second axis 442 is substantially perpendicular to the first axis
344, such that the linear structure can be driven along a fixed
direction, and the carbon nanotube composite wire structure can be
collected on the collecting shaft 44. Therefore, the second motor
42 can control the rotating speed of the collecting shaft 44. The
second motor 42 can also control the collecting speed of the carbon
nanotube composite wire structure.
[0066] The apparatus 100 can further include two locating elements
50. Each locating element 50 defines a locating hole (not labeled).
The center of the locating hole and the first axis 344 of the
hollow rotation shaft 34 are substantially collinear. The two
locating elements 50 ensure the linear structure is substantially
maintained at a same plane and does not contact the inner wall of
the hollow rotation shaft 34. One locating element 50 is fixed
between the supply unit 20 and the wrapping unit 30, thus the
linear structure is suspended in the hollow rotation shaft 34. The
other locating element 50 is positioned between the wrapping unit
30 and the collecting unit 40, so that the carbon nanotube
composite wire structure made by the apparatus 100 and the linear
structure can substantially stay on the same plane. The number of
the locating elements 50 can be selected as desired.
[0067] Specifically, the method for making the carbon nanotube
composite hollow structure using the apparatus 100 can include the
steps:
[0068] S10, providing a linear structure by the supply unit 20;
[0069] S20, passing the linear structure through the wrapping unit
30, and fixing the linear structure on the collecting unit 40;
[0070] S30, providing a carbon nanotube structure by the wrapping
unit 30, and adhering one end of the carbon nanotube structure to
the linear structure;
[0071] S40, rotating the face plate 36 and moving the linear
structure along a fixed direction to wind the carbon nanotube
structure around the linear structure such that a first carbon
nanotube composite wire structure is formed;
[0072] S50, applying a polymer liquid to the first carbon nanotube
composite wire structure, thereby forming a second carbon nanotube
composite wire structure; and
[0073] S60, removing the linear structure from the second carbon
nanotube composite wire structure.
[0074] The step S10 can include the steps: providing the linear
structure coiled around the bobbin 24; and supporting the bobbin 24
with the linear structure on the guiding shaft 28. The bobbin 24
with the linear structure coiled thereon can be moved around the
guiding shaft 28.
[0075] The step S20 can include the steps: passing a free end of
the linear structure through the hollow rotation shaft 34, and
fixing the free end of the linear structure on the surface of the
collecting shaft 44. In one embodiment, the linear structure will
pass through the two locating holes of the two locating elements 50
in sequence before the linear structure is fixed on the collecting
shaft 44, wherein the linear structure substantially overlaps with
the first axis of the hollow rotating shaft 34.
[0076] The step S30 can include the following sub-steps:
[0077] S31, providing at least one carbon nanotube array, wherein
each carbon nanotube array is grown on a growing substrate;
[0078] S32, fixing each growing substrate on the face plate 36;
and
[0079] S33, drawing a drawn carbon nanotube film or an untwisted
carbon nanotube wire from each carbon nanotube array using a
stretching tool, and adhering one end of the carbon nanotube film
or untwisted carbon nanotube wire to the linear structure.
[0080] In step S31, the carbon nanotube array is composed of a
plurality of carbon nanotubes. The plurality of carbon nanotubes
can be single-walled carbon nanotubes, double-walled nanotubes,
multi-walled carbon nanotubes, or any combination thereof. In one
embodiment, the plurality of carbon nanotubes comprises
substantially parallel multi-walled carbon nanotubes. The carbon
nanotube array is essentially free of impurities, such as
carbonaceous or residual catalyst particles. The carbon nanotube
array can be a super aligned carbon nanotube array. A method for
making the carbon nanotube array is unrestricted, and can be by
chemical vapor deposition methods or other methods.
[0081] In step S32, each growing substrate with the carbon nanotube
array grown thereon is fixed on the support stage 362 by adhesive,
mechanical tools, or vacuum absorption.
[0082] In step S33, each carbon nanotube film or untwisted carbon
nanotube wire can be formed by selecting one or more carbon
nanotubes having a predetermined width from each carbon nanotube
array, and pulling the carbon nanotubes at a uniform speed to form
carbon nanotube segments that are joined end to end to achieve the
uniform drawn carbon nanotube film or untwisted carbon nanotube
wire. During the pulling process, as the initial carbon nanotube
segments are drawn out, other carbon nanotube segments are also
drawn out end to end due to van der Waals attractive force between
ends of adjacent segments. The stretching tool can be a ruler,
tweezers, or an adhesive tape.
[0083] It is noted that because the carbon nanotubes in the carbon
nanotube array have a high purity and a high specific surface area,
the drawn carbon nanotube film or untwisted carbon nanotube wire is
adhesive. As such, the carbon nanotube film or untwisted carbon
nanotube wire can be adhered to the surface of the linear structure
directly and a plurality of drawn carbon nanotube films or
untwisted carbon nanotube wires can be adhered to a surface one
after another.
[0084] The step S40 can include the steps of operating the first
motor 322 to rotate the face plate 38 and controlling the
collecting unit 40 to move the linear structure along the fixed
direction, such that the carbon nanotube structure is wound around
the linear structure. Specifically, when the collecting unit 40 and
wrapping unit 30 are operated, the linear structure can be
continuously supplied by the supply unit 20 and move towards the
collecting unit 40. The drawn carbon nanotube film or untwisted
carbon nanotube wire can be continuously drawn from each carbon
nanotube array. Simultaneously, the first motor 322 drives the
hollow rotating shaft 34 to rotate around the first axis 344 of the
hollow rotating shaft 34 along a first direction. If the hollow
rotating shaft 34 rotates, the face plate 38 and the at least one
carbon nanotube array located on the face plate 38 can be rotated
around the first axis 344 of the hollow rotating shaft 34 along the
first direction. The drawn carbon nanotube film or untwisted carbon
nanotube wire stretched from each carbon nanotube array can be
wrapped around the surface of the linear structure along the first
direction. Therefore, the first carbon nanotube composite wire is
formed. If the second motor 42 drives the collecting shaft 44 to
rotate, the first carbon nanotube composite wire can be
automatically wound around the collecting shaft 44. Thus, the first
carbon nanotube composite wire can be continuously manufactured and
collected on the collecting shaft 44. Therefore, the rotating
speeds of the collecting shaft 44 and the face plate 38
cooperatively affect the thickness of the carbon nanotube
layer.
[0085] In one embodiment, the step S40 can further include a step
of repeating the above mentioned step S40, wherein the face plate
38 can be driven to rotate along a second direction opposite to the
first direction by the first motor 322. Thus, the drawn carbon
nanotube film or untwisted carbon nanotube wire is wound around the
linear structure along the second direction.
[0086] In one embodiment, the carbon nanotube composite hollow
structure 10 is a carbon nanotube silastic composite hollow
structure. The carbon nanotube silastic composite hollow structure
can be made by the following steps:
[0087] S100, providing an aluminum thread with a diameter of about
25 .mu.m by the supply unit 20;
[0088] S200, passing the aluminum thread through the hollow
rotation shaft 34, and fixing the aluminum thread on the collecting
unit 40;
[0089] S300, providing six drawn carbon nanotube films by the
wrapping unit 30, and adhering the six drawn carbon nanotube films
to the aluminum thread;
[0090] S400, rotating the face plate 38 and pulling the aluminum
thread along a fixed direction to wind the six drawn carbon
nanotube films around the aluminum thread, thereby forming a carbon
nanotube aluminum composite wire structure with a diameter of about
50 .mu.m;
[0091] S500, applying a silastic solution to the carbon nanotube
aluminum composite wire structure to form a carbon nanotube
aluminum silastic composite wire structure; and
[0092] S600, etching the aluminum thread in the carbon nanotube
aluminum silastic composite wire structure with hydrochloric acid
with a concentration of about 0.5 molars per liter (mol/L), to
remove the aluminum thread.
[0093] According to the above description, the carbon nanotube
composite hollow structure is a macro-scale hollow tube-shaped
structure. The carbon nanotube composite hollow structure can be
flexible, light-weight, with small thermal capacity and high
strength. Therefore, the carbon nanotube composite hollow structure
can be conveniently applied in various fields. Furthermore, the
carbon nanotubes in the carbon nanotube composite hollow structure
can be tightly combined via the polymer, such that the carbon
nanotube composite hollow structure can have high tensile strength
and high tensile index.
[0094] The macro-scale carbon nanotube composite hollow structure
can be made by winding the carbon nanotube structure around the
linear structure, applying polymer liquid to the wounded carbon
nanotube structure, and removing the linear structure. The method
for making the macro-scale carbon nanotube composite hollow
structure is simple, and quickly producible. The carbon nanotube
structure is a freestanding structure, and includes at least one
carbon nanotube film or at least one carbon nanotube wire. The at
least one carbon nanotube film or at least one carbon nanotube wire
also has an adhesive property. After being wrapped around the
linear structure, the overlapped carbon nanotube films or carbon
nanotube wires can be adhered to each other by van der Waals
attractive force. The polymer in the carbon nanotube composite
hollow structure is formed by curing polymer on the carbon nanotube
films or carbon nanotube wires. Thus, the carbon nanotube composite
hollow structure can have a stable structure.
[0095] It is also to be understood that the above description and
the claims drawn to a method may include some indication in
reference to certain steps. However, the indication used is only to
be viewed for identification purposes and not as a suggestion as to
an order for the steps.
* * * * *