TWI462872B - Method for preparing nano carbon tube film - Google Patents

Description

Method for preparing nano carbon tube film

The invention relates to a method for preparing a carbon nanotube film.

Carbon Nanotube (CNT) is a hollow tube made of graphene sheets. It has excellent mechanical, thermal and electrical properties and therefore has a wide range of applications. Since the size of a single carbon nanotube is nanometer, it is difficult to process. For practical application, a plurality of carbon nanotubes are tried as raw materials to form a macrostructure having a large size. The macrostructure consists of a plurality of carbon nanotubes and may be in the form of a film, a line or other shape. In the prior art, a macroscopic film structure composed of a plurality of carbon nanotubes is generally referred to as a Carbon Nanotube Film.

Feng Chen et al., in Chinese Patent Application Publication No. CN101239712A, discloses a carbon nanotube film obtained by directly pulling from a carbon nanotube array, which has a macroscopic scale and is self-supporting. It includes a number of carbon nanotubes connected end to end under the action of Van der Valli. Since the carbon nanotubes in the carbon nanotube film are arranged substantially in the same direction, the carbon nanotube film can exhibit various excellent properties such as conductivity and heat conduction in the axial direction of the carbon nanotube, and has a wide range of properties. Application prospects. In addition, the carbon nanotube film is relatively transparent and can be used as a transparent conductive film.

However, the carbon nanotube membranes are all pulled out from an array of carbon nanotubes, and the area of the membrane is limited by the size of the array of carbon nanotubes. The carbon nanotube array in the prior art is generally obtained by chemical vapor deposition, in particular, a flat circular bract is used as a substrate, a catalyst film is formed on one surface, placed in a reaction furnace for heating, and carbon is introduced. The source gas and the shielding gas are decomposed by the catalyst on the surface of the crucible, and a carbon nanotube is grown on the surface of the crucible. The reactor currently used to grow carbon nanotube arrays is a 10-inch diameter tubular reactor. Since the gas pressure in the tubular reactor is less than the atmospheric pressure outside the furnace during the above growth process, the furnace wall of the tubular reactor will be subjected to the inward pressure, making the inner diameter of the tubular reactor difficult to be large. Generally, when the tubular reactor has a diameter of 10 inches, a length of 2 meters, and an internal gas pressure of 10 Torr, the pressure difference between the inner and outer walls is 50,000 Newtons. When the diameter of the tubular reactor is increased to 40 inches, the pressure difference between the inner and outer walls can reach 200,000 Newtons. Moreover, when the diameter is increased, since the curvature of the furnace wall of the tubular reactor is lowered, the supporting action is also weakened, and the stability of the tubular reactor is deteriorated or even broken, which affects safety. Therefore, when a carbon nanotube array is grown in a 10-inch tubular reactor using a circular cymbal as a substrate, the circular cymbal has a maximum diameter of about 8 inches, allowing the nano-growth from the circular cymbal. The area of the carbon nanotube film drawn in the carbon tube array is limited and cannot meet the needs of practical applications.

In view of the above, it is necessary to provide a preparation method capable of obtaining a carbon nanotube film having a large width.

A method for preparing a carbon nanotube film, comprising the steps of: providing a curved carbon nanotube array; selecting a carbon nanotube segment from the carbon nanotube array by using a stretching tool; The direction of the curved carbon nanotube array moves the stretching tool to pull the selected carbon nanotube segments, so that the carbon nanotubes are continuously pulled out end to end to form a continuous carbon nanotube film.

Compared with the prior art, since the carbon nanotube array is curved, the carbon nanotube array prepared in the same existing reactor has a larger size than the planar carbon nanotube array, so that it can be pulled from The obtained carbon nanotube film also has a larger size.

Hereinafter, a method for preparing a carbon nanotube film of an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The carbon nanotube membrane comprises a plurality of carbon nanotubes, wherein at least a portion of the carbon nanotubes are connected end to end by a van der Waals force, thereby enabling the carbon nanotube membrane to be self-supporting. The preparation method of the carbon nanotube film according to the embodiment of the invention comprises the following steps:

Step 1: providing a curved carbon nanotube array;

Step two: selecting a carbon nanotube segment from the curved carbon nanotube array by using a stretching tool;

Step 3: moving the stretching tool in a direction away from the curved carbon nanotube array to pull the selected carbon nanotube segment, so that the carbon nanotubes are continuously pulled out end to end, thereby forming a continuous nai Carbon tube film.

The following describes each step separately.

First, step one is further explained. The curved carbon nanotube array is formed on a curved surface of a growth substrate by chemical vapor deposition, preferably a super-sequential carbon nanotube array. In this embodiment, the method for preparing the super-sequential carbon nanotube array specifically includes:

(a) providing a growth substrate, the growth substrate comprising a curved surface;

(b) uniformly forming a catalyst layer on the curved surface of the growth substrate;

(c) growing a carbon nanotube array on the curved surface of the growth substrate by chemical vapor deposition.

The growth substrate may be selected from a quartz substrate, a high temperature resistant glass substrate, a P-type or N-type germanium substrate, a metal substrate having a high melting point, or a germanium substrate formed with an oxide layer. The substrate described above is capable of withstanding the annealing and reaction temperatures during growth of the carbon nanotube array 120 without deformation or melting. The curved surface may be a cylindrical surface, and the cylindrical surface is represented as a surface formed by moving a straight line segment having a certain length along a curved trajectory. The moving straight line segment is called the straight bus bar of the cylinder, and the fixed curve is called the collimating line of the cylindrical surface. When the guideline is rounded, the resulting cylinder is called a cylindrical surface, and when the alignment is a spiral, the resulting cylinder is a spiral cylinder. Referring to FIG. 1, the curved surface 142 of the growth substrate 140 may be a surface formed by the straight line segments moving along a wavy line in parallel. The carbon nanotube array 120 is grown on the curved surface 142, thereby also having a curved shape. 2, the growth substrate 140a may also be a spiral growth substrate 140a. The curved surface 142a of the growth substrate 140a may be a surface formed by a straight line segment having a certain width and moving along a plane spiral track in parallel. The segment is perpendicular to the plane in which the plane spiral is located. The curved surface 142a may spirally grow the inner or outer surface of the substrate 140a. The spiral growth substrate 140a has an opening 144a at one end of the plane spiral outward, and a gap 146a defined by the spiral growth substrate 140a, the gap 146a being a spiral gap extending from the opening 144a to The spiral growth substrate 140a is centered. It can be understood that the curved surface of the growth substrate is not limited to the above-mentioned wavy or spiral shape, as long as a straight line segment having a certain width is moved in parallel along a curved trajectory. For example, the growth substrate may also be a spring-like growth substrate, and the curved surface may be represented as a surface formed by a linear segment having a certain width moving along a spatial spiral track. Alternatively, the growth substrate may be a cylindrical growth substrate or a columnar growth substrate such as a quartz tube or a quartz cylinder, and the carbon nanotube array is a cylindrical array. Referring to FIG. 6 and FIG. 7 , the curved surface 142 c of the growth substrate 140 c may be a surface formed by the straight line segment along a circular trajectory, and the curved surface may be an inner surface or an outer surface of the growth substrate 140 c .

The step (c) may specifically: annealing the growth substrate on which the catalyst layer is formed in air at 300 ° C to 900 ° C (eg, 700 ° C) for about 30 minutes to 90 minutes; and placing the growth substrate in a reaction furnace. It is heated to 500 ° C ~ 900 ° C (such as 740 ° C) in a protective gas atmosphere, and then reacted with a carbon source gas for about 5 minutes to 30 minutes to grow a super-aligned array of carbon nanotubes.

The catalyst layer material may be selected from one of iron (Fe), cobalt (Co), nickel (Ni) or any combination thereof, preferably an iron catalyst layer of about 5 nm thick. When the reaction furnace is a tubular reactor, the axial direction of the spiral growth substrate 140a may be disposed in the tubular reaction furnace parallel to the axial direction of the tubular reactor. Further, both ends of the growth substrate may be fixed by a bracket to suspend the growth substrate in the reaction furnace. The carbon source gas may be selected from acetylene, ethylene, ethane, etc., preferably a chemically active hydrocarbon such as acetylene, and the protective gas may be nitrogen, ammonia or an inert gas.

The carbon nanotube array is mainly composed of a plurality of carbon nanotubes, most of which are parallel to each other and perpendicular to the surface of the growth substrate. The top surface of the array of carbon nanotubes is parallel to the surface of the growth substrate. By controlling the growth conditions as described above, the carbon nanotube array contains substantially no impurities such as amorphous carbon or residual catalyst metal particles. The carbon nanotubes in the array of carbon nanotubes are in close contact with each other to form an array by van der Waals force. The growth area of the carbon nanotube array may be substantially the same as the area of the growth substrate curved surface. The carbon nanotubes in the carbon nanotube array may include at least one of a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube. The height of the carbon nanotubes in the carbon nanotube array is from 2 micrometers to 10 millimeters, preferably from 100 micrometers to 900 micrometers. The carbon nanotubes have a diameter of 1 to 50 nm.

Next, step 2 is further explained. Referring to FIG. 4, in the above step two, the carbon nanotube segment 143 is composed of one or a plurality of mutually parallel bundles of carbon nanotubes 145 in the array of carbon nanotubes. The stretching tool is used to select and pull the carbon nanotube segment 143. The stretching tool is preferably a tape having a certain width or a base strip having a surface having an adhesive. The process of selecting the carbon nanotube segments 143 can be contacted with the carbon nanotube array using a tape or a strip of adhesive. Preferably, the selected carbon nanotube segment 143 is located at the edge of the curved surface of the growth substrate where the straight segment is located. More preferably, the width of the selected carbon nanotube segment 143 is equal to the width of the straight segment, thereby drawing a carbon nanotube film having the width of the straight segment from the array of carbon nanotubes.

Then step 3 is further explained. The stretching tool is moved away from the array of carbon nanotubes to pull the selected carbon nanotube segment 143 at a certain speed. When the selected carbon nanotube segment 143 is gradually separated from the growth substrate in the pulling direction by the pulling force, other carbon nanotubes adjacent to the selected carbon nanotube segment 143 due to the van der Waals force The fragments are successively pulled out end to end to form a continuous, uniform carbon nanotube membrane. The width of the carbon nanotube film is substantially equal to the width of the selected carbon nanotube segment 143. Preferably, the stretching tool moves away from the array of carbon nanotubes in a direction perpendicular to the line. One end of the drawn carbon nanotube film is connected to the stretching tool, and the other end is connected to the curved carbon nanotube array at a junction of the carbon nanotube film and the curved carbon nanotube array. The angle between the carbon nanotube film and the cut surface of the substrate is less than 90 degrees, preferably less than 30 degrees. During the continuous drawing of the carbon nanotube film, the angle is maintained less than 30 degrees, that is, substantially all of the carbon nanotubes are pulled out along the cut surface of the substrate by less than 30 degrees. When the carbon nanotubes in the carbon nanotube array are successively pulled out from the carbon nanotube array, there is a boundary between the formed carbon nanotube film and the carbon nanotube array, and the boundary The carbon nanotube array is constantly being consumed and constantly moving. Preferably, the boundary is always in a straight line until all of the carbon nanotubes in the array of carbon nanotubes are pulled out.

Referring to FIG. 5, the carbon nanotube film is a self-supporting structure composed of a plurality of carbon nanotubes. The plurality of carbon nanotubes are arranged in a preferred orientation along the length of the carbon nanotube film. The preferred orientation means that the majority of the carbon nanotubes in the carbon nanotube film extend substantially in the same direction. Moreover, the overall direction of extension of the majority of the carbon nanotubes is substantially parallel to the surface of the carbon nanotube film. Further, most of the carbon nanotubes in the carbon nanotube membrane are connected end to end by van der Waals force. Specifically, each of the carbon nanotubes in the majority of the carbon nanotube membranes extending in the same direction and the carbon nanotubes adjacent in the extending direction are connected end to end by van der Waals force. Of course, there are a few carbon nanotubes in the carbon nanotube film that deviate from the extending direction. These carbon nanotubes do not significantly affect the overall orientation of most of the carbon nanotubes in the carbon nanotube film. The self-supporting carbon nanotube film does not require a large-area carrier support, but can maintain a self-membrane state as long as the supporting force is provided on both sides, that is, the carbon nanotube film is placed (or fixed on) When the two supports are disposed at a certain distance, the carbon nanotube film located between the two supports can be suspended to maintain the self-membrane state. The self-supporting is mainly achieved by the presence of a continuous carbon nanotube in the carbon nanotube film which is continuously arranged by van der Waals force. Specifically, most of the carbon nanotube membranes extending substantially in the same direction in the same direction are not absolutely linear, and may be appropriately bent; or may not be completely aligned in the extending direction, and may be appropriately deviated from the extending direction. Therefore, partial contact between the carbon nanotubes juxtaposed in the majority of the carbon nanotubes extending substantially in the same direction of the carbon nanotube film cannot be excluded.

Macroscopically, since most of the carbon nanotubes in the carbon nanotube film extend along the length of the carbon nanotube film, the carbon nanotube film has a conductivity and thermal conductivity superior to the width direction in the longitudinal direction. Since most of the carbon nanotubes are connected end to end by Van der Waals force, the carbon nanotube film is macroscopically self-supporting.

Specifically, each carbon nanotube film includes a plurality of continuous and aligned carbon nanotube segments 143. The plurality of carbon nanotube segments 143 are connected end to end by Van der Waals force. Each of the carbon nanotube segments 143 is composed of a plurality of mutually parallel carbon nanotubes 145 which are tightly bonded by van der Waals forces. The carbon nanotube segments 143 have any length, thickness, uniformity, and shape.

The carbon nanotube film has a thickness of 0.5 nm to 100 μm, and the length is related to the area of the carbon nanotube array. The specific surface area of the carbon nanotube film can be greater than 100 square meters per gram. The carbon nanotube film has good light transmittance, and the visible light transmittance can reach 75% or more.

Further, the present embodiment further provides a method of pulling the carbon nanotube film 100 and covering the carbon nanotube film 100 to a substrate while pulling. The method is suitable for continuously drawing the carbon nanotube film 100 from the surface of the growth substrate having a special shape. The method can include:

Providing a layered substrate wound on a first reel having a first surface and a second surface, the first surface having a bonding force to the carbon nanotubes being much larger than the second surface to the nanometer a bonding force of the carbon tube, the axial direction of the first reel being parallel to the straight line segment;

Contacting a portion of the carbon nanotube array with a first surface of the end of the layered substrate to select the carbon nanotube segment;

Rotating the first reel to gradually disengage the layered substrate from the first reel and pulling the selected carbon nanotube segment away from the array of carbon nanotubes, thereby pulling the plurality of ends in the same direction end to end A carbon nanotube segment, which in turn forms the continuous carbon nanotube film and covers the first surface of the layered substrate.

Further, a second reel may be provided, and the layered substrate covered with the carbon nanotube film is wound on the second reel while the carbon nanotube film is drawn and covered on the layered substrate.

Further, as the carbon nanotubes are continuously pulled out from the carbon nanotube array, the carbon nanotube array is continuously consumed, and the boundary between the carbon nanotube film and the carbon nanotube array is constantly moving. Therefore, the first reel and the second reel may move in parallel with respect to a curved surface of the growth substrate to keep the relative position of the first reel and the boundary line unchanged. Preferably, the diameter of the first reel is smaller than the minimum radius of curvature of the curved surface of the growth substrate.

As shown in FIG. 2 and FIG. 3, when the carbon nanotube film 100 is pulled from the carbon nanotube array 120a grown on the curved surface 142a of the spiral growth substrate 140a, the method is specifically as follows:

Step 1: providing a layered substrate 170 wound on a first reel 160 and a second reel 162 having a first surface 172 and a second surface 174, the first surface 172 The bonding force of the carbon nanotubes is much greater than the bonding force of the second surface 174 to the carbon nanotubes, and the axial direction of the first reel 160 and the second reel 162 is parallel to the straight line segment;

Step 2: contacting the carbon nanotube array 120a with the first surface 172 of the end of the layered layered substrate 170 to select the carbon nanotube segment 143;

Step 3: Rotating the first reel 160 to gradually separate the layered layered substrate 170 from the first reel 160, and pulling the selected carbon nanotube segment away from the carbon nanotube array 120a at a certain speed 143, thereby pulling out a plurality of carbon nanotube segments 143 in the same direction end to end, thereby forming the continuous carbon nanotube film 100 and covering the first surface 172 of the layered layered substrate 170. The layered substrate 170 is wound to the second reel 162;

Step 4: while the layered substrate 170 is wound to the second reel 162, the first reel 160 is moved in parallel with respect to the curved surface of the spiral growth substrate 140a, thereby opening 144a from the spiral growth substrate 140a. Enter the gap 146a.

The above steps 1 to 4 are further explained. The layered substrate 170 can be a flexible polymeric film, metal foil or paper having a coating on its surface. The material of the flexible polymer film may be plastic or resin, and in this embodiment, polyethylene terephthalate (PET). The coating may be formed from conventional coating materials on the surface of self-adhesive backing paper such as enamel, paraffin or Teflon. The surface of the layered substrate 170 having a coating is a second surface 174. Since the carbon nanotube film 100 has a large specific surface area, it has strong viscosity, and can directly adhere and bond when directly contacting the plastic, resin, metal foil or paper, and the carbon nanotube The adhesion strength of the film 100 to materials such as enamel, paraffin or Teflon is weak. Therefore, when one surface of the carbon nanotube film 100 is in contact with the first surface 172 of the layered substrate 170 and the other surface is in contact with the second surface 174, the carbon nanotube film 100 can be associated with the second surface. 174 is easily separated. In addition, the other surface of the layered substrate 170 may have an adhesive layer, and the surface having the adhesive layer is the first surface 172. Thereby, the carbon nanotube film 100 is more firmly bonded to the first surface 172. The adhesive layer can be a pressure sensitive adhesive layer, a hot melt adhesive layer or a photosensitive adhesive layer. The layered substrate 170 is wound on the first reel 160 and disposed parallel to the second reel 162 and parallel to the straight line segment.

In step 2, the portion of the first surface 172 of the layered substrate 170 at the end adheres to the carbon nanotubes in the carbon nanotube array 120a, thereby selecting the carbon nanotube as the stretching tool. Fragment 143. Preferably, the selected carbon nanotube segment 143 is substantially parallel to the axis of the first spool 160 so as to be substantially parallel to the straight segment. In this embodiment, the layered substrate 170 is a strip-shaped substrate wound on the first reel 160, and the first surface 172 of the strip-shaped layered substrate 170 contacts the carbon nanotubes parallel to the edge of the first reel 160. The array 120a is selected and the carbon nanotube segments 143 are selected.

In step 3, when the layered substrate 170 is wound on the second reel 162, the selected carbon nanotube segment 143 is selected due to the end of the layered substrate 170, the selected carbon nanotube segment The 143 is pulled out in a direction away from the carbon nanotube array 120a to form the carbon nanotube film 100. Preferably, the carbon nanotube segments 143 are pulled out at all times by adjusting the relative position of the first reel 160 to the said first reel 160. Specifically, one end of the carbon nanotube film 100 is connected to the layered substrate 170, and the other end is connected to the curved carbon nanotube array 120a, and the carbon nanotube film 100 and the curved carbon nanotube. At the junction of the array 120a, the carbon nanotube film 100 is at an angle of less than 90 degrees, preferably less than 30 degrees, to the facet of the growth substrate 140a. The drawn carbon nanotube film 100 is maintained at one end connected to the carbon nanotube array 120a, and the carbon nanotube film 100 is successively covered by the layered substrate 170 to the second reel 162. The first surface 172 of the layered substrate 170 generates a tensile force on the carbon nanotubes in the carbon nanotube array 120a, so that more carbon nanotube segments 143 are successively connected end from end to the carbon nanotube array 120a. The medium is pulled out and covers the first surface 172, and is wound on the second reel 162 together with the layered substrate 170. When wound on the second reel 162, as shown in FIG. 3, the second surface 174 of the uncovered carbon nanotube film 100 may be closer to the axis of the second reel 162, or the first surface 172 may be reversed. It is closer to the axis of the second reel 162.

As the carbon nanotube segments 143 are successively pulled out from the carbon nanotube array 120a, the area of the carbon nanotube array 120a is continuously reduced, and the carbon nanotube array 120a and the nanotube are The boundary line 122a between the carbon tube films 100 constantly moves. Therefore, in step 4, while the layered substrate 170 is wound around the second reel 162, the first reel 160 should be continuously moved in parallel with respect to the curved surface of the growth substrate 140a, thereby moving from the spiral growth substrate The opening 144a of the 140a enters the gap 146a. The second reel 162 can be continuously moved in parallel with the curved surface of the first reel 160 relative to the growth substrate 140a. It will be appreciated that the gap 146 should be wide enough to accommodate the layered substrate 170 and the second spool 162 that are wound around the first spool 160. By moving the layered substrate 170, the angle of the pulling direction and the growth substrate 140a are maintained constant, and the first reel 160 and the boundary line 122a are moved at a constant speed, thereby pulling the entire carbon nanotube array 120a. Finished.

Since the second surface 174 of the layered substrate 170 is easily separated from the carbon nanotube film 100, the layered substrate 170 wound on the second reel 162 can be flattened to form a carbon nanotube. A two-layer structure in which the film 100 is laminated with the layered substrate 170.

The method of moving the first reel 160 and the second reel 162 relative to the curved growth substrate can be applied to an array of carbon nanotubes grown in various other curved growth substrates.

Referring to FIG. 6, when the carbon nanotube film 100 is pulled from the carbon nanotube array 120b grown on the inner surface 142b of the cylindrical growth substrate 140b, the method of drawing the carbon nanotube film 100 may include :

Step 1: providing a layered substrate 170 wound on a first reel 160 and a second reel 162 having a first surface 172 and a second surface 174, the first surface 172 The bonding force of the carbon nanotubes is much larger than the bonding force of the second surface 174 to the carbon nanotubes, and the axial direction of the first reel 160 and the second reel 162 are parallel to the straight line segments, and are disposed in the cylindrical shape together Growing the inside of the substrate 140b;

Step 2: contacting the carbon nanotube array 120b with the first surface 172 of the end of the layered substrate 170 to select the carbon nanotube segment 143;

Step 3: By winding the layered substrate 170 to the second reel 162, the selected carbon nanotube segment 143 is pulled away from the carbon nanotube array 120b at a certain speed, thereby connecting end to end. Pulling a plurality of carbon nanotube segments 143 in the same direction to form the continuous carbon nanotube film 100 and covering the first surface 172 of the layered substrate 170;

Step 4: while the layered substrate 170 is wound to the second reel 162, the first reel 160 is moved in parallel with respect to the curved surface of the cylindrical growth substrate 140b, and the first reel 160 and the cylindrical growth substrate 140b are maintained. The distance is substantially constant and moves in the direction in which the carbon nanotube array 120b is consumed.

It is to be understood that the cylindrical growth substrate is not limited to a circular cylinder, and the cross section of the cylindrical growth substrate may be an ellipse or other polygon having rounded corners or the like. Referring to FIG. 7, the cylindrical growth substrate 140c may also be an unclosed cylindrical growth substrate 140c having an opening parallel to the axial direction of the cylindrical growth substrate 140c, the cylindrical growth substrate 140c having an unclosed circular cross section. . The carbon nanotube array is also not limited to being grown on the inner surface of the cylindrical growth substrate. When growing on the outer surface of the cylindrical growth substrate, the carbon nanotube film 100 may be pulled according to the above method. The carbon nanotube film 100 is covered on the surface of the layered substrate 170.

When the carbon nanotube film is pulled from the carbon nanotube array on the curved surface of each of the above-mentioned growth substrates, the carbon nanotube segments 143 are pulled out at all times by moving the first reel 160. Specifically, in the stretching process, one end of the carbon nanotube film 100 is connected to the layered substrate 170, and the other end is connected to the curved carbon nanotube array 120b, and the carbon nanotube film 100 is At the junction of the curved carbon nanotube array 120b, the carbon nanotube film 100 forms an angle of less than 90 degrees with the cut surface of the growth substrate 140b, preferably less than 30 degrees.

It can be understood that the method of covering the surface of the layered substrate 170 while forming the carbon nanotube film 100 while the side is drawn can be applied to a curved growth substrate of other shapes, such as the wavy growth substrate 120. , a spring-like growth substrate or a columnar growth substrate, and the like.

In addition, the embodiment of the present invention further provides another method for drawing a carbon nanotube film from a curved carbon nanotube array, which is also applicable to a carbon nanotube array having a complex curved surface, such as growing in the spiral shape. The carbon nanotube array 120a on the surface of the growth substrate 140a is grown. Referring to Figure 8, the method includes the following steps:

Providing a plurality of third reels 182 and a layered substrate 170a;

The plurality of third reels 182 are disposed parallel to the curved surface 142a of the spiral growth substrate 140a;

The layered substrate 170a is sequentially moved along a U-shaped path through the surface of the plurality of third reels 182. The U-shaped path is composed of a de-route, a vertex and a back path, and the layered substrate 170a is along the path of the de-path Moving into the direction of the gap 146a and bypassing the apex, moving in a direction away from the opening 144a at the return path portion;

A carbon nanotube film 100 is drawn from the carbon nanotube array 120a of the curved surface 142a grown on the spiral growth substrate 140a by a stretching tool, and the carbon nanotube film 100 is laid on the layered layer. The surface of the substrate 170a is moved from the opening 144a in a direction in which the carbon nanotube array 120a is consumed while moving the plurality of third reels 182 to move the layered substrate 170a along the U-shaped path. The gap 146a is such that more carbon nanotube film 100 is pulled out from the carbon nanotube array 120a and laid on the surface of the layered substrate 170a.

The plurality of third reels 182 can be disposed parallel to a straight line segment defining the curved surface 142a. The plurality of third reels 182 function to support the layered substrate 170a while slowly moving the layered substrate 170a to the spiral by moving parallel to the curved surface 142a of the spiral growth substrate 140a. The inside of the substrate 140a is grown to ensure that the carbon nanotubes grown inside the spiral growth substrate 140a can be smoothly pulled out. The layered substrate 170a is opposite in direction of movement of the de-route and return paths. The layered substrate 170a moves from the opening 144a in the gap 146a and enters the center of the spiral growth substrate 140a while moving along the U-shaped path. It can be understood that the movement speed of the plurality of third reels 182 is substantially equal to the consumption speed of the carbon nanotube array 120a. During the drawing, the carbon nanotubes should still be pulled out from the carbon nanotube array 120a at an angle, that is, in the carbon nanotube film 100 and the curved carbon nanotubes. At the junction of the array 120a, the carbon nanotube film 100 is at an angle of less than 90 degrees, preferably less than 30 degrees, to the facet of the growth substrate 140a.

The layered substrate 170a is a flexible substrate such as a flexible polymer film, metal foil or paper. The width of the layered substrate 170a may be equal to the length of the straight line segment of the curved surface of the spiral growth substrate 140a, and the length of the layered substrate 170a is not limited and may be long enough for all the drawn carbon nanotube film 100 Both can be laid on the surface of the layered substrate 170a.

It can be understood that the method of pulling the carbon nanotube film 100 from the carbon nanotube array 120a grown on the curved surface by the transport of the layered substrate 170a by the third reel 182 is not limited to pulling the naphthalene from the surface of the spiral growth substrate 140a. The carbon nanotube film 100, which one skilled in the art can readily apply, pulls the carbon nanotube film from any array of carbon nanotubes on a curved surface defined by a straight line along a curved path motion.

Since the growth substrate can have a large surface area for growing the carbon nanotube array, in the same reaction furnace as in the prior art, the space inside the reactor can be fully utilized to grow a larger size. The carbon nanotube array is such that the carbon nanotube film obtained from the carbon nanotube array has a large area. The carbon nanotube film having a large width can be conveniently used as a transparent conductive film in a device having a large touch screen and a liquid crystal display.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by those skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

100‧‧‧Nano carbon nanotube film

120, 120a, 120b‧‧‧n carbon nanotube array

122a‧‧

140, 140a, 140b, 140c‧‧‧ growth substrate

142, 142a, 142c‧‧‧ surface

142b‧‧‧ inner surface

143‧‧‧Nano carbon nanotube fragments

144a‧‧‧ openings

145‧‧・Nano carbon tube

146a‧‧‧ gap

160‧‧‧First scroll

162‧‧‧second reel

170, 170a‧‧‧ layered substrate

172‧‧‧ first surface

174‧‧‧ second surface

182‧‧‧ third reel

1 is a schematic view showing the structure of a carbon nanotube array formed on a wavy substrate according to an embodiment of the present invention.

2 is a schematic side view showing a structure in which a carbon nanotube film is drawn from a carbon nanotube array formed on a spiral substrate according to an embodiment of the present invention.

Figure 3 is a partial enlarged view of Figure 2.

Figure 4 is a schematic view showing the structure of a carbon nanotube segment.

Figure 5 is a scanning electron micrograph of a carbon nanotube film of an embodiment of the present invention.

Fig. 6 is a schematic side view showing the structure of a carbon nanotube film drawn from an inner carbon nanotube array formed on the inner surface of a cylindrical substrate according to an embodiment of the present invention.

Figure 7 is a side elevational view showing the embodiment of the present invention for drawing a carbon nanotube film from a carbon nanotube array formed on the inner surface of an open cylindrical substrate.

Fig. 8 is a schematic side view showing another embodiment of the present invention for drawing a carbon nanotube film from a carbon nanotube array formed on a spiral substrate.

120‧‧‧Nano Carbon Tube Array

140‧‧‧ Growth substrate

142‧‧‧ Surface

Claims (20)

A method for preparing a carbon nanotube film, comprising the steps of:
Providing a curved carbon nanotube array;
Selecting a carbon nanotube segment from the array of carbon nanotubes using a stretching tool; and moving the stretching tool to pull the selected carbon nanotube segment away from the curved carbon nanotube array The carbon nanotubes are continuously pulled out end to end to form a continuous carbon nanotube film. The method for producing a carbon nanotube film according to claim 1, wherein the curved carbon nanotube array is grown on a curved surface of a growth substrate. The method for producing a carbon nanotube film according to claim 2, wherein, in the stretching process, one end of the carbon nanotube film is connected to the stretching tool, and the other end is curved The carbon nanotube array is connected at a junction of the carbon nanotube film and the curved carbon nanotube array, the carbon nanotube film forming an angle of less than 90 degrees with the cut surface of the growth substrate. The method for producing a carbon nanotube film according to claim 3, wherein the angle is less than 30 degrees. The method for preparing a carbon nanotube film according to claim 2, wherein the method for preparing the carbon nanotube array comprises the following steps:
Providing the growth substrate, the growth substrate having the curved surface;
A catalyst layer is uniformly formed on the curved surface of the growth substrate; and a super-aligned carbon nanotube carbon nanotube array is grown on the curved surface of the growth substrate by chemical vapor deposition. The method for preparing a carbon nanotube film according to claim 5, wherein the growth substrate is a quartz substrate, a high temperature resistant glass substrate, a P-type germanium substrate, an N-type germanium substrate, a high temperature resistant metal substrate, or a formation. A ruthenium substrate with an oxide layer. The method for preparing a carbon nanotube film according to claim 2, wherein the curved surface is a surface formed by moving a straight line segment having a certain length in parallel along a curved trajectory. The method for preparing a carbon nanotube film according to claim 7, wherein the selected carbon nanotube segment is located at an edge of the curved line where the straight line segment is located, and the stretching tool is vertical Moving away from the array of carbon nanotubes in the direction of the straight line segment. The method for preparing a carbon nanotube film according to claim 7, wherein the method for extracting a carbon nanotube film from the carbon nanotube array by using a stretching tool further comprises the following steps:
Providing a layered substrate wound on a first reel having a first surface and a second surface, the first surface having a bonding force to the carbon nanotubes being much larger than the second surface to the nanometer a bonding force of the carbon tube, the axial direction of the first reel being parallel to the straight line segment;
Contacting a portion of the carbon nanotube array with a first surface of the end of the layered substrate to select the carbon nanotube segment; and rotating the first reel to gradually separate the layered substrate from the first reel and Pulling the selected carbon nanotube segments away from the array of carbon nanotubes, the carbon nanotubes are pulled out end to end to form the continuous carbon nanotube film and covering the layered substrate The first surface. The method for producing a carbon nanotube film according to claim 9, wherein a second reel is further provided, and the layered substrate covered with the carbon nanotube film is wound on the second reel. The method for producing a carbon nanotube film according to claim 10, wherein the first reel and the second reel are mutually opposed while the layered substrate is wound to the second reel The curved surface of the growth substrate moves in parallel. The method for preparing a carbon nanotube film according to claim 11, wherein the growth substrate is a spiral growth substrate, and the curved surface is a linear segment having a certain width and moves parallel along a planar spiral track. a surface of the spiral growth substrate having an opening at an outward end of the planar spiral, and a gap defined by the spiral growth substrate, the gap extending from the opening to the center of the spiral growth substrate during the stretching process The first reel and the second reel enter the gap from the opening of the spiral growth substrate and move in parallel with respect to the curved surface of the spiral growth substrate. The method for preparing a carbon nanotube film according to claim 11, wherein the growth substrate is a cylindrical growth substrate, the curved surface is an inner surface of a cylindrical growth substrate, and the first reel and the second The axial direction of the reel is parallel to the straight line segment and is disposed inside the cylindrical growth substrate. The distance of the first reel from the curved surface is substantially constant and moves in the direction in which the carbon nanotube array is consumed. The method for preparing a carbon nanotube film according to claim 9, wherein the material of the layered substrate is plastic, resin, metal foil or paper. The method for producing a carbon nanotube film according to claim 9, wherein the second surface of the layered substrate is formed with a ruthenium, a paraffin or a Teflon coating. The method for producing a carbon nanotube film according to claim 9, wherein the first surface of the layered substrate has an adhesive layer. The method for producing a carbon nanotube film according to claim 9, wherein the selected carbon nanotube segment is substantially parallel to an axis of the first reel. The method for preparing a carbon nanotube film according to claim 7, wherein the method for extracting a carbon nanotube film from the carbon nanotube array by using a stretching tool further comprises the following steps:
Providing a plurality of third reels and a layered substrate;
Setting the plurality of third reels parallel to a curved surface of the growth substrate;
The layered substrate is sequentially moved along the U-shaped path through the plurality of third reel surfaces, the U-shaped path is composed of a de-route, a vertex and a back path, and the movement of the layered substrate in the de-path and the return path In the opposite direction;
Laminating the carbon nanotube film drawn from the curved carbon nanotube array on the surface of the layered substrate, and moving the plurality of third reels to form the layered substrate along the U shape While the path moves, it moves in the direction in which the carbon nanotube array is consumed, so that the carbon nanotube film is pulled out from the array of carbon nanotubes and laid on the surface of the layered substrate. The method for preparing a carbon nanotube film according to claim 18, wherein the growth substrate is a spiral growth substrate, and the curved surface is a linear segment having a certain width and moves parallel along a planar spiral track. a surface of the spiral growth substrate having an opening at an outward end of the planar spiral, and a gap defined by the spiral growth substrate, the gap extending from the opening to a center of the spiral growth substrate, the layered substrate Moving in the direction of entering the gap in the de-path portion and bypassing the apex, moving in a direction outward from the opening in the return path portion, the plurality of third reels along the carbon nanotube array The direction of consumption enters the gap from the opening. The method for preparing a carbon nanotube film according to claim 1, wherein the carbon nanotube segment is a carbon nanotube or a bundle of substantially parallel carbon nanotubes. Carbon tube.