TWI386516B - Apparatus for fabrication of carbon nanotubes - Google Patents

Description

Nano carbon tube preparation equipment

The invention relates to a carbon nanotube preparation device, in particular to a thermochemically deposited carbon nanotube preparation device.

Nano carbon tube is a new type of one-dimensional nano carbon material, first discovered by Japanese researcher S. Iijima in 1991. The carbon nanotubes have excellent properties such as high tensile strength and high thermal stability, and the carbon nanotubes may exhibit metallic or semiconducting properties as the nanocarbon tube spirals. Since the carbon nanotubes have an ideal one-dimensional structure and excellent properties in the fields of mechanics, electricity, heat, etc., they have shown broad application prospects in the interdisciplinary fields such as materials science, chemistry, and physics. Therefore, the realization of the controllable growth of carbon nanotubes is the key to the application of nanocarbon tubes.

At present, the more commonly used method for preparing carbon nanotubes is chemical vapor deposition. The chemical vapor deposition method uses a carbon-containing gas as a carbon source gas to grow a multi-wall or single-walled carbon nanotube on a crucible or zeolite substrate. However, as shown in the first figure, the conventional thermal CVD carbon nanotube preparation apparatus 1 includes a quartz tube 17 including an air inlet 13 and an air outlet 15 disposed opposite the air inlet 13 . During the preparation of the carbon nanotubes, a substrate 2 having a catalyst layer 22 formed on its surface is loaded into the quartz tube 17, and the reaction gas 11 is blown horizontally from the gas inlet 13 to the gas outlet 15, that is, with the nanometer. The growth direction of the carbon tube is vertical. For the fine carbon nanotubes, even if the flow rate of the reaction gas is slow, it will cause poor collimation of the finally grown carbon nanotubes.

In view of this, it is necessary to provide a preparation apparatus for growing a collimated carbon nanotube.

A carbon nanotube preparation apparatus which can realize collimated growth of a carbon nanotube can be explained by way of example.

A carbon nanotube preparation apparatus includes a reaction chamber, a heating device and a flow guiding device. The reaction chamber includes a first air inlet and a first air outlet. The heating device is fixed to an outer wall of the reaction chamber, and an outer wall of the reaction chamber is in contact with outside air. The flow guiding device is located in the reaction chamber, and includes a gas delivery tube, a second air inlet and a second air outlet, wherein one end of the gas delivery tube is sealed with the first air inlet, and the other end is Sealing with the second air inlet, the second air inlet is disposed perpendicular to a base for growing the carbon nanotube, and the second air outlet is located on a side opposite to the second air inlet, the first The two air outlets are in communication with the first air outlet.

Compared with the prior art, the carbon nanotube preparation apparatus converts the flow direction of the conventional vertical carbon nanotubes into a growth direction by using a flow guiding device to change the flow of the reaction gas required for the growth of the carbon nanotubes. Parallel to the growth direction of the carbon nanotubes, this arrangement can provide better collimation of the carbon nanotubes.

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Referring to the second figure, a carbon nanotube preparation apparatus 10 according to a first embodiment of the present invention includes a heating device 12, a reaction chamber 20 and a flow guiding device. At 30, the flow guiding device 30 is disposed in the reaction chamber 20.

The reaction chamber 20 includes a first air inlet 22 and a first air outlet 24, and the reaction chamber 20 can be a quartz tube.

The flow guiding device 30 includes a gas delivery pipe 32, a second air inlet 34, and a second air outlet 36. In this embodiment, the portion of the flow guiding device 30 except the gas delivery pipe 32 has a groove structure without a bottom surface, and the material thereof may be a heat conductive material such as stainless steel.

One end of the gas delivery pipe 32 is sealed and sleeved with the first air inlet 22, and the other end is sealed with the second air inlet 34. The gas delivery tube 32 can include a bend section by which the first inlet port 22 and the second inlet port 34 can be in a substantially vertical state.

The second air inlet 34 is disposed perpendicular to the base 40 of the growth carbon nanotube. In the embodiment, the second air inlet 34 is disposed above the base 40 and substantially perpendicular to the base.

The second air outlet 36 is disposed at a bottom of the flow guiding device 30 and substantially parallel to the first air inlet 22 . The second air outlet 36 can also be disposed at the bottom of the flow guiding device 30 and substantially perpendicular to the first air inlet 22, as long as the second air outlet 36 is adjacent to the base 40.

The method of using the carbon nanotube preparation apparatus 10 provided in the present embodiment will be described in detail below in conjunction with the preparation process of the carbon nanotubes.

Referring to the second figure, a substrate 40 is first placed in the reaction chamber 20, and a catalyst layer 50 is formed on the surface of the substrate 40, and the flow guiding device 20 is disposed to completely surround the substrate 40. The substrate 40 can be selected from quartz, germanium, magnesium oxide and the like. sheet. The catalyst layer 50 may be selected from cobalt, nickel, iron, or an alloy thereof. Since the flow guiding device 30 adopts a groove structure without a bottom surface, the second air outlet 36 is disposed at the bottom of the flow guiding device 20 and substantially parallel to the first air inlet 22.

Then, a carrier gas is introduced from the first intake port 22 under normal pressure, and the carrier gas gas enters the top of the flow guiding device 30 through the gas delivery pipe 32 and the second intake port 34 and blows vertically. To the substrate 40. The carrier gas may be selected from hydrogen, nitrogen, ammonia or other inert gases. The catalyst layer 50 in the reaction chamber 20 is heated by the heating device 12. After the temperature of the catalyst layer 50 is raised to a predetermined temperature, it is generally 500 to 900 degrees, and a reaction gas is introduced from the first gas inlet 22. The reaction gas may be selected from a carbon source gas such as methane, ethane, ethylene or acetylene. The reaction gas enters the flow guiding device 30 through the gas delivery pipe 32 and the second intake port 34. Due to the catalytic action of the catalyst, the carbon source gas introduced into the reaction chamber 20 is thermally decomposed into carbon units and hydrogen gas, and the carbon units are adsorbed on the surface of the catalyst particles formed by the catalyst layer 50, and the carbon units adsorbed in the catalyst particles are saturated after being precipitated. Thereby, a carbon nanotube can be grown at the position of the catalyst particles. The carrier gas and the exhaust gas generated after the reaction can be discharged through the second air outlet 36 and the first air outlet 24 communicating therewith.

As shown in the third figure, the carbon nanotube preparation apparatus 100 of the second embodiment of the present invention includes a heating device 120, a reaction chamber 200, and a flow guiding device 300, wherein the flow guiding device 300 can be selected from a box having a bottom surface. Body structure. At this time, one end of the gas delivery tube 320 of the flow guiding device 300 is sealed and sleeved with the first air inlet 220, and the other end is sealed with the second air inlet 340; the second air inlet of the flow guiding device 300 340 is located at the top of the flow guiding device 300, The second air outlet 360 can be disposed at a bottom of the flow guiding device 300 substantially perpendicular to the first air inlet 220, and the second air outlet 360 can be disposed at the bottom of the flow guiding device 300 and the first air inlet. The position of the substantially parallel position, that is, the position relative to the second air inlet 340, may be such that the second air outlet 360 is adjacent to the position of the base 400.

In the second embodiment of the present invention, the substrate 400 on which the catalyst layer 500 is formed can be directly placed in the flow guiding device 300, and the flow guiding device 300 can be placed in the reaction chamber 200. A carrier device 600 can also be attached for supporting the substrate 400 and adjusting the distance between the substrate 400 and the second air inlet 340. The other steps for preparing the carbon nanotubes are the same as in the first embodiment.

The carbon nanotube preparation device provided by the embodiment of the invention changes the flow direction of the reaction gas for carbon nanotube growth by the flow guiding device, so as to be substantially parallel with the growth direction of the carbon nanotube, thereby realizing collimation Preparation of carbon nanotubes.

In addition, those skilled in the art can also make other changes within the spirit of the present invention, such as appropriately changing the shape and setting position of the flow guiding device, or changing the setting positions of the air inlet and the air outlet of the flow guiding device as long as they do not deviate from the present position. The effect of the invention can be achieved.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art of the present invention should be included in the following claims.

10,100‧‧‧Nano carbon tube preparation equipment

12, 120‧‧‧ heating device

20,200‧‧‧reaction chamber

22, 220‧‧‧ first air inlet

24, 240‧‧‧ first air outlet

30, 300‧‧‧ flow guiding device

32, 320‧‧‧ gas delivery tube

34, 340‧‧‧ second air inlet

36, 360‧‧‧ second air outlet

40,400‧‧‧Base

50, 500‧‧‧ catalyst layer

600‧‧‧ Carrying device

The first figure is a schematic diagram of the structure of a carbon nanotube preparation device in the prior art. .

The second drawing is a schematic structural view of a carbon nanotube preparation apparatus according to a first embodiment of the present invention.

The third drawing is a schematic structural view of a carbon nanotube preparation apparatus according to a second embodiment of the present invention.

10‧‧‧Nano Carbon Tube Preparation Equipment

12‧‧‧ heating device

20‧‧‧Reaction chamber

22‧‧‧First air inlet

24‧‧‧First air outlet

30‧‧‧ flow guiding device

32‧‧‧ gas delivery tube

34‧‧‧Second air inlet

36‧‧‧Second air outlet

40‧‧‧Base

50‧‧‧ catalyst layer

Claims (8)

A carbon nanotube preparation apparatus comprising: a reaction chamber including a first air inlet and a first air outlet; a heating device fixed to an outer wall of the reaction chamber, and an outer wall of the reaction chamber Contacting the outside air; a flow guiding device disposed in the reaction chamber, comprising a gas delivery tube, a second air inlet and a second air outlet; the gas delivery tube is sealed at one end from the first air inlet The other end is sealed with the second air inlet, the second air inlet is perpendicular to the base for growing the carbon nanotube, and the second air outlet is located on the opposite side of the second air inlet The second air outlet is in communication with the first air outlet. The carbon nanotube preparation apparatus according to claim 1, wherein the reaction chamber is a quartz tube. The carbon nanotube preparation apparatus according to claim 1, wherein the gas delivery tube comprises a bent section. The carbon nanotube preparation apparatus according to claim 1, wherein the second air outlet is substantially parallel to the first air inlet. The carbon nanotube preparation apparatus according to claim 1, wherein the second air outlet is substantially perpendicular to the first air inlet. The carbon nanotube preparation apparatus according to claim 1, wherein the flow guiding device is formed of a heat conductive material. The carbon nanotube preparation apparatus according to claim 6, wherein the heat conductive material comprises stainless steel. The carbon nanotube preparation apparatus according to claim 1, further comprising a carrying device for supporting the substrate to adjust the second intake air The distance between the mouth and the base.