TWI386514B - Apparatus for manufacturing carbon nanotubes - Google Patents

Description

Nano carbon tube preparation device

The invention relates to a carbon nanotube preparation device.

Since the Japanese researcher Mr. Iijima first discovered the carbon nanotubes in arc discharge products in 1991, he has excellent performance in mechanical, electronic, physical, chemical, etc., such as unique metal or semiconductor conductivity, extremely high. The mechanical strength, high-capacity hydrogen storage capacity and adsorption capacity, field-induced electron emission performance, directional thermal conductivity and strong broadband electromagnetic wave absorption characteristics make the carbon nanotubes subject to physical, chemical and materials science and high-tech industries. The department attaches great importance to it and promotes the extensive research and practical application of carbon nanotubes. At present, carbon nanotubes can be used as reinforcing materials for composite materials, field electron emission materials, supercapacitor electrode materials, gas adsorbing materials, catalytic materials, heat conducting materials, and sensing materials.

The method for preparing the carbon nanotubes includes an arc discharge method (Arc Discharge), a laser ablation method (Laser Ablation), a chemical vapor deposition method (CVD), and the like, wherein the CVD method has a device for growing carbon nanotubes. Simple, low cost and large size.

A typical CVD growth carbon nanotube device includes a high temperature heating furnace, a quartz furnace tube, a carrier boat disposed in the quartz furnace tube, and a substrate disposed in the carrier. When preparing the carbon nanotubes, a catalyst layer is first deposited on the substrate, then the quartz furnace tube is heated, a carbon source gas is introduced, and the carbon source gas is reacted on the catalyst layer at a high temperature to grow a carbon nanotube. In order to increase the growth rate of carbon nanotubes, people began to use low-pressure CVD method to grow carbon nanotubes. The method is to grow carbon nanotubes under low pressure conditions. The device used is the above-mentioned typical CVD growth carbon nanotube device. Further comprising a pumping low-pressure device, the pumping low-pressure device is in communication with the gas outlet of the quartz furnace tube for controlling the gas pressure in the quartz furnace tube during the reaction. The device grows carbon tubes in a manner of high-temperature thermal decomposition of carbon source gas at a low pressure, and the reaction temperature ranges from 500 to 1000 ° C, which causes continuous high-temperature residual gas flow to the pumping low-pressure device during the reaction, thereby seriously affecting the pumping low-voltage device. The service life.

In view of the above, it is necessary to provide a carbon nanotube preparation apparatus which can reduce the temperature of the exhaust gas.

A carbon nanotube preparation apparatus comprising: a reaction chamber having an air outlet; a reaction chamber cooling device disposed in the reaction chamber or outside the reaction chamber to react to the reaction after the reaction in the reaction chamber is completed The chamber is cooled; a pumping low-pressure device is connected to the gas outlet of the reaction chamber for reducing the gas pressure in the reaction chamber; a gas cooling device is disposed between the reaction chamber and the pumping low-pressure device for cooling reaction The gas discharged from the chamber.

In contrast to the prior art, the carbon nanotube preparation apparatus is provided with a gas cooling device between the reaction chamber and the pumping unit for cooling the gas discharged from the reaction chamber, thereby reducing the gas entering the pumping unit. The temperature, avoiding the contact of the low-pressure device with the high-temperature gas, can increase the service life of the pumping device.

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

Referring to the first embodiment, a carbon nanotube preparation apparatus 100 according to a first embodiment of the present invention includes a reaction chamber 10, a boat 30 disposed in the reaction chamber, and a substrate 40 disposed in the boat 30. The heating unit 20 for heating the reaction chamber 10, a gas cooling device 50, and a vacuuming device 60 are provided.

The reaction chamber 10 may be a sealable cavity formed by a material having stable chemical properties and high temperature resistance. The material is preferably quartz, and an air inlet 101 and an air outlet 102 are respectively disposed at two ends thereof; the substrate 40 may be porous. The ruthenium substrate or the ruthenium substrate may be a material which is resistant to high temperature and does not undergo chemical reaction or atomic penetration with the catalyst in the subsequent step, and the surface thereof is required to be clean without destroying the subsequent reaction conditions. The heating portion 20 is used to heat the reaction chamber 10. Preferably, the heating portion 20 is closely surrounding the reaction chamber 10 to achieve a uniform heating effect. The heating portion 20 may specifically be a heating furnace.

The low pressure device 60 communicates with the gas outlet 102 of the reaction chamber 10 for controlling the gas pressure in the reaction chamber 10 so that the internal pressure of the reaction chamber 10 during the growth of the carbon nanotubes is lower than the ambient pressure. In this embodiment, the pumping low pressure device 60 is connected to the air outlet 102 of the reaction chamber 10 through a connecting pipe 70. The pumping unit 60 uses an air pump.

The gas cooling device 50 is disposed between the reaction chamber 10 and the vacuuming device 60 for cooling the gas discharged from the reaction chamber 10. The gas cooling device 50 may be a fin-type cooling device or a liquid-cooled cooling device. Preferably, the gas cooling device 50 is a liquid-cooled cooling device. In the present embodiment, the gas cooling device 50 includes a cooling chamber 501 through which the connecting pipe 70 can be bored, and the cooling chamber 501 houses a cooling working substance. The cooling working substance may be a mixture of one or more of water, methanol, ethanol, acetone, hexane, liquid ammonia, and liquid nitrogen. Since the heat of the cooling working material is vaporized, in order to facilitate the long-term continuous use of the gas cooling device 50, a pneumatic valve 502 may be disposed on the wall of the cooling chamber 501 when the cooling chamber is secured. When the air pressure in 501 reaches a certain value, the air pressure valve 502 is opened to lower the air pressure in the cooling chamber 501. Preferably, the connecting tube 70 is serpentinely inserted into the cooling chamber 501. The gas cooling device 50 can use a water tank when a material that is less volatile and less expensive, such as water, is used as the cooling working substance.

The reaction chamber 10 generally uses a quartz tube. When the quartz tube used as the reaction chamber 10 is long, the portion extending from the heating portion 20 is long, and can be used to set the gas cooling device 50. The device 60 can be directly connected to the gas outlet 102 of the reaction chamber 10.

The carbon nanotube preparation apparatus 100 may further include a reaction chamber cooling device 80 disposed in the reaction chamber 10 or outside the reaction chamber 10 for accelerating the reaction chamber after the reaction in the reaction chamber 10 is completed. Cooling of 10 to shorten the cooling time of the reaction chamber 10, thereby increasing the efficiency of the carbon nanotube batch process. As shown in the second figure, when the reaction chamber cooling device 80 is disposed in the reaction chamber 10, the reaction chamber cooling device 80 may include an inner tube 803 disposed in the reaction chamber 10, in this embodiment. The inner tube 803 is parallel and coaxial with the reaction chamber 10. The wall of the inner tube 803 and the wall of the reaction chamber 10 form a lumen 801. The lumen 801 contains a cooling working substance, and the carrier 30 and the substrate 40 are disposed in the inner tube 803. The cooling working substance may be a mixture of one or more of water, methanol, ethanol, acetone, hexane, liquid ammonia, and liquid nitrogen. As shown in the third figure, the reaction chamber cooling device The 80 may also include at least one reaction chamber cooling tube 802. The reaction chamber cooling tube 802 includes a cooling working substance, and the cooling working material may be one of water, methanol, ethanol, acetone, hexane, liquid ammonia, liquid nitrogen or A mixture of several. Since the density of the gas is increased after condensation, the cold gas will sink and the hot gas will rise in the reaction chamber 10. Therefore, the temperature of the gas at the top of the reaction chamber 10 is high. To improve the cooling efficiency, the reaction chamber cooling tube 802 can be attached. The inner or outer wall of the reaction chamber 10 is distributed at the top and bottom of the reaction chamber 10, and the reaction chamber cooling tube 802 at the top of the reaction chamber 10 has a distribution density greater than the distribution density of the reaction chamber cooling tubes 802 at the bottom of the reaction chamber 10. In order to reduce the manufacturing cost, the reaction chamber cooling tube 802 may also be disposed outside the reaction chamber 10.

The reaction chamber cooling device 80 is different from the gas cooling device 50 when it is used. The gas cooling device 50 is opened when the reaction chamber 10 reacts, and is used to cool the high temperature gas discharged from the reaction chamber 10, and then cooled. The gas is discharged through the pumping unit 60. The reaction chamber cooling device 80 is opened after the reaction is completed to lower the temperature inside the reaction chamber 10 as quickly as possible, and the sample is quickly taken out.

Referring to FIG. 4, a carbon nanotube preparation apparatus 100' according to a second embodiment of the present invention, the carbon nanotube preparation apparatus 100' is different from the carbon nanotube preparation apparatus 100 of the first embodiment. The gas cooling device 50' includes at least one gas cooling pipe 503 disposed on the inner wall or the outer wall of the connecting pipe 70, and the gas cooling pipe 503 contains a cooling working substance. Preferably, the gas cooling tube 503 is disposed outside the connecting tube 70. The gas cooling pipe 503 may also be provided on the inner wall of the connecting pipe 70 as shown in FIG.

In contrast to the prior art, the carbon nanotube preparation apparatus is provided with a gas cooling device between the reaction chamber and the pumping unit for cooling the gas discharged from the reaction chamber, thereby reducing the gas entering the pumping unit. The temperature, avoiding the contact of the low-pressure device with the high-temperature gas, can increase the service life of the pumping device. And the carbon nanotube preparation device rapidly cools the reaction chamber after the reaction through a reaction chamber cooling device to shorten the reaction chamber cooling time, thereby increasing the efficiency of the carbon nanotube batch process.

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 persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧Reaction room

20‧‧‧heating department

30‧‧‧Scatter

40‧‧‧Substrate

50,50’‧‧‧ gas cooling unit

60‧‧‧Pumping device

70‧‧‧Connecting tube

80‧‧‧Reaction chamber cooling unit

100,100'‧‧‧Nano carbon tube preparation device

101‧‧‧air inlet

102‧‧‧ outlet

501‧‧‧ Cooling room

502‧‧‧Pneumatic valve

503‧‧‧ gas cooling tube

801‧‧‧ lumen

802‧‧‧reaction chamber cooling tube

803‧‧‧ inner tube

1 is a schematic cross-sectional view of a carbon nanotube preparation apparatus according to a first embodiment of the present invention; the second diagram is a schematic cross-sectional view of a first reaction chamber cooling device; and the third diagram is a schematic cross-sectional view of a second reaction chamber cooling device; A schematic cross-sectional view of a carbon nanotube preparation apparatus according to a second embodiment of the present invention; and a fifth diagram showing a gas cooling tube disposed on an inner wall of the connecting pipe.

100‧‧‧Nano carbon tube preparation device

10‧‧‧Reaction room

20‧‧‧heating department

30‧‧‧Scatter

40‧‧‧Substrate

50‧‧‧ gas cooling device

60‧‧‧Pumping device

70‧‧‧Connecting tube

80‧‧‧Reaction chamber cooling unit

101‧‧‧air inlet

102‧‧‧ outlet

501‧‧‧ Cooling room

502‧‧‧Pneumatic valve

Claims (12)

A carbon nanotube preparation apparatus comprising: a reaction chamber having an air outlet; a reaction chamber cooling device disposed in the reaction chamber or outside the reaction chamber to react to the reaction after the reaction in the reaction chamber is completed The chamber is cooled; a pumping low-pressure device is connected to the outlet of the reaction chamber for reducing the pressure in the reaction chamber; and the improvement is that a gas cooling device is disposed between the reaction chamber and the pumping unit for cooling The gas discharged from the reaction chamber. The carbon nanotube preparation device according to claim 1, wherein the carbon nanotube preparation device comprises a connection pipe connecting the reaction chamber outlet port and the pumping device. The carbon nanotube preparation apparatus according to claim 2, wherein the gas cooling device is a liquid cooling type cooling device. The carbon nanotube preparation apparatus according to claim 3, wherein the gas cooling device comprises a cooling chamber through which the connecting pipe is bored, the cooling chamber containing a cooling working substance. The carbon nanotube preparation apparatus according to claim 4, wherein the connecting tube is serpentinely passed through the cooling chamber. The carbon nanotube preparation apparatus according to claim 3, wherein the gas cooling device comprises at least one gas cooling pipe provided on an inner wall or an outer wall of the connecting pipe, and the gas cooling pipe includes cooling work. substance. The carbon nanotube preparation apparatus according to claim 6, wherein the gas cooling pipe is disposed outside the connection pipe. Such as the carbon nanotube preparation device described in claim 4 or 6, Wherein, the cooling working substance is a mixture of one or more of water, methanol, ethanol, acetone, hexane, liquid ammonia, and liquid nitrogen. The carbon nanotube preparation apparatus according to claim 1, wherein the reaction chamber cooling device comprises an inner tube disposed in the reaction chamber, and an outer wall of the inner tube and an inner wall of the reaction chamber are formed. A lumen containing a cooling working substance. The carbon nanotube preparation apparatus according to claim 1, wherein the reaction chamber cooling device comprises a plurality of reaction chamber cooling tubes, wherein the reaction chamber cooling tubes contain a cooling working substance. The carbon nanotube preparation apparatus according to claim 10, wherein the reaction chamber cooling tube is disposed around the reaction chamber. The carbon nanotube preparation device according to claim 10, wherein the reaction chamber cooling tubes are distributed at the top and bottom of the reaction chamber, and the reaction chamber cooling tubes at the top of the reaction chamber have a distribution density greater than the bottom of the reaction chamber. The reaction chamber cooling tube distribution density.