CN1951804A - Carbon nanotube preparation apparatus - Google Patents

Abstract

The invention discloses a preparing equipment of carbon nanometer pipe, which consists of reacting cavity and diversion device, wherein the reacting cavity contains the first inlet and outlet; the diversion device is set in the reacting cavity, which concludes gas transmitting pipe, second inlet and outlet; one end of gas transmitting pipe cases the first inlet closely and the other end cases the second inlet closely; the opening direction of second outlet is perpendicular to base of nanometer pipe; the second outlet lies on one side of second inlet; the second outlet connects the first outlet.

Description

Carbon nanotube preparation equipment

【Technical field】

The invention relates to a preparation device for carbon nanotubes, in particular to a preparation device for carbon nanotubes by thermal chemical vapor deposition.

【Background technique】

Carbon nanotubes are a new type of one-dimensional nanocarbon material, which was first discovered in 1991 by Japanese researcher Iijima Sumio (S.Iijima). Carbon nanotubes have excellent properties, such as high tensile strength and high thermal stability, and with the change of the helical mode of carbon nanotubes, carbon nanotubes can exhibit metallic or semiconducting properties. Because carbon nanotubes have an ideal one-dimensional structure and excellent properties in the fields of mechanics, electricity, and heat, they have shown broad application prospects in interdisciplinary fields such as materials science, chemistry, and physics. Therefore, realizing the controllable growth of carbon nanotubes is the key to promote the application of carbon nanotubes.

At present, the more commonly used method for preparing carbon nanotubes is chemical vapor deposition. The chemical vapor deposition method uses carbon-containing gas as a carbon source gas to grow multi-walled or single-walled carbon nanotubes on silicon or zeolite substrates. But, as shown in Figure 1, thermal CVD carbon nanotube preparation equipment 1 in the prior art comprises a quartz tube 17, and this quartz tube 17 comprises an air inlet 13 and a gas outlet that is arranged opposite to this air inlet 13 15. In the preparation process of carbon nanotubes, a substrate 2 with a catalyst layer 22 formed on the surface is loaded in the quartz tube 17, and the reaction gas 11 is blown from the gas inlet 13 to the gas outlet 15 in the horizontal direction, that is, it is mixed with the carbon nanotubes. The growth direction is vertical. For fine carbon nanotubes, even if the flow rate of the reaction gas is slow, it will lead to poor alignment of the finally grown carbon nanotubes.

In view of this, it is necessary to provide a preparation device capable of growing aligned carbon nanotubes.

【Content of invention】

A carbon nanotube preparation device will be described below with examples, which can realize the collimated growth of carbon nanotubes.

A preparation device for carbon nanotubes, which includes a reaction chamber and a flow guiding device. The reaction chamber includes a first gas inlet and a first gas outlet. The flow guiding device is located in the reaction chamber, and it includes a gas delivery tube, a second gas inlet and a second gas outlet, wherein one end of the gas delivery tube is sealed and sleeved with the first gas inlet, and the other end is Sealed with the second air inlet, the opening direction of the second air inlet is set perpendicular to the substrate for growing carbon nanotubes, the second air outlet is located on the opposite side of the second air inlet, The second air outlet communicates with the first air outlet.

Compared with the prior art, the carbon nanotube preparation equipment uses a diversion device to change the flow direction of the reaction gas required for the growth of the carbon nanotubes, so that the flow direction is changed from the vertical carbon nanotube growth direction in the prior art to Parallel to the growth direction of the carbon nanotubes, this arrangement can make the carbon nanotubes have better alignment.

【Description of drawings】

Fig. 1 is a schematic structural diagram of a carbon nanotube preparation equipment in the prior art.

Fig. 2 is a schematic structural diagram of a carbon nanotube preparation device according to the first embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a carbon nanotube preparation device according to a second embodiment of the present invention.

【Detailed ways】

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

Referring to FIG. 2, the carbon nanotube preparation equipment 10 provided by the first embodiment of the present invention includes a reaction chamber 20, a flow guide device 30 and a heating device 12, wherein the flow guide device 30 is arranged in the reaction chamber 20 Inside.

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

The flow guiding device 30 includes a gas delivery tube 32 , a second gas inlet 34 and a second gas outlet 36 . In this embodiment, the part of the flow guiding device 30 except the gas delivery pipe 32 is a tank structure without a bottom surface, and its material can be made of heat-conducting materials, such as stainless steel. One end of the gas delivery pipe 32 is tightly socketed with the first air inlet 22 , and the other end is airtightly socketed with the second air inlet 34 . The gas delivery pipe 32 may include a bent section, through which the opening directions of the first air inlet 22 and the second air inlet 34 can be in a vertical state. The opening direction of the second gas inlet 34 is set vertically relative to the substrate 40 for growing carbon nanotubes. In this embodiment, the second gas inlet 34 is arranged above the substrate 40 and perpendicular to the substrate. The second air outlet 36 is located at the bottom of the deflector 30 opposite to the second air inlet 34 , and the opening direction of the second air outlet 36 is parallel to the opening direction of the first air inlet 22 . It is also possible to arrange the second air outlet 36 at the bottom of the deflector 30 on the opposite side of the second air inlet 34, and make its opening direction perpendicular to the opening direction of the first air inlet 22, as long as Any position where the second air outlet 36 is adjacent to the base 40 is acceptable.

The heating device 12 is disposed around the reaction chamber 20 for heating the catalyst layer 50 for growing carbon nanotubes loaded in the reaction chamber 20 . The heating device 12 can be selected from heating equipment such as a high-temperature furnace and a high-frequency furnace.

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

Referring to FIG. 2 , a substrate 40 is first put into the reaction chamber 20 , a catalyst layer 50 is formed on the surface of the substrate 40 , and the flow guiding device 20 is arranged to completely surround the substrate 40 . The substrate 40 can be selected from quartz, silicon, magnesium oxide and other substrates. The catalyst layer 50 can be made of cobalt, nickel, iron, or alloy materials thereof. Since the flow guiding device 30 adopts a bottomless groove structure, the second air outlet 36 is arranged at the bottom of the flow guiding device 20 and its opening direction is parallel to the opening direction of the first air inlet 22 .

Then, under normal pressure, the carrier gas is passed from the first air inlet 22, the carrier gas passes through the gas delivery pipe 32 and the second air inlet 34, enters it from the top of the flow guiding device 30 and blows it vertically Base 40. The carrier gas may be 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 rises to a predetermined temperature, generally 500°C to 900°C, the reaction gas is introduced from the first air inlet 22 . The reaction gas can be selected from carbon source gases such as methane, ethane, ethylene, acetylene and the like. The reaction gas enters the flow guide device 30 through the gas delivery pipe 32 and the second gas inlet 34 . Due to the catalytic effect of the catalyst, the carbon source gas passed 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 will be precipitated after the carbon units adsorbed in the catalyst particles reach saturation. , so that carbon nanotubes can be grown at the position of catalyst particles. The waste gas generated after the reaction between the carrier gas and the reaction can be discharged through the second gas outlet 36 and the first gas outlet 24 connected thereto. The second gas outlet 36 and the first gas outlet 24 can be connected through a conduit, so that the carrier gas and the waste gas generated after the reaction are directly discharged from the second gas outlet 36 to the first gas outlet 24, or no conduit can be used. , the carrier gas and the waste gas generated after the reaction are directly discharged into the reaction chamber 20 from the second gas outlet 36 , and then discharged from the first gas outlet 24 through the flow of the gas.

As shown in Figure 3, the carbon nanotube production equipment 100 in the second embodiment of the present invention includes a heating device 120, a reaction chamber 200 and a flow guide device 300, wherein the flow guide device 300 can be selected as a box structure with a bottom surface . At this time, one end of the gas delivery pipe 320 of the flow guiding device 300 is tightly socketed with the first air inlet 220, and the other end is tightly socketed with the second air inlet 340; the second air inlet of the flow guiding device 300 340 is located at the top of the air guiding device 300, the second air outlet 360 can be arranged at the bottom of the air guiding device 300 and its opening direction is perpendicular to the opening direction of the first air inlet 220, and the second air outlet 360 can also be It is arranged at the bottom of the flow guiding device 300 and its opening direction is parallel to the opening direction of the first air inlet 220, that is, relative to the position of the second air inlet 340, as long as the second air outlet 360 is adjacent to the base 400 positions are available.

In the second embodiment of the present invention, the substrate 400 formed with the catalyst layer 500 can be directly put into the flow guiding device 300 , and the flow guiding device 300 can be put into the reaction chamber 200 . A carrying device 600 can also be added to support the base 400 and adjust the distance between the base 400 and the second air inlet 340 . Other steps of preparing carbon nanotubes are the same as those in the first embodiment.

It can be understood that, in the embodiment of the present invention, such as between the opening direction of the first air inlet and the second air inlet, between the opening direction of the first air inlet and the second air outlet, and the first The positional relationship between the opening direction of the air inlet and the base is not limited to being absolutely parallel or perpendicular, as long as the purpose of the present invention can be achieved.

The carbon nanotube preparation equipment provided by the embodiment of the present invention changes the flow direction of the reaction gas used for carbon nanotube growth through a flow guiding device so that it is parallel to the growth direction of carbon nanotubes, thereby realizing the alignment of carbon nanotubes preparation.

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 it does not deviate from the present invention. The implementation effect of the invention is enough. These changes made according to the spirit of the present invention should be included in the scope of the present invention.

Claims (8)

1. A kind of carbon nanotube preparation equipment, it comprises a reaction chamber, and this reaction chamber comprises a first air inlet and a first gas outlet, it is characterized in that further comprising: a flow guiding device, which is arranged in the reaction chamber, The flow guiding device includes a gas conveying pipe, a second air inlet and a second air outlet, one end of the gas conveying pipe is sealed and sleeved with the first air inlet, and the other end is sealed and sleeved with the second air inlet , the opening direction of the second air inlet is perpendicular to the substrate for growing carbon nanotubes, the second air outlet is located on the opposite side of the second air inlet, and the second air outlet is connected to the first air outlet conduction. 2. The carbon nanotube preparation equipment according to claim 1, characterized in that the reaction chamber is a quartz tube. 3 . The carbon nanotube preparation equipment according to claim 1 , wherein the gas delivery pipe comprises a bent section, so that the opening direction of the first gas inlet is perpendicular to the opening direction of the second gas inlet. 4 . 4. The carbon nanotube production equipment according to claim 1, characterized in that the opening direction of the second gas outlet is parallel to the opening direction of the first gas inlet. 5 . The carbon nanotube preparation device according to claim 1 , wherein the opening direction of the second gas outlet is perpendicular to the opening direction of the first air inlet. 6 . The carbon nanotube production equipment as claimed in claim 1 , wherein the flow guiding device is formed of a heat conducting material. 7 . 7. The carbon nanotube production equipment as claimed in claim 6, characterized in that said thermally conductive material comprises stainless steel. 8. The carbon nanotube preparation apparatus according to claim 1, further comprising a supporting device for supporting the substrate so as to adjust the distance between the second gas inlet and the substrate.

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