CN114808196B

CN114808196B - Carbon nanotube preparation device, injection assembly thereof and carbon nanotube preparation method

Info

Publication number: CN114808196B
Application number: CN202210408791.6A
Authority: CN
Inventors: 勇振中; 万子尧; 张永毅; 吴昆杰; 周涛; 詹祥和; 李清文
Original assignee: Jiangxi Nanotechnology Research Institute
Current assignee: Jiangxi Nanotechnology Research Institute
Priority date: 2022-04-19
Filing date: 2022-04-19
Publication date: 2023-06-23
Anticipated expiration: 2042-04-19
Also published as: CN114808196A

Abstract

The invention discloses a carbon nano tube preparation device, an injection assembly thereof and a method for preparing the carbon nano tube. The preparation device comprises: the reaction furnace tube is used for providing a carbon nano tube growth environment and comprises a first end, a middle section and a second end; an injection assembly sealingly connected to the first end; the temperature control assembly is arranged on the periphery of the reaction furnace tube and is used for controlling the process temperature of at least the middle section of the reaction furnace tube; the injection assembly includes: the injection flange is hermetically connected to the first end, a first raw material passage and a second raw material passage penetrating through the injection flange, and a sublimation tank; the sublimation tank is communicated with the first raw material passage and is used for accommodating and sublimating the catalytic source so that the gaseous catalytic source enters the reaction furnace tube through the first raw material passage, and the second raw material passage is used for injecting the carbon source into at least the reaction furnace tube. The preparation device, the components and the method thereof greatly improve the yield of the preparation of the carbon nano tube and the stability of the preparation process.

Description

Carbon nanotube preparation device, injection assembly thereof and carbon nanotube preparation method

Technical Field

The invention relates to the technical field of inorganic carbon materials, in particular to a carbon nanotube preparation device, an injection assembly thereof and a carbon nanotube preparation method.

Background

The carbon nano tube has excellent physical and chemical properties, and the carbon nano tube is assembled into a macroscopic body, for example, the fiber is one of important ways for realizing the macroscopic application of the carbon nano tube, and has important significance for the fields of national economy, national defense, aerospace and the like.

The preparation method of the carbon nano tube fiber mainly comprises a wet spinning method, an array spinning method and a floating catalysis direct spinning method. The floating catalytic carbon nanotube fiber has the advantages of high mechanical property, easiness in large-scale continuous preparation and the like, and is considered as the carbon nanotube fiber preparation method with the highest potential and application prospect.

Floating carbon nanotube fiber production efficiency is one of the main problems of interest to researchers in this field. The typical preparation method of the floating catalytic carbon nano tube fiber is that ferrocene (serving as a catalytic source)/thiophene (serving as a sulfur source)/ethanol (serving as a carbon source) solution is continuously injected into a high-temperature reaction cavity under the action of carrier gas, the ferrocene is first decomposed at high temperature to form iron catalytic source nano particles in a high-temperature gas phase environment, carbon atoms generated by high-temperature decomposition of an ethanol carbon source are saturated and separated out on the surfaces of the catalytic source particles, carbon nano tubes are grown and further aggregated to form a sleeve-shaped aerogel structure, and the carbon nano tube fiber precursor is densified to obtain the carbon nano tube fiber. The existing preparation of carbon nano tube fibers or other floating carbon nano tube materials has the phenomena of low preparation efficiency and unstable preparation process.

For example, in the process of preparing carbon nanotube fibers by a floating catalytic direct spinning method in most of the prior art, the catalytic source and the carbon source solvent are mainly supplied in the following ways: (1) The patent CN1005407764C prepares the solution by mixing the catalytic source and the carbon source solvent, and then the solution is injected into a high-temperature reaction furnace through a nozzle to prepare the carbon nano tube continuous fiber. (2) The patent CN103435029A prepares the solution by a catalytic source and a carbon source solvent, and the solution is injected into a high-temperature reaction furnace under the action of carrier gas in an ultrasonic atomization mode, so that the solution gasification efficiency and the fiber preparation efficiency can be improved to a certain extent. (3) The patent CN111020747A prepares the solution by the catalytic source and the carbon source solvent, and the solution is injected into a high-temperature reaction furnace by carrier gas after being pre-gasified by a gasification tank, so that the continuity and stability of the fiber process can be improved. However, with the above-mentioned schemes in the prior art, no matter how the raw material ratio and the process parameters are adjusted, a large yield and a stable preparation process can not be obtained at the same time.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a carbon nano tube preparation device, an injection component thereof and a carbon nano tube preparation method.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention comprises the following steps:

in a first aspect, the present invention provides an injection assembly for use in a carbon nanotube preparation apparatus, comprising:

an injection flange, a first raw material passage and a second raw material passage penetrating the injection flange, and a sublimation tank;

the sublimation tank is communicated with the first raw material passage and is used for accommodating and sublimating a catalytic source so that the catalytic source in a gaseous state enters the reaction furnace tube through the first raw material passage, and the second raw material passage is used for injecting a carbon source into at least the reaction furnace tube.

In a second aspect, the present invention also provides an apparatus for efficiently preparing carbon nanotubes, comprising: the reaction furnace tube is used for providing a carbon nano tube growth environment and comprises a first end, a middle section and a second end which are sequentially connected; an injection assembly sealingly connected to the first end; the temperature control assembly is arranged at the periphery of the reaction furnace tube and is used for controlling the process temperature of at least the middle section of the reaction furnace tube;

the injection assembly is the injection assembly described above, comprising: an injection flange hermetically connected to the first end, a first raw material passage and a second raw material passage penetrating the injection flange, and a sublimation tank;

the sublimation tank is communicated with the first raw material passage and is used for accommodating and sublimating a catalytic source so that the catalytic source in a gaseous state enters the reaction furnace tube through the first raw material passage, and the second raw material passage is used for injecting a carbon source into the reaction furnace tube at least.

In a third aspect, the present invention further provides a method for efficiently preparing carbon nanotubes, which is applied to the above efficient preparation system, and includes:

controlling the temperature of the middle section of the reaction furnace tube to reach the process temperature, and introducing process gas into the reaction furnace tube;

sublimating the catalytic source into a gaseous state in the sublimation tank, and entering the reaction furnace tube through a first raw material passage by carrying carrier gas;

enabling a carbon source to enter the reaction furnace tube through a second raw material passage;

and the carbon source and the catalytic source generate a carbon nanotube precursor in the reaction furnace tube and output the carbon nanotube precursor at the second end of the reaction furnace tube, and the carbon nanotube precursor is collected by a collecting assembly.

Based on the technical scheme, compared with the prior art, the invention has the beneficial effects that:

according to the high-efficiency preparation device, the components and the method thereof provided by the invention, the catalytic source is injected in a gaseous mode through the sublimation tank, so that the limitation of the solubility of the catalytic source in the carbon source can be avoided, the concentration of catalytic particles is greatly amplified, more carbon nano tube growth points are provided, the phenomenon of local precipitation of the catalytic source in the reaction furnace tube due to the influence of the heat absorption of the carbon source is avoided, and the preparation yield of the carbon nano tube and the stability of the preparation process are greatly improved.

The above description is only an overview of the technical solutions of the present invention, and in order to enable those skilled in the art to more clearly understand the technical means of the present application, the present invention may be implemented according to the content of the specification, the following description is given of the preferred embodiments of the present invention with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of a system for efficiently preparing carbon nanotubes according to an exemplary embodiment of the present invention;

FIG. 2 is a macroscopic photograph of a carbon nanotube fiber according to an exemplary embodiment of the present invention;

FIG. 3 is a surface morphology electron micrograph of a carbon nanotube fiber according to an exemplary embodiment of the present invention;

reference numerals illustrate: 1. a housing; 2. a raw material pipe; 3. a heating jacket; 4. a support table; 5. a sealing flange; 6. a carrier gas inlet; 7. a base; 8. a first raw material passage; 9. a first gas flow controller; 10. a syringe; 11. a second gas flow controller; 12. injecting a flange; 13. a reaction furnace tube; 14. a temperature control assembly; 15. a carbon nanotube precursor; 16. a liquid seal box chamber; 17. a tail gas outlet; 18. a water tank; 19. sealing the liquid; 20. a fiber winding device; 21. carbon nanotube fibers.

Detailed Description

The present inventors have long developed and practiced that, based on the existing floating catalytic carbon nanotube production method, it is impossible to obtain a larger yield and a more stable production process at the same time, and those skilled in the art may tend to increase the injection amount of the reaction raw materials to obtain a larger yield, however, the present inventors have found that the prior art method in which the catalytic source and the carbon source are configured as a solution is limited to the solubility of the catalytic source in the carbon source, the injection amount of the carbon source is increased in order to increase the injection amount of the catalytic source, at this time, the quality of the produced carbon nanotube precursor becomes worse, and there is an upper limit of the yield, above which even if the injection of the liquid material is increased, the larger yield cannot be obtained, and the opposite effect is also easily achieved. Thus, the inventors have found that, in order to increase the yield of carbon nanotubes, the injection ratio of the catalytic source to the carbon source should be of primary concern, rather than simply increasing the amount of catalytic source and/or carbon source.

Briefly, the present inventors have found that in the preparation of floating carbon nanotube fibers in the prior art methods, ferrocene (one of the catalytic sources) is pyrolyzed to form iron atoms, which agglomerate in a gas phase environment to form nanoparticles and serve as carbon nanotube growth catalytic source particles. The content of ferrocene is increased in the reaction system, so that the number of iron catalytic source particles in the system can be increased, and the yield of carbon tubes and carbon nanotube fibers is further improved. The method of dissolving ferrocene in liquid ethanol or acetone provides ferrocene to a reaction system, which is limited by the solubility of ferrocene in the solvent, the injection amount of ferrocene is limited, and the quantity of iron catalytic source nano particles and the yield of the final carbon nano tube are further limited.

In addition, the inventor also found that, in the prior art injection method, in the floating catalytic chemical reaction process, the liquid carbon source needs to be completely gasified before the subsequent catalytic reaction is performed, and the gasification and the pyrolysis of the carbon source all need to absorb heat. However, since the sublimation temperature of ferrocene is higher than the gasification temperature of solvents such as ethanol and acetone, volatilization of ethanol and acetone is easy to occur at the position of the liquid carbon source injection port in the reaction process, and the phenomenon that ferrocene is not completely volatilized or is continuously accumulated in part due to heat absorption of the carbon source after volatilization, so that the supply ratio of the carbon source to the catalytic source is unstable, and the stability and the continuity of the subsequent reaction process are affected.

Moreover, the present inventors have found in long-term practice that, in the prior art, the productivity is increased by increasing the injection amount of the liquid mixed carbon source or by other means such as introducing a large amount of sulfur-containing auxiliary agent or the like, and at the same time as the productivity is increased, the stability of the production process is lowered, namely: the prior art is unable to achieve both high yield and high stability.

In view of the shortcomings in the prior art, the inventor of the present invention has long studied and practiced in a large number of ways to propose the technical scheme of the present invention. The technical scheme, the implementation process, the principle and the like are further explained as follows.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced otherwise than as described herein, and therefore the scope of the present invention is not limited to the specific embodiments disclosed below.

Moreover, relational terms such as "first" and "second", and the like, may be used solely to distinguish one from another component or method step having the same name, without necessarily requiring or implying any actual such relationship or order between such components or method steps.

Referring to fig. 1, an embodiment of the present invention provides a device for efficiently preparing carbon nanotubes, including: the reaction furnace tube 13 for providing a carbon nanotube growth environment, the reaction furnace tube 13 comprises a first end, a middle section and a second end which are connected in sequence, an injection assembly which is connected with the first end of the reaction furnace tube 13 in a sealing manner, and a temperature control assembly 14 which is arranged on the periphery of the reaction furnace tube 13, wherein the temperature control assembly 14 is used for controlling at least the process temperature of the middle section of the reaction furnace tube 13.

In some embodiments, the injection assembly comprises: an injection flange 12 hermetically connected to the first end, a first raw material passage 8 and a second raw material passage penetrating the injection flange 12, and a sublimation tank; the sublimation tank is communicated with the first raw material passage 8 and is used for accommodating and sublimating a catalytic source so that the catalytic source in a gaseous state enters the reaction furnace tube 13 through the first raw material passage 8, and the second raw material passage is used for injecting a carbon source into at least the reaction furnace tube 13.

In some embodiments, the first feedstock pathway 8 is provided with an insulating structure.

In some embodiments, the insulating structure is capable of maintaining the temperature of the first feedstock pathway 8 above 150 ℃ when carbon nanotube preparation is performed.

In some embodiments, the insulating structure comprises an insulating layer and/or an active heating structure. The active heating structure may be, for example, an electric heating wire or an electric heating winding belt, which may individually wrap the first raw material passage 8, or may cooperate with an insulation layer to achieve a better insulation effect, and for insulation of the first raw material passage 8, a person skilled in the art may perform a variant or replacement according to the prior art teachings, but all fall within the protection scope of the present invention.

In some embodiments, the sublimation tank comprises a sealed tank body, a feedstock tube 2 disposed within the tank body, and a heating jacket 3 surrounding the feedstock tube 2. The tank body is provided with a carrier gas inlet 6 and a catalytic source outlet which is communicated with the first raw material passage 8; the two ends of the raw material pipe 2 are provided with openings for accommodating the catalytic source, and the heating sleeve 3 is used for controlling at least the temperature in the raw material pipe 2.

In some embodiments, the material of the raw material pipe 2 includes any one or a combination of quartz and corundum.

In some embodiments, the main body of the heating jacket 3 is made of a heat conducting material, and the heat conducting material includes metal and/or graphite, and in some further embodiments, the main body of the heating jacket 3 is preferably copper. The copper material is generally referred to as copper-containing metal having high thermal conductivity such as pure copper and copper alloy. Of course, the heating jacket 3 may have a heating structure such as an electric heating wire or an electric heating rod fixed to the outside or inside of the copper body.

In some embodiments, the heating jacket 3 is capable of controlling the temperature within the feedstock pipe 2 to 100300 ℃.

In some embodiments, the tank comprises a combinable or detachable outer shell 1 and a sealing flange 5, the feed pipe 2 and the heating jacket 3 being thermally isolated from the sealing flange 5. The main purpose of the above-mentioned thermal insulation is to prevent the heat transfer of the feed tube 2 and the heating mantle 3 to the sealing flange 5, resulting in a high temperature ageing failure of the sealing material.

In some embodiments, the feed tube 2 and the heating mantle 3 are connected to the sealing flange 5 via a support table 4.

In some embodiments, the opening of the feed tube 2 is disposed adjacent to the catalytic source outlet.

In some embodiments, the first feedstock pathway 8 extends through the injection flange 12 back into the reaction furnace tube 13 such that when the intermediate section of the reaction furnace tube 13 reaches the process temperature, the temperature at the end of the first feedstock pathway 8 is above 300 ℃. The present inventors have found that when the end temperature of the first raw material passage 8 reaches 300 ℃ or higher, the re-precipitation phenomenon that may occur due to the influence of the carbon source heat absorption by the catalytic source can be avoided to the maximum extent.

In some embodiments, the high-efficiency preparation device further comprises a first gas flow controller 9 and a second gas flow controller 11, wherein the first gas flow controller 9 is used for controlling the flow rate of the carrier gas, and the second gas flow controller 11 is used for pumping the process gas with the required flow rate into the reaction furnace tube 13, and the first gas flow controller 9 and the second gas flow controller 11 are communicated with the interior of the reaction furnace tube 13. The carrier gas may be argon, nitrogen or other process gases, or may even be a gaseous second carbon source, and the second gas may be hydrogen, argon, nitrogen, or the like, and those skilled in the art may adaptively adjust the pumping type and flow rate of the set gas, or may add even more gas flow controllers, and all variations made by those skilled in the art according to the main technical concept of the present invention and their practical needs fall within the scope of the present invention.

Based on the above technical solutions, as some typical application examples, the main structure of one exemplary device provided by the present invention includes: ferrocene sublimation jar, control sampling module, fiber growth module and fiber collection module.

The ferrocene sublimation tank comprises a stainless steel sublimation tank shell 1, a Dan Yingyuan material pipe 2 for containing ferrocene, a copper uniform heating sleeve 3, a corresponding temperature control device, a supporting table 4, a sealing flange 5, a carrier gas inlet 6 and a base 7. The control sample injection module comprises a sublimated gas heat preservation pipeline (namely the first raw material passage 8), a first gas flow controller 9, a carbon source solution injection pump, a second gas flow controller 11 and a reaction furnace sealing flange 5 (namely the injection flange 12). The fiber growth module includes a high temperature reaction furnace tube 13, an electric heating furnace (i.e., the temperature control assembly 14 described above). The fiber collecting module comprises a liquid seal box chamber 16, a tail gas outlet 17, a water tank 18, sealing liquid 19 and a fiber winding device 20.

In the above-described exemplary apparatus, the ferrocene sublimation pot is used to enable the ferrocene as a catalyst to be directly added to the carbon nanotube reaction growth system in a gaseous form, for example, 5-10g of solid ferrocene may be first charged into the quartz raw material tube 2, the Dan Yingyuan tube 2 is placed on the support table 4, and then the stainless steel sealing case 1 is covered and sealed by the sublimation pot sealing flange 5. The raw material pipe 2 is heated to a preset temperature through the copper uniform heating sleeve 3, the temperature of the copper uniform heating sleeve 3 can be precisely controlled by a thermocouple to 350 ℃ at most, and the copper with good heat conduction is adopted as a heat transfer medium, so that the temperature of the raw material pipe 2 is uniformly distributed, and the phenomenon of nonuniform heating is avoided. The sublimation temperature of ferrocene is higher than 100 ℃, and the temperature of the copper uniform heating sleeve 33 can be set to be 100-300 ℃ according to the quantity of sublimation needed when the ferrocene is used. Because of the high design use temperature, the sealing gasket cannot withstand if the heating jacket 3 is in direct contact with the sealing flange 5, and therefore the heating jacket 3 needs to be isolated from the sealing flange 5 by the support table 4. Then, argon is introduced through the carrier gas inlet 6, and ferrocene sublimated into gas in the sublimation tank is carried out of the sublimation tank. The opening of the Dan Yingyuan material pipe 2 is close to the position of the catalytic source outlet of the sublimation tank, so that most of sublimated ferrocene can be brought out of the sublimation tank, and the sublimated gas is prevented from being accumulated after being condensed at other positions in the sublimation tank.

The control sample injection module is used for adjusting the gas flow mainly through a gas flow controller. The sublimated ferrocene vapor in the sublimation tank is brought into the reaction furnace system for reaction through the heat-preserving first raw material passage 8, the heat preservation of the pipeline is to prevent the sublimated gas from being re-solidified due to the temperature reduction in the pipeline conveying process, and the temperature of the heat-preserving pipeline can be set to be 150 ℃ for example. The flow rate of argon can be adjusted by the first gas flow controller 9 according to the amount of ferrocene sublimation gas required. The carbon source solution at the other side can be injected through the injector 10, the injection rate can be 25-30ml/h, the flow of argon and hydrogen can be regulated and controlled through the second gas flow controller 11, and the gasified carbon source solution is driven to enter the reaction chamber. The gas flow of hydrogen and argon can range, for example, from 1 to 5SLM.

The foregoing is illustrative of the high efficiency manufacturing apparatus provided by the present invention which is capable of stably and substantially producing carbon nanotubes, wherein the carbon nanotubes produced by the apparatus are still in a precursor state and are a fluffy aerogel, and can be achieved by combining the carbon nanotube material, such as carbon nanotube fibers or films, with a collection assembly to form a total system. Therefore, the embodiment of the invention further provides a system based on the device.

With continued reference to fig. 1, in some embodiments, the preparation apparatus further includes a collection assembly connected to the second end of the reaction furnace tube 13 for collecting the carbon nanotube precursor 15 output from the second end of the reaction furnace tube 13.

In some embodiments, the collection assembly comprises a carbon nanotube fiber collection assembly or a carbon nanotube film collection assembly.

As an example, the carbon nanotube fiber collecting assembly may be a carbon nanotube fiber finished product obtained by drawing the carbon nanotube aerogel precursor generated in the reaction furnace tube 13 out of the chamber by the carrier gas, then drawing the precursor into water in the liquid seal box chamber 16 for densification, then drawing the precursor out of the water, and collecting the precursor by winding the precursor by a roller through the fiber winding device 20, wherein the winding rate may be 5-30m/min, for example.

Of course, it is not important in the manner of the collection assembly according to the present invention, and those skilled in the art can easily substitute various carbon nanotube collection assemblies disclosed in other prior art, such as thin film collection, aerogel collection, even collection into carbon nanotube dispersion or composite material, etc., or design themselves to be different from the collection assemblies and methods of the prior art. Any collection mode change and substitution based on the core concept of the invention still fall within the protection scope of the invention.

The embodiment of the invention also provides a high-efficiency preparation method of the carbon nano tube, which is applied to the high-efficiency preparation device and comprises the following steps:

the temperature of the middle section of the reaction furnace tube 13 is controlled to reach the process temperature, and process gas is introduced into the reaction furnace tube 13.

The catalyst is sublimated from the sublimation tank into a gaseous state and carried by the carrier gas through the first raw material passage 8 into the reaction furnace tube 13.

The carbon source is introduced into the reaction furnace tube 13 through the second raw material passage.

The carbon source and the catalytic source generate a carbon nanotube precursor 15 in the reaction furnace tube 13 and output the carbon nanotube precursor 15 at the second end of the reaction furnace tube 13, and the carbon nanotube precursor 15 is collected by a collecting assembly.

In some embodiments, the process temperature is 1000-1500 ℃, and the process gas comprises hydrogen and argon.

In some embodiments, the yield of the carbon nanotubes is above 3 g/h.

As an example, in the high temperature reaction furnace tube 13, the vaporized ferrocene is decomposed into an iron catalyst, which catalyzes the carbon source to form the carbon nanotube precursor 15. The diameter of the high-temperature reaction furnace tube 13 may be 50250mm, for example, and the length may be 50200cm, for example. The furnace body is heated by means of an electric heating rod, and the furnace temperature of the electric heating furnace can be set to 1000-1500 ℃ for example.

The embodiment of the invention also provides the carbon nano tube prepared by the high-efficiency preparation method.

In some embodiments, the macroscopic morphology of the carbon nanotubes is carbon nanotube fibers.

In some embodiments, the carbon nanotube fiber has a continuity of 1000m or more.

As some typical application examples, the device for introducing the catalyst precursor (ferrocene) gasification tank on the basis of the device for preparing the carbon nano tube fibers by the floating catalytic CVD method is adopted, the supply of ferrocene is changed into sublimation gas supply, and the supply amount is not limited by solubility, so that the growth of the carbon nano tube fibers is more efficient. And after the ferrocene is dissolved in the carbon source solution, the ferrocene enters a high-temperature reaction furnace chamber to generate a local precipitation phenomenon. By introducing the device of the catalyst precursor (ferrocene) gasification tank, ferrocene and a carbon source can be separated, and then the separated ferrocene is independently introduced into the reaction furnace tube 13 after sublimation gasification, so that the phenomenon of local precipitation of ferrocene is avoided, the carbon source/catalyst is supplied more uniformly in the growth process, and the uniformity and the continuity of the growth of carbon nanotube fibers are enhanced.

The technical scheme of the invention is further described in detail below through a plurality of embodiments and with reference to the accompanying drawings. However, the examples are chosen to illustrate the invention only and are not intended to limit the scope of the invention.

Example 1

The present embodiment provides a specific example of the preparation of carbon nanotube fiber, and the process is as follows:

this example employs a carbon nanotube production system as shown in fig. 1, in which a sublimation tank includes a stainless steel housing 1 in which a raw material tube 2 of quartz is provided, a heating jacket 3 of a copper body is fitted around the outer periphery of the raw material tube 2, the raw material tube 2 and the heating jacket 3 are both placed on a support table 4, and the support table 4 is fixed on a sealing flange 5; the reaction furnace tube 13 is a corundum tube, the inner diameter of which is 100mm, and the length of which is 1350mm;

the outlet of the sublimation tank is connected with a first raw material passage 8, and the first raw material passage 8 extends all the way and penetrates through an injection flange 12 which is hermetically arranged at the first end of a reaction furnace tube 13, and then continues to extend a certain distance into the reaction furnace tube 13, so that the tail end temperature is above 300 ℃ during preparation;

the second raw material passage is communicated with a carbon source injector 10, wherein liquid alcohol is accommodated in the carbon source injector 10, and 1% of thiophene is dissolved in the alcohol as a sulfur source;

the collecting end adopts the assembly shown in figure 1 and comprises a liquid seal box cavity 16 connected with the second end of the reaction furnace tube 13, the opening section of the liquid seal box cavity 16 is immersed in sealing liquid 19 in a water tank 18, a tail gas outlet 17 is formed in one side of the liquid seal box cavity, and a fiber winding device 20 is arranged on one side of the water tank 18;

when the preparation system is adopted to prepare the carbon nano tube fibers 21, the heating jacket 3 in the sublimation tank is set to be 200 ℃, the flow rate of carrier gas (argon) entering the sublimation tank is controlled to be 1SLM through the first gas flow controller 9, the injection rate of the alcohol carbon source is injected at the other side, the mixed gas of hydrogen and argon with the volume ratio of 1:1 of 5SLM is introduced through the second gas flow controller 11, the temperature of the reaction furnace tube 13 is controlled to be 1350 ℃, and the winding speed of the fiber winding device 20 is 20m/min.

The carbon nanotube fiber 21 prepared in this example has an extremely high productivity of 3.5g/h and a continuity of 1000m, and the macroscopic state of the fiber is shown in fig. 2, the microscopic appearance is shown in fig. 3, and it is noted that the continuity is limited by the capacity limitation of the carbon source injector 10, and the continuity is theoretically higher if an injection pump capable of continuously and stably supplying a liquid carbon source is used, which means that the carbon nanotube preparation of this example has an extremely high productivity and an extremely high stability.

Example 2

This example provides an example of a specific carbon nanotube fiber preparation process, which is substantially similar to example 1, except that:

the temperature of the heating jacket 3 was regulated to 250 ℃.

The productivity of the prepared carbon nano tube fiber 21 is 3g/h, and the continuity reaches 1000m.

Example 3

the liquid carbon source is acetone.

Example 4

the reaction furnace tube 13 is a quartz tube.

The productivity of the prepared carbon nano tube fiber 21 is 2g/h, and the continuity reaches 600m.

Comparative example 1

This comparative example provides an example of the preparation of a specific carbon nanotube fiber, which is described below:

by adopting the sample injection mode of the invention, the temperature of the ferrocene injection pipe at the extending position is 150 ℃, the ferrocene injection pipe does not enter the high-temperature reaction chamber (300 ℃), and the other structures and the material sizes are the same as those of the embodiment 1.

The carbon nanotube fiber 21 prepared in this comparative example had a productivity of only 1g/h and a continuity (stability) significantly weaker than that of example 1, with a continuity of 300m. Ferrocene segregation was observed at the outlet of the injection tube.

Comparative example 2

the prepared liquid carbon source is saturated ferrocene ethanol solution by adopting the existing solution injection method, and the thiophene concentration is the same as that of the example 1;

the structure and material dimensions were the same as those of example 1, except that the sublimation tank, the corresponding first raw material passage 8 and the first gas flow controller 9 were not provided.

The carbon nanotube fiber 21 prepared in this comparative example had a productivity of only 1.5g/h and a continuity (stability) significantly weaker than that of example 1, and a continuity of 400m.

Based on the above examples and comparative examples, it is clear that the efficient preparation apparatus, the assembly and the method thereof provided by the present invention can inject the catalytic source in a gaseous state through the sublimation tank, can avoid the limitation of the solubility of the catalytic source in the carbon source, greatly amplify the concentration of the catalytic particles, provide more carbon nanotube growth points, and avoid the local precipitation phenomenon of the catalytic source in the reaction furnace tube 13 due to the influence of the heat absorption of the carbon source, thereby greatly improving the yield of the preparation of the carbon nanotubes and the stability of the preparation process.

It should be understood that the above embodiments are merely for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the present invention and implement the same according to the present invention without limiting the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.

Claims

1. An injection assembly for a carbon nanotube fabrication apparatus, comprising:

the sublimation tank is communicated with the first raw material passage and is used for accommodating and sublimating a catalytic source so that the catalytic source in a gaseous state enters the reaction furnace tube through the first raw material passage, and the second raw material passage is used for injecting a carbon source into at least the reaction furnace tube;

the first raw material passage is provided with a heat-insulating structure, the heat-insulating structure can enable the temperature of the first raw material passage to be maintained above 150 ℃ when the carbon nano tube is prepared, and the heat-insulating structure comprises a heat-insulating layer and/or an active heating structure;

the sublimation tank comprises a sealed tank body, a raw material pipe arranged in the tank body and a heating jacket surrounding the raw material pipe, wherein the tank body is provided with a carrier gas inlet and a catalytic source outlet, and the catalytic source outlet is communicated with the first raw material passage; the two ends of the raw material pipe are provided with openings for accommodating the catalytic source, and the heating sleeve is used for controlling at least the temperature in the raw material pipe.

2. The injection assembly of claim 1, wherein the material of the feed tube comprises any one or a combination of quartz and corundum.

3. The injection assembly of claim 2, wherein the heating jacket comprises a body of a thermally conductive material comprising metal and/or graphite.

4. The injection assembly of claim 2, wherein the heating jacket is capable of controlling the temperature within the feed tube to between 100 and 300 ℃.

5. The injection assembly of claim 1, wherein the tank comprises a combinable or detachable outer housing and a sealing flange, the feed tube and heating jacket being thermally isolated from the sealing flange;

the raw material pipe and the heating sleeve are connected with the sealing flange through a supporting table;

the opening of the feed tube is adjacent to the catalytic source outlet.

6. A device for producing carbon nanotubes, comprising:

the reaction furnace tube is used for providing a carbon nano tube growth environment and comprises a first end, a middle section and a second end which are sequentially connected; the injection assembly of any one of claims 1-5, the injection assembly being sealingly connected to the first end; and the temperature control component is arranged on the periphery of the reaction furnace tube and is used for controlling the process temperature of the middle section of the reaction furnace tube at least.

7. The manufacturing apparatus of claim 6, wherein the first feedstock pathway of the injection assembly extends through the injection flange and back into the reaction furnace tube such that when the intermediate section reaches the process temperature, a temperature of an end of the first feedstock pathway is above 300 ℃.

8. The apparatus of claim 6 further comprising a first gas flow controller in communication with the interior of the reactor tube for controlling the flow of carrier gas and a second gas flow controller for pumping a desired flow of process gas into the reactor tube.

9. The apparatus of claim 6, further comprising a collection assembly coupled to the second end of the reaction furnace for collecting carbon nanotube precursor output from the second end of the reaction furnace.

10. The manufacturing apparatus of claim 9, wherein the collection assembly comprises a carbon nanotube fiber collection assembly or a carbon nanotube film collection assembly.

11. A method for producing a carbon nanotube, applied to the production apparatus according to any one of claims 6 to 10, comprising:

and the carbon source and the catalytic source generate a carbon nanotube precursor in the reaction furnace tube and output the carbon nanotube precursor at the second end of the reaction furnace tube, and the carbon nanotube precursor is collected by utilizing a collecting assembly and converted into a carbon nanotube macroscopic body.

12. The method of claim 11, wherein the process temperature is 1000-1500 ℃, and the process gas comprises hydrogen and argon.

13. The method according to claim 11, wherein the yield of the carbon nanotubes is 3g/h or more;

the carbon nano tube macroscopic body comprises carbon nano tube fibers or carbon nano tube films, and the continuity of the carbon nano tube fibers is more than 1000m.