Device and method for depositing carbon nanotubes on carbon fiber interface

Abstract

The device and the method are used for continuously depositing the carbon nanotubes on the surfaces of the carbon fibers, the device at least comprises a deposition module, a box body module and a power supply module, the carbon fibers are loaded with a catalyst through the deposition module, and the carbon nanotubes continuously grow on the surfaces of the carbon fibers in the box body module; an inlet and an outlet of the box body module construct a closed environment through liquid seal; the two ends of the carbon fiber in the box body module are connected to the power supply module, the carbon source near the carbon fiber is split and recombined through Joule heat, and the carbon source is in a liquid phase or a gas phase; and the two ends of the power supply module realize continuous movement of the carbon fibers through rolling or rotating static contact. The method solves the problems of high energy consumption and discontinuous growth of the carbon nanotubes grown on the carbon fiber interface in the prior art.

Description

Technical Field

[0001] This invention relates to the field of new materials, and in particular to a device and method for depositing carbon nanotubes at the carbon fiber interface. Background Technology

[0002] Carbon fiber reinforced composites are prone to cracking and poor transverse thermal conductivity. The root cause is that there is an easily peelable interface between carbon fiber and resin. Adding carbon nanotubes between carbon fiber and resin can form a root-like structure, which can not only strengthen the resin matrix and effectively transfer heat, but also act as a bridge to achieve a stronger bond.

[0003] In existing carbon nanotube-modified carbon fiber technologies, there are two main approaches: one is to grow carbon nanotubes on the carbon fiber surface, and the other is to add carbon nanotubes to the carbon fiber surface through some technical means. For the addition approach, methods such as chemical grafting, spraying, electrophoretic deposition, and impregnation have emerged, but these methods often have problems such as carbon nanotube dispersion. The other approach is to grow carbon nanotubes on the carbon fiber surface through CVD. This method heats the carbon fiber surface with external heat, but the energy consumption is particularly high, the time is long, and the continuity cannot be guaranteed.

[0004] Therefore, it is urgent and necessary to invent a low-energy-consumption, continuous carbon fiber interface deposition device and method for carbon nanotubes. Summary of the Invention

[0005] This invention provides a device and method for carbon nanotube deposition at the carbon fiber interface to solve the problems of high energy consumption and discontinuous growth in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0007] This invention provides a carbon nanotube deposition device and method for carbon fiber interface deposition, which is used for continuous deposition of carbon nanotubes on the surface of carbon fiber. It includes at least a deposition module (20), a box module, and a power module (40). The carbon fiber is loaded with a catalyst through the deposition module (20), and carbon nanotubes are continuously grown on the surface of the carbon fiber in the box module.

[0008] The inlet and outlet of the enclosure module are sealed off using a liquid seal structure.

[0009] The two ends of the carbon fiber in the housing module are connected to the power module (40), and the carbon source near the carbon fiber is decomposed and recombined by Joule heating. The carbon source is either liquid or gas.

[0010] The power module (40) achieves continuous movement of carbon fiber through rolling or rotating static contact at both ends.

[0011] Preferably, the step of continuously growing carbon nanotubes on the surface of carbon fibers is as follows:

[0012] (1) The catalyst is loaded by immersing it in ferric nitrate solution or a mixed solution of ferric nitrate and liquid carbon source with a concentration of 0.01-0.2 mol / L for 2-100 min;

[0013] (2) A protective gas is introduced into the box module to create an oxygen-free environment, and hydrogen is introduced to reduce the catalyst. Under the action of carbon source and Joule heating, the desired carbon nanotubes are grown on the carbon fiber surface. The protective gas is preferably argon.

[0014] The power module (40) is a DC power supply, and the energizing voltage of the carbon fiber is 15-50V, and the current is 2-10A;

[0015] The liquid-phase carbon source includes at least one of ethanol and ethylene glycol, and the gas-phase carbon source includes at least one of carbon monoxide, carbon dioxide, propylene, and methane.

[0016] The catalyst is supported as an iron salt solution or iron oxide particles; the iron oxide particles are generated by a redox reaction.

[0017] The liquid-sealed substance is at least one of the catalyst, the liquid-phase carbon source, and water.

[0018] Preferably, the rotational static contact (41) is achieved by having a rotating mechanism in the housing module, with the carbon fiber at least partially on the surface of the rotating mechanism, and the carbon fiber in static frictional contact with the surface of the rotating mechanism.

[0019] Preferably, the electrochemical oxidation is carried out simultaneously or separately from the supported catalyst; the separate oxidation refers to the electrochemical oxidation treatment of the carbon fiber before the supported catalyst, wherein the treatment method is to immerse it in ammonium dihydrogen phosphate with a concentration of 2wt%-10wt% for electrochemical oxidation, wherein the voltage is 5-20V and the current is 0.1-5A.

[0020] The simultaneous process involves mixing the supported catalyst solution with the electrochemical oxidation solution.

[0021] Preferably, the carbon fiber is desizing before electrochemical oxidation, and the desizing is carried out in an environment of 200-500°C for 1-3 hours;

[0022] The loaded catalyst is then dried, and the desizing and drying are preferably carried out by heating the carbon fiber with thermal radiation.

[0023] Preferably, the housing module further includes a non-contact temperature sensor, which is used to measure the ambient temperature near the carbon fiber in real time.

[0024] The deposition module (20) is at least partially placed inside the housing, and the solution in the deposition module (20) is evenly distributed on the carbon fiber surface by spraying.

[0025] Preferably, the housing module further includes a distribution plate, which is a plate-like structure with small holes on its surface, and the distribution plate is used to change the gas flow distribution within the housing module.

[0026] This invention provides a continuous growth environment through a liquid-sealed structure, and the liquid-sealed material is related to the catalyst or carbon source, allowing for further sufficient growth. Joule heating enables rapid temperature rise of the thin layer on the carbon fiber surface, achieving growth in seconds, whereas traditional CVD methods require heating and cooling times of several hours. The power module (40) can be either in rolling contact or rotating static contact at both ends to achieve controllable movement of the carbon fiber. For more uniform growth, the carbon fiber can be desizing and electrochemically oxidized. Since the walls of the housing module are cold and the entire environment is at room temperature, temperature measurement is more convenient. Simultaneously, the deposition module (20) and housing module can be integrated for growth, or grown separately for greater flexibility. Finally, adding a distribution plate allows for more uniform gas flow within the housing. This invention solves the problems of high energy consumption and discontinuous growth found in existing technologies. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This diagram illustrates an integrated rotary static contact deposition apparatus provided in an embodiment of the present invention.

[0029] Figure 2 This diagram illustrates a rotating static contact deposition apparatus provided in an embodiment of the present invention.

[0030] Figure 3 This diagram illustrates a rolling contact continuous deposition apparatus with temperature measurement function provided in an embodiment of the present invention.

[0031] Figure 4 This diagram illustrates another deposition apparatus with a distribution plate provided in an embodiment of the present invention.

[0032] Figure 5 A diagram showing another continuous deposition apparatus for porous structures provided in an embodiment of the present invention;

[0033] Figure 6This shows an electron microscope image of carbon nanotubes deposited using a liquid-phase carbon source provided in an embodiment of the present invention.

[0034] Figure 7 This shows an electron microscope image of carbon nanotubes deposited from a gas-phase carbon source according to an embodiment of the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] (10) Carbon fiber; (20) Deposition module; (30) Box module; (31) Non-contact temperature sensor; (32) Distribution plate; (40) Power module; (41) Rotary static contact; (50) Carbon nanotube. Detailed Implementation

[0037] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive step are within the scope of protection of the present invention.

[0038] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0039] See Figure 1-7 The present invention provides a carbon nanotube deposition device and method for carbon fiber interface deposition, for continuous deposition of carbon nanotubes on the surface of carbon fiber (10), including at least a deposition module (20), a box module (30) and a power module (40). The carbon fiber (10) is loaded with a catalyst through the deposition module (20), and carbon nanotubes (50) are continuously grown on the surface of the carbon fiber (10) in the box module (30).

[0040] The inlet and outlet of the enclosure module are sealed off using a liquid seal structure.

[0041] The carbon fiber (10) in the housing module (30) is connected to the power module (40) at both ends. The carbon source near the carbon fiber (10) is decomposed and recombined by Joule heating. The carbon source is either liquid or gas.

[0042] The power module (40) achieves continuous movement of carbon fiber (10) through rolling or rotating static contact at both ends.

[0043] This invention establishes a continuous growth environment through a liquid-sealed structure, and the liquid-sealed material is related to the catalyst or carbon source, allowing for further sufficient growth. Joule heating enables rapid temperature rise of the thin layer on the surface of the carbon fiber (10), achieving growth in seconds, whereas the traditional CVD method requires heating and cooling for several hours. The power module (40) can be configured for either rolling contact or rotating static contact (41) at both ends to achieve controllable movement of the carbon fiber (10). For more uniform growth, the carbon fiber (10) can be desizing and electrochemically oxidized. Since the walls of the housing module (30) are cold and the entire environment is at room temperature, temperature measurement is more convenient. Simultaneously, the deposition module (20) and housing module (30) can be grown in an integrated manner or separately for greater flexibility. Finally, the addition of a distribution plate (32) allows for more uniform gas flow within the housing. This invention solves the problems of high energy consumption and discontinuous growth found in existing technologies.

[0044] It should be noted that in the embodiments of the present invention, the positive and negative terminals of the power supply are in direct contact with the carbon fiber (10), so that the carbon fiber (10) is connected to the circuit. After the carbon fiber (10) becomes conductive, it will rapidly heat up based on the electrothermal effect, causing the carbon source to decompose and providing growth conditions for the growth of carbon nanotubes. In contrast, the CVD method involves the power supply directly heating the resistance wire, which generates heat under the action of the resistance wire. The heated gas is then deposited on the surface of the carbon fiber (10). One of these is an internal heat source formed by heat conduction, while CVD is an external heat source formed by heat radiation or heat convection. The two are fundamentally different.

[0045] It should be noted that in this embodiment of the invention, there are two ways for the power supply electrode to contact the carbon fiber (10). One is rolling contact, in which conductive rollers are applied to each pole at both ends of the carbon fiber (10) to achieve conductivity without affecting the movement of the carbon fiber (10).

[0046] It should be noted that, in the embodiments of the present invention, another type is rolling static contact, in which electrodes are evenly distributed at equal intervals in the circumferential direction of the rotating disk, the positive and negative electrodes are arranged in an alternating manner, the rotation speed of the disk is controlled, which can be uniform or periodically variable, and the carbon fiber (10) conducts electricity and heat transfer between the two electrodes.

[0047] It should be noted that, in this embodiment of the invention, the housing module (30) can be designed as a cover opening and closing structure, which can be sealed by a rubber gasket or liquid seal.

[0048] It should be noted that, in the embodiments of the present invention, the catalyst is an active metal salt or oxide, which can be reduced to obtain active metal iron, cobalt, and nickel.

[0049] This method can also be used to achieve discontinuous growth and stepped growth of carbon nanotubes, and the formation of interwoven carbon nanotube networks can be achieved by adjusting the power supply.

[0050] It should be noted that in this embodiment of the invention, a temperature measuring device is added to achieve real-time temperature capture and establish a correspondence with the input power, thereby accurately predicting the growth of carbon nanotubes. The method for establishing the correspondence is based on a deep learning neural network, using temperature and power as the output and input conditions, respectively, to obtain the optimal weight value.

[0051] It should be noted that, in addition to the liquid-sealed inlet and outlet carbon fiber (10), the box module (30) also needs to add gas inlet and outlet interfaces to facilitate the entry and exit of carbon source, hydrogen and protective gas.

[0052] It should be noted that, in the embodiments of the present invention, the contact between the carbon fiber (10) and the electrode can also be such that the electrode has a porous structure and the carbon fiber (10) passes through the porous structure.

[0053] Preferably, the step of continuously growing carbon nanotubes on the surface of carbon fiber (10) is as follows:

[0054] (1) The catalyst is loaded by immersing it in ferric nitrate solution or a mixed solution of ferric nitrate and liquid carbon source with a concentration of 0.01-0.2 mol / L for 2-100 min;

[0055] (2) A protective gas is introduced into the box module (30) to construct an oxygen-free environment, and hydrogen is introduced to reduce the catalyst. Under the action of carbon source and Joule heating, the desired carbon nanotubes are grown on the surface of carbon fiber (10). The protective gas is preferably argon.

[0056] It should be noted that, in the embodiments of the present invention, the protective gas may also be nitrogen.

[0057] It should be noted that, in the embodiments of the present invention, iron-based catalysts are cheaper and have a wider range of applications than nickel-cobalt-based catalysts.

[0058] It should be noted that, in the embodiments of the present invention, the growth conditions of carbon nanotubes are as follows: under anaerobic conditions, the required energy is set to satisfy carbon decomposition and catalyst adsorption, and carbon nanotubes can be grown.

[0059] Preferably, the power module (40) is a DC power supply, and the energizing voltage of the carbon fiber (10) is 15-50V and the current is 2-10A;

[0060] The liquid-phase carbon source includes at least one of ethanol and ethylene glycol, and the gas-phase carbon source includes at least one of carbon monoxide, carbon dioxide, propylene, and methane.

[0061] The catalyst is supported as an iron salt solution or iron oxide particles; the iron oxide particles are generated by a redox reaction.

[0062] The liquid-sealed substance is at least one of the catalyst, the liquid-phase carbon source, and water.

[0063] The electrochemical oxidation method uses graphite as the cathode, carbon fiber (10) as the anode, and a solution between the cathode and anode. The oxidation-reduction voltage is 5-20V, 0.1-5A, and the processing time is 2-200s.

[0064] Preferably, the rotational static contact occurs when a rotating mechanism exists in the housing module (30), the carbon fiber (10) is at least partially located on the surface of the rotating mechanism, and the carbon fiber (10) is in static frictional contact with the surface of the rotating mechanism.

[0065] Preferably, the electrochemical oxidation is carried out simultaneously or separately from the supported catalyst; the separate oxidation refers to the electrochemical oxidation treatment of carbon fiber (10) before the supported catalyst, wherein the treatment method is to immerse the carbon fiber (10) in ammonium dihydrogen phosphate with a concentration of 2wt%-10wt% and then electrochemically oxidize it by passing an electric current through it, wherein the voltage of the electric current is 5-20V and the current is 0.1-5A.

[0066] The simultaneous process involves mixing the supported catalyst solution with the electrochemical oxidation solution.

[0067] Preferably, the carbon fiber (10) is desizing before electrochemical oxidation, and the desizing is carried out in an oxygen-free environment at 200-500°C for 1-3 hours;

[0068] The loaded catalyst is then dried, and the desizing and drying are preferably carried out by heating the carbon fiber (10) with thermal radiation.

[0069] Preferably, the housing module (30) further includes a non-contact temperature sensor (31), which is used to measure the ambient temperature near the carbon fiber (10) in real time.

[0070] The deposition module (20) is at least partially placed inside the housing, and the solution in the deposition module (20) is evenly distributed on the surface of the carbon fiber (10) by spraying.

[0071] Preferably, the housing module (30) further includes a distribution plate, which is a plate-like structure with small holes on its surface, and the distribution plate is used to change the gas flow distribution inside the housing module (30).

[0072] It should be noted that, in the embodiments of the present invention, the placement position of the distribution plate is not limited, nor are the number of distribution plates or the number of openings.

[0073] Case 1:

[0074] Carbon fiber was desizing in a high-temperature furnace at 450°C for 1.5 hours. A mixed solution of 5 wt% (5 g) ammonium dihydrogen phosphate and 100 g water was prepared. Electrochemical oxidation was carried out in the solution at 10 V and 0.2 A for 80 s. After drying (80°C), the carbon fiber was immersed in a 0.02 mol / L mixed solution of ferric nitrate and ethanol (79 g ethanol and 0.8 g ferric nitrate). The carbon fiber was immersed for 10 min and then dried in an oven (80°C). The carbon fiber was transferred from the deposition module (20) to the box module (30). Nitrogen gas (700 sccm) was introduced into the box module (30) for 3 min. Hydrogen and propylene were then introduced. The nitrogen gas was adjusted to 150 sccm, the hydrogen gas to 110 sccm, and the propylene gas to 50 sccm. The carbon fiber was energized at 20 V, 4.5 A for 30 s. Carbon nanotubes were then grown on the surface of the carbon fiber. Figure 7 ).

[0075] Case 2:

[0076] Carbon fibers were desizing in a high-temperature furnace at 450℃ for 1.5 hours. A mixed solution of 5 wt% (5 g) ammonium dihydrogen phosphate and 100 g water was prepared, and electrochemical oxidation was carried out in the solution at 10 V and 0.2 A for 80 seconds. After desizing, the fibers were dried at 80℃ and then immersed in a 0.02 mol / L mixed solution of ferric nitrate and ethanol (79 g ethanol and 0.8 g ferric nitrate) for 10 minutes. After drying in an oven at 80℃, ethylene glycol was sprayed into the oven module, and nitrogen gas (700 sccm) was introduced into the oven module for 3 minutes. The nitrogen flow rate was adjusted to 200 sccm, and the carbon fibers were energized at 20 V and 4.5 A for 30 seconds, resulting in the growth of carbon nanotubes on the carbon fiber surface. Figure 6 ).

[0077] Case 3:

[0078] Carbon fiber was desizing in a high-temperature furnace at 450°C for 1.5 hours. A mixed solution of 5 wt% (5 g) ammonium dihydrogen phosphate and 100 g water was prepared. Electrochemical oxidation was carried out in the solution at 10 V and 0.2 A for 80 s. After the treatment, the carbon fiber was dried at 80°C. Then it was soaked in a 0.02 mol / L mixed solution of ferric nitrate and ethylene glycol (112 g ethylene glycol and 0.8 g ferric nitrate were mixed). The carbon fiber was soaked for 10 min. The carbon fiber was transferred from the deposition module (20) into the box module. Nitrogen gas (700 sccm) was introduced into the box module for 3 min. The nitrogen gas was adjusted to 200 sccm. The carbon fiber was energized at 20 V, 4.5 A for 30 s. Carbon nanotubes were then grown on the surface of the carbon fiber.

[0079] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0080] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0081] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A carbon fiber interfacial deposition carbon nanotube apparatus and method, characterized by, The application relates to a device for continuously depositing carbon nanotubes (50) on the surface of carbon fibers (10), which comprises at least a deposition module (20), a box module (30) and a power module (40), the carbon fibers are loaded with catalysts through the deposition module, and the carbon nanotubes (50) are continuously grown on the surface of the carbon fibers in the box module. The inlet and outlet of the box module (30) are closed by a liquid seal structure to form a closed environment. The two ends of the carbon fibers in the box module (30) are connected to the power module (40), and the carbon source near the carbon fibers is cracked and recombined by Joule heat, the carbon source being in liquid phase or gas phase. The two ends of the power module (40) are connected to the carbon fibers (10) through rolling or rotating static contact (41) to realize continuous movement of the carbon fibers (10).

2. The carbon fiber interfacial deposition of carbon nanotubes apparatus and method of claim 1, wherein, The steps for continuously growing carbon nanotubes on the surface of carbon fibers are as follows: (1) the carbon fibers are soaked in an iron nitrate solution or a mixed solution of iron nitrate with a concentration of 0.01-0.2 mol / L and liquid carbon source for 2-100 min to load catalysts; (2) a protective gas is introduced into the box module to form an oxygen-free environment, hydrogen is introduced to reduce the catalysts, and the carbon nanotubes (50) are grown on the surface of the carbon fibers (10) under the action of the carbon source and the Joule heat, and the protective gas is preferably argon.

3. The carbon fiber interfacial deposition of carbon nanotubes apparatus and method of claim 1, wherein, The power module (40) is a direct-current power supply, the voltage of the carbon fibers (10) is 15-50 V, and the current is 2-10 A.

4. The carbon fiber interfacial deposition of carbon nanotubes apparatus and method of claim 1, wherein, The liquid carbon source comprises at least one of ethanol and ethylene glycol, and the gas carbon source comprises at least one of carbon monoxide, carbon dioxide, propylene and methane; The loaded catalysts are a salt solution of iron or iron oxide particles, and the iron oxide particles are obtained through a redox reaction; The liquid seal substance is at least one of the catalysts, the liquid carbon source and water.

5. The carbon fiber interfacial deposition carbon nanotube apparatus and method of claim 1, wherein, The rotating static contact is that a rotating mechanism exists in the box module (30), the carbon fibers are at least partially on the surface of the rotating mechanism, and the carbon fibers are in static friction contact with the surface of the rotating mechanism.

6. The carbon fiber interfacial deposition of carbon nanotubes apparatus and method of claim 1, wherein, An electrochemical oxidation is further included, and the electrochemical oxidation is simultaneously or separately performed with the loading of the catalysts; the separate performance is that the carbon fibers are electrochemically oxidized before the loading of the catalysts, the treatment method is soaking in 2wt%-10wt% ammonium dihydrogen phosphate to electrochemically oxidize, the voltage is 5-20 V, and the current is 0.1-5 A; The simultaneous performance is that the loaded catalyst solution is mixed with an electrochemical oxidation solution.

7. The carbon fiber interfacial deposition carbon nanotube apparatus and method of claim 6, wherein, Before the electrochemical oxidation, the carbon fibers are preferably subjected to desizing treatment, and the desizing is performed in an oxygen-free environment at 200-500 DEG C for 1-3 h; After the loading of the catalysts, drying treatment is performed, and the desizing and drying are both preferably performed by heating the carbon fibers through heat radiation.

8. The carbon fiber interfacial deposition of carbon nanotubes apparatus and method of claim 1, wherein, The box module (30) further comprises a non-contact temperature measuring sensor (31), and the sensor is used for measuring the temperature of the environment near the carbon fibers in real time.

9. The carbon fiber interfacial deposition of carbon nanotubes apparatus and method of claim 1, wherein, The deposition module (20) is at least partially arranged in the box, and the solution in the deposition module is uniformly distributed on the surface of the carbon fibers through a spraying mode.

10. The carbon fiber interfacial deposition of carbon nanotubes apparatus and method of claim 1, wherein, The box module (30) further comprises a distribution plate (32) inside the box module (30), the distribution plate (32) being a plate-like structure with a surface of small holes, the distribution plate (32) being configured to change the gas flow distribution inside the box module (30).

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