Method and device for preparing single-walled carbon nanotubes based on the host-guest interaction of pillararenes with metallocenes

Abstract

The application discloses a method and device for preparing single-walled carbon nanotubes based on pillar arene and metallocene host-guest interaction. The method comprises: forming a host-guest complex by allowing a host compound and a guest compound to interact; the host compound comprises a pillar arene or a derivative thereof, and the guest compound comprises a metallocene complex or a derivative thereof; allowing a mixed reaction system comprising the host-guest complex and a polymerization inhibitor to react at high temperature to obtain nanoscale catalyst particles; and then allowing the nanoscale catalyst particles to contact with a carbon source, so that the carbon source is decomposed and grown on the surface of the nanoscale catalyst particles to obtain single-walled carbon nanotubes. The method is mainly based on the strong inclusion behavior of the host compound and the guest compound, and the compatibility of the host compound is utilized to effectively improve the solubility of the metallocene in an organic solvent, prolong the decomposition time of the metallocene at high temperature, realize in-situ controllable preparation of nanoscale catalyst particles, and further improve the yield and quality of the single-walled carbon nanotubes.

Description

Technical Field

[0001] This invention relates to a method for preparing carbon nanotubes, specifically a method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals, belonging to the field of carbon nanomaterial preparation. Background Technology

[0002] Carbon nanomaterials have attracted widespread attention from academia and industry due to their rich and unique physicochemical properties. Among the many carbon nanomaterials, carbon nanotubes (i.e., carbon nanotubes) have huge market application prospects due to their excellent electrical, mechanical, and thermal properties. The preparation technology of multi-walled carbon nanotubes is relatively mature, and market supply is gradually stabilizing. However, the low-cost, high-yield large-scale technology for single-walled carbon nanotubes remains a challenge for the industry. Compared to multi-walled carbon nanotubes, single-walled carbon nanotubes have better flexibility and conductivity. Correspondingly, the preparation of single-walled carbon nanotubes is more complex, specifically in the difficulty of simultaneously achieving high crystallinity and high yield. The key challenge lies in the difficulty of effectively controlling the catalyst.

[0003] In terms of preparation methods, the current preparation technologies for single-walled carbon nanotubes mainly include flotation CVD, electric arc method, laser ablation method, and high-pressure carbon monoxide method. The differences between different technical routes are mainly reflected in temperature control, catalyst preparation method, feeding and discharging. Among them, catalyst preparation is mainly affected by temperature and the properties of catalyst precursors. Taking flotation CVD as an example (Advanced Functional Materials, 2022, 32(11): 2108541.), the commonly used catalyst precursor is ferrocene. Since the solubility of ferrocene in different solvents varies greatly, there are fewer organic carbon sources to choose from. In addition, ferrocene will begin to decompose at lower temperatures, making the subsequent growth of the catalyst more uncontrollable, which in turn affects the quality or yield of carbon nanotubes, so that the production capacity of a single equipment remains at the gram level and cannot achieve large-scale preparation.

[0004] The main challenges in the large-scale preparation of single-walled carbon nanotubes using the flotation CVD method can be summarized as follows: (1) how to ensure the uniformity and stability of heat and mass transfer; (2) how to achieve precise release of catalyst precursors; and (3) how to achieve efficient conversion of carbon sources. The uniformity and stability of heat and mass transfer rely on equipment innovation, while the catalyst can be controlled by introducing key chemical control methods. How to control the catalyst precursor to achieve efficient preparation of single-walled carbon nanotubes has long been a focus of research in the industry. Summary of the Invention

[0005] The main objective of this invention is to provide a method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals, so as to solve the above-mentioned and other potential problems of the prior art.

[0006] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0007] This invention provides a method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals, comprising:

[0008] The host compound and the guest compound form a host-guest complex; the host compound includes columnar aromatics and / or columnar aromatic derivatives, and the guest compound includes metallocene complexes and / or metallocene derivatives.

[0009] The mixed reaction system containing the host-guest complex and the polymerization inhibitor is reacted at high temperature to obtain nanoscale catalyst particles.

[0010] The nanoscale catalyst particles are brought into contact with a carbon source, and the carbon source decomposes and grows on the surface of the nanocatalyst particles to obtain single-walled carbon nanotubes.

[0011] The present invention also provides single-walled carbon nanotubes prepared by the aforementioned method, wherein the purity of the single-walled carbon nanotubes is above 85% and the G / D ratio is greater than 35.

[0012] This invention also provides an apparatus for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals, applied in the aforementioned method, comprising:

[0013] The sampler unit is used at least to deliver a mixed reaction system containing a host-guest complex and a polymerization inhibitor, and a carbon source;

[0014] The furnace unit of the chemical vapor deposition apparatus has a reaction chamber for the growth of single-walled carbon nanotubes, and the reaction chamber is connected to the sampler unit;

[0015] The transition chamber unit is connected to the reaction chamber and is used at least to receive the single-walled carbon nanotubes generated by the reaction.

[0016] The receiving unit is connected to the transition chamber unit and is used to receive at least the single-walled carbon nanotubes output by the transition chamber unit.

[0017] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0018] (1) The method for preparing single-walled carbon nanotubes provided by the present invention adopts a host-guest chemistry strategy to introduce an adjustable phase-pillar aromatic hydrocarbon as the host molecule. Its cavity size and solubility properties can be controlled. It can form a good inclusion complex with cyclopentadienyl metal compounds, which can also improve the solubility of cyclopentadienyl metal compounds in organic carbon sources. Moreover, through the strong inclusion effect between the host and the guest, the decomposition behavior of the guest (cyclopentadienyl metal and its derivatives) is delayed, making the catalyst particles prepared in situ more uniform and increasing the effective volume concentration of the catalyst.

[0019] (2) Through the above regulation of catalyst particle preparation, this invention is conducive to promoting the decomposition and growth of carbon source on catalyst surface, thereby achieving efficient preparation of single-walled carbon nanotubes. The quality and yield of single-walled carbon nanotubes are significantly improved compared with those before the addition of host molecules, and it has important market prospects in the high-quality continuous preparation of single-walled carbon nanotubes. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a host-guest complex formed by the host compound and the guest compound in a typical embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of an apparatus for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatic hydrocarbons and cyclopentadienyl metals in a typical embodiment of the present invention.

[0023] Figure 3 These are the NMR contrast spectra of the host compound, the guest compound, and the host-guest complex in Example 1 of this invention;

[0024] Figure 4 This is a scanning electron microscope image of the single-walled carbon nanotube product in Example 1 of the present invention;

[0025] Figure 5 This is a transmission electron microscope image of the single-walled carbon nanotube product in Example 1 of the present invention;

[0026] Figure 6 This is a Raman spectroscopy result of the single-walled carbon nanotube product in Example 1 of the present invention;

[0027] Figure 7 This is a thermogravimetric analysis (TGA) result of the single-walled carbon nanotube product in Example 1 of the present invention.

[0028] Reference numerals: 1-Injector unit, 2-CVD furnace unit, 3-Reaction chamber, 4-Transition chamber unit, 5-Gas vent, 6-Control valve unit, 7-Receiving unit. Detailed Implementation

[0029] To address the problems existing in the prior art, the inventors of this case explored the regulation of catalysts by introducing key chemical control methods. For example, by assembling catalyst precursors with macrocyclic host molecules in a host-guest manner, host-guest complexes with unique physicochemical properties can be formed. Currently, there are no reports on the application of the host-guest interaction between columnar aromatics and metallocene complexes in the preparation of carbon nanotubes.

[0030] The following will further explain the technical solution, its implementation process, and its principles. However, it should be understood that within the scope of this invention, the above-mentioned technical features of this invention and the technical features specifically described below (in embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here.

[0031] As one aspect of the technical solution of this invention, a method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals includes:

[0032] The host compound and the guest compound form a host-guest complex; the host compound includes columnar aromatics and / or columnar aromatic derivatives, and the guest compound includes metallocene complexes and / or metallocene derivatives.

[0033] The mixed reaction system containing the host-guest complex and the polymerization inhibitor is reacted at high temperature to obtain nanoscale catalyst particles.

[0034] The nanoscale catalyst particles are brought into contact with a carbon source, and the carbon source decomposes and grows on the surface of the nanocatalyst particles to obtain single-walled carbon nanotubes.

[0035] In some implementation schemes, such as Figure 1As shown, the host-guest complex is assembled from a host compound and a guest compound in a molar ratio of 1:1 to 2. This invention employs a host-guest chemistry strategy to introduce a tunable phase—a columnar aromatic hydrocarbon—as the host molecule. Its cavity size and solubility properties are controllable, allowing it to form a well-inclusion complex with the metallocene compound, thereby increasing the solubility of the metallocene compound in organic carbon sources. This invention, through the strong inclusion interaction between the host and guest, delays the decomposition behavior of the guest (metallocene and its derivatives), resulting in more uniform catalyst particles prepared in situ. If the molar ratio of the host compound to the guest compound exceeds this range, such as an excess of the host compound, the free columnar aromatic hydrocarbon will increase costs; if an excess of the guest compound, the metallocene will become free, thus failing to exert the sustained-release effect of the host-guest inclusion complex.

[0036] In some embodiments, the structural formula of the columnar aromatic hydrocarbon is:

[0037]

[0038] Where n is 5 to 10 (e.g., 5, 6, 7, 8, 9, 10, etc.), and R includes -(CH2). m Any one of -CH3, -OH, -NH2, -SH, -COOH, -COOCH3, etc., where m is 1 to 5.

[0039] In some more preferred embodiments, Figure 1 The column[n]aromatic hydrocarbons shown can be P[5]A, P[6]A, P[7]A, P[8]A, P[9]A, P

[10] A, etc., and more preferably ethoxy-substituted column[6]aromatic hydrocarbons, hydroxy-substituted column[7]aromatic hydrocarbons, aminoethoxy-substituted column

[10] aromatic hydrocarbons, hydroxyethyl-substituted column[6]aromatic hydrocarbons, etc., but are not limited to these.

[0040] In some implementation schemes, such as Figure 1 As shown, the cyclopentadienyl metal complex may include one or more combinations of ferrocene, cobalt dicene, nickel dicene, etc., more preferably carboxylated ferrocene, hydroxyethyl cobalt dicene, mercapto nickel dicene, etc., but is not limited thereto.

[0041] In some embodiments, the polymerization inhibitor may include one or more of dimethyl sulfoxide, thiourea, thiophene, sulfur, sodium sulfate, sodium sulfide, iron sulfide, etc., but is not limited thereto.

[0042] In some embodiments, the molar ratio of the guest compound to the polymerization inhibitor is 1:0.001 to 1000.

[0043] In some embodiments, the preparation method specifically includes:

[0044] The host-guest complex is dispersed in a solvent, and then a polymerization inhibitor is added to form the mixed reaction system.

[0045] Under the protection of an inert gas, the mixed reaction system is transported to the reaction chamber of a chemical vapor deposition device and reacted at a high temperature. The host-guest complex dissociates and releases the guest compound, which is further pyrolyzed and re-nucleated to obtain nanoscale catalyst particles.

[0046] A carbon source is introduced into the reaction chamber, which then comes into contact with nanoscale catalyst particles, and the carbon source decomposes and grows on the surface of the nanoscale catalyst particles to obtain single-walled carbon nanotubes.

[0047] Furthermore, the solvent may include any one or more combinations of water, methanol, ethanol, isopropanol, acetonitrile, diethyl ether, dichloromethane, chloroform, acetone, toluene, xylene, cyclohexane, dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), etc., but is not limited thereto.

[0048] In some preferred embodiments, the mixed reaction system is delivered into the reaction chamber at a rate of 0.1 to 100 g / min.

[0049] In some preferred embodiments, the set temperature within the reaction chamber is 800–1600°C. Temperatures that are too high or too low will affect the formation and quality of carbon nanotubes. For example, when the temperature is below 800°C, the catalyst cannot effectively decompose into nuclei, and the carbon source cannot decompose into carbon atoms, resulting in the inability to grow carbon nanotubes. Conversely, when the temperature is above 1600°C, the catalyst cannot effectively condense into nuclei, affecting subsequent catalytic effects, and single-walled nanotubes will undergo structural reorganization at high temperatures, affecting crystallinity.

[0050] In some preferred embodiments, the inert gas may include one or more combinations of argon, helium, nitrogen, etc., but is not limited thereto.

[0051] In some preferred embodiments, the particle size of the nanoscale catalyst particles is 1–10 nm.

[0052] In some preferred embodiments, the carbon source includes one or more combinations of methane, ethane, propane, ethylene, propylene, carbon monoxide, carbon dioxide, etc., but is not limited thereto.

[0053] In some preferred embodiments, the molar ratio of the guest compound to the carbon source is 0.00001 to 0.01:1.

[0054] In some preferred embodiments, the preparation method further includes: before conveying the mixed reaction system to the reaction chamber, first removing the air from the reaction chamber and introducing an inert gas, setting the temperature inside the reaction chamber and heating it to the set value.

[0055] In some preferred embodiments, the preparation method further includes: conveying the obtained single-walled carbon nanotubes to a transition chamber unit. The purpose of the transition chamber unit in this invention is to facilitate the removal of combustible gases from the reaction products, and to allow the carbon nanotube products to accumulate for a period of time before safely collecting them in a receiving hopper.

[0056] Furthermore, the preparation method also specifically includes: conveying the single-walled carbon nanotubes in the transition chamber unit to the receiving unit.

[0057] Furthermore, the transition chamber unit needs to be connected to an external gas vent, and the gas vent needs to be further connected to an external exhaust gas treatment device.

[0058] Furthermore, the receiving unit needs to be connected to an external gas inlet and outlet, and the gas involved in the inlet and outlet is at least one of air, nitrogen, argon, and helium.

[0059] In some implementation schemes, the yield of single-walled carbon nanotubes prepared by the method of the present invention is 0.1 to 1 kg / day, which can achieve continuous batch processing and has important commercial application value.

[0060] The method for preparing single-walled carbon nanotubes based on the host-guest interaction of columnar aromatics and cyclopentadienyl metals of the present invention is mainly as follows: the first step is to form a host-guest complex of columnar aromatics and cyclopentadienyl metals in a solvent; the second step is to release and further decompose the cyclopentadienyl metal in the host-guest complex at high temperature to form an atomic-scale catalyst precursor, and further grow it to the nanoscale size; the third step is to introduce a polymerization inhibitor to prevent further aggregation of catalyst particles; the fourth step is to contact the nanoscale catalyst particles with a carbon source and grow single-walled carbon nanotubes on the surface of the nanoscale catalyst particles.

[0061] In some preferred embodiments, a method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals specifically includes the following steps:

[0062] a. Remove the air from the reaction system and introduce an inert gas to protect the chamber. Set the reaction chamber temperature and heat it to the set value.

[0063] b. Using the sample introduction unit, an organic phase system containing host-guest complex and polymerization inhibitor is delivered to the reaction chamber, where the release, decomposition and further growth of the metallocene to the nanoscale are completed at high temperature. Under the action of the polymerization inhibitor, the catalyst particles are maintained at the nanoscale.

[0064] c. Nanoscale catalyst particles react with carbon source to generate single-walled carbon nanotubes, which are then carried into the transition chamber unit by the downward airflow. When the material in the transition chamber unit accumulates to a certain amount, the baffle valve is opened, allowing the single-walled carbon nanotube material to enter the receiving unit. After gas replacement and cooling are completed, the product can be taken out.

[0065] This invention employs the above-mentioned method for preparing single-walled carbon nanotubes based on host-guest interactions. By pre-forming a host-guest complex with the macrocyclic host compound, columnar aromatics, the disordered decomposition behavior of the catalyst precursor is contained, achieving the following objectives: (1) By adjusting the amphiphilicity of the host columnar aromatic molecules, the solubility of the catalyst precursor in organic carbon sources is increased; (2) The decomposition process of ferrocene is delayed, enabling the catalyst to narrow its temperature range from a broad spectrum, resulting in a narrower particle size distribution of the prepared catalyst. The achievement of these two objectives further facilitates the decomposition and growth of carbon sources, thereby achieving the goal of efficient preparation of single-walled carbon nanotubes.

[0066] As another aspect of the technical solution of the present invention, it also relates to single-walled carbon nanotubes prepared by the aforementioned method, wherein the purity of the single-walled carbon nanotubes can reach more than 85% and the G / D ratio is greater than 35.

[0067] As another aspect of the technical solution of the present invention, it also relates to an apparatus for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals, applied in the aforementioned method, the apparatus comprising:

[0068] The sampler unit is used at least to deliver a mixed reaction system containing a host-guest complex and a polymerization inhibitor, and a carbon source;

[0069] The furnace unit of the chemical vapor deposition apparatus has a reaction chamber for the growth of single-walled carbon nanotubes, and the reaction chamber is connected to the sampler unit;

[0070] The transition chamber unit is connected to the reaction chamber and is used at least to receive the single-walled carbon nanotubes generated by the reaction.

[0071] The receiving unit is connected to the transition chamber unit and is used to receive at least the single-walled carbon nanotubes output by the transition chamber unit.

[0072] In some implementations, the transition chamber unit is provided with an external gas vent, which needs to be further connected to an external exhaust gas treatment device.

[0073] In some implementations, a control valve unit is provided between the transition chamber unit and the receiving unit. When the material in the transition chamber unit accumulates to a certain amount, the control valve unit is opened, allowing the single-walled carbon nanotube material to enter the receiving unit.

[0074] like Figure 2As shown, an apparatus for preparing single-walled carbon nanotubes based on the host-guest interaction of columnar aromatics and cyclopentadienyl metals includes an injection unit 1, a CVD furnace unit 2 (i.e., the furnace unit of a chemical vapor deposition equipment), a reaction chamber 3 (i.e., a carbon nanotube growth chamber), a transition chamber unit 4, a gas vent 5, a control valve unit 6 (i.e., a control valve), and a receiving unit 7 (i.e., a receiving bin).

[0075] The methods for preparing single-walled carbon nanotubes using this device include:

[0076] The host-guest complex, formed by the host compound (such as columnar aromatics) and the guest compound (such as metallocene complexes), is pre-dispersed in a solvent and enters the carbon nanotube growth chamber, which has been preheated to a specified temperature, through the sampler unit. Under high temperature, the host-guest complex dissociates, releasing the metallocene guest, which further pyrolyzes and re-nucleates into nanoparticles with a size of less than 10 nm. Subsequently, the carbon source contacts the nanoscale catalyst particles through the sampler unit, completing decomposition and growth on their surface until single-walled carbon nanotubes are formed. After the single-walled carbon nanotubes are formed, they enter the transition chamber unit with the downward airflow, and the waste gas is transported to the external tail gas treatment device for treatment through the gas vent. After the product is cooled to a certain temperature, it finally enters the receiving unit through the control valve unit.

[0077] In summary, this invention is primarily based on the strong inclusion behavior between the host compound (pillar aromatics and their derivatives) and the guest compound (metallocenes and their derivatives). Utilizing the compatibility of the host compound, it effectively enhances the solubility of metallocenes in organic solvents and prolongs their decomposition time at high temperatures, achieving controllable preparation of nanoscale catalyst particles and thereby improving the yield and quality of single-walled carbon nanotubes. This invention achieves in-situ controllable preparation of nanoscale catalyst particles by regulating the host-guest interaction behavior and reaction process parameters, resulting in a significant improvement in the quality and yield of single-walled carbon nanotubes compared to before the addition of the host molecule. It holds significant market potential for the high-quality continuous preparation of single-walled carbon nanotubes.

[0078] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. It should be noted that the following embodiments are intended to facilitate understanding of this invention and do not constitute any limitation thereof. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the manufacturer.

[0079] Example 1

[0080] A method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals includes the following steps:

[0081] Step 1: Prepare a host-guest inclusion complex of ethoxylated fully substituted aromatic hydrocarbon and carboxylated ferrocene with a molar concentration of approximately 0.1 mol / L in the solvent chloroform. The stoichiometric ratio of the two compounds is approximately 1:1. After stirring at room temperature for about 0.5 hours and standing for about 1 hour, the NMR contrast spectra of the host compound, the guest compound, and the host-guest complex are shown below. Figure 3 As shown in the figure. Then, the polymerization inhibitor thiophene was added to a concentration of approximately 0.01 mol / L, and the mixture was left to stand for later use.

[0082] Step 2: Purge the gas from the reaction system and fill it with argon. Start the heating program of the CVD furnace unit and set the temperature to 1100℃.

[0083] Step 3: After the set temperature is reached, the mixed solution prepared in Step 1 (approximately 15 g / min), argon (approximately 20 L / min), and methane (approximately 100 mL / min) are introduced through the sampler unit. The molar ratio of carboxylated ferrocene to methane is 0.00024:1. Subsequently, the catalyst growth, carbon source pyrolysis, and single-walled carbon nanotube generation are completed in the CVD furnace.

[0084] Step 4: The product then enters the transition chamber unit with the downward airflow, and the gas is discharged after passing through the exhaust gas treatment device. After the material cools to 100°C, it enters the receiving unit through the control valve unit for further cooling.

[0085] After the reaction was completed, an appropriate amount of sample was taken for characterization. The microstructure, size, crystallinity, and carbon content of the single-walled carbon nanotubes were determined by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and thermogravimetric analysis, respectively. For specific characterization methods, please refer to GB / T 32869-2016, GB / T 30534-2014, GB / T 32871-2016, and GB / T 24490-2009.

[0086] The characterization results of the single-walled carbon nanotube products prepared in this embodiment, including scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and thermogravimetric analysis, are as follows: Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown. Thermogravimetric characterization results indicate that the prepared single-walled carbon nanotube primary product has a carbon content of approximately 95 wt%. In the Raman spectrum ( Figure 6 ), respectively at 1570cm- 1 1350em- 1The 0-200 cm⁻¹ band shows a sharp graphite peak (G band), an unusually small disorder peak (D band), and a highly pronounced radial breathing pattern characteristic peak (RBM). The G / D ratio is 55, indicating high crystallinity of the carbon nanotubes. In the transmission electron microscopy characterization results (… Figure 5 As can be seen, the size of the nano-scale catalyst particles is relatively uniform.

[0087] Example 2

[0088] A method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals includes the following steps:

[0089] Step 1: Prepare a host-guest inclusion complex of a fully substituted hydroxyl column[7] aromatic hydrocarbon and hydroxyethyl cobalt 1, with a molar concentration of about 0.1 mol / L in the solvent acetonitrile. The stoichiometric ratio of the two is about 1:1. Stir at room temperature for about 0.5 hours and let stand for about 1 hour. Then add the polymerization inhibitor thiourea to make its concentration about 0.01 mol / L and let it stand for later use.

[0090] Step 2: Purge the gas from the reaction system and fill it with nitrogen. Start the heating program of the CVD furnace unit and set the temperature to 1500℃.

[0091] Step 3: After the set temperature is reached, the mixed solution prepared in Step 1 (approximately 7.8 g / min), nitrogen (approximately 15 L / min), and ethane (approximately 10 mL / min) are introduced through the sampler unit. The molar ratio of hydroxyethyl cobaltene to ethane is 0.0025:1. Subsequently, the catalyst growth, carbon source pyrolysis, and single-walled carbon nanotube generation are completed in the CVD furnace.

[0092] Step 4: The product then enters the transition chamber unit with the downward airflow, and the gas is discharged after passing through the tail gas treatment unit. After the material cools to 100°C, it enters the receiving unit through the control valve unit for further cooling.

[0093] Example 3

[0094] A method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals includes the following steps:

[0095] Step 1: Prepare a host-guest inclusion complex of aminoethoxy-substituted column

[10] aromatics and mercaptodicyclopentadiene in a mixed solvent of chloroform / ethanol (volume ratio of approximately 1:1) with a molar concentration of approximately 0.05 mol / L (actual molar concentration of mercaptodicyclopentadiene is approximately 0.1 mol / L). The stoichiometric ratio of the two is approximately 1:2. After stirring at room temperature for about 0.5 hours, let stand for about 1 hour, and then add the polymerization inhibitor dimethyl sulfoxide to make its concentration approximately 0.008 mol / L. Let stand for later use.

[0096] Step 2: Purge the gas from the reaction system and fill it with argon. Start the heating program of the CVD furnace unit and set the temperature to 1300℃.

[0097] Step 3: After the set temperature is reached, the mixed solution prepared in Step 1 (approximately 11.5 g / min), argon (approximately 2 L / min), and ethylene (approximately 20 mL / min) are introduced through the sampler unit. The molar ratio of mercaptodiene nickel to ethylene is 0.00125:1. Subsequently, the catalyst growth, carbon source pyrolysis, and single-walled carbon nanotube generation are completed in the CVD furnace.

[0098] Step 4: The product then enters the transition chamber unit with the downward airflow, and the gas is discharged after passing through the tail gas treatment unit. After the material cools to 100°C, it enters the receiving unit through the control valve unit for further cooling.

[0099] Example 4

[0100] A method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals includes the following steps:

[0101] Step 1: Prepare a host-guest complex of hydroxyethyl fully substituted columnar aromatic hydrocarbons [6] with ferrocene and cobalt stoichiometry in a mixed solvent of toluene / ethanol (volume ratio 1:1) with a molar concentration of about 0.02 mol / L. The stoichiometric ratio of the three is about 1:0.5:0.5. Stir at room temperature for about 0.5 hours and let stand for about 1 hour. Then add the polymerization inhibitor thiourea to make its concentration about 0.01 mol / L and let stand for later use.

[0102] Step 2: Purge the gas from the reaction system and fill it with argon. Start the heating program of the CVD furnace unit and set the temperature to 1200℃.

[0103] Step 3: After the set temperature is reached, the mixed solution prepared in Step 1 (approximately 6.7 g / min), argon (approximately 200 L / min), and propylene (approximately 50 mL / min) are introduced through the sampler unit. The molar ratio of ferrocene, cobalt dicene, and propylene is 0.00008:1. Subsequently, the catalyst growth, carbon source pyrolysis, and single-walled carbon nanotube generation are completed in the CVD furnace.

[0104] Step 4: The product then enters the transition chamber unit with the downward airflow, and the gas is discharged after passing through the tail gas treatment unit. After the material cools to 100°C, it enters the receiving unit through the control valve unit for further cooling.

[0105] Example 5

[0106] A method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals includes the following steps:

[0107] Step 1: Prepare a host-guest complex of hydroxyl-substituted columnar aromatic hydrocarbons and cobalt dicene and nickel dicene with a molar concentration of about 1 mol / L in the solvent acetonitrile. The stoichiometric ratio of the two is about 1:0.5:0.5. After stirring at room temperature for about 0.5 hours, let stand for about 1 hour, and then add the polymerization inhibitor thiophene to make its concentration about 0.001 mol / L. Let it stand for later use.

[0108] Step 2: Purge the gas from the reaction system and fill it with nitrogen. Start the heating program of the CVD furnace unit and set the temperature to 800℃.

[0109] Step 3: After the set temperature is reached, the mixed solution prepared in Step 1 (approximately 16 g / min), nitrogen (approximately 15 L / min), and ethane (approximately 5 mL / min) are introduced through the sampler unit. The molar ratio of cobalt dicene, nickel dicene, and ethane is 0.01:1. Subsequently, the catalyst growth, carbon source pyrolysis, and single-walled carbon nanotube generation are completed in the CVD furnace.

[0110] Step 4: The product then enters the transition chamber unit with the downward airflow, and the gas is discharged after passing through the tail gas treatment unit. After the material cools to 100°C, it enters the receiving unit through the control valve unit for further cooling.

[0111] Example 6

[0112] A method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals includes the following steps:

[0113] Step 1: Prepare a host-guest complex of a fully substituted carboxyl group[7] aromatic hydrocarbon with a molar concentration of approximately 0.001 mol / L and ferrocene and nickel stoichiometry in acetonitrile solvent, with a stoichiometric ratio of approximately 1:0.5:0.5. Stir at room temperature for about 0.5 hours and let stand for about 1 hour. In addition, prepare a 1 mol / L sodium sulfide aqueous solution and let it stand for later use.

[0114] Step 2: Purge the gas from the reaction system and fill it with nitrogen. Start the heating program of the CVD furnace unit and set the temperature to 1600℃.

[0115] Step 3: After the set temperature is reached, the acetonitrile solution (approximately 0.8 g / min), sodium sulfide aqueous solution (approximately 1 mL / min), nitrogen gas (approximately 10 L / min), and carbon monoxide (approximately 2 mL / min) prepared in Step 1 are introduced through the sampler unit. The molar ratio of ferrocene, nickel dicene, and carbon monoxide is 0.00001:1. Subsequently, the catalyst growth, carbon source pyrolysis, and single-walled carbon nanotube generation are completed in the CVD furnace.

[0116] Step 4: The product then enters the transition chamber unit with the downward airflow, and the gas is discharged after passing through the tail gas treatment unit. After the material cools to 100°C, it enters the receiving unit through the control valve unit for further cooling.

[0117] Comparative Example 1

[0118] The difference between this comparative example and Example 1 is that carboxylated ferrocene was not added in step 1.

[0119] Then, single-walled carbon nanotubes cannot be generated, and the products formed are mainly amorphous carbon.

[0120] Comparative Example 2

[0121] The difference between this comparative example and Example 1 is that no ethoxylated fully substituted columnar aromatic hydrocarbons were added in step 1.[6]

[0122] The purity of the prepared single-walled carbon nanotubes is 45%, and the G / D ratio is 10.

[0123] Comparative Example 3

[0124] The difference between this comparative example and Example 1 is that: in step 1, no ethoxylated fully substituted columnar aromatic hydrocarbons [6] were added and the molar ratio of carboxylated ferrocene was 2:1.

[0125] The purity of the prepared single-walled carbon nanotubes is 89%, and the G / D ratio is 35.

[0126] Comparative Example 4

[0127] The difference between this comparative example and Example 1 is that: in step 1, no ethoxylated fully substituted columnar aromatic hydrocarbons [6] were added and the molar ratio of carboxylated ferrocene was 1:3.

[0128] The purity of the prepared single-walled carbon nanotubes is 55%, and the G / D ratio is 20.

[0129] Comparative Example 5

[0130] The difference between this comparative example and Example 1 is that the polymerization inhibitor thiophene was not added in step 1.

[0131] The purity of the prepared single-walled carbon nanotubes is 36%, and the G / D ratio is 6.

[0132] Comparative Example 6

[0133] The difference between this comparative example and Example 1 is that the temperature in step 2 is set to 600°C.

[0134] The formation of single-walled carbon nanotube products cannot be observed.

[0135] Comparative Example 7

[0136] The difference between this comparative example and Example 1 is that the temperature in step 2 is set to 1800°C.

[0137] The purity of the prepared single-walled carbon nanotubes is 80%, and the G / D ratio is 10.

[0138] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0139] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing single-walled carbon nanotubes based on the host-guest interaction between columnar aromatics and cyclopentadienyl metals, characterized in that, include: To enable the host compound and the guest compound to form a host-guest complex; The host compound includes columnar aromatics and / or columnar aromatic derivatives, the guest compound includes metallocene complexes and / or metallocene derivatives, and the molar ratio of the host compound to the guest compound is 1:1~2; The host-guest complex is dispersed in a solvent, and then a polymerization inhibitor is added to form a mixed reaction system; Under the protection of an inert gas, the mixed reaction system is transported to the reaction chamber of a chemical vapor deposition device and reacted at a high temperature. The host-guest complex dissociates and releases the guest compound, which is further pyrolyzed and re-nucleated to obtain nanoscale catalyst particles. The set temperature in the reaction chamber is 800~1600℃. A carbon source is introduced into the reaction chamber, which then comes into contact with nanoscale catalyst particles, and the carbon source decomposes and grows on the surface of the nanoscale catalyst particles to obtain single-walled carbon nanotubes.

2. The method according to claim 1, characterized in that, The structural formula of the columnar aromatic hydrocarbon is: ； Where n is 5~10, and R includes -(CH2). m Any one of -CH3, -OH, -NH2, -SH, -COOH, -COOCH3, where m is 1 to 5.

3. The method according to claim 1, characterized in that: The cyclopentadiene metal complex includes one or more combinations of ferrocene, cobalt dicene, and nickel dicene.

4. The method according to claim 1, characterized in that: The polymerization inhibitor includes one or more of the following: dimethyl sulfoxide, thiourea, thiophene, sulfur, sodium sulfate, sodium sulfide, and iron sulfide.

5. The method according to claim 1, characterized in that: The molar ratio of the guest compound to the polymerization inhibitor is 1:0.001~1000.

6. The method according to claim 1, characterized in that: The solvent includes one or more of the following: water, methanol, ethanol, isopropanol, acetonitrile, diethyl ether, dichloromethane, chloroform, acetone, toluene, xylene, cyclohexane, dimethyl sulfoxide, and N,N-dimethylformamide.

7. The method according to claim 1, characterized in that: The mixed reaction system is delivered into the reaction chamber at a rate of 0.1~100 g / min.

8. The method according to claim 1, characterized in that: The inert gas includes one or more combinations of argon, helium, and nitrogen.

9. The method according to claim 1, characterized in that: The nanoscale catalyst particles have a particle size of 1~10 nm.

10. The method according to claim 1, characterized in that: The carbon source includes one or more combinations of methane, ethane, propane, ethylene, propylene, carbon monoxide, and carbon dioxide.

11. The method according to claim 1, characterized in that: The molar ratio of the guest compound to the carbon source is 0.00001 to 0.01:

1.

12. The method according to claim 1, characterized in that, Also includes: Before the mixed reaction system is delivered to the reaction chamber, the air in the reaction chamber is removed and an inert gas is introduced. The temperature inside the reaction chamber is then set and heated to the set value.

13. The method according to claim 1, characterized in that, The method further includes: conveying the prepared single-walled carbon nanotubes to the transition chamber unit.

14. The method according to claim 13, characterized in that, The method further includes: conveying the single-walled carbon nanotubes in the transition chamber unit to the receiving unit.

15. The method according to claim 1, characterized in that, The method described yields 0.1-1 kg / day of single-walled carbon nanotubes.

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