Method and system for preparing horizontal array carbon nanotubes from light petroleum

Abstract

The invention belongs to the field of nano materials, and relates to a method and a system for preparing horizontal array carbon nanotubes from light petroleum. According to the method, C13-C22 polycyclic alkane and / or C13-C22 polycyclic aromatic hydrocarbon are / is used as a carbon source, and the horizontal array carbon nanotubes are prepared by using a chemical vapor deposition method. The raw materials are cheap and easy to obtain, and the process temperature is low, so that compared with a traditional preparation process taking methane as a carbon source, the method has the advantage that the cost of the array carbon nanotube can be greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials, specifically relating to a method and system for preparing horizontally arrayed carbon nanotubes from lightweight petroleum. Background Technology

[0002] Carbon nanotubes as sp 2 One-dimensional linear carbon nanomaterials, composed of hybrid carbon arranged in a spatially regular pattern, possess excellent mechanical, thermal, electrical, and chemical stability, and have wide applications in numerous fields. Arrayed carbon nanotubes, with their oriented arrangement and perfect structure, exhibit physicochemical properties closer to their intrinsic characteristics. They have extremely high application value in areas such as mechanical reinforcement.

[0003] The main method for preparing arrayed carbon nanotubes employs chemical vapor deposition (CVD), using methane as the carbon source and a catalyst to grow carbon nanotubes on a substrate under high-temperature conditions. This method involves high reaction temperatures and high energy consumption; the preparation efficiency of carbon nanotubes is low, and the cost is high, severely hindering their large-scale, mass production. Summary of the Invention

[0004] This invention proposes a method and system for preparing arrayed carbon nanotubes using polycyclic hydrocarbons, enabling the preparation of arrayed carbon nanotubes at low temperatures. Due to the inexpensive and readily available raw materials and the low process temperature, this method can significantly reduce costs.

[0005] The first aspect of the present invention provides a method for preparing horizontally arrayed carbon nanotubes from light petroleum, using C 13 -C 22 Polycyclic alkanes and / or C 13 -C 22 The horizontal array of carbon nanotubes was prepared using polycyclic aromatic hydrocarbons as a carbon source and chemical vapor deposition.

[0006] A second aspect of the present invention provides a system for preparing horizontally arrayed carbon nanotubes from light petroleum, for performing the above-described method, the system comprising a raw material preheating furnace, a horizontal reactor, and an inert carrier gas feed line;

[0007] The inert carrier gas feed line is divided into two branches, one of which is connected to the horizontal reactor and the other is connected to the raw material preheating furnace.

[0008] The raw material preheating furnace is equipped with a discharge pipeline, which is divided into two branches. One branch is connected to the horizontal reactor, and the other branch is connected to the outside of the system.

[0009] A third aspect of the present invention provides a method for preparing horizontally arrayed carbon nanotubes using the above-described system, comprising the following steps:

[0010] (1) Place the reaction substrate in a horizontal reaction furnace;

[0011] (2) Inert carrier gas enters the raw material preheating furnace and the horizontal reactor through the inert carrier gas feed pipeline to replace the air in the reaction system;

[0012] (3) Under the condition of introducing inert carrier gas, the horizontal reactor and the raw material preheating furnace are heated to the predetermined temperature respectively;

[0013] (4) An inert carrier gas flows through the raw material preheating furnace, and the gasified carbon source and catalyst are carried into the horizontal reaction furnace through the discharge pipeline. Under the action of the catalyst, horizontal array carbon nanotubes are prepared.

[0014] This invention proposes a method utilizing C 13 -C 22 A method for preparing arrayed carbon nanotubes using polycyclic alkanes and polycyclic aromatic hydrocarbons as carbon sources. Due to the inexpensive and readily available raw materials and the low process temperature, this method can significantly reduce the cost of arrayed carbon nanotubes compared to the traditional method using methane as a carbon source.

[0015] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] Exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0017] Figure 1 A system for preparing horizontally arrayed carbon nanotubes from light petroleum is shown in one embodiment of the present invention.

[0018] Figure 2 An electron microscope image of a horizontally arrayed carbon nanotube obtained according to a specific embodiment of the present invention is shown. Detailed Implementation

[0019] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0020] This invention provides a method for preparing horizontally arrayed carbon nanotubes from light petroleum, using C 13 -C 22 Polycyclic alkanes and / or C 13 -C 22 The horizontal array of carbon nanotubes was prepared using polycyclic aromatic hydrocarbons as a carbon source and chemical vapor deposition.

[0021] The term "polycyclic alkane" is known to those skilled in the art and refers to a hydrocarbon containing two or more alkyl ring structures. This invention does not impose any particular limitation on the number of rings or the number of carbons in each ring of the polycyclic alkane, as long as the total number of carbons is 13-22.

[0022] The term "polycyclic aromatic hydrocarbon" is known to those skilled in the art and refers to a hydrocarbon containing two or more aromatic ring structures. This invention does not impose any particular limitation on the number of rings or the number of carbons in each ring of the polycyclic aromatic hydrocarbon, as long as the total number of carbons is 13-22.

[0023] The carbon source of this invention can be a single-component C. 13 -C 22 Polycyclic alkanes and C 13 -C 22 One of the polycyclic aromatic hydrocarbons, which can also be C 13 -C 22 Polycyclic alkanes and C 13 -C 22 A mixture of various polycyclic aromatic hydrocarbons.

[0024] The carbon source described above can be commercially available or can be a component from an industrial reaction that meets the above composition.

[0025] According to a specific embodiment of the present invention, the method includes the following steps:

[0026] Under the protection of an inert carrier gas and in the presence of a catalyst, a preheated carbon source enters a horizontal reactor containing a substrate for chemical vapor deposition to obtain the horizontal array of carbon nanotubes.

[0027] The chemical vapor deposition of the present invention can be performed at a lower temperature and conventional pressure. Preferably, the chemical vapor deposition conditions include: a temperature of 600-900°C, more preferably 650-850°C, a pressure of atmospheric pressure, and a time of 0.3-12 hours, more preferably 0.5-10 hours.

[0028] According to the present invention, the purpose of preheating is to achieve gas-liquid equilibrium of the liquid carbon source at a certain temperature, so that the gas phase composition meets the carbon source feed requirements. Preferably, the preheating is carried out in a raw material preheating furnace, and the temperature of the raw material preheating furnace is 70-200°C, more preferably 80-150°C.

[0029] The present invention uses a chemical vapor deposition method to prepare horizontal array carbon nanotubes, which requires the use of a catalyst. The catalyst is preferably ferrocene. A more preferred method is to dissolve the catalyst in a carbon source, and the concentration of the dissolution can be 0.001 mol / L-1 mol / L.

[0030] According to the present invention, the inert carrier gas can be an inert gas conventionally used in chemical vapor deposition methods, preferably one of nitrogen and argon or a mixture of the two in any ratio.

[0031] According to the present invention, the substrate may be a silicon substrate, a silicon oxide substrate, or a silicon / silicon oxide substrate.

[0032] According to a preferred embodiment of the present invention, the horizontal array carbon nanotubes obtained by the above method of the present invention are ultra-long carbon nanotubes with a length of 10 to 1000 mm.

[0033] The present invention also provides a system for preparing horizontally arrayed carbon nanotubes from light petroleum, for performing the above-described method, the system comprising a raw material preheating furnace, a horizontal reactor, and an inert carrier gas feed line;

[0034] The inert carrier gas feed line is divided into two branches, one of which is connected to the horizontal reactor and the other is connected to the raw material preheating furnace.

[0035] The raw material preheating furnace is equipped with a discharge pipeline, which is divided into two branches. One branch is connected to the horizontal reactor, and the other branch is connected to the outside of the system.

[0036] The raw material preheating furnace is also equipped with a raw material carbon source inlet for injecting raw material carbon source into it.

[0037] To achieve better control, valves are installed on each branch of the inert carrier gas feed line and each branch of the raw material preheating furnace discharge line.

[0038] According to the present invention, a substrate is provided inside the horizontal reactor; the substrate is preferably a silicon substrate, a silicon oxide substrate, or a silicon / silicon oxide substrate.

[0039] This invention provides a method for preparing horizontally arrayed carbon nanotubes using the above-described system, comprising the following steps:

[0040] (1) Place the reaction substrate in the horizontal reaction furnace, connect the pipeline, and check the airtightness;

[0041] (2) Inert carrier gas enters the raw material preheating furnace and the horizontal reactor through the inert carrier gas feed pipeline to replace the air in the reaction system; specifically, such as Figure 1 As shown, one carrier gas enters the horizontal reactor b through pipeline 1 and pipeline 5, and another carrier gas enters the raw material preheating furnace a through pipeline 2, and then enters the horizontal reactor b through pipeline 3 and pipeline 5. Finally, both are discharged from pipeline 6, realizing air replacement in the reaction system.

[0042] (3) Under the condition of introducing inert carrier gas, the horizontal reactor and the raw material preheating furnace are heated to the predetermined temperature respectively;

[0043] (4) An inert carrier gas flows through the raw material preheating furnace, and the gasified carbon source and catalyst are carried into the horizontal reaction furnace through the discharge pipeline. Under the action of the catalyst, horizontal array carbon nanotubes are prepared.

[0044] In one specific embodiment, the preparation method further includes:

[0045] (5) After the reaction has proceeded for a certain period of time, the horizontal reactor and the raw material preheating furnace are cooled to room temperature respectively;

[0046] (6) Close all gas lines and the reaction ends.

[0047] According to the method of the present invention, the inert carrier gas can be regulated by a valve to enter any one branch or simultaneously enter two branches, and the flow distribution ratio between the two branches is usually controlled to be 10:1 to 1:10.

[0048] According to the method of the present invention, the predetermined temperature of the horizontal reactor is the reaction temperature of chemical vapor deposition, preferably 600-900°C, more preferably 650-850°C, and the predetermined temperature of the raw material preheating furnace is preferably 70-200°C, more preferably 80-150°C.

[0049] In the method of the present invention, the catalyst is preferably dissolved in a liquid carbon source in a raw material preheating furnace. The specific selection of the catalyst and the reaction conditions in the horizontal reactor can be as described above, and will not be repeated here.

[0050] The present invention will be further described below with reference to the embodiments, but the scope of the present invention is not limited to these embodiments.

[0051] In the following embodiments:

[0052] Polycyclic alkane feedstock A is a mixture of cyclohexylmethylcyclohexane (CAS No.: 3178-23-2), (1r,1's,4R,4'R)-4-ethyl-4'-propyl-1,1'-bicyclohexane (CAS No.: 96624-41-8), and (trans,trans)-4-propyl-4'-pentyl-1,1'-bicyclohexane (CAS No.: 92263-41-7) in equal weight proportions.

[0053] Polycyclic alkane feedstock B is a mixture of cyclohexylmethylcyclohexane and 1,2-dicyclohexylethane (CAS No.: 3321-50-4) blended in equal weight ratio.

[0054] The polycyclic aromatic hydrocarbon feedstock is a mixture of phenanthrene (CAS No.: 85-01-8), 1,2-benzophenanthrene (CAS No.: 218-01-9), and indo(1,2,3-cd)pyrene (CAS No.: 193-39-5) in equal weight proportions.

[0055] Example 1

[0056] This embodiment illustrates a system for preparing horizontally arrayed carbon nanotubes from light petroleum according to the present invention, such as... Figure 1 As shown, the system includes a raw material preheating furnace a, a horizontal reactor b, and an inert carrier gas feed line;

[0057] The inert carrier gas feed line is divided into two branches, with pipeline 1 connected to the horizontal reactor b and pipeline 2 connected to the raw material preheating furnace a; the flow rate of the carrier gas in pipeline 1 and pipeline 2 is adjustable, and each pipeline is equipped with a valve that can be independently controlled to open and close; a base plate is installed inside the horizontal reactor b.

[0058] The raw material preheating furnace a is equipped with a discharge pipeline, which is divided into two branches. Pipeline 3 is connected to the horizontal reactor b, and pipeline 4 is connected to the outside of the system. Both pipeline 3 and pipeline 4 are equipped with valves that can be independently controlled.

[0059] Example 2

[0060] This embodiment illustrates a method for preparing horizontally arrayed carbon nanotubes from light petroleum according to the present invention, using the system of Example 1. The method uses polycyclic alkane feedstock A as the carbon source and employs chemical vapor deposition to prepare the arrayed carbon nanotubes, specifically including the following steps:

[0061] (1) The ferrocene catalyst is dissolved in a liquid carbon source and placed in a raw material preheating furnace a, with a concentration of 0.001 mol / L.

[0062] (2) Place the silicon substrate in the horizontal reactor b, connect the pipeline, and check the airtightness.

[0063] (3) Nitrogen is used as the carrier gas. It enters the raw material preheating furnace a through pipeline 2 and then enters the pipeline 5 through pipeline 3. It also enters the horizontal reactor b through pipeline 1 and pipeline 5 and then exits through pipeline 6 to replace the air in the reaction system. The flow distribution ratio of pipeline 1 and pipeline 2 is 10:1.

[0064] (4) Heat the horizontal reactor b and the raw material preheating furnace a to the predetermined temperatures of 650°C and 150°C, respectively; use carrier gas to introduce the material from the raw material preheating furnace a into the horizontal reactor b through pipes 3 and 5; prepare arrayed carbon nanotubes in the horizontal reactor b under the action of the catalyst; react for 0.5 hours under normal pressure.

[0065] (5) Open pipe 4 and close pipe 3 to cool horizontal reactor b and raw material preheating furnace a to room temperature respectively.

[0066] (6) Close all gas lines and the reaction ends.

[0067] The prepared carbon nanotubes were analyzed by SEM, such as... Figure 2 As shown, it is confirmed to be an array, with the carbon nanotubes having a length of 100 mm.

[0068] Example 3

[0069] This embodiment illustrates a method for preparing horizontally arrayed carbon nanotubes from light petroleum according to the present invention, using the system of Example 1. The method uses polycyclic aromatic hydrocarbons as a carbon source and employs chemical vapor deposition to prepare the arrayed carbon nanotubes, specifically including the following steps:

[0070] (1) The ferrocene catalyst is dissolved in a liquid carbon source and placed in a raw material preheating furnace a, with a concentration of 1 mol / L.

[0071] (2) Place the silicon oxide substrate in the horizontal reactor b, connect the pipeline, and check the airtightness.

[0072] (3) Nitrogen and argon (1:1, v / v) are used as carrier gases. They enter the raw material preheating furnace a through pipeline 2 and then enter the pipeline 5 through pipeline 3. They also enter the horizontal reactor b through pipeline 1 and pipeline 5 and then exit through pipeline 6 to replace the air in the reaction system. The flow distribution ratio of pipeline 1 and pipeline 2 is 1:10.

[0073] (4) Heat the horizontal reactor b and the raw material preheating furnace a to the predetermined temperatures of 850°C and 80°C respectively; use carrier gas to introduce the material of the raw material preheating furnace a into the horizontal reactor b through pipelines 3 and 5; prepare arrayed carbon nanotubes in the horizontal reactor b under the action of the catalyst; react for 10 hours under normal pressure.

[0074] (5) Open pipe 4 and close pipe 3 to cool horizontal reactor b and raw material preheating furnace a to room temperature respectively.

[0075] (6) Close all gas lines and the reaction ends.

[0076] The prepared carbon nanotubes were tested and confirmed to be in an array morphology with a length of 1000 mm.

[0077] Example 4

[0078] This embodiment illustrates a method for preparing horizontally arrayed carbon nanotubes from light petroleum according to the present invention, using the system of Example 1. The method uses polycyclic alkane feedstock B as the carbon source and employs chemical vapor deposition to prepare the arrayed carbon nanotubes, specifically including the following steps:

[0079] (1) The ferrocene catalyst is dissolved in a liquid carbon source and placed in a raw material preheating furnace a, with a concentration of 0.1 mol / L.

[0080] (2) Place the silicon substrate in the horizontal reactor b, connect the pipeline, and check the airtightness.

[0081] (3) Argon is used as the carrier gas. It enters the raw material preheating furnace a through pipeline 2 and then enters the pipeline 5 through pipeline 3. It also enters the horizontal reaction furnace b through pipeline 1 and pipeline 5 and then exits through pipeline 6 to replace the air in the reaction system. The flow distribution ratio of pipeline 1 and pipeline 2 is 1:1.

[0082] (4) Heat the horizontal reactor b and the raw material preheating furnace a to the predetermined temperatures of 750°C and 120°C, respectively; use carrier gas to introduce the material from the raw material preheating furnace a into the horizontal reactor b through pipes 3 and 5; prepare arrayed carbon nanotubes in the horizontal reactor b under the action of a catalyst; react for 5 hours under normal pressure.

[0083] (5) Open pipe 4 and close pipe 3 to cool horizontal reactor b and raw material preheating furnace a to room temperature respectively.

[0084] (6) Close all gas lines and the reaction ends.

[0085] The prepared carbon nanotubes were tested and confirmed to be in an array morphology, with a length of 10 mm.

[0086] Example 5

[0087] This embodiment illustrates a method for preparing horizontally arrayed carbon nanotubes from light petroleum according to the present invention, using the system of Example 1. The method uses polycyclic aromatic hydrocarbon phenanthrene as the carbon source and employs chemical vapor deposition to prepare the arrayed carbon nanotubes, specifically including the following steps:

[0088] (1) The ferrocene catalyst is dissolved in a liquid carbon source and placed in a raw material preheating furnace a, with a concentration of 0.5 mol / L.

[0089] (2) Place the silicon oxide substrate in the horizontal reactor b, connect the pipeline, and check the airtightness.

[0090] (3) Nitrogen and argon (1:2, v / v) are used as carrier gases. They enter the raw material preheating furnace a through pipeline 2 and then enter the pipeline 5 through pipeline 3. They also enter the horizontal reactor b through pipeline 1 and pipeline 5 and then exit through pipeline 6 to replace the air in the reaction system. The flow distribution ratio of pipeline 1 and pipeline 2 is 1:5.

[0091] (4) Heat the horizontal reactor b and the raw material preheating furnace a to the predetermined temperatures of 850°C and 100°C, respectively; use carrier gas to introduce the material from the raw material preheating furnace a into the horizontal reactor b through pipes 3 and 5; prepare arrayed carbon nanotubes in the horizontal reactor b under the action of the catalyst; react for 1 hour under normal pressure.

[0092] (5) Open pipe 4 and close pipe 3 to cool horizontal reactor b and raw material preheating furnace a to room temperature respectively.

[0093] (6) Close all gas lines and the reaction ends.

[0094] The prepared carbon nanotubes were tested and confirmed to be in an array morphology with a length of 80 mm.

[0095] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0096] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A method for preparing horizontally arrayed carbon nanotubes from light petroleum, characterized in that, With C 13 -C 22 Polycyclic alkanes and / or C 13 -C 22 The horizontal array of carbon nanotubes was prepared using polycyclic aromatic hydrocarbons as a carbon source and chemical vapor deposition.

2. The method according to claim 1, wherein, The method includes the following steps: Under the protection of an inert carrier gas and in the presence of a catalyst, a preheated carbon source enters a horizontal reactor containing a substrate for chemical vapor deposition to obtain the horizontal array of carbon nanotubes.

3. The method according to claim 1 or 2, wherein, The conditions for chemical vapor deposition include: a temperature of 600–900°C, preferably 650–850°C, a pressure of atmospheric pressure, and a time of 0.3–12 hours, preferably 0.5–10 hours.

4. The method according to claim 2, wherein, The preheating is carried out in a raw material preheating furnace, the temperature of which is 70-200°C, preferably 80-150°C.

5. The method according to claim 2, wherein, The catalyst is ferrocene; preferably, the catalyst is dissolved in a carbon source at a concentration of 0.001 mol / L to 1 mol / L.

6. The method according to claim 2, wherein, The inert carrier gas is one of nitrogen and argon or a mixture of the two in any ratio; The substrate is a silicon substrate, a silicon oxide substrate, or a silicon / silicon oxide substrate.

7. The method according to claim 1 or 2, wherein, The horizontally arrayed carbon nanotubes are ultra-long carbon nanotubes with a length of 10–1000 mm.

8. A system for preparing horizontally arrayed carbon nanotubes from light petroleum, for performing the method according to any one of claims 1-7, the system comprising a raw material preheating furnace, a horizontal reactor, and an inert carrier gas feed line; The inert carrier gas feed line is divided into two branches, one of which is connected to the horizontal reactor and the other is connected to the raw material preheating furnace. The raw material preheating furnace is equipped with a discharge pipeline, which is divided into two branches. One branch is connected to the horizontal reactor, and the other branch is connected to the outside of the system.

9. The system according to claim 8, wherein, Valves are installed on each branch of the inert carrier gas feed line and each branch of the raw material preheating furnace discharge line.

10. The system according to claim 8, wherein, A substrate is provided inside the horizontal reactor; the substrate is preferably a silicon substrate, a silicon oxide substrate, or a silicon / silicon oxide substrate.

11. A method for preparing horizontally arrayed carbon nanotubes using the system according to any one of claims 8-10, comprising the following steps: (1) Place the reaction substrate in a horizontal reaction furnace; (2) Inert carrier gas enters the raw material preheating furnace and the horizontal reactor through the inert carrier gas feed pipeline to replace the air in the reaction system; (3) Under the condition of introducing inert carrier gas, the horizontal reactor and the raw material preheating furnace are heated to the predetermined temperature respectively; (4) An inert carrier gas flows through the raw material preheating furnace, and the gasified carbon source and catalyst are carried into the horizontal reaction furnace through the discharge pipeline. Under the action of the catalyst, horizontal array carbon nanotubes are prepared.

12. The method according to claim 11, wherein, The flow distribution ratio of the inert carrier gas in the two branches is 10:1 to 1:

10.

13. The method according to claim 11, wherein, The predetermined temperature of the horizontal reactor is 600-900℃, preferably 650-850℃, and the predetermined temperature of the raw material preheating furnace is 70-200℃, preferably 80-150℃.

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