CN106995214A - Graphene/carbon nano-tube nano laminated composite thin film and preparation method thereof - Google Patents

Abstract

The invention provides a graphene/carbon nanotube nano-lamination composite film and a preparation method thereof. The graphene/carbon nanotube nano-stack composite film is composed of graphene ultra-thin films formed on the water surface and carbon nano-tube ultra-thin films drawn from carbon nanotube arrays, graphene ultra-thin films and carbon nanotube ultra-thin films alternately Stacking forms a nano-lamination structure, and the weight percentage of the graphene ultra-thin film in the nano-lamination composite film is 0-100%. Inject the graphene dispersion onto the water surface to form a graphene ultra-thin film, pull out the carbon nanotube ultra-thin film from the carbon nanotube array, transfer and stack the graphene ultra-thin film and the carbon nanotube ultra-thin film repeatedly to form a graphene/carbon Nanotube nanolamination composite film. The graphene/carbon nanotube nano-stack composite film can be used in fields such as electromagnetic shielding, supercapacitors, lithium batteries, solar batteries, heat dissipation, and reinforcement of composite materials.

Description

Graphene/carbon nanotube nano-laminated composite film and preparation method thereof

technical field

The invention relates to the field of nanomaterial science and technology, in particular to the field of graphene and carbon nanotube composite materials.

Background technique

Carbon nanotubes and graphene have typical one-dimensional and two-dimensional carbon nanostructures, and have attracted extensive attention since their appearance. In 1991, carbon nanotubes were accidentally discovered by Dr. Iijima, an electron microscope expert at the Basic Research Laboratory of NEC Corporation of Japan. Carbon nanotubes are one-dimensional tubular nanomaterials with a special structure (the radial dimension is on the order of nanometers, and the axial dimension is on the order of microns or even millimeters). It is mainly composed of several layers of carbon atoms arranged in hexagons. Up to tens of layers of coaxial circular tubes, the distance between layers is kept fixed, about 0.34 nanometers, and the diameter is generally 2-50 nanometers. Carbon nanotubes have high mechanical strength, high electrical conductivity, high thermal conductivity and excellent electrochemical performance in the axial direction. Graphene was first successfully prepared in 2004 by physicists Andre Geim and Konstantin Novoselov of the University of Manchester, UK. Graphene is a two-dimensional crystal, which is composed of carbon atoms neatly arranged in a hexagonal lattice structure. It has a stable structure and has high mechanical strength, high electrical conductivity, high thermal conductivity and excellent thermal conductivity in the plane direction. electrochemical performance.

Graphene/carbon nanotube composites have aroused extensive research interest. The geometric advantages of graphene and carbon nanotubes are integrated to produce a synergistic effect, showing superior mechanical strength, thermal conductivity, electrical conductivity and Electrochemical energy storage performance has good application prospects in composite material reinforcement, heat dissipation, electromagnetic shielding, supercapacitors, and energy storage batteries. The graphene/carbon nanotube composite materials that have been reported so far are mainly divided into three categories. The first category uses graphene powder or carbon nanotube powder as raw materials, and the two are dispersed together in a certain solvent, and then sprayed by spin coating, Spraying, suction filtration, electrodeposition and other methods of film formation, the resulting graphene/carbon nanotube composite material has the following disadvantages: 1) graphene and carbon nanotubes are not uniformly dispersed, 2) graphene and carbon nanotubes are randomly distributed , with no orientation structure. The second type uses graphene powder or carbon nanotube powder as the raw material. Through surface chemical modification, the surface of graphene and carbon nanotubes is charged with opposite charges, dispersed in water, and formed into a film by electrostatically driven layer-by-layer self-assembly. The obtained graphene/carbon nanotube composite material has the following disadvantages: the surface chemical modification seriously destroys the structures of graphene and carbon nanotubes, and reduces various properties of the composite film. The third method is the in-situ chemical vapor deposition method, which grows graphene and carbon nanotubes successively on the substrate to form a graphene/carbon nanotube composite film, such as the patent of Tsinghua University and Hongfujin Precision Industry (Shenzhen) Co., Ltd. CN105174204A, CN103359717A, CN102796991A, CN102794945A and CN102724620A all utilize the chemical vapor deposition method to grow graphene and carbon nanotube successively on the substrate, but the graphene/carbon nanotube composite film of gained has following shortcoming: 1) carbon nanotube vertical Distributed in the film plane direction, it is difficult to distribute along the film plane direction, 2) the technology is complicated, the cost is high, and it is difficult to industrialize.

Contents of the invention

For the problems of the technologies described above, the object of the present invention is to provide a kind of graphene/carbon nanotube nano-lamination composite film, and described graphene/carbon nanotube nano-lamination composite film comprises the graphene ultra-thin film that forms on water surface and Highly oriented carbon nanotube ultra-thin films drawn from carbon nanotube arrays, the weight fraction of graphene ultra-thin films in graphene/carbon nanotube nano-laminated composite films is less than 100%, graphene ultra-thin films and carbon nanotube ultra-thin films Thin films form nanoscale stacked structures.

Another object of the present invention is to propose a kind of method for preparing graphene/carbon nanotube nano-stack composite film, and step comprises:

1) pulling out the carbon nanotube ultra-thin film from the carbon nanotube array, and stacking the y-layer carbon nanotube ultra-thin film to form a carbon nanotube layer CNT _y ;

2) Injecting the graphene dispersion into the water surface to form a graphene ultra-thin film;

3) Import the y-layer carbon nanotube ultra-thin film of step 1 into water and export it, so that the transfer of the graphene ultra-thin film on the water surface in step 2 covers the surface of the carbon nanotube film, repeat x times, to transfer the x-layer graphene ultra-thin film On the y-layer carbon nanotube ultra-thin film, a graphene/carbon nanotube double layer (G _x /CNT _y ) ₁ is formed;

4) Cover the carbon nanotube layer CNT _y on the graphene/carbon nanotube bilayer (G _x /CNT _y ) ₁ , and then transfer x graphene ultra-thin films to form two graphene/carbon nanotube bilayers (G _x /CNT _y ) ₂ , and so on, repeat n times to obtain a graphene/carbon nanotube nano-lamination composite film (G _x /CNT _y ) _n .

It may further include step 5) heat-treating the graphene/carbon nanotube nanolayer composite film (G _x /CNT _y ) _n under an inert gas to obtain a graphene/carbon nanotube nanolayer composite film.

The concentration of the graphene dispersion is 0.001-2mg/ml, and the solvent in the dispersion is a water-miscible organic solvent, including N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide One or more of amides, N-vinylpyrrolidone, methanol, ethanol, isopropanol, acetone, and dimethyl sulfoxide;

The thickness of the graphene ultra-thin film is in the range of 0.34 nanometers to 100 nanometers;

The thickness of the carbon nanotube ultra-thin film is in the range of 2 nanometers to 100 nanometers;

The y value is greater than or equal to 1, the x value is greater than or equal to 1, and the n value is greater than or equal to 1.

The heat treatment temperature in the above step 5) is from room temperature to 3000 degrees Celsius. Heat treatment can further improve the electrical conductivity and thermal conductivity of the composite film. The higher the heat treatment temperature, the better the performance. It has no effect when the treatment temperature is lower than room temperature, and it is technically difficult to achieve a treatment temperature higher than 3000 degrees Celsius. Therefore, the heat treatment temperature is from room temperature to 3000 degrees Celsius.

The graphene/carbon nanotube nano-stack composite film obtained by the method has the advantages of good flexibility, high mechanical strength, high thermal conductivity, high electrical conductivity, and the like. The obtained graphene/carbon nanotube nano-stack composite film has a wide range of practical application values in the fields of heat dissipation, electromagnetic shielding, super capacitors, lithium batteries, solar cells and the like.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Example 1

(1) Pull out a transparent carbon nanotube ultra-thin film with a width of 3 cm from the carbon nanotube array, cover it on a clean glass sheet, soak the glass sheet in ethanol, wet it, take it out, and let it dry naturally.

(2) Slowly inject the 1mg/ml graphene/N-methylpyrrolidone dispersion into a petri dish filled with water to form a transparent graphene ultra-thin film.

(3) Use the glass sheet in step 1 to carry out filming in a petri dish, that is, transfer the graphene ultra-thin film to the carbon nanotube ultra-thin film, and dry naturally to form a graphene/carbon nanotube double-layer (G ₁ / CNT ₁ ) ₁ .

(4) Cover a layer of carbon nanotube ultra-thin film on the graphene/carbon nanotube bilayer (G ₁ /CNT ₁ ) ₁ , and then transfer a layer of graphene ultra-thin film to form two graphene/carbon nanotube bilayers (G ₁ /CNT ₁ ) ₂ , and so on, repeated n times, to obtain a graphene/carbon nanotube nano-lamination composite film (G ₁ /CNT ₁ ) _n .

(5) heat-treat the graphene/carbon nanotube nanolayer composite film (G ₁ /CNT ₁ ) _n in step 4 under the protection of argon at 2850°C for 2 hours to obtain flexible, high thermal conductivity and high electrical conductivity graphene/carbon nanotubes Nano laminate composite film.

Example 2

(1) Pull out a carbon nanotube ultra-thin film with a width of 5 cm from the carbon nanotube array, cover a clean glass sheet with a carbon nanotube ultra-thin film, and immerse the glass sheet in N,N-dimethylformamide Take it out after getting wet and let it dry naturally.

(2) Slowly inject 0.2mg/ml graphene/ethanol dispersion into a petri dish filled with water to form a transparent graphene ultra-thin film.

(3) Use the glass sheet in step 1 to carry out film removal in a petri dish, promptly form a layer of uniform graphene ultra-thin film on the surface of carbon nanotube ultra-thin film, dry naturally, then repeat the film drying twice, that is, Three layers of graphene ultra-thin films are stacked on the surface of one layer of carbon nanotube ultra-thin film to form a graphene/carbon nano-tube bilayer (G ₃ /CNT ₁ ) ₁ .

(4) Cover a layer of carbon nanotube ultra-thin film on the graphene/carbon nanotube bilayer (G ₃ /CNT ₁ ) ₁ , and then transfer three layers of graphene ultra-thin film to form two graphene/carbon nanotube bilayers (G ₃ /CNT ₁ ) ₂ , and so on, repeat n times to obtain a graphene/carbon nanotube nano-lamination composite film (G ₃ /CNT ₁ ) _n .

(5) heat-treat the graphene/carbon nanotube nano-lamination composite film (G ₃ /CNT ₁ ) _n in step 4 under the protection of argon at 3000°C for 24 hours to obtain flexible, high-thermal and high-conductivity graphene/carbon nanotubes Nano laminate composite film.

Example 3

(1) Pull out a carbon nanotube ultra-thin film with a width of 7 cm from the carbon nanotube array, cover 3 layers of carbon nano-tube ultra-thin film on a clean glass sheet, soak the glass sheet in ethanol and wet it, then take it out and let it dry naturally .

(2) Slowly inject the 0.5mg/ml graphene/N-methylpyrrolidone dispersion into a petri dish filled with water to form a transparent graphene ultra-thin film.

(3) use the glass sheet in step 1 to carry out filming in a petri dish, promptly form a layer of uniform graphene film on the carbon nanotube surface, dry naturally, form a graphene/carbon nanotube double-layer (G ₁ /CNT ₃ ) ₁ .

(4) Cover 3 layers of carbon nanotube ultra-thin film on the graphene/carbon nanotube bilayer (G ₁ /CNT ₃ ) ₁ , and then transfer a layer of graphene ultra-thin film to form two graphene/carbon nanotube bilayers (G ₁ /CNT ₃ ) ₂ , and so on, repeated n times, to obtain a graphene/carbon nanotube nano-lamination composite film (G ₁ /CNT ₃ ) _n .

(5) Heat-treat the graphene/carbon nanotube nano-laminated composite film (G ₁ /CNT ₃ ) _n in step 4 under nitrogen protection at 2000°C for 10 hours to obtain a flexible, high-thermal and high-conductivity graphene/carbon nanotube nano Laminated composite film.

Example 4

(1) Pull out a carbon nanotube ultra-thin film with a width of 5 cm from the carbon nanotube array, cover a clean glass sheet with a carbon nanotube ultra-thin film, and immerse the glass sheet in N,N-dimethylformamide Take it out after getting wet and let it dry naturally.

(2) Slowly inject 0.8mg/ml graphene/ethanol dispersion into a petri dish filled with water to form a transparent graphene ultra-thin film.

(3) Use the glass sheet in step 1 to remove the film in the petri dish, that is, form a layer of uniform graphene film on the surface of the carbon nanotube, dry it naturally, then repeat the film drying twice, that is, in a layer of carbon nanotubes Three layers of graphene ultra-thin films are stacked on the surface of the nanotube ultra-thin film to form a graphene/carbon nanotube bilayer (G ₃ /CNT ₁ ) ₁ .

(4) Cover a layer of carbon nanotube ultra-thin film on the graphene/carbon nanotube bilayer (G ₃ /CNT ₁ ) ₁ , and then transfer three layers of graphene ultra-thin film to form two graphene/carbon nanotube bilayers (G ₃ /CNT ₁ ) ₂ , and so on, repeat n times to obtain a graphene/carbon nanotube nano-lamination composite film (G ₃ /CNT ₁ ) _n .

(5) heat-treat the graphene/carbon nanotube nano-laminated composite film (G ₃ /CNT ₁ ) _n in step 4 under the protection of argon at 1000°C for 2 hours to obtain flexible, high-thermal and high-conductivity graphene/carbon nanotubes Nano laminate composite film.

Example 5

(1) Pull out a carbon nanotube ultra-thin film with a width of 5 cm from the carbon nanotube array, cover a clean glass sheet with three layers of carbon nanotube ultra-thin film, and immerse the glass sheet in N,N-dimethylformamide Take it out after getting wet and let it dry naturally.

(2) Slowly inject 0.8mg/ml graphene/ethanol dispersion into a petri dish filled with water to form a transparent graphene ultra-thin film.

(3) Use the glass sheet in step 1 to remove the film in the petri dish, that is, form a layer of uniform graphene film on the surface of the carbon nanotube, dry it naturally, then repeat the film drying twice, that is, in a layer of carbon nanotubes Three layers of graphene ultra-thin films are stacked on the surface of the nanotube ultra-thin film to form a graphene/carbon nanotube bilayer (G ₃ /CNT ₃ ) ₁ .

(4) Cover the graphene/carbon nanotube bilayer (G ₃ /CNT ₃ ) ₁ with a three-layer carbon nanotube ultra-thin film, and then transfer the three-layer graphene ultra-thin film to form two graphene/carbon nanotube bilayers (G ₃ /CNT ₃ ) ₂ , and so on, repeated n times to obtain a flexible, high thermal conductivity and high conductivity graphene/carbon nanotube nano-lamination composite film (G ₃ /CNT ₃ ) _n .

Claims (10)

1. a kind of graphene/carbon nano-tube nano laminated composite thin film, it is characterised in that：Included in the graphene of water surface formation Ultrathin membrane and the CNT ultrathin membrane pulled out from carbon nano pipe array, graphene extra-thin film is in graphene/carbon nano-tube nanometer Weight fraction in laminated composite thin film is that graphene extra-thin film and CNT ultrathin membrane are alternately stacked to be formed less than 100% Nano-stack structure.

2. graphene/carbon nano-tube nano laminated composite thin film according to claim 1, it is characterised in that graphene is ultra-thin The thickness of film is in 0.34 nanometer to 100 nanometer ranges.

3. graphene/carbon nano-tube nano laminated composite thin film according to claim 1, it is characterised in that CNT surpasses The thickness of film is in 2 nanometers to 100 nanometer ranges.

4. a kind of method for preparing the graphene/carbon nano-tube nano laminated composite thin film described in claim any one of 1-3, institute The method stated comprises the following steps：

1) the CNT ultrathin membrane of orientation is pulled out from carbon nano pipe array, y layers of CNT ultrathin membrane are stacked；

2) graphene dispersing solution is expelled to water surface one layer graphene ultrathin membrane of formation；

3) the y layer CNTs ultrathin membrane of step 1 is imported in water and exported so that the graphene of water surface is ultra-thin in step 2 Film transfer covers carbon nano-tube film surface, repeats x times, to shift x layer graphenes ultrathin membrane to y layers of CNT ultrathin membrane On, form a graphene/carbon nano-tube bilayer (G_x/CNT_y)₁；

4) in the graphene/carbon nano-tube bilayer (G of step 3_x/CNT_y)₁Upper y layers of CNT ultrathin membrane of covering, then shift x Layer graphene ultrathin membrane, forms two graphene/carbon nano-tube bilayer (G_x/CNT_y)₂, the like, move in circles n times, obtain Graphene/carbon nano-tube nano laminated composite thin film (G_x/CNT_y)_n。

5. method according to claim 4, it is characterised in that also comprising step 5) above-mentioned graphene/carbon nano-tube is received Rice laminated composite thin film (G_x/CNT_y)_nIt is heat-treated under an inert gas, obtains graphene/carbon nano-tube nano-stack THIN COMPOSITE Film.

6. method according to claim 4, it is characterised in that the concentration of described graphene dispersing solution is 0.001-2mg/ Solvent in ml, dispersion liquid is organic solvent miscible with water, including 1-METHYLPYRROLIDONE, DMF, N, N- It is a kind of or several in dimethyl acetamide, NVP, methanol, ethanol, isopropanol, acetone, dimethyl sulfoxide (DMSO) Kind；Described graphene extra-thin film is formed in water surface, and its thickness is in 0.34-100 nanometer thickness；Described CNT ultrathin membrane Pulled out from carbon nano pipe array, its thickness is at 2-100 nanometers.

7. method according to claim 4, it is characterised in that y values are more than or equal to 1, x values and are more than or equal to 1, n values More than or equal to 1.

8. method according to claim 5, it is characterised in that heat treatment temperature is in room temperature to 3000 degrees Celsius.

9. method according to claim 4, it is characterised in that the graphene/carbon nano-tube nano laminated composite thin film With graphene extra-thin film and CNT ultrathin membrane alternating stacked configuration.

10. the use of graphene/carbon nano-tube nano laminated composite thin film prepared by the method described in claim any one of 4-9 On the way, for radiating, being electromagnetically shielded, ultracapacitor, lithium battery or area of solar cell.