Conductive film containing carbon nanotubes and preparation method thereof

Abstract

The invention relates to the technical field of conductive film preparation, in particular to a conductive film containing carbon nanotubes and a preparation method of the conductive film. The netted carbon nanotube prepared by the method is formed by interweaving crisscrossed carbon nanotube monomers, so that a conductive network of the netted carbon nanotube is greatly expanded and improved, and compared with a traditional carbon nanotube product, the netted carbon nanotube prepared by the method is more prominent in conductivity, and the conductivity of the netted carbon nanotube prepared by the method is higher than that of the traditional carbon nanotube product. The preparation method comprises the following steps: putting a reticular carbon nanotube into ethanol, carrying out ultrasonic dispersion on the reticular carbon nanotube, spraying the obtained carbon nanotube dispersion liquid on a ceramic substrate in an atomization manner under the protection of nitrogen after the carbon nanotube dispersion liquid is uniformly dispersed, carrying out heating treatment, and then carrying out irradiation treatment on the carbon nanotube dispersion liquid, so that the conductivity and the mechanical property of the reticular carbon nanotube are remarkably improved; and the conductive film is used as a raw material for preparing the conductive film, so that the conductivity and the mechanical property of the conductive film are effectively ensured, and the grade and the quality of the conductive film are improved.

Description

Technical Field

[0001] The invention relates to the technical field of conductive film preparation, in particular to a conductive film containing carbon nanotubes and a preparation method thereof. Background Art

[0002] Conductive film is a thin film with conductive function. The charged carriers of the conductive film are scattered by the surface and interface during the transport process. When the thickness of the film is comparable to the free path of the electrons, the influence on the surface and interface will become significant. This phenomenon is called the size effect of the film. It is equivalent to the reduction of the free path of the carriers, so the conductivity of the film is smaller than that of the bulk of the same material.

[0003] A patent document with application number "CN200610157000.8" ​​discloses a method for preparing a transparent conductive film, which is to form a desired transparent conductive film on the surface of a glass element. The method for preparing the transparent conductive film mainly includes: preparing carbon nanotube slurry; forming a carbon nanotube slurry layer on the surface of the glass element with the prepared carbon nanotube slurry; drying the carbon nanotube slurry layer; and heating the glass element with the carbon nanotube slurry layer to 300-500°C under the protection of nitrogen or inert gas and keeping it warm for a certain period of time, and then cooling it to room temperature, thereby forming a carbon nanotube transparent conductive film on the surface of the glass element.

[0004] Although the conductive film prepared in the above patent document has certain light transmittance and conductivity, and its preparation process is simple, easy to operate, and low cost. However, its conductivity and mechanical properties are relatively insufficient, which affects its quality to a certain extent. Based on this, the present invention provides a conductive film containing carbon nanotubes and a preparation method thereof! Summary of the invention

[0005] The purpose of the present invention is to provide a conductive film containing carbon nanotubes and a preparation method thereof. The prepared conductive film not only has excellent conductive properties, but also has excellent mechanical properties, effectively ensuring its quality.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing a conductive film containing carbon nanotubes, comprising the following steps:

[0008] Under room temperature conditions, modified carbon nanotubes with a mass of 6-12% of polyvinyl alcohol and 15-25% of poly(sulfide-1,4-phenylene) are added in sequence to a 0.05-0.15 g / mL polyvinyl alcohol aqueous solution. After ultrasonic dispersion, the obtained mixed solution is dropped on the surface of a glass substrate, and then transferred into a high-temperature calcination device for high-temperature calcination. After calcination, it is firstly peeled off in an alkaline solution environment and then dried to obtain a conductive film containing carbon nanotubes.

[0009] Furthermore, the preparation method of the modified carbon nanotubes comprises the following steps:

[0010] Step 1: adding the reticulated carbon nanotubes into ethanol at a dosage ratio of 0.05 to 0.1 g / mL, and after uniform ultrasonic dispersion, spraying the obtained carbon nanotube dispersion on the ceramic substrate in an atomized manner using a pneumatic spray brush under nitrogen protection, and stopping the spraying when the transmittance of the carbon nanotube mixture at a visible light wave of 550 nm is 62 to 65%;

[0011] Step 2: Take out the sprayed carbon nanotube mixture and heat it for 35 to 45 minutes at a vacuum degree of less than 0.001 Pa and a temperature of 800 to 900 K. After the heating is completed, cool the obtained solid powder naturally to room temperature and store it for future use.

[0012] Step 3: Place the solid powder obtained in step 2 in the target chamber of the irradiation equipment, evacuate to 0.0001Pa, raise the temperature to 800-900K, and then irradiate the solid powder. After the irradiation is completed, naturally cool to room temperature in a vacuum environment and take it out to obtain the modified carbon nanotubes.

[0013] Furthermore, the preparation method of the reticulated carbon nanotubes is as follows: nickel oxide is put into an organic acid aqueous solution at a solid-liquid ratio of 0.05 to 0.1 g / mL, the temperature is raised to 50 to 70°C, and then the mixture is soaked at this temperature for 5 to 8 hours; after the soaking is completed, the mixture is filtered, and the obtained solid filter material is dried at a temperature of 550 to 750°C for 30 to 50 minutes; after the drying is completed, the mixture is transferred into a tubular furnace, and the temperature is raised to 650 to 850°C under nitrogen protection, and then hydrogen and propylene are continuously introduced into the furnace at a flow ratio of 0.2 to 0.4:1, and the mixture is kept warm for reaction for 1 to 3 hours and then naturally cooled to room temperature, and finally the obtained solid material is taken out to obtain the reticulated carbon nanotubes.

[0014] Furthermore, the power of the ultrasonic dispersion is 50 to 350 W, and the ultrasonic dispersion time is 20 to 50 h.

[0015] Furthermore, the temperature of the high-temperature calcination is set to 290-310° C., and the time of the high-temperature calcination is set to 3-4 hours.

[0016] Furthermore, the alkali solution is selected from any one of a sodium hydroxide aqueous solution and a potassium hydroxide aqueous solution, and the concentration of the alkali solution is 3-5wt%.

[0017] Furthermore, the organic acid is 3-hydroxy-3-carboxy-1,5-pentanedioic acid, and the concentration of the organic acid in the organic acid aqueous solution is 20-30 wt %.

[0018] Furthermore, the flow rate of the nitrogen gas is 300-500 sccm, and the flow rate of the hydrogen gas is 100-300 sccm.

[0019] Furthermore, the ion beam used for irradiation is an argon ion beam, and the energy range of the argon ion beam is 50-100 KeV, and the irradiation dose is set to 1×10 16 ~1×10 17 ions / cm 2 .

[0020] In a second aspect, the present invention provides a conductive film containing carbon nanotubes, which is prepared by the preparation method described above.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention first soaks nickel oxide in an organic acid aqueous solution, then successively filters and high-temperature dry treatments before transferring it into a tubular furnace, and uses it as a reaction accelerator under the protection of nitrogen, then introduces hydrogen and propylene into the furnace, and prepares a topologically structured mesh carbon nanotube after heat preservation reaction. The prepared mesh carbon nanotube is formed by crisscrossing carbon nanotube monomers, which greatly expands and improves its conductive network. Compared with traditional carbon nanotube products, the conductivity of the mesh carbon nanotube prepared by the present invention is more prominent. The prepared mesh carbon nanotube is put into ethanol and ultrasonically dispersed, and after being evenly dispersed, the obtained carbon nanotube dispersion is sprayed on a ceramic substrate in an atomized manner under the protection of nitrogen, and then irradiated after heating treatment, which significantly improves the conductive performance and mechanical properties of the mesh carbon nanotube. It is used as a raw material for preparing a conductive film, effectively ensuring its conductive performance while also ensuring its mechanical properties, and improving its grade and quality.

[0023] In summary, the conductive film prepared by the present invention not only has excellent conductive properties, but also has excellent mechanical properties, which effectively guarantees its quality. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] A method for preparing a conductive film containing carbon nanotubes comprises the following steps:

[0027] Under room temperature conditions, 6% of modified carbon nanotubes and 15% of poly(sulfide-1,4-phenylene) were added to a 0.05 g / mL poly(vinyl alcohol) aqueous solution in sequence, and the resulting mixed solution was dropped on the surface of a glass substrate after being uniformly dispersed by ultrasonication, and then transferred to a high-temperature calcination device for high-temperature calcination. After the calcination was completed, the mixture was firstly peeled off in an alkaline solution environment, and then dried to obtain a conductive film containing carbon nanotubes;

[0028] The power of ultrasonic dispersion is 50W, and the ultrasonic dispersion time is 50h; the temperature of high-temperature calcination is set to 290°C, and the time of high-temperature calcination is set to 4h; the alkali solution is a sodium hydroxide aqueous solution with a concentration of 3-5wt%.

[0029] The method for preparing modified carbon nanotubes comprises the following steps:

[0030] Step 1: Add the reticulated carbon nanotubes into ethanol at a dosage of 0.05 g / mL, and after ultrasonic dispersion, spray the obtained carbon nanotube dispersion on the ceramic substrate in an atomized manner using a pneumatic spray brush under nitrogen protection, and stop spraying when the transmittance of the carbon nanotube mixture at 550 nm visible light wave is 62%;

[0031] Step 2: Take out the sprayed carbon nanotube mixture and heat it for 35 minutes under the condition of vacuum degree less than 0.001Pa and temperature of 800K. After heating, cool the obtained solid powder to room temperature naturally and store it for future use.

[0032] Step 3: placing the solid powder obtained in step 2 in the target chamber of the irradiation equipment, evacuating the chamber to 0.0001 Pa, raising the temperature to 800 K, and then irradiating the solid powder. After the irradiation is completed, the solid powder is naturally cooled to room temperature in a vacuum environment and then taken out to obtain the modified carbon nanotubes; wherein the ion beam used for irradiation is an argon ion beam, and the energy range of the argon ion beam is 50 KeV, and the irradiation dose is set to 1×10 16 ions / cm 2 .

[0033] The preparation method of the network carbon nanotube is as follows: nickel oxide is put into an organic acid aqueous solution at a solid-liquid ratio of 0.05g / mL, and the temperature is raised to 50°C and then soaked at this temperature for 5h; after soaking, it is filtered and the obtained solid filter material is dried at a temperature of 550°C for 30min; after drying, it is transferred into a tubular furnace and the temperature is raised to 650°C under nitrogen protection, and then hydrogen and propylene are continuously introduced into the furnace at a flow ratio of 0.2:1, and the reaction is kept warm for 1h and then naturally cooled to room temperature, and finally the obtained solid material is taken out to obtain the network carbon nanotube; wherein, the organic acid is 3-hydroxy-3-carboxyl-1,5-pentanedioic acid, and the concentration of the organic acid in the organic acid aqueous solution is 20wt%; the flow rate of nitrogen is 300sccm, and the flow rate of hydrogen is 100sccm.

[0034] Example 2

[0035] A method for preparing a conductive film containing carbon nanotubes comprises the following steps:

[0036] Under room temperature conditions, 10% of modified carbon nanotubes and 20% of poly(sulfide-1,4-phenylene) were added to a 0.1 g / mL poly(vinyl alcohol) aqueous solution in sequence, and the resulting mixed solution was dropped on the surface of a glass substrate after being uniformly dispersed by ultrasonication, and then transferred to a high-temperature calcination device for high-temperature calcination. After calcination, the mixture was firstly stripped in an alkaline solution environment, and then dried to obtain a conductive film containing carbon nanotubes;

[0037] Among them, the power of ultrasonic dispersion is 200W, and the ultrasonic dispersion time is 35h; the temperature of high-temperature calcination is set to 300°C, and the time of high-temperature calcination is set to 3.5h; the alkali solution is a 4wt% potassium hydroxide aqueous solution with a concentration of.

[0038] The method for preparing modified carbon nanotubes comprises the following steps:

[0039] Step 1: adding the reticulated carbon nanotubes into ethanol at a dosage ratio of 0.08 g / mL, and after uniform ultrasonic dispersion, spraying the obtained carbon nanotube dispersion on the ceramic substrate in an atomized manner using a pneumatic spray brush under nitrogen protection, and stopping the spraying when the transmittance of the carbon nanotube mixture at 550 nm visible light wave is 62%;

[0040] Step 2: Take out the sprayed carbon nanotube mixture and heat it for 40 minutes under the conditions of vacuum degree less than 0.001Pa and temperature of 850K. After heating, cool the obtained solid powder naturally to room temperature and store it for future use.

[0041] Step 3: placing the solid powder obtained in step 2 in the target chamber of the irradiation equipment, evacuating the chamber to 0.0001 Pa, raising the temperature to 850 K, and then irradiating the solid powder. After the irradiation is completed, the solid powder is naturally cooled to room temperature in a vacuum environment and then taken out to obtain the modified carbon nanotubes; wherein the ion beam used for irradiation is an argon ion beam, and the energy range of the argon ion beam is 80 KeV, and the irradiation dose is set to 3×10 16 ions / cm 2 .

[0042] The preparation method of the network carbon nanotube is as follows: nickel oxide is put into an organic acid aqueous solution at a solid-liquid ratio of 0.08g / mL, and the temperature is raised to 60°C and then soaked at this temperature for 6h; after soaking, it is filtered and the obtained solid filter material is dried at 650°C for 40min; after drying, it is transferred into a tubular furnace and the temperature is raised to 750°C under nitrogen protection, and then hydrogen and propylene are continuously introduced into the furnace at a flow ratio of 0.3:1, and the reaction is kept warm for 2h and then naturally cooled to room temperature, and finally the obtained solid material is taken out to obtain the network carbon nanotube; wherein, the organic acid is 3-hydroxy-3-carboxyl-1,5-pentanedioic acid, and the concentration of the organic acid in the organic acid aqueous solution is 25wt%; the flow rate of nitrogen is 400sccm, and the flow rate of hydrogen is 200sccm.

[0043] Example 3

[0044] A method for preparing a conductive film containing carbon nanotubes comprises the following steps:

[0045] Under room temperature conditions, 12% of modified carbon nanotubes and 25% of poly(sulfide-1,4-phenylene) were added to a 0.15 g / mL poly(vinyl alcohol) aqueous solution in sequence, and the resulting mixed solution was dropped on the surface of a glass substrate after being uniformly dispersed by ultrasonication, and then transferred to a high-temperature calcination device for high-temperature calcination. After the calcination was completed, the mixture was firstly peeled off in an alkaline solution environment, and then dried to obtain a conductive film containing carbon nanotubes;

[0046] The power of ultrasonic dispersion is 350W, and the ultrasonic dispersion time is 20h; the temperature of high-temperature calcination is set to 310°C, and the time of high-temperature calcination is set to 3h; and the alkali solution is a sodium hydroxide aqueous solution with a concentration of 5wt%.

[0047] The method for preparing modified carbon nanotubes comprises the following steps:

[0048] Step 1: Add the reticulated carbon nanotubes into ethanol at a dosage of 0.1 g / mL, and after uniform ultrasonic dispersion, spray the obtained carbon nanotube dispersion on the ceramic substrate in an atomized manner using a pneumatic spray brush under nitrogen protection, and stop spraying when the transmittance of the carbon nanotube mixture at 550 nm visible light wave is 65%;

[0049] Step 2: Take out the sprayed carbon nanotube mixture and heat it for 45 minutes under the condition of vacuum degree less than 0.001Pa and temperature of 900K. After heating, cool the obtained solid powder to room temperature naturally and store it for future use.

[0050] Step 3: placing the solid powder obtained in step 2 in the target chamber of the irradiation equipment, evacuating the chamber to 0.0001 Pa, raising the temperature to 900 K, and then irradiating the solid powder. After the irradiation is completed, the solid powder is naturally cooled to room temperature in a vacuum environment and then taken out to obtain the modified carbon nanotubes; wherein the ion beam used for irradiation is an argon ion beam, and the energy range of the argon ion beam is 100 KeV, and the irradiation dose is set to 1×10 17 ions / cm 2 .

[0051] The preparation method of the network carbon nanotube is as follows: nickel oxide is put into an organic acid aqueous solution at a solid-liquid ratio of 0.1g / mL, and the temperature is raised to 70°C and then soaked at this temperature for 8h; after soaking, it is filtered and the obtained solid filter material is dried at 750°C for 50min; after drying, it is transferred into a tubular furnace and the temperature is raised to 850°C under nitrogen protection, and then hydrogen and propylene are continuously introduced into the furnace at a flow ratio of 0.4:1, and the reaction is kept warm for 3h and then naturally cooled to room temperature, and finally the obtained solid material is taken out to obtain the network carbon nanotube; wherein, the organic acid is 3-hydroxy-3-carboxyl-1,5-pentanedioic acid, and the concentration of the organic acid in the organic acid aqueous solution is 30wt%; the flow rate of nitrogen is 500sccm, and the flow rate of hydrogen is 300sccm.

[0052] Comparative Example 1: The difference between this embodiment and embodiment 1 is that in this embodiment, an equal amount of reticulated carbon nanotubes is used instead of modified carbon nanotubes, and they are directly used as raw materials for preparing the conductive film.

[0053] Comparative Example 2: The difference between this embodiment and embodiment 1 is that in this embodiment, an equal amount of ordinary carbon nanotubes are used instead of mesh carbon nanotubes, which are directly used as raw materials for preparing conductive films; wherein the ordinary carbon nanotubes are single-walled carbon nanotubes with a diameter of 3.0 nm and a length of 30 μm.

[0054] Performance test: The relevant properties of the conductive film samples prepared in Examples 1 to 3 and Comparative Examples 1 to 2 were tested as follows:

[0055] 1. Conductivity test: Use a dual-electric four-probe tester to test the conductivity of each group of conductive film samples. The test conditions are room temperature, relative humidity of 60%, film diameter of 35mm, and the front and back sides are measured 3 times each to take the average value;

[0056] 2. Tensile strength test: Cut the conductive film into rectangular strip samples of 15mm×20mm, and measure the thickness. Use a high-strength material universal testing instrument to perform tensile tests on each group of conductive film samples. The tensile rate is constant at 10mm / min. Each group of conductive film samples is tested in parallel 5 times, and the average value is finally taken.

[0057] The test data obtained are recorded in the following table:

[0058]

[0059]

[0060] By comparing and analyzing the relevant data in the table, it can be seen that the conductive film prepared by the present invention not only has excellent conductive properties, but also has excellent mechanical properties, which effectively guarantees its quality. This shows that the conductive film containing carbon nanotubes and the preparation method thereof provided by the present invention have a broader market prospect and are more suitable for promotion.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0062] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a conductive film containing carbon nanotubes, characterized in that: The following steps are involved: Under room temperature conditions, modified carbon nanotubes with a mass of 6-12% of polyvinyl alcohol and 15-25% of poly(sulfide-1,4-phenylene) are added in sequence to a 0.05-0.15 g / mL polyvinyl alcohol aqueous solution. After ultrasonic dispersion, the obtained mixed solution is dropped on the surface of a glass substrate, and then transferred into a high-temperature calcination device for high-temperature calcination. After calcination, it is firstly peeled off in an alkaline solution environment and then dried to obtain a conductive film containing carbon nanotubes.

2. The method for preparing a conductive film containing carbon nanotubes according to claim 1, characterized in that: The preparation method of the modified carbon nanotubes comprises the following steps: Step 1: adding the reticulated carbon nanotubes into ethanol at a dosage ratio of 0.05 to 0.1 g / mL, and after uniform ultrasonic dispersion, spraying the obtained carbon nanotube dispersion on the ceramic substrate in an atomized manner using a pneumatic spray brush under nitrogen protection, and stopping the spraying when the transmittance of the carbon nanotube mixture at a visible light wave of 550 nm is 62 to 65%; Step 2: Take out the sprayed carbon nanotube mixture and heat it for 35 to 45 minutes at a vacuum degree of less than 0.001 Pa and a temperature of 800 to 900 K. After the heating is completed, cool the obtained solid powder naturally to room temperature and store it for future use. Step 3: Place the solid powder obtained in step 2 in the target chamber of the irradiation equipment, evacuate to 0.0001Pa, raise the temperature to 800-900K, and then irradiate the solid powder. After the irradiation is completed, naturally cool to room temperature in a vacuum environment and take it out to obtain the modified carbon nanotubes.

3. The method for preparing a conductive film containing carbon nanotubes according to claim 2, characterized in that: The preparation method of the reticulated carbon nanotubes is as follows: nickel oxide is added into an organic acid aqueous solution at a solid-liquid ratio of 0.05 to 0.1 g / mL, and the temperature is raised to 50 to 70°C and then soaked at this temperature for 5 to 8 hours; after the soaking is completed, it is filtered, and the obtained solid filter material is dried at a temperature of 550 to 750°C for 30 to 50 minutes; after the drying is completed, it is transferred into a tubular furnace, and the temperature is raised to 650 to 850°C under nitrogen protection, and then hydrogen and propylene are continuously introduced into the furnace at a flow ratio of 0.2 to 0.4:1, and the reaction is kept warm for 1 to 3 hours and then naturally cooled to room temperature, and finally the obtained solid material is taken out to obtain the reticulated carbon nanotubes.

4. The method for preparing a conductive film containing carbon nanotubes according to claim 1, characterized in that: The power of the ultrasonic dispersion is 50 to 350 W, and the ultrasonic dispersion time is 20 to 50 hours.

5. The method for preparing a conductive film containing carbon nanotubes according to claim 1, characterized in that: The temperature of the high temperature calcination is set to 290-310° C., and the time of the high temperature calcination is set to 3-4 hours.

6. The method for preparing a conductive film containing carbon nanotubes according to claim 1, characterized in that: The alkali solution is selected from any one of a sodium hydroxide aqueous solution and a potassium hydroxide aqueous solution, and the concentration of the alkali solution is 3-5wt%.

7. The method for preparing a conductive film containing carbon nanotubes according to claim 3, characterized in that: The organic acid is 3-hydroxy-3-carboxyl-1,5-pentanedioic acid, and the concentration of the organic acid in the organic acid aqueous solution is 20-30 wt %.

8. The method for preparing a conductive film containing carbon nanotubes according to claim 3, characterized in that: The flow rate of the nitrogen gas is 300-500 sccm, and the flow rate of the hydrogen gas is 100-300 sccm.

9. The method for preparing a conductive film containing carbon nanotubes according to claim 2, characterized in that: The ion beam used for irradiation is an argon ion beam with an energy range of 50 to 100 KeV. The irradiation dose is set to 1×10 16 ~1×10 17 ions / cm 2 .

10. A conductive film containing carbon nanotubes, characterized in that: The conductive film is prepared by the method for preparing a conductive film containing carbon nanotubes as described in any one of claims 1 to 9.

Images