N-type single-walled carbon nanotube thermoelectric thin film with stable air, preparation method and application of N-type single-walled carbon nanotube thermoelectric thin film

Abstract

The invention provides an air-stable N-type single-walled carbon nanotube thermoelectric film, a preparation method and application thereof, and the preparation method specifically comprises the following steps: S1, diluting a single-walled carbon nanotube and poly (benzodifuran diketone) to a certain concentration to obtain a single-walled carbon nanotube dispersion liquid and a poly (benzodifuran diketone) dispersion liquid; s2, adding a polyethyleneimine solution into the single-walled carbon nanotube dispersion liquid, stirring at room temperature for 20-30 hours, uniformly mixing, and carrying out vacuum filtration to obtain a film A; s3, poly (benzodifuran diketone) dispersion liquid is introduced into the film A, suction filtration is performed, and a film B of a laminated structure is obtained; and S4, immersing the thin film B in a post-treatment solution, carrying out post-treatment, taking out the thin film B, and carrying out vacuum drying at 50-70 DEG C for 0.5-1.5 h to obtain the film.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoelectric materials, and in particular to an air-stable N-type single-walled carbon nanotube thermoelectric film, a preparation method and applications thereof. Background Art

[0002] Thermoelectric materials are a type of key material that can convert thermal energy into electrical energy or electrical energy into thermal energy. They are widely used in the fields of renewable energy utilization and energy efficiency improvement. Flexible thermoelectric devices have attracted much attention because of their ability to adapt to various curved surfaces and their thinness and flexibility. Traditional thermoelectric materials such as lead sulfide and bismuth selenide have attracted widespread attention due to their excellent thermoelectric properties, but their application in flexible devices is limited by mechanical stability and preparation complexity. Therefore, the development of new flexible thermoelectric materials that have both stability and high performance has become one of the current research focuses.

[0003] Carbon nanotubes (CNTs) have become a hot topic in thermoelectric material research due to their excellent electron transport properties and unique structural characteristics. In particular, single-walled carbon nanotubes (SWCNTs) have extremely high electrical conductivity and good solution processing capabilities, making them widely used in flexible electronic devices.

[0004] In order to make single-walled carbon nanotubes have more excellent thermoelectric properties, we need to convert P-type SWCNTs into n-type SWCNTs. However, N-type SWCNTs easily undergo nucleophilic reactions with oxygen, water, and carbon dioxide in the air, thereby turning them back into P-type, which limits their widespread use in applications that require high environmental stability.

[0005] Therefore, the current technical problem to be solved is how to convert P-type SWCNT into N-type SWCNT, and at the same time improve the stability of N-type single-walled carbon nanotube thermoelectric film in air environment so that it has excellent thermoelectric performance. Summary of the invention

[0006] The present invention is made to solve the above problems, and aims to provide an air-stable N-type single-walled carbon nanotube thermoelectric film, a preparation method and application thereof.

[0007] The invention provides a method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film, which has the following characteristics and specifically comprises the following steps: S1, diluting single-walled carbon nanotubes and poly(benzodifurandione) to a certain concentration to obtain a single-walled carbon nanotube dispersion and a poly(benzodifurandione) dispersion; S2, adding a polyethyleneimine solution to the single-walled carbon nanotube dispersion, stirring at room temperature for 20-30 hours, and vacuum filtering after mixing evenly to obtain a film A; S3, introducing the poly(benzodifurandione) dispersion into the film A and filtering to obtain a film B with a laminated structure; S4, immersing the film B in a post-treatment solution, performing post-treatment, and vacuum drying at 50-70°C for 0.5-1.5 hours after taking out the film B.

[0008] The method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film provided by the present invention may also have the following characteristics: wherein, in step S1, the dispersion solvent of the single-walled carbon nanotube dispersion is a polar solvent.

[0009] The method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film provided by the present invention may also have the following characteristics: wherein the polar solvent is water or N-methyl-2-pyrrolidone.

[0010] The method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film provided by the present invention may also have the following characteristics: wherein the concentrations of the single-walled carbon nanotube dispersion and the poly(benzodifurandione) dispersion are both 0.1-0.3 mg / mL.

[0011] The method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film provided by the present invention may also have the following characteristics: wherein, in step S4, the post-treatment solution is a polyethyleneimine solution, and the dispersing solvent of the polyethyleneimine solution is at least one of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, water and ethanol.

[0012] The method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film provided by the present invention may also have the following characteristics: wherein, in step S4, the specific steps of post-treatment are as follows: the post-treatment solution without film B is heated to 15-200° C. and maintained for 8-24 hours.

[0013] The method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film provided by the present invention may also have the following characteristics: wherein, in step S2, the specific steps of vacuum filtration are as follows: the single-walled carbon nanotube dispersion is vacuum filtered through a microporous filter membrane.

[0014] The method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film provided by the present invention may also have the following characteristics: wherein the pore size of the microporous filter membrane is 0.4-0.5 μm.

[0015] The present invention also provides an air-stable N-type single-walled carbon nanotube thermoelectric film, which is prepared by the above-mentioned method for preparing the air-stable N-type single-walled carbon nanotube thermoelectric film.

[0016] The present invention also provides the application of air-stable N-type single-wall carbon nanotube thermoelectric film in flexible electronic devices.

[0017] Functions and Effects of the Invention

[0018] According to the air-stable N-type single-walled carbon nanotube thermoelectric film, preparation method and application thereof involved in the present invention, the semiconductor behavior of the laminated film is converted from P-type to N-type by adding polyethyleneimine. At the same time, based on the laminated structure of the present invention and the introduction of poly(benzodifurandione), while preparing the N-type single-walled carbon nanotubes, it also has good air stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the chemical structures of single-walled carbon nanotubes, polyethyleneimine and poly(benzodifurandione) in an embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the vacuum filtration and solvent post-treatment process in the embodiment of the present invention;

[0021] Figure 3 The thermoelectric performance of the laminated filtration film and the physical hybrid film in Example 1 of the present invention;

[0022] Figure 4 The thermoelectric properties of the polyethyleneimine laminated filtration film with and without the addition of polyethyleneimine in Example 1-2 of the present invention;

[0023] Figure 5 is the thermoelectric performance of the thin films after treatment at different temperatures in Examples 1 and 4 of the present invention; and

[0024] Figure 6 It is the long-term stability of the film in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and drawings specifically describe the air-stable N-type single-walled carbon nanotube thermoelectric film, preparation method and application thereof.

[0026] Figure 1 Schematic diagram of the chemical structures of single-walled carbon nanotubes, polyethyleneimine and poly(benzodifurandione) in an embodiment of the present invention. Figure 2It is a schematic diagram of the vacuum filtration and solvent post-treatment process in an embodiment of the present invention.

[0027] Example 1

[0028] S1, diluting the dispersion of single-walled carbon nanotubes and poly(benzofurandione) to 0.2 mg / mL to obtain a single-walled carbon nanotube solution and a poly(benzofurandione) dispersion.

[0029] S2, adding 1 mL of polyethyleneimine solution to the single-walled carbon nanotube dispersion, stirring at room temperature for 24 hours, and vacuum filtering the diluted single-walled carbon nanotube dispersion through a microporous filter membrane with a pore size of 0.45 μm to obtain a film A.

[0030] S3, introducing the poly(benzofurandione) dispersion into the film A, vacuum filtering and vacuum drying at 60°C for 1 hour to obtain a film B with a laminated structure.

[0031] S4, preparing a polyethyleneimine / dimethyl sulfoxide mixed solution with a mass concentration of 25 mg / mL as a post-treatment solution, placing the film B therein, raising the temperature to 100° C. and maintaining it for 12 hours, thereby obtaining an N-type single-walled carbon nanotube thermoelectric film.

[0032] Example 2

[0033] This embodiment is based on Embodiment 1, and Step S4 is omitted.

[0034] Example 3

[0035] In this embodiment, based on the embodiment 1, step S4 is omitted, and step S2 is replaced by "the diluted single-walled carbon nanotube dispersion is vacuum filtered through a microporous filter membrane with a pore size of 0.45 μm to obtain a film A."

[0036] Example 4

[0037] Based on Example 1, this example replaces "placing film B therein and heating it to 100° C. and maintaining it for 12 hours" in step 4 with "placing film B therein and maintaining it at room temperature for 12 hours".

[0038] Figure 3 The thermoelectric performance of the laminated filtration film and the physical mixed film in Example 1 of the present invention.

[0039] like Figure 3 As shown, compared with direct physical mixing, the laminated film has better thermoelectric properties.

[0040] Figure 4 The thermoelectric properties of the polyethyleneimine laminated filtration membranes in Examples 1-2 of the present invention with and without addition thereof.

[0041] like Figure 4 As shown, the addition of polyethyleneimine can better transform the semiconductor behavior of the stacked film from P-type to N-type.

[0042] Figure 5 The thermoelectric properties of the films after treatment at different temperatures in Examples 1 and 4 of the present invention.

[0043] like Figure 5 As shown, the post-treatment of elevated temperature can further improve the thermoelectric performance of the N-type stacked film.

[0044] Figure 6 It is the long-term stability of the film in Example 1 of the present invention.

[0045] like Figure 6 As shown, the thermoelectric performance of the laminated film treated at elevated temperature has better stability.

[0046] Functions and Effects of the Embodiments

[0047] According to the air-stable N-type single-walled carbon nanotube thermoelectric film, preparation method and application thereof involved in the present invention, the semiconductor behavior of the laminated film is converted from P-type to N-type by adding polyethyleneimine. At the same time, based on the laminated structure of the present invention and the introduction of poly(benzodifurandione), while preparing the N-type single-walled carbon nanotubes, it also has good air stability.

[0048] The film prepared by the present invention has broad application prospects in the field of low-grade thermoelectric energy collection at room temperature.

[0049] The present invention combines polyethyleneimine and other solvents in the post-processing process, effectively improving the stability and thermoelectric performance of the single-walled carbon nanotube film, and is suitable for applications in the fields of flexible electronic devices and energy conversion.

[0050] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film, characterized in that: The specific steps include: S1, diluting single-walled carbon nanotubes and poly(benzofurandione) to a certain concentration to obtain a single-walled carbon nanotube dispersion and a poly(benzofurandione) dispersion; S2, adding polyethyleneimine solution to the single-walled carbon nanotube dispersion, stirring at room temperature for 20-30 hours, mixing evenly and vacuum filtering to obtain film A; S3, introducing the poly(benzodifurandione) dispersion into the film A and filtering it to obtain a film B with a laminated structure; S4, immersing the film B in a post-treatment solution for post-treatment, taking it out and drying it in vacuum at 50-70° C. for 0.5-1.5 h to obtain the film.

2. The method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 1, characterized in that: in, In step S1, the dispersion solvent of the single-walled carbon nanotube dispersion is a polar solvent.

3. The method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 2, characterized in that: in, The polar solvent is water or N-methyl-2-pyrrolidone.

4. The method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 1, characterized in that: in, The concentrations of the single-walled carbon nanotube dispersion and the poly(benzodifurandione) dispersion are both 0.1-0.3 mg / mL.

5. The method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 1, characterized in that: in, In step S4, the post-treatment solution is a polyethyleneimine solution, and the dispersing solvent of the polyethyleneimine solution is at least one of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, water and ethanol.

6. The method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 1, characterized in that: in, In step S4, the specific steps of the post-treatment are as follows: the post-treatment solution without the film B is heated to 15-200° C. and maintained for 8-24 hours.

7. The method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 1, characterized in that: in, In step S2, the specific steps of the vacuum filtration are as follows: the single-walled carbon nanotube dispersion is vacuum filtered through a microporous filter membrane.

8. The method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 7, characterized in that: in, The pore size of the microporous filter membrane is 0.4-0.5 μm.

9. The air-stable N-type single-walled carbon nanotube thermoelectric film according to claim 1, characterized in that: The film is prepared by the method for preparing an air-stable N-type single-walled carbon nanotube thermoelectric film according to any one of claims 1 to 8.

10. Use of the air-stable N-type single-walled carbon nanotube thermoelectric film as claimed in claim 9 in flexible electronic devices.

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