Flexible carbon nanotube-based transparent conductive film and preparation method and application thereof
By using a multilayer flexible carbon nanotube-based transparent conductive film, the brittleness and cost issues of indium tin oxide films have been solved, achieving a balance between high conductivity and light transmittance, making it suitable for flexible electronic devices and electromagnetic shielding devices.
Patent Information
- Application Number
- CN202511688472.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-18
- Publication Date
- 2026-02-13
AI Technical Summary
Existing transparent conductive films mostly use indium tin oxide as raw material, which has problems such as high brittleness, scarcity of indium resources, high cost, and complex processes. In addition, single-walled carbon nanotubes are prone to aggregation, which leads to a decrease in conductivity.
A flexible carbon nanotube-based transparent conductive film with a multilayer structure, comprising a substrate layer, modified carbon nanotubes, a two-dimensional conductive material, and a conductive polymer, is prepared by spraying and spin coating methods. The modifier is gallic acid, the two-dimensional material is MXene nanosheets, and the conductive polymer is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.
It achieves a balance between high conductivity and light transmittance, possesses high flexibility and durability, has a simple manufacturing process, low cost, and is suitable for flexible electronic devices and electromagnetic shielding devices.
Smart Images
Figure CN121528616A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optoelectronic functional materials, specifically to a flexible carbon nanotube-based transparent conductive film, its preparation method, and its applications. Background Technology
[0002] In recent years, transparent conductive films have attracted much attention from researchers due to their excellent flexibility and light transmittance, and have been widely used in various flexible electronic devices such as transparent flexible heaters, light-emitting diodes, and solar cells. However, traditional transparent flexible conductive films mostly use indium tin oxide (ITO) as the main raw material. Conductive films prepared from this material have problems such as high brittleness, scarcity of indium resources, high cost, and complex processes.
[0003] Carbon nanotubes (SNTs) have become a strong competitor in the field of transparent conductive films due to their excellent conductivity, mechanical strength, and flexibility. Compared with indium tin oxide (ITO), SNTs exhibit better cost-effectiveness, more abundant resource reserves, and better compatibility with advanced industrial needs. However, many problems still need to be solved. The significantly large aspect ratio of single-walled carbon nanotubes (SWCNTs) and the combination of van der Waals forces cause them to naturally tend to aggregate into bundles, which leads to a decrease in the conductivity of the film. Currently, most transparent conductive films are prepared by modifying conductive materials and compositing multiple conductive materials to achieve ideal performance. However, the preparation process is complex and costly.
[0004] Therefore, it is necessary to study a method for preparing flexible carbon nanotube-based transparent conductive films that can ensure high conductivity and light transmittance while also meeting the requirements for the film's mechanical properties and durability. Summary of the Invention
[0005] Therefore, the purpose of this invention is to provide a flexible carbon nanotube-based transparent conductive film, its preparation method, and its application, which can solve the technical problems involved in the background art.
[0006] The technical problem solved by this invention is achieved through the following technical solution: According to a first aspect of the present invention, a flexible carbon nanotube-based transparent conductive film is provided, comprising a substrate layer and a conductive layer, wherein the substrate layer is polyethylene terephthalate, and a conductive layer is deposited on the substrate layer, the conductive layer having a multilayer stacked structure, wherein from the substrate layer to the surface layer are modified carbon nanotubes, a two-dimensional conductive material and a conductive polymer, the three together constituting the conductive layer.
[0007] Preferably, the modifier used for the modified carbon nanotubes in the conductive layer is gallic acid.
[0008] Preferably, the two-dimensional conductive material is MXene nanosheets.
[0009] Preferably, the conductive polymer is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.
[0010] According to a second aspect of the present invention, a method for preparing a flexible carbon nanotube-based transparent conductive film is provided, wherein the method comprises the following steps: S1. Mix carbon nanotubes and modifiers in a certain proportion to prepare modified carbon nanotube powder, and disperse the powder in deionized water to obtain modified carbon nanotube dispersion. S2. Deposit the dispersion prepared in S1 onto a polyethylene terephthalate substrate to obtain a thin film; S3. Deposit a two-dimensional conductive material onto the thin film obtained in S2; S4. The conductive polymer is deposited onto the film obtained in S3 to obtain a flexible carbon nanotube-based transparent conductive film.
[0011] Furthermore, the specific preparation steps of the modified carbon nanotube dispersion in S1 include: (1) Carbon nanotubes and gallic acid were dispersed in deionized water at a mass ratio of 1:4, stirred at 60°C for 24 hours, then centrifuged, washed, and dried to obtain modified carbon nanotube powder. (2) The modified carbon nanotubes and sodium dodecylbenzenesulfonate were dispersed in deionized water at a mass ratio of 1:10, and the mixture was sonicated and centrifuged to obtain a 1 mg / mL modified carbon nanotube dispersion.
[0012] Furthermore, the modifier mentioned in S1 is gallic acid.
[0013] Furthermore, the two-dimensional conductive material described in S3 is MXene nanosheets.
[0014] Furthermore, the specific preparation method of the two-dimensional conductive material described in S3 includes: Lithium fluoride powder and concentrated hydrochloric acid of 9M were added to a polytetrafluoroethylene beaker at a mass-to-volume ratio of 1g:10mL and stirred for 30min. Then, Ti3AlC2 precursor powder was added in portions, with a mass ratio of Ti3AlC2 precursor powder to lithium fluoride powder of 1:2. The mixture was stirred thoroughly at 40℃ for 24h. The resulting solution was washed with deionized water and centrifuged repeatedly at 3500rpm for 15min until the pH value was greater than 6. The supernatant was collected as the final few-layer MXene dispersion, the effective component of which is MXene nanosheets.
[0015] Furthermore, the deposition method in S2 is spraying.
[0016] Furthermore, the deposition method in S3 and S4 is spin coating.
[0017] Furthermore, the conductive polymer described in S4 is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.
[0018] According to a third aspect of the present invention, an application of a flexible carbon nanotube-based transparent conductive film in the manufacture of a transparent heater and an electromagnetic shield is provided.
[0019] The present invention has the following advantages: 1. Multilayer transparent conductive films are prepared by spraying and spin coating. The prepared transparent conductive films maintain high conductivity and light transmittance while also having high flexibility and durability. The preparation process is simple and cost-effective.
[0020] 2. Green and pollution-free gallic acid was used to modify carbon nanotubes, which improved the problem of easy aggregation of carbon nanotubes and enhanced their conductivity.
[0021] 3. The tight bonding between different conductive materials, with the top conductive polymer protecting the internal conductive layer, improves device lifespan. It shows great promise for applications in the manufacture of flexible electronic devices, transparent heaters, and electromagnetic shielding. Attached Figure Description
[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.
[0023] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.
[0024] Figure 1 A schematic diagram of the structure of a flexible carbon nanotube-based transparent conductive film provided by the present invention; Figure 2 A flowchart illustrating the operation of Example 1 of a flexible carbon nanotube-based transparent conductive film provided by the present invention; Figure 3 A flowchart illustrating the operation of Example 2 of a flexible carbon nanotube-based transparent conductive film provided by the present invention; Figure 4SEM images of a flexible carbon nanotube-based transparent conductive film provided by the present invention, wherein (a), (b), and (c) correspond to the films obtained in S3, S4, and S5 of Example 1, respectively; Figure 5 Temperature change curves of an applied voltage of 10, 15, 20 and 25V are collected using a flexible carbon nanotube-based transparent conductive film as a transparent heater, as provided by the present invention. Figure 6 The electromagnetic shielding performance of flexible carbon nanotube-based transparent conductive films with different transmittances provided by this invention as electromagnetic shielding materials was collected at 8.2~12.4 GHz. Among them, sample 1: transmittance 80.14%, sample 2: transmittance 70.2%, and sample 3: transmittance 69.53%. Detailed Implementation
[0025] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0026] According to a first aspect of the present invention, a flexible carbon nanotube-based transparent conductive film is provided, comprising a substrate layer and a conductive layer, such as... Figure 1 As shown, the substrate is polyethylene terephthalate (PET), and the conductive layer includes modified carbon nanotubes, MXene nanosheets, and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS).
[0027] According to a second aspect of the present invention, a method for preparing a flexible carbon nanotube-based transparent conductive film is provided, comprising the following steps: S1. Mix carbon nanotubes and modifiers in a certain proportion to prepare modified carbon nanotube powder, and disperse the powder in deionized water to obtain modified carbon nanotube dispersion. S2. Deposit the dispersion prepared in S1 onto a polyethylene terephthalate substrate to obtain a thin film; S3. Deposit a two-dimensional conductive material onto the thin film obtained in S2; S4. The conductive polymer is deposited onto the film obtained in S3 to obtain a flexible carbon nanotube-based transparent conductive film.
[0028] The specific preparation steps of the modified carbon nanotube dispersion in S1 include: (1) Carbon nanotubes and gallic acid were dispersed in deionized water at a mass ratio of 1:4, stirred at 60°C for 24 hours, then centrifuged, washed, and dried to obtain modified carbon nanotube powder. (2) The modified carbon nanotubes and sodium dodecylbenzenesulfonate were dispersed in deionized water at a mass ratio of 1:10, and the mixture was sonicated and centrifuged to obtain a 1 mg / ml modified carbon nanotube dispersion.
[0029] The modifier in S1 is gallic acid.
[0030] Among them, the two-dimensional conductive material in S3 is MXene nanosheets.
[0031] The specific preparation method of the two-dimensional conductive material in S3 includes: Lithium fluoride powder and 9M concentrated hydrochloric acid were added to a polytetrafluoroethylene beaker at a mass-to-volume ratio of 1 g: 10 mL and stirred for 30 min. Then, Ti3AlC2 precursor powder was added in portions, with a mass ratio of Ti3AlC2 precursor powder to lithium fluoride powder of 1:2. The mixture was stirred thoroughly at 40 °C for 24 h. The resulting solution was washed with deionized water and centrifuged repeatedly at 3500 rpm for 15 min until the pH value was greater than 6. The supernatant was collected as the final few-layer MXene dispersion, the effective component of which is MXene nanosheets.
[0032] The deposition method in S2 is spraying.
[0033] The deposition method in S3 and S4 is spin coating.
[0034] The conductive polymer in S4 is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.
[0035] Example 1 like Figure 2 The diagram shown is an operation flowchart of Embodiment 1 provided by the present invention.
[0036] S1. Carbon nanotubes and gallic acid were dispersed in deionized water at a mass ratio of 1:4, stirred at 60°C for 24 hours, then centrifuged, washed, and dried to obtain modified carbon nanotube powder; modified carbon nanotubes and sodium dodecylbenzenesulfonate were dispersed in deionized water at a mass ratio of 1:10, and after sonication and centrifugation, a 1 mg / mL modified carbon nanotube dispersion was obtained.
[0037] S2. Add 2g of lithium fluoride powder and 20mL of 9M concentrated hydrochloric acid to a polytetrafluoroethylene beaker and stir for 30min. Then add 1g of Ti3AlC2 precursor powder in portions and stir thoroughly at 40℃ for 24h. Wash the resulting solution with deionized water and centrifuge repeatedly at 3500rpm for 15min until the pH value is greater than 6. Collect the supernatant as the final few-layer MXene dispersion, the effective component of which is MXene nanosheets.
[0038] S3. The dispersion prepared in S1 is deposited onto a polyethylene terephthalate substrate by spraying to obtain a thin film.
[0039] S4. The MXene nanosheet dispersion prepared in S2 is deposited onto the film obtained in S3 by spin coating.
[0040] S5. Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is deposited onto the film obtained in S4 by spin coating to obtain a flexible carbon nanotube-based transparent conductive film.
[0041] Example 2 like Figure 3 The diagram shown is an operation flowchart of Embodiment 2 provided by the present invention.
[0042] S1. Carbon nanotubes and gallic acid were dispersed in deionized water at a mass ratio of 1:1, stirred at 100℃ for 24h, then centrifuged, washed, and dried to obtain modified carbon nanotube powder; modified carbon nanotubes and sodium dodecylbenzenesulfonate were dispersed in deionized water at a mass ratio of 1:10, and after sonication and centrifugation, a 1mg / mL modified carbon nanotube dispersion was obtained.
[0043] S2. Add 2g of lithium fluoride powder and 20mL of 9M concentrated hydrochloric acid to a polytetrafluoroethylene beaker and stir for 30min. Then add 1g of Ti3AlC2 precursor powder in portions and stir thoroughly at 40℃ for 24h. Wash the resulting solution with deionized water and centrifuge repeatedly at 3500rpm for 15min until the pH value is greater than 6. Collect the supernatant as the final few-layer MXene dispersion, the effective component of which is MXene nanosheets.
[0044] S3. The dispersion prepared in S1 is deposited onto a polyethylene terephthalate substrate by spraying to obtain a thin film.
[0045] S4. The MXene nanosheet dispersion prepared in S2 is deposited onto the film obtained in S3 by spin coating.
[0046] S5. Poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is deposited onto the film obtained in S4 by spin coating to obtain a flexible carbon nanotube-based transparent conductive film.
[0047] The difference between Example 1 and Example 2 lies in the ratio of carbon nanotubes to gallic acid and the stirring temperature when preparing the modified carbon nanotube dispersion.
[0048] The microstructure of flexible carbon nanotube-based transparent conductive films was characterized using scanning electron microscopy, such as... Figure 4 The image shown is a SEM image of the transparent conductive film provided by the present invention, wherein... Figure 4 Figures (a), (b), and (c) correspond to the films obtained in S3, S4, and S5 of Example 1, respectively. It can be seen that Figure (a) exhibits a good disordered network structure, and the network structure gradually becomes denser from Figure (a) to Figure (c), ultimately forming a smooth and dense film. This is because carbon nanotubes are deposited in S3 to construct the basic network structure, MXene nanosheets are deposited in S4 to fill the gaps in the network structure, and conductive polymers are deposited in S5 to further fill the gaps in the network, indicating that the conductive layer of the flexible carbon nanotube-based transparent conductive film is well bonded.
[0049] In this application, a pre-prepared flexible carbon nanotube-based transparent conductive film is connected to a thermocouple and a computer to collect temperature changes of the film under different voltages. During the application of voltage to the flexible carbon nanotube-based transparent conductive film, an electrical energy to heat energy conversion occurs, resulting in a temperature rise, which is then monitored and collected by the computer. The temperatures of the conductive film at applied voltages of 10, 15, 20, and 25V are as follows: Figure 5 As shown in the figure. The results show that the temperature of the film increases significantly with the increase of the applied voltage, and it can be rapidly heated to the maximum temperature within 60 seconds, indicating that it has good electrothermal performance.
[0050] In this application, a prepared flexible carbon nanotube-based transparent conductive film is used as an electromagnetic shielding material. The shielding performance against electromagnetic waves is achieved through the absorption and reflection efficiency of the conductive material. For example... Figure 6 The figures shown are electromagnetic shielding performance diagrams of flexible carbon nanotube-based transparent conductive films with transmittances of 80.14%, 70.2%, and 69.53% at 8.2–12.4 GHz. The results indicate that the present invention achieves a good balance between transmittance and electromagnetic shielding performance.
[0051] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A flexible carbon nanotube-based transparent conductive film, characterized in that, It includes a base layer and a conductive layer. The base layer is polyethylene terephthalate, and a conductive layer is deposited on the base layer. The conductive layer has a multi-layer stacked structure, consisting of modified carbon nanotubes, two-dimensional conductive materials, and conductive polymers from the base layer to the surface layer. The three components together constitute the conductive layer.
2. The flexible carbon nanotube-based transparent conductive film according to claim 1, characterized in that, The modifier used for the modified carbon nanotubes in the conductive layer is gallic acid.
3. The flexible carbon nanotube-based transparent conductive film according to claim 1, characterized in that, The two-dimensional conductive material is MXene nanosheets.
4. The flexible carbon nanotube-based transparent conductive film according to claim 1, characterized in that, The conductive polymer is poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.
5. A method for preparing a flexible carbon nanotube-based transparent conductive film, characterized in that, Includes the following steps: S1. Mix carbon nanotubes and modifiers in a certain proportion to prepare modified carbon nanotube powder, and disperse the powder in deionized water to obtain modified carbon nanotube dispersion. S2. Deposit the dispersion prepared in S1 onto a polyethylene terephthalate substrate to obtain a thin film; S3. Deposit a two-dimensional conductive material onto the thin film obtained in S2; S4. The conductive polymer is deposited onto the film obtained in S3 to obtain a flexible carbon nanotube-based transparent conductive film.
6. The method for preparing a flexible carbon nanotube-based transparent conductive film according to claim 5, characterized in that, The preparation steps of the modified carbon nanotube dispersion include: (1) Carbon nanotubes and modifiers were dispersed in deionized water at a mass ratio of 1:4, stirred at 60°C for 24 hours, then centrifuged, washed, and dried to obtain modified carbon nanotube powder. (2) The modified carbon nanotubes and sodium dodecylbenzenesulfonate were dispersed in deionized water at a mass ratio of 1:10, and the mixture was sonicated and centrifuged to obtain a 1 mg / mL modified carbon nanotube dispersion.
7. The method for preparing a flexible carbon nanotube-based transparent conductive film according to claim 5, characterized in that, The preparation steps of the two-dimensional conductive material include: Lithium fluoride powder and concentrated hydrochloric acid of 9M were added to a polytetrafluoroethylene beaker at a mass-to-volume ratio of 1g:10mL and stirred for 30min. Then, Ti3AlC2 precursor powder was added in portions, with a mass ratio of Ti3AlC2 precursor powder to lithium fluoride powder of 1:
2. The mixture was stirred thoroughly at 40℃ for 24h. The resulting solution was washed with deionized water and centrifuged repeatedly at 3500rpm for 15min until the pH value was greater than 6. The supernatant was collected as the final few-layer MXene dispersion, the effective component of which is MXene nanosheets.
8. The method for preparing a flexible carbon nanotube-based transparent conductive film according to claim 5, characterized in that, in, The deposition method in step S2 is spraying.
9. The method for preparing a flexible carbon nanotube-based transparent conductive film according to claim 5, characterized in that, in, The deposition method for steps S3 and S4 is spin coating.
10. The application of the flexible carbon nanotube-based transparent conductive film according to claim 1 or the film prepared by any one of claims 5-9 in the preparation of flexible electronic devices, transparent heaters and electromagnetic shields.