Pedot:pamps powder, its preparation method and application

Abstract

The application provides a PEDOT:PAMPS powder and a preparation method and application thereof, and belongs to the technical field of conductive material preparation. The preparation method uses PAMPS with no benzene ring in the molecular chain to replace rigid PSS as a template for EDOT polymerization, so that the PAMPS and the PEDOT generate electrostatic interaction to generate PEDOT:PAMPS. Compared with the PEDOT:PSS system, the PAMPS has strong acidic sulfonic acid groups and flexible alkyl main chains, and the conductivity and flexibility are considered from the molecular level. At the same time, because the flexible chain of PAMPS has a higher segment mobility, the oxidation polymerization of EDOT monomers can be efficiently completed at room temperature (20-30 DEG C), without heating, the reaction time is significantly shortened, and a high-purity dispersion liquid can be obtained only by simple dialysis purification. The application first realizes the coordination and unity of high conductivity and intrinsic flexibility in the same material, and the prepared PEDOT:PAMPS conductive dispersion liquid has good storage stability and dispersion uniformity, and is not easy to agglomerate and settle.

Description

Technical Field

[0001] This application relates to the field of conductive material preparation technology, and in particular to a PEDOT:PAMPS powder, its preparation method and application. Background Technology

[0002] The conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) possesses advantages such as high electrical conductivity, good environmental stability, and excellent biocompatibility, and has been widely studied in fields such as flexible electronics, biosensors, supercapacitors, and neural electrodes. However, PEDOT itself is insoluble and requires doping and dispersion with the aid of polyanionic templates to obtain processable aqueous dispersions. Commercially available PEDOT:PSS (polystyrene sulfonate) utilizes PSS as a dopant equilibria and template to achieve aqueous processing of PEDOT. Building upon this, researchers are continuously exploring alternative materials to replace or enhance PSS to modulate the electrical, mechanical, and biological properties of the composites.

[0003] Existing technologies mainly fall into two categories: First, using natural polymers such as sodium alginate and cellulose to replace PSS as a template. While this improves biocompatibility and flexibility, the lack of strong acidic sulfonic acid groups results in insufficient doping efficiency and poor regularity of the PEDOT main chain structure, leading to conductivity far below application requirements. Second, post-processing modification of PEDOT:PSS by adding polar solvents or blending with conductive nanomaterials improves conductivity to some extent, but it does not address the root cause of film brittleness caused by the rigid benzene rings in the PSS molecular chain. When the film is bent, stress concentration still causes microcracks that propagate rapidly, eventually leading to cracking and failure. Furthermore, the post-processing increases manufacturing costs and performance instability, failing to achieve a synergistic coexistence of high conductivity and excellent flexibility within the same material system. In other words, existing technologies cannot fundamentally solve the problems of poor long-term dispersion, excessive rigidity, and film brittleness associated with PEDOT:PSS. Summary of the Invention

[0004] The purpose of this application is to provide a PEDOT:PAMPS powder, its preparation method, and its applications. This preparation method uses PAMPS instead of PSS as the template for PEDOT, yielding PEDOT:PAMPS powder with good long-term dispersibility, excellent electrical conductivity, and good flexibility. Furthermore, this preparation method allows for rapid and controllable template construction at room temperature, achieving low-energy processing while avoiding side reactions caused by thermal initiation, thus improving the electrical conductivity, uniformity, and functional integration of PEDOT:PAMPS.

[0005] To achieve the above-mentioned objectives, this application provides a method for preparing PEDOT:PAMPS powder, comprising the following steps: S1, add lithium phenyl (2,4,6-trimethylbenzoyl) phosphate to sodium 2-acrylamido-2-methylpropanesulfonate, stir in the dark until completely dissolved and stabilize the temperature at 20~40℃ to prepare AMPS solution; S2, the AMPS solution was irradiated under ultraviolet light at a wavelength of 365 nm for 60-120 s to form poly(2-acrylamido-2-methylpropanesulfonic acid); then, the formed poly(2-acrylamido-2-methylpropanesulfonic acid) was added to ultrapure water and stirred until completely dissolved to obtain a PAMPS solution. S3, mix PAMPS solution and 3,4-ethylenedioxythiophene evenly; then add ammonium persulfate and ferric chloride, and react at 20~40℃ for 8~30 h to obtain PEDOT:PAMPS dispersion; then pour PEDOT:PAMPS dispersion into a dialysis bag with a molecular weight cutoff of 8000~14000 and dialyze for 48~72 h; finally, freeze-dry the dialysate to obtain PEDOT:PAMPS powder.

[0006] Furthermore, in the PEDOT:PAMPS dispersion, the mass ratio of PAMPS to PEDOT is 1:(0.3~1).

[0007] Furthermore, in step S3, the mass ratio of ammonium persulfate to 3,4-ethylenedioxythiophene is (1~4):1, and the mass ratio of ferric chloride to 3,4-ethylenedioxythiophene is (0.05~0.15):1.

[0008] This application also provides a PEDOT:PAMPS powder, which is prepared by the preparation method described in any of the foregoing technical solutions.

[0009] This application also provides a method for preparing a PEDOT:PAMPS conductive dispersion, comprising the following steps: mixing the PEDOT:PAMPS powder described in the aforementioned technical solution with ultrapure water to prepare a PEDOT:PAMPS conductive dispersion with a mass fraction of 0.5% to 1%.

[0010] Furthermore, the method includes the following step: adjusting the pH of the PEDOT:PAMPS conductive dispersion to 1-2.

[0011] Furthermore, the solution used to adjust the pH is dilute hydrochloric acid.

[0012] This PEDOT:PAMPS conductive dispersion can be used to prepare flexible conductive films.

[0013] The beneficial effects of this invention are: 1. This application provides a method for preparing PEDOT:PAMPS powder, and for the first time proposes using PAMPS, whose molecular chain does not contain benzene rings, to replace rigid PSS as a template for EDOT polymerization, allowing PAMPS and PEDOT to interact electrostatically to generate PEDOT:PAMPS. PAMPS combines strong acidic sulfonic acid groups (ensuring efficient doping and carrier concentration) with a flexible alkyl backbone (eliminating the rigid constraint of benzene rings), thus achieving both conductivity and flexibility at the molecular level. Simultaneously, due to the higher segment mobility of the flexible PAMPS chain, EDOT monomers can efficiently complete oxidative polymerization at room temperature (20-30℃) without heating, significantly shortening the reaction time. High-purity dispersions can be obtained simply through dialysis purification. The resulting PEDOT:PAMPS film possesses a "rigid-flexible" combined microphase separation structure, with the PEDOT-enriched region providing a conductive pathway and the PAMPS continuous phase providing stress buffering.

[0014] 2. Compared with existing technologies, this application has achieved the following breakthroughs: First, it solves the problem of poor conductivity of natural polymer templates and the problem of high rigidity of PSS systems, achieving for the first time a synergistic unity of high conductivity and intrinsic flexibility in the same material; Second, the preparation process is significantly simplified compared to the traditional PEDOT:PSS system, with room temperature two-step synthesis and no need for complex post-processing, significantly reducing energy consumption and process costs; Third, PAMPS does not contain benzene rings, avoiding the potential biotoxicity problems of PSS, while the synthesized polymer backbone ensures long-term stability, and the overall performance is superior to existing technical solutions.

[0015] 3. The conductivity of the PEDOT:PAMPS conductive dispersion prepared in this application is significantly improved. In fact, by replacing the sheet template PSS with the chain template PAMPS and optimizing the pH value, a conductivity 4 times higher than that of traditional PEDOT:PSS can be obtained.

[0016] 4. The PEDOT:PAMPS conductive dispersion prepared in this application exhibits good storage stability and dispersion uniformity, and is not prone to agglomeration and sedimentation. This enables it to form a uniform and defect-free wet film during subsequent solution processing such as spin coating, spraying, or printing.

[0017] 5. Because the main chain of PAMPS is a typical carbon-carbon single bond connection, it lacks large rigid side groups. Although the side chain groups are not small in size, they are connected to the main chain through a flexible branch, and the resistance to the movement of the main chain is much less than that of directly connected benzene rings. This allows the single bonds on the main chain to rotate more freely, giving the entire molecular chain flexibility. Therefore, the film prepared using the PEDOT:PAMPS conductive dispersion of this application has excellent flexibility and tensile strength, fundamentally solving the industry pain point that traditional PEDOT:PSS films are prone to microcracks or even breakage when bent or stretched due to their high rigidity and brittleness. This breakthrough makes it perfectly suited for applications with stringent requirements for mechanical stability, such as flexible wearable devices, foldable displays, and bioelectronic devices.

[0018] 6. This application employs a two-step synthesis method at room temperature and pressure, which not only significantly shortens the reaction time and reduces heat consumption, but also avoids side reactions caused by high temperatures, improving the controllability and safety of the reaction. It also boasts high raw material utilization, saving on raw material and process costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of PAMPS and EDOT forming PEDOT:PAMPS in this application.

[0020] Figure 2 FT-IR images of AMPS, EDOT and PEDOT:PAMPS powder prepared in Example 1.

[0021] Figure 3 SEM comparison of PEDOT:PAMPS and PEDOT:PSS.

[0022] Figure 4 A TEM comparison diagram of PEDOT:PAMPS and PEDOT:PSS.

[0023] Figure 5 The graphs show the water dispersibility of a 1% PEDOT:PSS aqueous solution (control group) and the PEDOT:PAMPS conductive dispersions from Examples 2-10. The first row, from left to right, shows the water dispersibility of the PEDOT:PAMPS conductive dispersions prepared in Examples 3, 2, and 4-10 after 0 hours of storage. The second row, from left to right, shows the water dispersibility of the PEDOT:PAMPS conductive dispersions prepared in Examples 3, 2, and 4-10 after 72 hours of storage.

[0024] Figure 6 The graph shows a comparison of the water dispersibility of a 1% PEDOT:PSS aqueous solution and the PEDOT:PAMPS conductive dispersion from Example 2, diluted 20 times.

[0025] Figure 7 The |Z|-frequency diagrams of PAMPS / PEDOT:PSS hydrogels with 1% PEDOT:PSS added and PAMPS / PEDOT:PAMPS hydrogels with PEDOT:PAMPS conductive dispersions from Examples 11, 2, 6, and 12.

[0026] Figure 8 Ionic conductivity graphs of PAMPS / PEDOT:PSS hydrogels with 1% PEDOT:PSS added and PAMPS / PEDOT:PAMPS hydrogels with PEDOT:PAMPS conductive dispersions from Examples 11, 2, 6, and 12 added.

[0027] Figure 9 Electron conductivity graphs of PAMPS / PEDOT:PSS hydrogels with 1% PEDOT:PSS by mass and PAMPS / PEDOT:PAMPS hydrogels with PEDOT:PAMPS conductive dispersions from Examples 11, 2, 6, and 12.

[0028] Figure 10 Conductivity diagrams of conductive dispersions of PEDOT:PAMPS with a mass fraction of 1% prepared from PEDOT:PSS aqueous solution, Example 2, and Examples 13-16.

[0029] Figure 11 Zeta potential diagrams of 1% PEDOT:PSS aqueous solution, Example 2, and 13-16 prepared PEDOT:PAMPS conductive dispersions with a mass fraction of 1%.

[0030] Figure 12 pH values ​​of PEDOT:PSS solution and PEDOT:PAMPS solutions with different mass ratios before and after pH=2.13.

[0031] Figure 13 Conductivity graphs of PEDOT:PSS solution and PEDOT:PAMPS solution with different mass ratios before and after pH=2.13.

[0032] Figure 14 Conductivity graphs of PEDOT:PSS solution and PEDOT:PAMPS solution with different mass ratios before and after pH=2.

[0033] Figure 15Conductivity graphs of PEDOT:PSS solution and PEDOT:PAMPS solution with different mass ratios before and after pH=1. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0036] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] This invention provides a method for preparing PEDOT:PAMPS powder, comprising the following steps: S1, add lithium phenyl (2,4,6-trimethylbenzoyl) phosphate to sodium 2-acrylamido-2-methylpropanesulfonate, stir at room temperature in the dark until completely dissolved, and stabilize the temperature at 20~40℃ to prepare AMPS solution; S2, the AMPS solution was irradiated under ultraviolet light at a wavelength of 365 nm for 60-120 s to form poly(2-acrylamido-2-methylpropanesulfonic acid); then, the formed poly(2-acrylamido-2-methylpropanesulfonic acid) was added to ultrapure water and stirred until completely dissolved to obtain a PAMPS solution. S3, mix PAMPS solution and 3,4-ethylenedioxythiophene evenly; then add ammonium persulfate and ferric chloride, and react at 20~40℃ for 8~30 h to obtain PEDOT:PAMPS dispersion; then pour PEDOT:PAMPS dispersion into a dialysis bag with a molecular weight cutoff of 8000~14000 and dialyze for 48~72 h; finally, freeze-dry the dialysate to obtain PEDOT:PAMPS powder.

[0038] In the PEDOT:PAMPS dispersion, the mass ratio of PAMPS to PEDOT is 1:(0.3~1).

[0039] The mass ratio of ammonium persulfate to 3,4-ethylenedioxythiophene is (1~4):1, and the mass ratio of ferric chloride to 3,4-ethylenedioxythiophene is (0.05~0.15):1.

[0040] In this application, PAMPS is used instead of PSS as the template for PEDOT. PSS is replaced by a more flexible PAMPS chain as the template and negative charge donor. 3,4-Ethylenedioxythiophene (EDOT) undergoes oxidative coupling polymerization in the presence of ammonium persulfate (APS) and FeCl3 to generate PEDOT, which is positively charged. PAMPS and PEDOT are combined through electrostatic interaction to obtain PEDOT:PAMPS with better long-term dispersibility, stronger conductivity, and better flexibility.

[0041] Because PSS contains a benzene ring, a large and rigid planar structure, its presence restricts the free rotation of single bonds on the polymer backbone. In contrast, the PAMPS backbone is typically composed of carbon-carbon single bonds without large, rigid side groups. Although the side chain groups are not small, they are connected to the backbone via flexible branches, thus hindering backbone movement far less than a directly connected benzene ring. This allows the single bonds on the backbone to rotate more freely, giving the entire molecular chain flexibility.

[0042] The PEDOT:PAMPS powder obtained by the aforementioned method was mixed with ultrapure water to prepare a PEDOT:PAMPS conductive dispersion with a mass fraction of 0.5% to 1%.

[0043] In some embodiments, the method further includes the step of adjusting the pH of the PEDOT:PAMPS conductive dispersion to 1-2.

[0044] The solution used to adjust the pH is dilute hydrochloric acid.

[0045] This PEDOT:PAMPS conductive dispersion exhibits good storage stability and dispersion uniformity, is not prone to aggregation and sedimentation, and can form a uniform, defect-free wet film, making it suitable for preparing flexible conductive films. The resulting flexible conductive films can be used as electrode layers, hole transport layers, or sensitive layers in flexible optoelectronic devices.

[0046] The preparation method of PEDOT:PAMPS powder provided in this application will be described below with reference to specific embodiments. Unless otherwise specified, the raw materials and reagents used in the embodiments of this application were purchased commercially.

[0047] Example 1 Please see Figure 1 As shown, this embodiment provides a method for preparing PEDOT:PAMPS powder, including the following steps: Preparation of S1, AMPS solution: Weigh 0.02 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate (LAP), add it to 10 mL of sodium 2-acrylamido-2-methylpropanesulfonate (AMPS), stir at room temperature in the dark until completely dissolved, and stabilize the temperature at 25 °C to prepare an AMPS solution.

[0048] Synthesis of S2 and PAMPS: Pipette 0.4 mL of AMPS solution and heat at a wavelength of 365 nm and an intensity of 30 mW / cm. 2 Poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) was formed by irradiation under ultraviolet light for 90 s. Subsequently, the formed PAMPS was added to 10 mL of ultrapure water and stirred until completely dissolved to obtain a PAMPS solution.

[0049] S3, PEDOT: Synthesis of PAMPS: 10 mL of PAMPS solution and 0.07 mL of 3,4-ethylenedioxythiophene (EDOT) were mixed thoroughly. 200 mg of ammonium persulfate (APS) and 12 mg of ferric chloride (FeCl3) were weighed and added to the mixture. The reaction was carried out at 25 °C for 24 h to obtain a PEDOT:PAMPS dispersion. The mass ratio of APS to EDOT was 2:1, and the mass ratio of FeCl3 to EDOT was 0.12:1. The reacted liquid was poured into a dialysis bag with a molecular weight cutoff of 14000 and dialyzed for 48 h. Finally, the dialysate was freeze-dried to obtain PEDOT:PAMPS powder.

[0050] In this embodiment, the AMPS solution contains 50 wt%. 0.4 mL of AMPS is used to form PAMPS, containing 0.2 g of PAMPS. 0.07 mL of EDOT is completely converted to PEDOT in excess APS and FeCl3, with a PEDOT content of 0.1 g. Therefore, in this example, the mass ratio of PAMPS to PEDOT is 1:0.5.

[0051] Figure 2 FT-IR images of AMPS, EDOT and PEDOT:PAMPS powder prepared in Example 1.

[0052] As can be seen, at 1620 cm -1 At 1480 cm⁻¹, the -C=C⁻ peak of AMPS clearly disappeared. -1 The obvious appearance of the stretching vibration peak of the -C=C- double bond on the thiophene ring of EDOT indicates the successful synthesis of PEDOT:PAMPS.

[0053] Example 2 Take 0.1 g of PEDOT:PAMPS powder prepared in Example 1 and mix it with 10 mL of ultrapure water to prepare a PEDOT:PAMPS conductive dispersion with a mass fraction of 1%.

[0054] Using a 1% PEDOT:PSS aqueous solution as a control group, the 1% PEDOT:PAMPS conductive dispersion prepared in Example 2 and the 1% PEDOT:PSS aqueous solution were freeze-dried to obtain solid powders, respectively. The powders were then subjected to SEM testing, and the results are as follows: Figure 3 As shown.

[0055] Figure 3 The results show that PEDOT: PAMPS polymer chains are uniformly arranged, and PEDOT is deposited on the PAMPS chains as a template; PEDOT: PSS is distributed in sheets, and PEDOT deposition can be seen on the surface of the sheets.

[0056] The 1% PEDOT:PAMPS conductive dispersion and the 1% PEDOT:PSS aqueous solution prepared in Example 2 were diluted 50 times with ultrapure water, respectively. TEM tests were then performed using the diluted solutions, and the results are as follows: Figure 4 As shown.

[0057] Figure 4 The results show that on the surface of the PAMPS polymer chains in PEDOT:PAMPS, PEDOT is deposited on the PAMPS chains using PAMPS as a template, with a large and relatively uniform distribution, and PEDOT is arranged in a spherical and tightly packed manner; on the surface of the PSS sheet-like layer in PEDOT:PSS, PEDOT deposition can be seen, with varying brightness and uneven distribution.

[0058] Examples 3-10 Compared with Example 2, the difference lies in the different mass ratios of PAMPS and PEDOT, and the different mass fractions of the PEDOT:PAMPS conductive dispersion; as shown in Table 1; the rest is roughly the same as Example 2, and will not be repeated here.

[0059] Table 1 Using a 1% PEDOT:PSS aqueous solution as a control group, the water dispersibility of the 1% PEDOT:PSS aqueous solution and the PEDOT:PAMPS conductive dispersions from Examples 2-10 were compared. The test results are as follows: Figure 5 As shown.

[0060] Experiments showed that after 3 days (72 hours), dispersions with mass ratios of 1:1 and 1:2 all showed varying degrees of sedimentation. The 2% concentration dispersion showed more significant sedimentation. A mass ratio of approximately 1:(0.5-1) was selected as the best dispersion ratio, and the optimal mass fraction was approximately 1%.

[0061] After 5 months of storage, the PEDOT:PAMPS conductive dispersions prepared in Examples 2-3 and 5-6 showed slight sedimentation at the bottom, but still exhibited good dispersibility after shaking. The PEDOT:PAMPS conductive dispersions prepared in Examples 4 and 7-10 showed heavier sedimentation, but could still be dispersed after shaking without agglomeration. However, after 5 months of storage, PEDOT:PSS showed agglomeration at the bottom and could not be dispersed evenly after shaking.

[0062] After one year of storage, 0.5 mL of the PEDOT:PAMPS conductive dispersion from Example 2 and a 1% PEDOT:PSS aqueous solution were respectively added to the culture medium and mixed with 9.5 mL of ultrapure water. The water dispersibility of the two was compared, and the test results are as follows. Figure 6 As shown.

[0063] As can be seen, PEDOT:PAMPS exhibits good dispersibility, while PEDOT:PSS shows significant aggregation.

[0064] Example 11 The difference from Example 2 is that the mass ratio of PAMPS to PEDOT is 1:0.1; the rest is roughly the same as Example 2, and will not be repeated here.

[0065] Example 12 The difference from Example 2 is that the mass ratio of PAMPS to PEDOT is 1:1.5; the rest is roughly the same as Example 2, and will not be repeated here.

[0066] A 1% PEDOT:PSS aqueous solution was used as a control group.

[0067] A 1% PEDOT:PSS aqueous solution (control group) and the PEDOT:PAMPS conductive dispersions from Examples 11, 2, 6, and 12 were mixed with 20 wt% AMPS, 2‰ LAP, and 3‰ N,N'-methylenebisacrylamide (MBAA) to obtain hydrogel precursor solutions. The 1% PEDOT:PSS and the PEDOT:PAMPS conductive dispersions from Examples 11, 2, 6, and 12 comprised 5% of the total mass of the hydrogel precursor solution. Subsequently, the hydrogel precursor solution was injected into a mold at 365 nm and 30 mW / cm².2 PAMPS conductive hydrogels with a mass fraction of 5% were prepared by irradiation under UV light for 180 s. These hydrogels were then used to fabricate button cells. The electronic and ionic conductivity of each cell was measured using an electrochemical workstation. The test results are as follows: Figure 7-9 As shown in Table 2.

[0068] Table 2 As can be seen, under the same PAMPS hydrogel and the same amount of addition, the hydrogel formed by PAMPS:PEDOT at a mass ratio of 1:0.5 has higher ionic and electronic conductivity than the PEDOT:PSS hydrogel. This indicates that the PEDOT:PAMPS chain structure is more extended and forms a more continuous conductive structure together with the PAMPS hydrogel chain.

[0069] Examples 13-16 The difference from Example 2 is that the mass ratio of PAMPS to PEDOT is different; as shown in Table 3; the rest is roughly the same as Example 2, and will not be repeated here.

[0070] Table 3 A 1% PEDOT:PSS aqueous solution was used as a control group. The conductivity of the 1% PEDOT:PAMPS conductive dispersions prepared in Examples 2 and 13-16 was tested using a conductivity meter, and the results are as follows. Figure 10 As shown.

[0071] The results showed that the conductivity of PEDOT:PAMPS was lower than that of PEDOT:PSS, but the difference was not by orders of magnitude.

[0072] A 1% PEDOT:PSS aqueous solution was used as a control group. The Zeta potential of the 1% PEDOT:PAMPS conductive dispersions prepared in Examples 2 and 13-16 was tested using a Zeta potential particle size analyzer, and the results are as follows. Figure 11 As shown in the figure. The results showed no significant differences between the groups.

[0073] A 1% PEDOT:PSS aqueous solution was used as a control group. The pH values ​​of the 1% PEDOT:PSS aqueous solution, and the 1% PEDOT:PAMPS conductive dispersions prepared in Examples 13-14, 2, and 15-16 were tested. The initial pH values ​​of the solutions were measured as 2.13, 2.81, 2.85, 3.17, 2.73, and 2.76, respectively. A significant difference in pH between PEDOT:PSS and PEDOT:PAMPS was observed, suggesting that the low conductivity was due to pH differences. The pH values ​​of the PEDOT:PAMPS conductive dispersions at different mass ratios were adjusted to approximately 2.13 (comparable to PEDOT:PSS) using dilute hydrochloric acid. A pH graph showing the values ​​before and after adjustment was obtained, as shown below. Figure 12 As shown.

[0074] The conductivity of the solution before and after pH adjustment was measured using a conductivity meter, and the results are as follows: Figure 13 As shown.

[0075] The results showed that after adjusting the pH of the PEDOT:PAMPS conductive dispersion to around 2.13 (similar to PEDOT:PSS), the conductivity of all mass ratios of the PEDOT:PAMPS conductive dispersion was comparable to that of PEDOT:PSS, showing a significant improvement compared to before pH adjustment.

[0076] The pH of the solution was further adjusted, and the conductivity of each solution was measured using a conductivity meter when pH=2. The results showed that at pH=2, the conductivity of PEDOT:PSS and PEDOT:PAMPS was comparable. Figure 14 As shown.

[0077] The pH of the solutions was further adjusted, and the conductivity of each solution was measured using a conductivity meter when pH=1. The results showed that when pH=1, the conductivity of PEDOT:PAMPS increased several times compared to PEDOT:PSS, indicating a significant improvement in conductivity. Specifically, as shown below... Figure 15 As shown in Table 4.

[0078] Table 4 As shown in the table above, before pH adjustment, the conductivity of Examples 13, 14, 2, 15, and 16 was lower than that of the control group. After pH was adjusted to 1, the conductivity of all examples except the control group was significantly improved, and the conductivity of Example 2 was the most improved.

[0079] In summary, when the mass ratio of PAMPS to PEDOT is controlled at 1:(0.3~1) and the pH range is 1-2, the PEDOT:PAMPS conductive dispersion exhibits stronger conductivity. When the mass fraction is 0.5%~1%, the long-term dispersibility of the PEDOT:PAMPS conductive dispersion is better.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a PEDOT:PAMPS conductive dispersion, characterized in that, Includes the following steps: S1, add lithium phenyl (2,4,6-trimethylbenzoyl) phosphate to sodium 2-acrylamido-2-methylpropanesulfonate, stir in the dark until completely dissolved and stabilize the temperature at 20~40℃ to prepare AMPS solution; S2, the AMPS solution was irradiated under ultraviolet light at a wavelength of 365 nm for 60-120 s to form poly(2-acrylamido-2-methylpropanesulfonic acid); then, the formed poly(2-acrylamido-2-methylpropanesulfonic acid) was added to ultrapure water and stirred until completely dissolved to obtain a PAMPS solution. S3, PAMPS solution and 3,4-ethylenedioxythiophene are mixed and stirred evenly; then, ammonium persulfate and ferric chloride are added, and the mixture is reacted at 20-40℃ for 8-30 h to obtain PEDOT:PAMPS dispersion; then, the PEDOT:PAMPS dispersion is poured into a dialysis bag with a molecular weight cutoff of 8000-14000 and dialyzed for 48-72 h; finally, the dialysate is freeze-dried to obtain PEDOT:PAMPS powder; wherein, the mass ratio of PAMPS to PEDOT in the PEDOT:PAMPS dispersion is 1:(0.3-1). S4, mix the obtained PEDOT:PAMPS powder with ultrapure water to prepare a PEDOT:PAMPS conductive dispersion with a mass fraction of 0.5%~1%, and adjust the pH of the PEDOT:PAMPS conductive dispersion to 1-2.

2. The method for preparing PEDOT:PAMPS conductive dispersion according to claim 1, characterized in that, In step S3, the mass ratio of ammonium persulfate to 3,4-ethylenedioxythiophene is (1~4):1, and the mass ratio of ferric chloride to 3,4-ethylenedioxythiophene is (0.05~0.15):

1.

3. The method for preparing PEDOT:PAMPS conductive dispersion according to claim 2, characterized in that, The solution used to adjust the pH is dilute hydrochloric acid.

4. An application of a PEDOT:PAMPS conductive dispersion, characterized in that, The PEDOT:PAMPS conductive dispersion is prepared by the preparation method according to any one of claims 1-3, and the PEDOT:PAMPS conductive dispersion is used to prepare flexible conductive films.

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