A method for preparing high conductivity PEDOT conductive powder

Abstract

This invention belongs to the field of conductive polymer technology, and more specifically, relates to a method for preparing high-conductivity PEDOT conductive powder. This invention utilizes an alcohol-water mixed solvent to replace the water solvent in the traditional preparation process, transforming the suspension polymerization process into a solution polymerization process. This yields high-performance PEDOT conductive powder without adding any additives. This method is highly efficient and energy-saving. Under room temperature conditions, by controlling the proportion of reactants and the reaction time, high-conductivity PEDOT powder is obtained. Furthermore, the product prepared by this process exhibits good stability and high repeatability. Compared to currently available mainstream PEDOT products, this PEDOT powder product possesses higher conductivity and processability.

Description

Technical Field

[0001] This invention belongs to the field of conductive polymer technology, and more specifically, relates to a method for preparing high-conductivity PEDOT conductive powder. Background Technology

[0002] After more than 40 years of development, researchers have conducted in-depth studies on conductive polymers, resulting in the emergence of various conductive materials that are now widely used in display materials, batteries, conductive materials, biomedical materials, sensors, and electromagnetic protection. Among these materials, PEDOT has become a popular conductive polymer due to its high conductivity, high stability, low toxicity, and environmental friendliness. Its preparation process is simple, its application range is wide, and it possesses high practicality.

[0003] Currently, PEDOT products are mainly PEDOT:PSS conductive inks, which are mostly applied through brushing, spraying, or dip coating to form a film. Compared to conductive inks, powders have a wider range of applications. Besides being reconfigured into inks, powders can also be added directly as fillers to paints and coatings to improve their antistatic properties. Furthermore, powders are easier to store and more stable, making their commercial potential significantly greater than that of conductive inks.

[0004] Currently, most PEDOT powder preparation processes rely on suspension precipitation polymerization, which requires continuous heating and stirring with strict temperature control, resulting in high energy consumption and low electrical conductivity of the produced PEDOT powder. Furthermore, water-based suspension polymerization reacts rapidly, making conductivity difficult to control and leading to unstable product conductivity. In addition, current industrial production of PEDOT faces challenges such as the use of numerous raw materials, small-scale production, complex production methods, and environmental unfriendliness.

[0005] Currently, in commercially available PEDOT:PSS, the addition of large amounts of non-conductive PSS acts as an insulating barrier, significantly reducing the conductivity of PEDOT products. Other existing literature has described the preparation of PEDOT powders with higher conductivity via suspension polymerization by introducing dispersants such as sodium dodecyl sulfonate. However, these methods demonstrate that the surfactants are extremely difficult to remove, greatly increasing the difficulty and cost of cleaning the PEDOT product. Furthermore, these impurities are difficult to completely remove, negatively impacting the quality of the PEDOT product and its subsequent practical use. Therefore, there is an urgent need for a method to prepare high-conductivity PEDOT conductive powder that is energy-efficient, produces fewer impurities, and has a simple process. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing high conductivity PEDOT powder, which aims to solve the technical problems of complex preparation process and introduction of impurities in the prior art.

[0007] To achieve the above objectives, the present invention provides a method for preparing high-conductivity PEDOT conductive powder, comprising the following steps:

[0008] (1) Dissolve 3,4-ethylenedioxythiophene monomer in anhydrous ethanol to obtain EDOT solution;

[0009] (2) Dissolve the oxidizing agent ferric chloride in water to obtain a ferric chloride solution;

[0010] (3) The EDOT solution and the ferric chloride solution are mixed to obtain a mixed solution, wherein the volume ratio of anhydrous ethanol to water in the mixed solution is (1-2):1;

[0011] (4) The mixed solution described in step (3) is continuously stirred for several days to allow it to undergo a polymerization reaction. After the reaction is completed, the solid and liquid are separated, and the obtained solid product is washed and dried to obtain high conductivity PEDOT conductive powder.

[0012] Preferably, the mass percentage concentration of 3,4-ethylenedioxythiophene monomer in the EDOT solution in step (1) is 3-8 wt%.

[0013] Preferably, the molar ratio of the 3,4-ethylenedioxythiophene monomer in step (1) to the oxidant ferric chloride in step (2) is 1:6-10.

[0014] Preferably, the volume ratio of anhydrous ethanol to water in the mixed solution in step (3) is (1.2-1.8):1.

[0015] Preferably, in step (3), the ferric chloride solution is added to the EDOT solution all at once, or the ferric chloride solution is added dropwise to the EDOT solution.

[0016] Preferably, in step (4), the mixed solution is continuously stirred at 20-30°C for 3-9 days.

[0017] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0018] (1) This invention proposes to use a mixed solvent of anhydrous ethanol and water in a specific ratio to prepare high conductivity PEDOT powder by solution polymerization, transforming the traditional suspension polymerization method into a solution polymerization method. Using ferric chloride solution as an oxidant, high conductivity PEDOT powder is prepared at room temperature by controlling the reaction time without adding any other additives.

[0019] (2) This invention utilizes ethanol as the solvent for EDOT monomers and controls the alcohol-to-water volume ratio of the total solvent in the reaction system. This allows EDOT monomers and ferric chloride to be dissolved in the same phase for reaction, transforming the suspension precipitation polymerization process commonly used in PEDOT powder preparation into solution precipitation polymerization. This solves the problem of impurity introduction caused by adding dispersants in suspension polymerization. Furthermore, the reaction is easier to control, resulting in finer particles and making it easier to obtain conductive powder with high electrical conductivity. The reaction occurs at room temperature, eliminating the need for precise temperature control, which greatly saves energy and reduces production costs. This method has a simple process flow, low energy consumption, easy operation, fewer types of raw materials used, fewer toxic and harmful substances in the raw materials, and low environmental hazard, making it suitable for large-scale production.

[0020] (3) This invention can stably prepare materials with an electrical conductivity of 10 by adjusting the polymerization process parameters. 0 PEDOT powder with a yield on the order of S / cm. It should be noted that, compared with suspension polymerization using water as a solvent, the yield of PEDOT powder did not decrease significantly, the conductivity remained stable and controllable, and other properties of the powder were not significantly affected. Attached Figure Description

[0021] Figure 1 A reaction route diagram for PEDOT polymerization;

[0022] Figure 2 This is a process flow diagram of the preparation method of the present invention;

[0023] Figure 3 The PEDOT powder prepared according to this invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0026] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0027] This invention provides a high conductivity PEDOT conductive powder (conductivity at 10). 0 The preparation method (on the order of S / cm) includes the following steps:

[0028] (1) Dissolve 3,4-ethylenedioxythiophene monomer (abbreviated as EDOT) in anhydrous ethanol to obtain EDOT solution;

[0029] (2) Dissolve the oxidizing agent ferric chloride in water to obtain a ferric chloride solution;

[0030] (3) The EDOT solution and the ferric chloride solution are mixed to obtain a mixed solution, wherein the volume ratio of anhydrous ethanol to water in the mixed solution is (1-2):1, more preferably (1.2-1.8):1;

[0031] (4) The mixed solution described in step (3) is continuously stirred for several days without adding any other additives to allow it to undergo a polymerization reaction. After the reaction is complete, the solid and liquid phases are separated. The obtained solid product is washed and dried to obtain high-conductivity PEDOT conductive powder. The reaction route diagram is shown below. Figure 1 As shown.

[0032] In some embodiments, the molar ratio of the 3,4-ethylenedioxythiophene monomer in step (1) to the oxidant ferric chloride in step (2) is 1:6-10. The mass percentage concentration of the 3,4-ethylenedioxythiophene monomer in the EDOT solution in step (1) is 3-8 wt%.

[0033] In some embodiments, step (3) involves adding the ferric chloride solution to the EDOT solution all at once, or adding the ferric chloride solution dropwise to the EDOT solution.

[0034] In a preferred embodiment, step (2) involves adding the ferric chloride solution dropwise to the EDOT solution. The dropwise addition time is generally controlled within 2 hours, and the dropwise addition is made as uniformly as possible to improve the uniformity of the reaction.

[0035] In some embodiments, the ferric chloride is ferric chloride hexahydrate or anhydrous ferric chloride.

[0036] In some embodiments, step (4) involves continuously stirring the mixed solution at 20-30°C for 3-9 days. Stirring is performed mechanically or magnetically. Step (4) involves washing the solid product obtained from solid-liquid separation alternately in dilute hydrochloric acid (e.g., 1M hydrochloric acid), water, and ethanol. The drying in step (4) is performed under vacuum at 70-90°C for 36-72 hours.

[0037] In some embodiments, the water described in this invention is one or more of ultrapure water, deionized water, double-distilled water, pure water, and distilled water.

[0038] To address the numerous shortcomings of traditional PEDOT:PSS preparation methods and water-based precipitation polymerization methods for preparing PEDOT powder, such as the large variety of impurities, high energy consumption (requiring heating), complex production processes, and low electrical conductivity, this invention provides a controllable preparation method for PEDOT solution precipitation polymerization. The aim is to ensure that, by adjusting process parameters, PEDOT powder with high electrical conductivity (with a conductivity of 10) can be stably obtained at room temperature. 0 This invention provides a method for the precipitation polymerization of PEDOT powder using an ethanol-water mixed solvent, achieving high conductivity PEDOT powder without additional temperature control. This method is simple to operate, requires few raw materials, saves energy, and exhibits good reproducibility. The resulting PEDOT product has stable performance and high conductivity, making it commercially significant for large-scale industrial production.

[0039] In some embodiments, such as Figure 2 As shown, the specific steps include the following:

[0040] S1. Dissolution of EDOT: Add a certain amount of ethanol to the reaction vessel and add EDOT monomer. Stir continuously to fully dissolve the EDOT monomer and obtain a clear and transparent light yellow EDOT ethanol solution.

[0041] S2. Addition of ferric chloride hexahydrate solution as oxidant: Take a certain amount of ferric chloride hexahydrate and dissolve it in water. The amount of water needed needs to be calculated to ensure a specific volume ratio between the ethanol used in S1 and the water contained in this step. While maintaining continuous stirring in the reaction vessel, add the ferric chloride solution to the reaction vessel.

[0042] Polymerization of S3 and EDOT: Keep stirring continuously to maintain the reaction for several days.

[0043] S4. Collection, Washing, and Drying of PEDOT: After the reaction is complete, the reaction solution is separated into solid and liquid phases using filtration, leaving the solid product. The solid product is then thoroughly dispersed in 1M hydrochloric acid and washed using ultrasonic heating for 30 minutes at 80°C each time. After ultrasonic cleaning, the solid PEDOT product is separated by filtration, and this washing process is repeated several times. After hydrochloric acid washing, the product is washed several times with water in the same manner. The solid product is then placed in a vacuum drying oven and dried at 80°C for 48 hours to obtain PEDOT powder.

[0044] This invention provides a method for preparing high-conductivity PEDOT conductive powder with low energy consumption, few impurities, and a simple process. EDOT is soluble in ethanol, and ferric chloride is soluble in both ethanol and water. Therefore, using an ethanol-water mixed solvent changes the polymerization method from suspension polymerization to solution polymerization. Ethanol, as an EDOT polymerization inhibitor, can slow down the polymerization rate of EDOT. Furthermore, conducting the reaction at room temperature further slows down and stabilizes the polymerization rate. The slow polymerization rate also reduces the impact of temperature fluctuations on the EDOT polymerization rate, resulting in PEDOT powder with stable conductivity. In addition, since PSS is not added, the para-anion in the reaction system is chloride ion, thus improving the insulation barrier problem.

[0045] This invention utilizes an alcohol-water mixed solvent to replace the water solvent in traditional preparation processes, transforming suspension polymerization into solution polymerization. This yields high-performance PEDOT powder without the addition of any additives. This method is highly efficient and energy-saving. Under room temperature conditions, by controlling the proportion of reactants and reaction time, high-conductivity PEDOT powder is obtained. Furthermore, the product prepared by this process exhibits good stability and high reproducibility. Compared to currently available mainstream PEDOT products, this PEDOT powder product possesses higher conductivity and processability.

[0046] The following are specific examples:

[0047] Example 1

[0048] S1. Dissolution of EDOT: Add 150 mL of anhydrous ethanol and 5 g of EDOT to an Erlenmeyer flask, and add a magnetic stir bar to the flask. Then place the flask in a room temperature water bath with a magnetic stirrer and stir for 30 min to obtain a completely dissolved EDOT ethanol solution.

[0049] S2. Addition of ferric chloride: Take 76.1 g of ferric chloride hexahydrate (8 times the molar amount of EDOT, containing 30.4 mL of water) and add 49.6 mL of distilled water. Disperse by sonication until the ferric chloride hexahydrate is completely dissolved. Transfer the prepared ferric chloride hexahydrate solution to a constant pressure dropping funnel and slowly add it dropwise to the EDOT-ethanol solution over at least 2 hours. After the addition is complete, rinse the glassware with 20 mL of distilled water and add the rinsing solution to the reaction mixture (at this point, the system contains 100 mL of water and 150 mL of anhydrous ethanol).

[0050] Polymerization of S3 and EDOT: Keep stirring continuously and react for a total of 7 days at a reaction temperature of 20-30℃.

[0051] S4. Collection, Washing, and Drying of PEDOT: After the reaction was complete, the reaction solution was filtered using a G6 sintered glass funnel to obtain a blue-black PEDOT solid. The PEDOT solid was transferred to a 500 mL beaker, and 200 mL of 1M hydrochloric acid was added. The PEDOT solid was dispersed in the 1M hydrochloric acid by sonication at 80°C for 3 hours. After sonication, the solid product was separated by filtration using a sintered glass funnel. The product was then washed with 1M hydrochloric acid using sonication for 30 minutes each time, for a total of 6 washes. Then, distilled water was used, and the product was ultrasonically dispersed and washed 6 times. Finally, the product was placed in a vacuum drying oven and dried at 80°C for 48 hours. The appearance of the dried PEDOT solid product was as follows. Figure 3 As shown. The obtained PEDOT solid product was placed in an agate mill and ground into a fine powder to obtain PEDOT powder.

[0052] Tests on the prepared PEDOT powder:

[0053] 1. PEDOT Conductivity Test Method: A certain amount of PEDOT powder was poured into a tableting mold, pressurized to 40 mPa, and held at that pressure for 30 min. The PEDOT tablet was then removed, its thickness was measured, and its conductivity was tested using a four-probe resistivity meter (model: Mitsubishi MCP-TP610, probes: Mitsubishi MCP-TP06P, probe calibrator: Mitsubishi RMH311). The measured conductivity of the PEDOT powder was 7.786 × 10⁻⁶. 0 With a conductivity of S / cm, it exhibits excellent electrical conductivity.

[0054] 2. PEDOT Conversion Rate Testing Method: The conversion rate calculation formula is as follows:

[0055]

[0056] Where: m PEOOT To collect the quality of the product; m EDOTThe mass of EDOT monomer added is given. After drying, the PEDOT solid was collected, and the conversion rate of PEDOT was calculated to be 70.4% according to this formula, which is a high yield.

[0057] Example 2

[0058] S1. Dissolution of EDOT: Add 150 mL of anhydrous ethanol and 5 g of EDOT to an Erlenmeyer flask, and add a magnetic stir bar to the flask. Then place the flask in a room temperature water bath with a magnetic stirrer and stir for 30 min to obtain a completely dissolved EDOT ethanol solution.

[0059] S2. Addition of ferric chloride: Take 76.1 g of ferric chloride hexahydrate (8 times the molar amount of EDOT, containing 30.4 mL of water) and add 49.6 mL of distilled water. Disperse by sonication until the ferric chloride hexahydrate is completely dissolved. Transfer the prepared ferric chloride hexahydrate solution to a constant pressure dropping funnel and slowly add it dropwise to the EDOT-ethanol solution over at least 2 hours. After the addition is complete, rinse the glassware with 20 mL of distilled water and add the rinsing solution to the reaction mixture (at this point, the system contains 100 mL of water and 150 mL of anhydrous ethanol).

[0060] Polymerization of S3 and EDOT: Keep stirring continuously and react for a total of 5 days at a reaction temperature of 20-30℃.

[0061] S4. Collection, Washing, and Drying of PEDOT: After the reaction was complete, the reaction solution was filtered using a G6 sintered glass funnel to obtain a blue-black PEDOT solid. The PEDOT solid was transferred to a 500 mL beaker, and 200 mL of 1M hydrochloric acid was added. The PEDOT solid was dispersed in the 1M hydrochloric acid by sonication for 3 hours at 80°C. After sonication, the solid product was separated by filtration using a sintered glass funnel. The product was then washed with 1M hydrochloric acid using sonication for 30 minutes each time, for a total of 6 washes. Then, distilled water was used, and the product was ultrasonically dispersed and washed 6 times. Finally, the product was placed in a vacuum drying oven and dried at 80°C for 48 hours. The obtained PEDOT solid product was then ground into a fine powder using an agate mill to obtain PEDOT powder.

[0062] Testing of the prepared PEDOT powder: The testing method for the PEDOT powder was the same as in Example 1. The conductivity of the PEDOT powder was measured to be 7.006 × 10⁻⁶. 0 S / cm, conversion rate 55.6%.

[0063] Example 3

[0064] S1. Dissolution of EDOT: Add 150 mL of anhydrous ethanol and 5 g of EDOT to an Erlenmeyer flask, and add a magnetic stir bar to the flask. Then place the flask in a room temperature water bath with a magnetic stirrer and stir for 30 min to obtain a completely dissolved EDOT ethanol solution.

[0065] S2. Addition of ferric chloride: Take 76.1 g of ferric chloride hexahydrate (8 times the molar amount of EDOT, containing 30.4 mL of water) and add 49.6 mL of distilled water. Disperse by sonication until the ferric chloride hexahydrate is completely dissolved. Transfer the prepared ferric chloride hexahydrate solution to a constant pressure dropping funnel and slowly add it dropwise to the EDOT-ethanol solution over at least 2 hours. After the addition is complete, rinse the glassware with 20 mL of distilled water and add the rinsing solution to the reaction mixture (at this point, the system contains 100 mL of water and 150 mL of anhydrous ethanol).

[0066] Polymerization of S3 and EDOT: Keep stirring continuously for a total of 9 days, and the reaction temperature is 20-30℃.

[0067] S4. Collection, Washing, and Drying of PEDOT: After the reaction was complete, the reaction solution was filtered using a G6 sintered glass funnel to obtain a blue-black PEDOT solid. The PEDOT solid was transferred to a 500 mL beaker, and 200 mL of 1M hydrochloric acid was added. The PEDOT solid was dispersed in the 1M hydrochloric acid by sonication for 3 hours at 80°C. After sonication, the solid product was separated by filtration using a sintered glass funnel. The product was then washed with 1M hydrochloric acid using sonication for 30 minutes each time, for a total of 6 washes. Then, distilled water was used, and the product was ultrasonically dispersed and washed 6 times. Finally, the product was placed in a vacuum drying oven and dried at 80°C for 48 hours. The obtained PEDOT solid product was then ground into a fine powder using an agate mill to obtain PEDOT powder.

[0068] Testing of the prepared PEDOT powder: The testing method for the PEDOT powder was the same as in Example 1. The conductivity of the PEDOT powder was measured to be 5.129 × 10⁻⁶. 0 S / cm, conversion rate 76%.

[0069] Example 4

[0070] S1. Dissolution of EDOT: Add 150 mL of anhydrous ethanol and 5 g of EDOT to an Erlenmeyer flask, and add a magnetic stir bar to the flask. Then place the flask in a room temperature water bath with a magnetic stirrer and stir for 30 min to obtain a completely dissolved EDOT ethanol solution.

[0071] S2. Addition of ferric chloride: Take 76.1 g of ferric chloride hexahydrate (8 times the molar amount of EDOT, containing 30.4 mL of water) and add 49.6 mL of distilled water. Disperse by sonication until the ferric chloride hexahydrate is completely dissolved. Transfer the prepared ferric chloride hexahydrate solution to a constant pressure dropping funnel and slowly add it dropwise to the EDOT-ethanol solution over at least 2 hours. After the addition is complete, rinse the glassware with 20 mL of distilled water and add the rinsing solution to the reaction mixture (at this point, the system contains 100 mL of water and 150 mL of anhydrous ethanol).

[0072] Polymerization of S3 and EDOT: Keep stirring continuously and react for a total of 3 days at a reaction temperature of 20-30℃.

[0073] S4. Collection, Washing, and Drying of PEDOT: After the reaction was complete, the reaction solution was filtered using a G6 sintered glass funnel to obtain a blue-black PEDOT solid. The PEDOT solid was transferred to a 500 mL beaker, and 200 mL of 1M hydrochloric acid was added. The PEDOT solid was dispersed in the 1M hydrochloric acid by sonication for 3 hours at 80°C. After sonication, the solid product was separated by filtration using a sintered glass funnel. The product was then washed with 1M hydrochloric acid using sonication for 30 minutes each time, for a total of 6 washes. Then, distilled water was used, and the product was ultrasonically dispersed and washed 6 times. Finally, the product was placed in a vacuum drying oven and dried at 80°C for 48 hours. The obtained PEDOT solid product was then ground into a fine powder using an agate mill to obtain PEDOT powder.

[0074] Testing of the prepared PEDOT powder: The testing method for the PEDOT powder was the same as in Example 1. The conductivity of the PEDOT powder was measured to be 6.919 × 10⁻⁶. 0 S / cm, conversion rate 37.2%.

[0075] Comparing Examples 1, 2, 3, and 4, it can be found that the PEDOT powder prepared by this method has excellent electrical conductivity, achieving both high conductivity and high conversion rate. Compared to Example 1, in Example 2, reducing the reaction time has little effect on conductivity, but the conversion rate decreases significantly; in Example 3, extending the reaction time slightly decreases conductivity but significantly improves conversion rate; in Example 4, when the reaction time is significantly reduced, the conductivity remains at the same order of magnitude, but the conversion rate decreases significantly.

[0076] Comparative Example 1

[0077] S1. Dissolution of EDOT: Add 150 mL of anhydrous ethanol and 5 g of EDOT to an Erlenmeyer flask, and add a magnetic stir bar to the flask. Then place the flask in a room temperature water bath with a magnetic stirrer and stir for 30 min to obtain a completely dissolved EDOT ethanol solution.

[0078] S2. Addition of Ferric Chloride: Take 76.1 g of ferric chloride hexahydrate (8 times the molar amount of EDOT, containing 30.4 mL of water) and add 49.6 mL of anhydrous ethanol. Disperse the solution by sonication until the ferric chloride hexahydrate is completely dissolved. Transfer the prepared ferric chloride hexahydrate solution to a constant pressure dropping funnel and slowly add it dropwise to the EDOT-ethanol solution over at least 2 hours. After the addition is complete, rinse the glassware with 20 mL of anhydrous ethanol and add the rinsing solution to the reaction mixture (at this point, the system contains a total of 30.4 mL of water and 219.6 mL of anhydrous ethanol).

[0079] Polymerization of S3 and EDOT: Keep stirring continuously and react for a total of 15 days at a reaction temperature of 20-30℃.

[0080] S4. Collection, Washing, and Drying of PEDOT: After the reaction was complete, the reaction solution was filtered using a G6 sintered glass funnel to obtain a blue-black PEDOT solid. The PEDOT solid was transferred to a 500 mL beaker, and 200 mL of 1M hydrochloric acid was added. The PEDOT solid was dispersed in the 1M hydrochloric acid by sonication for 3 hours at 80°C. After sonication, the solid product was separated by filtration using a sintered glass funnel. The product was then washed with 1M hydrochloric acid using sonication for 30 minutes each time, for a total of 6 washes. Then, distilled water was used, and the product was ultrasonically dispersed and washed 6 times. Finally, the product was placed in a vacuum drying oven and dried at 80°C for 48 hours. The obtained PEDOT solid product was then ground into a fine powder using an agate mill to obtain PEDOT powder.

[0081] Testing of the prepared PEDOT powder: The testing method for the PEDOT powder was the same as in Example 1. The conductivity of the PEDOT powder was measured to be 5.936 × 10⁻⁶. -3 S / cm, conversion rate 52.6%.

[0082] Comparative Example 2

[0083] S1. Dissolution of EDOT: Add 150 mL of anhydrous ethanol and 5 g of EDOT to an Erlenmeyer flask, and add a magnetic stir bar to the flask. Then place the flask in a room temperature water bath with a magnetic stirrer and stir for 30 min to obtain a completely dissolved EDOT ethanol solution.

[0084] S2. Addition of Ferric Chloride: Take 76.1 g of ferric chloride hexahydrate (8 times the molar amount of EDOT, containing 30.4 mL of water) and add 49.6 mL of anhydrous ethanol. Disperse the solution by sonication until the ferric chloride hexahydrate is completely dissolved. Transfer the prepared ferric chloride hexahydrate solution to a constant pressure dropping funnel and slowly add it dropwise to the EDOT-ethanol solution over a period of at least 2 hours. After the addition is complete, rinse the glassware with 20 mL of anhydrous ethanol and add the rinsing solution to the reaction mixture (at this point, the system contains a total of 30.4 mL of water and 219.6 mL of anhydrous ethanol).

[0085] Polymerization of S3 and EDOT: Keep stirring continuously and react for a total of 20 days at a reaction temperature of 20-30℃.

[0086] S4. Collection, Washing, and Drying of PEDOT: After the reaction was complete, the reaction solution was filtered using a G6 sintered glass funnel to obtain a blue-black PEDOT solid. The PEDOT solid was transferred to a 500 mL beaker, and 200 mL of 1M hydrochloric acid was added. The PEDOT solid was dispersed in the 1M hydrochloric acid by sonication for 3 hours at 80°C. After sonication, the solid product was separated by filtration using a sintered glass funnel. The product was then washed with 1M hydrochloric acid using sonication for 30 minutes each time, for a total of 6 washes. Then, distilled water was used, and the product was ultrasonically dispersed and washed 6 times. Finally, the product was placed in a vacuum drying oven and dried at 80°C for 48 hours. The obtained PEDOT solid product was then ground into a fine powder using an agate mill to obtain PEDOT powder.

[0087] Testing of the prepared PEDOT powder: The testing method for the PEDOT powder was the same as in Example 1. The conductivity of the PEDOT powder was measured to be 4.360 × 10⁻⁶. -5 S / cm, conversion rate 71.8%.

[0088] During the experiments, tests were conducted to increase the ethanol ratio. However, no cases of high conversion rates were obtained within a short period, rendering the results impractical for industrial production. For example, in Comparative Example 1, significantly increasing the ethanol ratio in the solvent may have resulted in an excessively slow reaction rate due to the inhibitory effect of ethanol on PEDOT polymerization. Even with a reaction time of 15 days, a high conversion rate could not be achieved. Furthermore, the prolonged reaction time exacerbated particle agglomeration and aging, potentially leading to a sharp decrease in conductivity after extended reaction. In Comparative Example 2, even with an extremely slow reaction rate and a significantly extended reaction time of 20 days, a conversion rate of 71.8% was achieved, but the conductivity was drastically reduced, rendering it unsuitable for industrial production. The conductivity and conversion rate results of the PEDOT powders prepared in different examples and comparative examples are shown in Table 1.

[0089] Table 1. Conductivity and conversion rate of PEDOT powder prepared in different embodiments and comparative examples.

[0090]

[0091]

[0092] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing high-conductivity PEDOT conductive powder, characterized in that, Includes the following steps: (1) Dissolve 3,4-ethylenedioxythiophene monomer in anhydrous ethanol to obtain EDOT solution; (2) Dissolve the oxidant ferric chloride in water to obtain a ferric chloride solution; (3) The EDOT solution and the ferric chloride solution are mixed to obtain a mixed solution, wherein the volume ratio of anhydrous ethanol to water in the mixed solution is (1-2):1; (4) The mixed solution described in step (3) is continuously stirred for several days to allow it to undergo a polymerization reaction. After the reaction is completed, the solid and liquid are separated, and the obtained solid product is washed and dried to obtain high conductivity PEDOT conductive powder.

2. The preparation method according to claim 1, characterized in that, The mass percentage concentration of 3,4-ethylenedioxythiophene monomer in the EDOT solution in step (1) is 3-8 wt%.

3. The preparation method according to claim 1, characterized in that, The molar ratio of the 3,4-ethylenedioxythiophene monomer in step (1) to the oxidant ferric chloride in step (2) is 1:6-10.

4. The preparation method according to claim 1, characterized in that, Step (3) Add the ferric chloride solution to the EDOT solution all at once, or add the ferric chloride solution dropwise to the EDOT solution.

5. The preparation method according to claim 1, characterized in that, Step (4) Stir the mixture continuously at 20-30°C for 3-9 days.

6. The preparation method according to claim 1, characterized in that, Step (4) The solid product obtained from solid-liquid separation is washed alternately in dilute hydrochloric acid, water and ethanol.

7. The preparation method according to claim 1, characterized in that, The drying in step (4) is vacuum drying at 70-90℃ for 36-72 hours.

8. The preparation method according to claim 1, characterized in that, The conductivity of the high-conductivity PEDOT conductive powder is at 10. 0 On the order of S / cm.

Images