A method for preparing a conductivity-controllable PEDOT conductive powder

Abstract

This invention belongs to the field of conductive polymer technology, and more specifically, relates to a method for preparing PEDOT conductive powder with controllable conductivity. By replacing water in the traditional preparation process with ethanol as the solvent, the suspension polymerization process is transformed into a solution polymerization process. Without adding any additives, PEDOT powders with various conductivity values ​​can be obtained by controlling the process conditions. This method has the characteristic of controllability; by controlling process parameters such as reaction temperature, reaction time, or oxidant dosage, PEDOT powders with different conductivity values ​​can be obtained. Furthermore, the products prepared by this process have good stability and high repeatability. Compared with mainstream PEDOT products currently on the market, this PEDOT powder product has higher processability and a wider range of applications.

Description

Technical Field

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

[0002] Poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most important polythiophenes, with a wide range of electrical conductivity, falling between that of a conductor and a semiconductor. PEDOT powders with different conductivity levels have significantly different applications. PEDOT conductive powder exhibits excellent environmental stability and has broad application prospects in photovoltaics, thermoelectrics, medicine, antistatics, and electromagnetic shielding.

[0003] The main methods for synthesizing PEDOT include chemical oxidative polymerization, electrochemical polymerization, and chemical vapor deposition. Chemical oxidative polymerization is widely used due to its relatively simple preparation method, large production scale, and good product form. Currently, among the methods of chemical oxidative polymerization, water-based suspension precipitation polymerization is mainly used as a solvent. Through the addition of surfactants and high-speed stirring, water-insoluble EDOT monomers are dispersed into micelles or small droplets, which are then polymerized into PEDOT particles with high conductivity (conductivity of 1-10 or higher).

[0004] Different applications often have different requirements for the conductivity of PEDOT. For example, in materials such as conductive fabrics, the conductivity needs to be as high as possible; while in materials for antistatic and microwave absorption, the conductivity needs to be relatively low, within the conductivity range of semiconductors. The conductivity of conductive polymers can fluctuate within a wide range due to the influence of the manufacturing process. If a stable product is to be launched on the market, a PEDOT product with stable conductivity must be manufactured. However, current technology uses water as a solvent to prepare PEDOT conductive powder, resulting in a fast reaction rate, difficulty in controlling the reaction process, and difficulty in accurately and stably preparing relatively low conductivity (on the order of 10). -5 ~10 -3 PEDOT conductive powder with controllable conductivity (S / cm) is urgently needed. Therefore, there is an urgent need to propose a method for preparing PEDOT conductive powder with controllable conductivity. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing PEDOT conductive powder with adjustable conductivity, so as to solve many problems in the traditional preparation of PEDOT powder, such as uncontrollable conductivity, uniform distribution, complex preparation process, and large environmental pollution.

[0006] To achieve the above objectives, the present invention provides a method for preparing PEDOT conductive powder with controllable conductivity. The method uses 3,4-ethylenedioxythiophene monomer as raw material, anhydrous ethanol as solvent, and ferric chloride as oxidant, without adding any other additives. By controlling one or more of the reaction temperature, reaction time, and amount of oxidant, PEDOT conductive powder with different conductivity can be prepared.

[0007] Preferably, the preparation method includes the following steps:

[0008] (1) Mix anhydrous ethanol and EDOT monomer and stir to dissolve EDOT monomer to obtain EDOT solution; dissolve ferric chloride oxidant in anhydrous ethanol to obtain anhydrous ethanol solution of ferric chloride oxidant.

[0009] (2) The EDOT solution is mixed with the anhydrous ethanol solution of the oxidant ferric chloride to obtain a mixed reaction system, and the molar ratio of EDOT to ferric chloride is 1:(1~10).

[0010] (3) A polymerization reaction occurs at the set reaction temperature to obtain a reaction product. The reaction product is then separated into solid and liquid phases, washed, and dried to obtain PEDOT conductive powder.

[0011] Preferably, in step (2), the EDOT solution is mixed with the anhydrous ethanol solution of the oxidant ferric chloride, wherein the anhydrous ethanol solution of ferric chloride is added to the EDOT solution in one go or added dropwise.

[0012] Preferably, the mass percentage of EDOT in the mixed reaction system described in step (2) is 1-5%.

[0013] Preferably, the molar ratio of EDOT to ferric chloride in the mixed reaction system described in step (2) is 1:(2-5).

[0014] Preferably, the reaction temperature is between 0°C and the ethanol reflux temperature, and the reaction time is greater than or equal to 24 hours.

[0015] Preferably, the PEDOT conductive powders with different conductivity values ​​have a conductivity of 10. -3 ~10 -5 The range is on the order of S / cm.

[0016] This invention utilizes ethanol as a solvent to replace water in traditional preparation processes, transforming suspension polymerization into solution polymerization. Without adding any additives, PEDOT conductive powders with various electrical conductivities can be obtained by controlling process conditions. This method is controllable; by controlling process parameters such as reaction temperature, reaction time, or oxidant dosage, PEDOT powders with different electrical conductivities can be obtained. Furthermore, the products prepared using this process exhibit good stability and high repeatability. Compared to currently available mainstream PEDOT products, this PEDOT powder product possesses higher processability and a wider range of applications. Overall, the technical solution conceived by this invention, compared with existing technologies, mainly possesses the following technical advantages:

[0017] (1) This invention utilizes ethanol as a solvent for EDOT monomers, enabling the EDOT monomers and ferric chloride to dissolve in the same phase for reaction. This transforms the suspension polymerization process commonly used in PEDOT powder preparation into solution polymerization, resulting in the preparation of PEDOT powder with an conductivity on the order of 10. -5 ~10 -3 PEDOT powder with a conductivity of S / cm. Experiments have shown that in an ethanol solvent environment, the higher the amount of oxidant, the higher the temperature, and the longer the reaction time, the higher the conversion rate and the lower the conductivity. Moreover, the conductivity of the prepared PEDOT powder is stable and controllable.

[0018] (2) Compared to water, ethanol makes it more difficult for ferric chloride to ionize, resulting in a lower concentration of iron ions in the system. This leads to a decrease in the efficiency of EDOT oxidation polymerization and a slower reaction rate. Experiments in this invention have shown that using ethanol as a solvent can inhibit PEDOT polymerization to a certain extent, making the degree of polymerization controllable and thus controlling its conductivity. Therefore, this invention can control the conductivity of the prepared PEDOT powder by controlling the reaction time, reaction temperature, or the amount of oxidant.

[0019] (3) The present invention uses ethanol as a reaction solvent. The PEDOT conductive powder product prepared has stable performance, simple process, easy operation, fewer types of raw materials, fewer toxic and harmful substances in the raw materials, and less environmental hazard, making it suitable for large-scale production. Attached Figure Description

[0020] Figure 1 A reaction route diagram for PEDOT polymerization;

[0021] Figure 2 This is a process flow diagram of the preparation method according to an embodiment of the present invention;

[0022] Figure 3 The PEDOT powder prepared in Example 1 of this invention. Detailed Implementation

[0023] 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.

[0024] 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.

[0025] 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.

[0026] In this invention, unless otherwise specified and / or stated, all values ​​relating to component amounts are in parts by weight throughout. Process parameters in the following examples that do not specify particular conditions are generally performed under conventional conditions.

[0027] Existing technologies for preparing PEDOT powder utilize chemical oxidative polymerization, typically carried out in an aqueous solvent. However, due to the near-insolubility of EDOT in water, water-based suspension precipitation polymerization using water as a solvent to prepare PEDOT conductive particles results in a rapid reaction rate, difficulty in process control, sensitivity to environmental influences, and significant fluctuations in the conductivity of the prepared PEDOT product. Furthermore, it is challenging to obtain a stable and low conductivity range (on the order of 10⁻⁶). -5 ~10 - 3 PEDOT powder (S / cm).

[0028] Based on this, this invention attempts to use ethanol instead of water as the reaction solvent. Ethanol, as an organic solvent, can effectively dissolve EDOT, and ferric chloride also has a relatively high solubility in ethanol. Furthermore, experiments in this invention have shown that using ethanol as a solvent can transform the EDOT droplets (oil phase) and the ferric salt aqueous solution (aqueous phase) in water-based solutions into a single phase, changing suspension precipitation polymerization into solution precipitation polymerization. Once the synthesized PEDOT reaches a certain molecular weight, it precipitates and disperses from the ethanol. The PEDOT particles prepared in this way are smaller, have better dispersibility, and use simpler raw materials with fewer impurities.

[0029] Meanwhile, since ferric chloride is difficult to ionize in ethanol, ethanol can act as an inhibitor of EDOT polymerization, significantly slowing down the PEDOT reaction rate and providing greater operational flexibility in adjusting polymerization process parameters. Experiments have shown that by controlling process conditions such as oxidant dosage, polymerization temperature, and polymerization reaction time, PEDOT powder with a certain conductivity level can be produced controllably, stably, and efficiently. The reaction equation for PEDOT polymerization and the flowchart for the preparation of PEDOT according to this invention are as follows: Figure 1 and Figure 2 As shown.

[0030] Specifically, the present invention provides a method for preparing PEDOT conductive powder with controllable conductivity, using 3,4-ethylenedioxythiophene monomer (abbreviated as EDOT) as raw material, anhydrous ethanol as solvent, ferric chloride as oxidant, without adding any other additives, and by controlling one or more of the reaction temperature, reaction time, and amount of oxidant, PEDOT conductive powder with different conductivity can be prepared.

[0031] In some embodiments, the preparation method includes the following steps:

[0032] (1) Mix anhydrous ethanol and EDOT monomer and stir to dissolve EDOT monomer to obtain EDOT solution; dissolve ferric chloride oxidant in anhydrous ethanol to obtain anhydrous ethanol solution of ferric chloride oxidant.

[0033] (2) The EDOT solution is mixed with the anhydrous ethanol solution of the oxidant ferric chloride to obtain a mixed reaction system, and the molar ratio of EDOT to ferric chloride is 1:(1~10).

[0034] (3) A polymerization reaction occurs at the set reaction temperature to obtain a reaction product. The reaction product is then separated into solid and liquid phases, washed, and dried to obtain PEDOT conductive powder.

[0035] In some embodiments, step (2) introduces an anhydrous ethanol solution of ferric chloride, an oxidant, into the EDOT solution, wherein the anhydrous ethanol solution of ferric chloride is added to the EDOT solution in one go or added dropwise.

[0036] In a preferred embodiment, the anhydrous ethanol solution of ferric chloride is slowly added dropwise to the EDOT solution, and the addition time is generally controlled within 2 hours to improve the uniformity of the reaction by adding the solution at the most uniform rate.

[0037] In some embodiments, the mass percentage of EDOT in the mixed reaction system of step (2) is 1-5%. The molar ratio of EDOT to ferric chloride in the mixed reaction system of step (2) is 1:(2-5).

[0038] In some embodiments, the reaction temperature is between 0°C and the ethanol reflux temperature, and the reaction time is greater than or equal to 24 hours.

[0039] In some embodiments, step (3) involves washing the solid product obtained from solid-liquid separation with one or more washing solvents selected from water, anhydrous ethanol, and acetone. Preferably, water, anhydrous ethanol, and acetone are used for multiple alternating washes. During washing, the solid product obtained from solid-liquid separation is dispersed in water, magnetically stirred, and heated to 80-100°C for continuous dispersion for at least 30 minutes, followed by solid-liquid separation. In some embodiments, anhydrous ethanol is used to wash the solid product obtained from solid-liquid separation before drying to improve drying efficiency.

[0040] The present invention describes the preparation of PEDOT conductive powders with different conductivity by controlling one or more of the following: reaction temperature, reaction time, and amount of oxidant. The conductivity of these PEDOT conductive powders is typically within the range of 10. -3 ~10 -5 The range is on the order of S / cm.

[0041] 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.

[0042] This invention provides a method for preparing PEDOT powder with controllable conductivity, high production efficiency, and simple process. Both EDOT and ferric chloride are soluble in ethanol; therefore, using ethanol as a solvent allows the polymerization method to be changed from suspension polymerization to solution polymerization. Ethanol, as an EDOT polymerization inhibitor, can slow down the polymerization rate of EDOT, which is beneficial for controlling the polymerization reaction. By controlling the amount of oxidant, reaction temperature, and reaction time, the reaction rate and extent of PEDOT can be controlled, thereby obtaining PEDOT powder with different conductivity.

[0043] The following are specific examples:

[0044] Example 1

[0045] S1. Dissolution of EDOT: Add 50 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.

[0046] S2. Addition of ferric chloride: Dissolve 17.11 g of anhydrous ferric chloride (3 times the molar amount of EDOT) in 90 mL of anhydrous ethanol, stirring for a long time until the ferric chloride is completely dissolved. Transfer the prepared anhydrous ferric chloride-ethanol solution to a constant pressure dropping funnel, and slowly add the anhydrous ferric chloride-ethanol solution dropwise to the EDOT-ethanol solution at room temperature (25℃) for at least 2 hours. After the addition is complete, rinse the glassware with 10 mL of anhydrous ethanol, and add the rinsing solution to the reaction solution.

[0047] Polymerization of S3 and EDOT: The temperature is slowly increased in a gradient until it reaches the ethanol reflux temperature. Once the temperature is reached, the reaction time is set and the reaction is carried out for 24 hours.

[0048] 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. 150 mL of distilled water was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. 150 mL of anhydrous ethanol was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. The solid was then removed and placed in a 500 mL beaker, with 200 mL of distilled water added. A magnetic stir bar was added, and the mixture was placed in an 80°C water bath with a magnetic stirrer and stirred for 30 minutes. The mixture was then removed and filtered again using a G6 sintered glass funnel. This step was repeated six times. The solid product was then dispersed with anhydrous ethanol and filtered. The sintered glass funnel containing the solid product was then placed in a vacuum drying oven at 80°C for 48 hours. The dried PEDOT solid product is shown below. Figure 3 As shown. The obtained PEDOT solid product was placed in an agate mill and ground into a fine powder, thus obtaining PEDOT powder, as shown. Figure 3 As shown.

[0049] Tests on the prepared PEDOT powder:

[0050] 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 4.014 × 10⁻⁶. -3 S / cm.

[0051] 2. PEDOT Conversion Rate Testing Method: The conversion rate calculation formula is as follows:

[0052]

[0053] Where: m PEDOTTo collect the quality of the product; m EDOT The mass of EDOT monomer added is given. After drying, the PEDOT solid is collected, and the conversion rate of PEDOT is calculated to be 92% according to this formula, indicating a high yield.

[0054] Example 2

[0055] S1. Dissolution of EDOT: Add 50 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.

[0056] S2. Addition of Ferric Chloride: Dissolve 13.28 g of anhydrous ferric chloride (2.33 times the molar amount of EDOT) in 90 mL of anhydrous ethanol, stirring for a long time until the ferric chloride is completely dissolved. Transfer the prepared anhydrous ferric chloride solution to a constant pressure dropping funnel, and slowly add the anhydrous ferric chloride ethanol solution dropwise to the EDOT-ethanol solution at room temperature (25℃) over a period of not less than 2 hours. After the addition is complete, rinse the glassware with 10 mL of anhydrous ethanol and add the rinsing solution to the reaction solution.

[0057] Polymerization of S3 and EDOT: The temperature is slowly increased in a gradient until it reaches the ethanol reflux temperature. Once the temperature is reached, the reaction time is set and the reaction is carried out for 24 hours.

[0058] 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. 150 mL of distilled water was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. 150 mL of anhydrous ethanol was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. The solid was then removed and placed in a 500 mL beaker, with 200 mL of distilled water added. A magnetic stir bar was added, and the mixture was placed in an 80°C water bath with a magnetic stirrer and stirred for 30 minutes. The mixture was then removed and filtered again using a G6 sintered glass funnel. This step was repeated six times. The solid product was then dispersed with anhydrous ethanol and filtered. The sintered glass funnel containing the solid product was then placed in a vacuum drying oven at 80°C and dried for 48 hours. The obtained PEDOT solid product was ground into a fine powder using an agate mill to obtain PEDOT powder.

[0059] Tests on the prepared PEDOT powder:

[0060] 1. The PEDOT conductivity test method is the same as in Example 1, and the conductivity of the PEDOT powder was found to be 9.192 × 10⁻⁶. - 3 S / cm.

[0061] 2. The PEDOT conversion rate test method is the same as in Example 1, and the calculated conversion rate of PEDOT is 87.6%.

[0062] Example 3

[0063] S1. Dissolution of EDOT: Add 50 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.

[0064] S2. Addition of Ferric Chloride: Dissolve 28.52 g of ferric chloride hexahydrate (3 times the molar amount of EDOT) in 90 mL of anhydrous ethanol, stirring for a long time until the ferric chloride is completely dissolved. Transfer the prepared ferric chloride hexahydrate ethanol solution to a constant pressure dropping funnel, and slowly add the ferric chloride hexahydrate ethanol solution dropwise to the EDOT-ethanol solution at room temperature (25℃) for at least 2 hours. After the addition is complete, rinse the glassware with 10 mL of anhydrous ethanol, and add the rinsing solution to the reaction solution.

[0065] Polymerization of S3 and EDOT: The temperature is slowly increased in a gradient until it reaches the ethanol reflux temperature. Once the temperature is reached, the reaction time is set and the reaction is carried out for 24 hours.

[0066] 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. 150 mL of distilled water was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. 150 mL of anhydrous ethanol was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. The solid was then removed and placed in a 500 mL beaker, with 200 mL of distilled water added. A magnetic stir bar was added, and the mixture was placed in an 80°C water bath with a magnetic stirrer and stirred for 30 minutes. The mixture was then removed and filtered again using a G6 sintered glass funnel. This step was repeated six times. The solid product was then dispersed with anhydrous ethanol and filtered. The sintered glass funnel containing the solid product was then placed in a vacuum drying oven at 80°C and dried for 48 hours. The obtained PEDOT solid product was ground into a fine powder using an agate mill to obtain PEDOT powder.

[0067] Tests on the prepared PEDOT powder:

[0068] 1. The PEDOT conductivity test method is the same as in Example 1. The test results show that the conductivity of the PEDOT powder is 2.255 × 10⁻⁶. - 3 S / cm.

[0069] 2. The PEDOT conversion rate test method is the same as in Example 1, and the calculated conversion rate of PEDOT is 89.2%.

[0070] Comparing Example 1 and Example 2, as the amount of oxidant used decreased from 3 times the molar amount of EDOT to 2.33 times, the conductivity of the product slightly increased, but remained at 10. -3 The conversion rate was orders of magnitude higher, but the product conversion rate decreased significantly. Comparing Examples 1 and 3, replacing anhydrous ferric chloride with ferric chloride hexahydrate had no significant impact on product performance.

[0071] Example 4

[0072] S1. Dissolution of EDOT: Add 50 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.

[0073] S2. Addition of ferric chloride: Dissolve 17.11 g of anhydrous ferric chloride (3 times the molar amount of EDOT) in 90 mL of anhydrous ethanol, stirring for a long time until the ferric chloride is completely dissolved. Transfer the prepared anhydrous ferric chloride-ethanol solution to a constant pressure dropping funnel, and slowly add the anhydrous ferric chloride-ethanol solution dropwise to the EDOT-ethanol solution at room temperature (25℃) for at least 2 hours. After the addition is complete, rinse the glassware with 10 mL of anhydrous ethanol, and add the rinsing solution to the reaction solution.

[0074] Polymerization of S3 and EDOT: Slowly increase the temperature to 50°C, and start timing after the temperature is reached, react for 12 hours; then slowly increase the temperature to the ethanol reflux temperature, and react for 12 hours after the temperature is reached.

[0075] 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. 150 mL of distilled water was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. 150 mL of anhydrous ethanol was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. The solid was then removed and placed in a 500 mL beaker, with 200 mL of distilled water added. A magnetic stir bar was added, and the mixture was placed in an 80°C water bath with a magnetic stirrer and stirred for 30 minutes. The mixture was then removed and filtered again using a G6 sintered glass funnel. This step was repeated six times. The solid product was then dispersed with anhydrous ethanol and filtered. The sintered glass funnel containing the solid product was then placed in a vacuum drying oven at 80°C and dried for 48 hours. The obtained PEDOT solid product was ground into a fine powder using an agate mill to obtain PEDOT powder.

[0076] Tests on the prepared PEDOT powder:

[0077] 1. The conductivity test method for PEDOT is the same as in Example 1. The conductivity of the PEDOT powder was found to be 6.346 × 10⁻⁶. - 4 S / cm.

[0078] 2. The PEDOT conversion rate test method is the same as in Example 1, and the PEDOT conversion rate is calculated to be 80%.

[0079] Example 5

[0080] S1. Dissolution of EDOT: Add 50 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.

[0081] S2. Addition of Ferric Chloride: Dissolve 22.82 g of anhydrous ferric chloride (4 times the molar amount of EDOT) in 90 mL of anhydrous ethanol, stirring for a long time until the ferric chloride is completely dissolved. Transfer the prepared anhydrous ferric chloride-ethanol solution to a constant pressure dropping funnel, and slowly add the anhydrous ferric chloride-ethanol solution dropwise to the EDOT-ethanol solution at room temperature (25℃) for at least 2 hours. After the addition is complete, rinse the glassware with 10 mL of anhydrous ethanol, and add the rinsing solution to the reaction solution.

[0082] Polymerization of S3 and EDOT: Slowly increase the temperature to 50°C, and start timing after the temperature is reached, react for 12 hours; then slowly increase the temperature to the ethanol reflux temperature, and react for 12 hours after the temperature is reached.

[0083] 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. 150 mL of distilled water was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. 150 mL of anhydrous ethanol was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. The solid was then removed and placed in a 500 mL beaker, with 200 mL of distilled water added. A magnetic stir bar was added, and the mixture was placed in an 80°C water bath with a magnetic stirrer and stirred for 30 minutes. The mixture was then removed and filtered again using a G6 sintered glass funnel. This step was repeated six times. The solid product was then dispersed with anhydrous ethanol and filtered. The sintered glass funnel containing the solid product was then placed in a vacuum drying oven at 80°C and dried for 48 hours. The obtained PEDOT solid product was ground into a fine powder using an agate mill to obtain PEDOT powder.

[0084] Tests on the prepared PEDOT powder:

[0085] 1. The conductivity test method for PEDOT is the same as in Example 1. The conductivity of the PEDOT powder was found to be 1.240 × 10⁻⁶. - 4 S / cm.

[0086] 2. The PEDOT conversion rate test method is the same as in Example 1, and the calculated conversion rate of PEDOT is 91.4%.

[0087] Comparing Examples 1 and 4, shortening the ethanol reflux reaction time from 24 hours in Example 1 to 12 hours in Example 2 resulted in a significant decrease in conductivity by an order of magnitude; the conversion rate also decreased significantly, but remained at a high level. Comparing Examples 4 and 5, as the amount of oxidant used increased from 3 times the molar amount of EDOT to 4 times, the conductivity of the product decreased, but the conversion rate of the product increased significantly.

[0088] Example 6

[0089] S1. Dissolution of EDOT: Add 50 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.

[0090] S2. Addition of ferric chloride: Dissolve 17.11 g of anhydrous ferric chloride (3 times the molar amount of EDOT) in 90 mL of anhydrous ethanol, stirring for a long time until the ferric chloride is completely dissolved. Transfer the prepared anhydrous ferric chloride-ethanol solution to a constant pressure dropping funnel, and slowly add the anhydrous ferric chloride-ethanol solution dropwise to the EDOT-ethanol solution at room temperature (25℃) for at least 2 hours. After the addition is complete, rinse the glassware with 10 mL of anhydrous ethanol, and add the rinsing solution to the reaction solution.

[0091] Polymerization of S3 and EDOT: Slowly increase the temperature to 50°C, start timing after the temperature is reached, and react for 60 hours.

[0092] 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. 150 mL of distilled water was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. 150 mL of anhydrous ethanol was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. The solid was then removed and placed in a 500 mL beaker, with 200 mL of distilled water added. A magnetic stir bar was added, and the mixture was placed in an 80°C water bath with a magnetic stirrer and stirred for 30 minutes. The mixture was then removed and filtered again using a G6 sintered glass funnel. This step was repeated six times. The solid product was then dispersed with anhydrous ethanol and filtered. The sintered glass funnel containing the solid product was then placed in a vacuum drying oven at 80°C and dried for 48 hours. The obtained PEDOT solid product was ground into a fine powder using an agate mill to obtain PEDOT powder.

[0093] Tests on the prepared PEDOT powder:

[0094] 1. The PEDOT conductivity test method is the same as in Example 1, and the conductivity of the PEDOT powder was found to be 1.202 × 10⁻⁶. - 5 S / cm.

[0095] 2. The PEDOT conversion rate test method is the same as in Example 1, and the calculated conversion rate of PEDOT is 86.2%.

[0096] Example 7

[0097] S1. Dissolution of EDOT: Add 50 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.

[0098] S2. Addition of Ferric Chloride: Dissolve 14.26 g of anhydrous ferric chloride (2.5 times the molar amount of EDOT) in 90 mL of anhydrous ethanol, stirring for a long time until the ferric chloride is completely dissolved. Transfer the prepared anhydrous ferric chloride-ethanol solution to a constant pressure dropping funnel, and slowly add the anhydrous ferric chloride-ethanol solution dropwise to the EDOT-ethanol solution at room temperature (25℃) for at least 2 hours. After the addition is complete, rinse the glassware with 10 mL of anhydrous ethanol, and add the rinsing solution to the reaction solution.

[0099] Polymerization of S3 and EDOT: Slowly increase the temperature to 50°C, start timing after the temperature is reached, and react for 60 hours.

[0100] 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. 150 mL of distilled water was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. 150 mL of anhydrous ethanol was added to the funnel, and the solid was stirred and dispersed, then filtered. This process was repeated three times. The solid was then removed and placed in a 500 mL beaker, with 200 mL of distilled water added. A magnetic stir bar was added, and the mixture was placed in an 80°C water bath with a magnetic stirrer and stirred for 30 minutes. The mixture was then removed and filtered again using a G6 sintered glass funnel. This step was repeated six times. The solid product was then dispersed with anhydrous ethanol and filtered. The sintered glass funnel containing the solid product was then placed in a vacuum drying oven at 80°C and dried for 48 hours. The obtained PEDOT solid product was ground into a fine powder using an agate mill to obtain PEDOT powder.

[0101] Tests on the prepared PEDOT powder:

[0102] 1. The conductivity test method for PEDOT is the same as in Example 1. The conductivity of the PEDOT powder was found to be 1.846 × 10⁻⁶. - 5 S / cm.

[0103] 2. The PEDOT conversion rate test method is the same as in Example 1, and the calculated conversion rate of PEDOT is 74%.

[0104] Comparing Examples 6 and 7, as the amount of oxidant used decreased from 3 times the molar amount of EDOT to 2.5 times, the conductivity of the product slightly increased, but remained at 10. -5 The conversion rate of the product decreased significantly, but this is consistent with the comparison between Example 1 and Example 2.

[0105] Comparing Examples 1, 4, and 6, it can be concluded that in an anhydrous ethanol reaction system with an oxidant dosage of 3 times the molar amount of EDOT, by limiting the reaction temperature and time to ethanol reflux temperature -24h, 50℃ -12h - ethanol reflux temperature -12h, and 50℃ -60h, respectively, a stable conductivity of 10 can be obtained. -3 S / cm, 10 -4 S / cm, 10 -5 PEDOT semiconductor powder products in the S / cm range, with a guaranteed conversion rate of no less than 80%.

[0106]

[0107]

[0108] 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 PEDOT conductive powder with controllable conductivity, characterized in that, The preparation of PEDOT conductive powder with different conductivities is realized by using 3,4-vinyldioxythiophene monomer as raw material, using anhydrous ethanol solvent and ferric chloride as oxidant, and by adjusting one or more of the reaction temperature, the reaction time and the amount of oxidant; the conductivity of the PEDOT conductive powder with different conductivities is in the order of 10 -3 ~10 -5 S / cm. The preparation method includes the following steps: (1) Mix anhydrous ethanol and EDOT monomer and stir to dissolve EDOT monomer to obtain EDOT solution; dissolve ferric chloride oxidant in anhydrous ethanol to obtain anhydrous ethanol solution of ferric chloride oxidant. (2) The EDOT solution is mixed with the anhydrous ethanol solution of the oxidant ferric chloride to obtain a mixed reaction system, wherein the molar ratio of EDOT to ferric chloride is 1:(1~10); the mass percentage of EDOT in the mixed reaction system is 1~5%; (3) A polymerization reaction occurs at the set reaction temperature to obtain the reaction product. The reaction product is then separated into solid and liquid phases, washed, and dried to obtain PEDOT conductive powder.

2. The preparation method according to claim 1, characterized in that, Step (2) Mix the EDOT solution with the anhydrous ethanol solution of the oxidant ferric chloride, wherein the anhydrous ethanol solution of ferric chloride is added to the EDOT solution in one go or added dropwise.

3. The preparation method according to claim 1, characterized in that, In step (2), the molar ratio of EDOT to ferric chloride in the mixed reaction system is 1:(2~5).

4. The preparation method according to claim 1, characterized in that, The reaction temperature is between 0°C and the ethanol reflux temperature, and the reaction time is greater than or equal to 24 hours.

5. The preparation method according to claim 1, characterized in that, Step (3) Wash the solid product obtained from solid-liquid separation with one or more washing solvents selected from water, anhydrous ethanol, and acetone.

6. The preparation method according to claim 1, characterized in that, During washing, the solid product obtained from the solid-liquid separation is dispersed in water, magnetically stirred and heated to 80-100°C for continuous dispersion for no less than 30 minutes, and then solid-liquid separation is performed.

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