PEDOT powder and preparation method thereof

Abstract

The invention discloses PEDOT powder and a preparation method thereof. The preparation method comprises the following steps: providing a mixed solution of an EDOT monomer and hydrochloric acid, a ferric trichloride solution and a hydrogen peroxide solution; the method comprises the following steps: mixing a mixed solution of an EDOT monomer and hydrochloric acid with a ferric trichloride solution, then adding a hydrogen peroxide solution, and carrying out oxidative polymerization reaction, solid-liquid separation, washing and drying to obtain PEDOT powder. By adopting a double-oxidation system of a proper amount of hydrogen peroxide and a catalytic amount of ferric chloride, the oxidation efficiency of the reaction is greatly improved; by regulating and controlling the dosage of hydrochloric acid, the pH value of a reaction system can be regulated, doping of single anions of a PEDOT product can be controlled, and finally preparation of high-yield and high-conductivity PEDOT powder is achieved. The method disclosed by the invention is simple and convenient to operate, relatively low in energy consumption, high in yield, relatively few in impurities, green and pollution-free, and the PEDOT product is stable in performance and high in conductivity and has important significance on industrial mass production.

Description

Technical Field

[0001] This invention relates to the field of conductive polymer materials technology, and in particular to a PEDOT powder and its preparation method. Background Technology

[0002] Intrinsically conductive polymers are conductive high-molecular polymers, also known as conductive plastics or conductive resins. The flow of π electrons makes intrinsically conductive polymers capable of conducting electricity. These polymers possess extended conjugated double bonds, and the delocalized π electrons are not bound by the atomic nucleus, allowing them to move freely along the polymer chain. After doping, electrons can be removed to create holes or electrons can be added, allowing electrons or holes to move freely along the molecular chain, thus forming conductive molecules.

[0003] PEDOT is a common intrinsically conductive polymer, polymerized from 3,4-ethylenedioxythiophene monomer (EDOT). It features a simple molecular structure, small band gap, and high conductivity. Due to its low preparation cost, ease of synthesis, and strong film-forming properties, PEDOT is widely used in thermoelectric materials, photothermal materials, supercapacitors, and electrodes. Currently, the main commercially available PEDOT product is PEDOT:PSS conductive ink. Compared to conductive ink, neutral conductive powder exhibits higher conductivity, easier storage, and a wider range of applications. Currently, the main synthesis methods for PEDOT include electrochemical polymerization and chemical oxidative polymerization. The electrochemical polymerization method for PEDOT is relatively expensive. Compared to electrochemical polymerization, traditional oxidative polymerization is lower in cost, but it requires a larger amount of iron salt as an oxidant. When using ferric chloride as an oxidant, the ratio of ferric chloride to EDOT monomer is generally 2.33:1 or higher. Furthermore, the reaction is prone to problems such as over-oxidation and excessive residual iron salt ions. At the same time, the reaction temperature and reaction time of traditional oxidative polymerization are relatively high, resulting in problems such as high energy consumption, low conversion rate, low product purity, and uncontrollable anion doping during the production process.

[0004] Therefore, there is an urgent need to provide a new PEDOT powder and its preparation method to solve the technical problems of high energy consumption, low conversion rate, low product purity, and uncontrollable anion doping in the traditional oxidative polymerization process for preparing PEDOT. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a PEDOT powder and its preparation method, thereby solving the technical problems of high energy consumption, low conversion rate, low product purity, large amount of iron salt, and uncontrollable anion doping in the traditional oxidative polymerization process for preparing PEDOT in the prior art.

[0006] In a first aspect, the present invention provides a method for preparing PEDOT powder, comprising the following steps: Provides a mixture of EDOT monomer and hydrochloric acid, ferric chloride solution and hydrogen peroxide solution; A mixture of EDOT monomer and hydrochloric acid was mixed with a ferric chloride solution, followed by the addition of hydrogen peroxide solution. After oxidative polymerization, solid-liquid separation, washing, and drying, PEDOT powder was obtained. The molar ratio of hydrochloric acid to EDOT monomer was (1-3):1; the molar ratio of hydrogen peroxide to EDOT monomer was (1.1-1.3):1; and the molar ratio of ferric chloride to EDOT monomer was (0.01-0.04):1.

[0007] Secondly, the present invention provides a PEDOT powder, which is obtained by the preparation method of PEDOT powder provided in the first aspect of the present invention.

[0008] Compared with the prior art, the beneficial effects of the present invention include: Compared to traditional water-based precipitation oxidation polymerization, this invention significantly improves the oxidation efficiency of the reaction by employing a dual oxidation system of appropriate amounts of hydrogen peroxide and ferric chloride as catalysts. By controlling the amount of hydrochloric acid used, the pH of the reaction system can be adjusted, and the doping of the PEDOT product with a single anion can be controlled, ultimately achieving the preparation of high-yield, high-conductivity PEDOT powder. The method of this invention is simple to operate, has low energy consumption, high yield, few impurities, is environmentally friendly and pollution-free, and produces stable PEDOT products with high conductivity, making it of great significance for large-scale industrial production. Attached Figure Description

[0009] Figure 1 This is a SEM image of the PEDOT powder prepared in Example 3 of the present invention. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0011] In a first aspect, the present invention provides a method for preparing PEDOT powder, comprising the following steps: S1. Provide a mixture of EDOT monomer and hydrochloric acid, ferric chloride solution and hydrogen peroxide solution; S2. Mix the mixture of EDOT monomer and hydrochloric acid with ferric chloride solution, then add hydrogen peroxide solution, and proceed with oxidative polymerization, solid-liquid separation, washing, and drying to obtain PEDOT powder.

[0012] This invention significantly improves the oxidation efficiency of the reaction by using an appropriate amount of the green oxidant hydrogen peroxide and a catalytic amount of ferric chloride as the oxidant. Since this invention uses only a catalytic amount of iron salt, it is beneficial to improve the cleaning efficiency and purity of the product. Furthermore, due to the significant improvement in oxidation efficiency, compared to traditional oxidative polymerization reactions, this invention can obtain the desired high-conductivity, high-conversion-rate PEDOT powder at a lower temperature and in a shorter time. By adjusting the pH of the reaction system with hydrochloric acid, the reaction can achieve the required acidic environment, and the chloride ions can be controlled to be a single-coordinated anion, which is beneficial to obtaining PEDOT powder with a single-coordinated anion, ultimately achieving the preparation of high-yield, high-conductivity PEDOT powder.

[0013] In this embodiment, the molar ratio of hydrochloric acid to EDOT monomer is (1-3):1, including but not limited to 1:1, 1.5:1, 2:1, 2.5:1, 3:1, etc.

[0014] In this embodiment, the molar ratio of ferric chloride to EDOT monomer is (0.01-0.04):1, including but not limited to 0.01:1, 0.02:1, 0.03:1, 0.04:1, etc.

[0015] In this embodiment, the molar ratio of hydrogen peroxide to EDOT monomer is (1.1-1.3):1, including but not limited to 1.1:1, 1.2:1, 1.3:1, etc.

[0016] In this embodiment, the concentration of EDOT monomer in the mixture of EDOT monomer and hydrochloric acid is 0.2-0.4 mol / L, including but not limited to 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, etc., and the concentration of hydrochloric acid is 0.3-0.9 mol / L, including but not limited to 0.3 mol / L, 0.5 mol / L, 0.7 mol / L, 0.9 mol / L, etc.

[0017] In this embodiment, the preparation process of the mixture of EDOT monomer and hydrochloric acid includes: mixing hydrochloric acid and water, then adding EDOT monomer, and dispersing the EDOT monomer fully under high-speed stirring to obtain the mixture of EDOT monomer and hydrochloric acid.

[0018] Preferably, during the preparation of the mixture of EDOT monomer and hydrochloric acid, the temperature is 10-20℃, preferably 15℃, the stirring time is 0.5-1.5h, and the stirring speed is 650-800rpm.

[0019] In this embodiment, the concentration of the ferric chloride solution is 0.4-0.6 mol / L, including but not limited to 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, 0.55 mol, 0.6 mol / L, etc.

[0020] In this embodiment, the concentration of the hydrogen peroxide solution is 0.55-0.8 mol / L, including but not limited to 0.55 mol / L, 0.6 mol / L, 0.65 mol / L, 0.72 mol / L, 0.75 mol / L, 0.8 mol / L, etc.

[0021] In this embodiment, the process of mixing the mixture of EDOT monomer and hydrochloric acid with ferric chloride solution includes: adding ferric chloride solution dropwise to the mixture of EDOT monomer and hydrochloric acid.

[0022] Preferably, during the dropwise addition of ferric chloride solution, the temperature is 10-20℃, more preferably 15℃, the time is 15-25min, including but not limited to 15min, 18min, 20min, 22min, 25min, etc., and the stirring speed is 650-800rpm.

[0023] In this embodiment, hydrogen peroxide solution is added dropwise.

[0024] Preferably, during the dropwise addition of hydrogen peroxide solution, the temperature is 10-20℃, more preferably 15℃, the time is 2-3 hours, and the stirring speed is 650-800 rpm.

[0025] In this embodiment, during the oxidative polymerization reaction, the temperature is 10-20℃, preferably 15℃, the time is 4-8h, preferably 5-6h, and the stirring speed is 650-800rpm.

[0026] In this embodiment, the washing process includes: repeatedly washing with ethanol and water until the washing solution becomes neutral.

[0027] In this embodiment, freeze drying is used, with a freeze drying temperature of -50℃ to -30℃ and a freeze drying time of 24-36 hours.

[0028] Secondly, the present invention provides a PEDOT powder, which is obtained by the preparation method of PEDOT powder provided in the first aspect of the present invention.

[0029] Comparative Example 1 (1) Preparation of a mixture of EDOT monomer and hydrochloric acid: Weigh 3.04g of concentrated hydrochloric acid (mass fraction of 36%-38%, molar ratio of HCl to EDOT of about 1:1), 100mL of distilled water and 4.34g of EDOT monomer into a round-bottom flask, then fix the round-bottom flask in a low-temperature constant temperature reaction bath, and stir at 15℃ alcohol-water bath (i.e., a mixture of ethanol and water) and 650rpm for 1h to fully disperse the EDOT monomer and obtain a mixture of EDOT monomer and hydrochloric acid.

[0030] (2) Adding ferric chloride: In a 15°C alcohol-water bath with continuous mechanical high-speed stirring at 650 rpm, take 0.6 mL of ferric chloride hexahydrate aqueous solution (0.137 g / mL) with a syringe to make the molar ratio of ferric chloride to EDOT 0.01:1, and add it dropwise to a round-bottom flask for 20 min.

[0031] (3) Add hydrogen peroxide dropwise: Weigh 4.08g of 30% hydrogen peroxide solution and dilute it with 50mL of distilled water. Under the conditions of a 15℃ alcohol-water bath and continuous mechanical high-speed stirring at 650rpm, slowly add the hydrogen peroxide solution dropwise into the round-bottom flask using a drip infusion set for 2.5h.

[0032] (4) Oxidative polymerization of EDOT: After adding hydrogen peroxide, the reaction was carried out for 48 hours under a 15°C alcohol-water bath and continuous mechanical high-speed stirring at 650 rpm.

[0033] Observe the phenomena during the reaction process. At 2h, 4h, 6h, 10h, 24h, and 48h, take 1mL of the reaction solution into 5mL capped centrifuge tubes and dilute with distilled water to 3mL. Observe the yield and color of the product. At the moment hydrogen peroxide is added to the flask, a light blue oligomer product appears rapidly, forming a dispersion in the solution. As the reaction proceeds, the product in the flask gradually increases, and the solution color gradually deepens, changing from light blue to dark blue and then to dark black. Simultaneously, in the capped centrifuge tubes, it was observed that the product amount was low at 2h, 4h, 6h, and 10h, and the product dispersion had turned dark black at 24h and 48h, indicating the presence of peroxide.

[0034] Comparative Example 2 Compared with Comparative Example 1, the only difference is that the amount of ferric chloride was adjusted so that the molar ratio of ferric chloride to EDOT was 0.02:1. All other steps and conditions were the same as in Comparative Example 1. The phenomena and results of the reaction were also similar to those in Comparative Example 1.

[0035] Comparative Example 3 Compared with Comparative Example 1, the only difference is that the amount of ferric chloride is adjusted so that the molar ratio of ferric chloride to EDOT is 0.03:1. All other steps and conditions are the same as those in Comparative Example 1.

[0036] The blue oligomer product appeared rapidly the instant hydrogen peroxide was added to the flask, forming a dispersion in the solution. As the reaction proceeded, the amount of product in the flask gradually increased, and the color of the solution gradually deepened, changing from blue to dark blue and then to dark black. Simultaneously, observations in the capped centrifuge tubes showed that the product amount was low at 2, 4, and 6 hours of reaction, slightly increased at 10 hours, and the dispersion had turned dark black at 24 and 48 hours, indicating the presence of hydrogen peroxide.

[0037] Comparative Example 4 Compared with Comparative Example 1, the only difference is that the amount of ferric chloride is adjusted so that the molar ratio of ferric chloride to EDOT is 0.04:1. All other steps and conditions are the same as those in Comparative Example 1.

[0038] The moment hydrogen peroxide was added to the flask, a deep blue oligomer product rapidly appeared, forming a dispersion in the solution. As the reaction proceeded, the amount of product in the flask gradually increased, the solution color deepened, and the deep blue of the dispersion continued to intensify, eventually turning dark black. Simultaneously, observations in the capped centrifuge tubes showed that the product amount was low at 2 hours of reaction, slightly increased at 4 hours, and was substantial at 6 hours. At 24 and 48 hours, the product dispersion had turned dark black, indicating the presence of hydrogen peroxide.

[0039] Comparative Example 5 Compared with Comparative Example 1, the only difference is that the amount of ferric chloride is adjusted so that the molar ratio of ferric chloride to EDOT is 0:1. All other steps and conditions are the same as those in Comparative Example 1.

[0040] Throughout the reaction, no blue precipitate appeared, and the solution color changed from milky white to pale yellow, with a few black oily droplets appearing.

[0041] Comparison of Examples 1-5 revealed that when the molar ratio of ferric chloride to EDOT was 0:1 (i.e., no ferric chloride was added), the desired PEDOT product was not obtained. When the molar ratio of ferric chloride to EDOT was (0.01-0.02):1, the product yield was very low within 0-10 hours, and peroxidation occurred with increasing reaction time. When the molar ratio of ferric chloride to EDOT was 0.03:1, the product yield increased slightly after 10 hours, but peroxidation also occurred with increasing reaction time. When the molar ratio of ferric chloride to EDOT was 0.04:1, the product yield was already high within 6 hours, but peroxidation also occurred with increasing reaction time. Therefore, a molar ratio of ferric chloride to EDOT of 0.04:1 was selected as the reaction condition in subsequent experiments to obtain more product within the same time frame.

[0042] Comparative Example 6 (1) Preparation of a mixture of EDOT monomer and hydrochloric acid: Weigh 3.04g of concentrated hydrochloric acid (mass fraction of 36%-38%, molar ratio of HCl to EDOT of about 1:1), 100mL of distilled water and 4.34g of EDOT monomer into a round-bottom flask, then fix the round-bottom flask in a low-temperature constant temperature reaction bath, and stir at 15℃ alcohol-water bath and 650rpm for 1h to fully disperse the EDOT monomer and obtain a mixture of EDOT monomer and hydrochloric acid.

[0043] (2) Adding ferric chloride: In a 15°C alcohol-water bath with continuous mechanical high-speed stirring at 650 rpm, 2.4 mL of ferric chloride hexahydrate aqueous solution (0.137 g / mL) was added dropwise into a round-bottom flask using a syringe over a period of 20 min.

[0044] (3) Add hydrogen peroxide dropwise: Weigh 4.08g of 30% hydrogen peroxide solution and dilute it with 50mL of distilled water. Under the conditions of a 15℃ alcohol-water bath and continuous mechanical high-speed stirring at 650rpm, slowly add the hydrogen peroxide solution dropwise into the round-bottom flask using a drip infusion set for 2.5h.

[0045] (4) Oxidative polymerization of EDOT: After adding hydrogen peroxide, the reaction was carried out for 4 hours under a 15°C alcohol-water bath and continuous mechanical high-speed stirring at 650 rpm.

[0046] (5) Washing and drying of PEDOT: After the reaction, the reaction solution was separated into solid and liquid phases using a G6 sintered glass funnel, and the PEDOT solid product was collected. Since the solid contained residual hydrogen peroxide, hydrochloric acid, small amounts of iron salts, oligomers, and unreacted monomers, the product was first washed three times with anhydrous ethanol to dissolve the unreacted monomers and oligomers. The PEDOT solid product was then transferred to a 500 mL beaker, and 200 mL of distilled water was added. The mixture was sonicated at room temperature for 30 min to fully disperse the PEDOT product and dissolve the residual hydrogen peroxide, hydrochloric acid, and iron salt impurities in the distilled water. After sonication, the PEDOT solid product was separated using a G6 sintered glass funnel. The product was washed several times with distilled water until the washing solution became neutral. After washing, the washed solid product was placed in a freeze-drying oven for 24 h (temperature -50℃). The freeze-dried PEDOT solid was then ground into a fine powder in an agate mortar to obtain the desired PEDOT powder sample.

[0047] The electrical conductivity of the PEDOT powder was measured to be 3.45 × 10⁻⁶. -4 S / cm, conversion rate 47.4%.

[0048] Comparative Example 7 Compared with Comparative Example 6, the only difference is that the reaction time was adjusted to 5 hours, while the other steps and conditions were the same as those in Comparative Example 6.

[0049] The electrical conductivity of the PEDOT powder was measured to be 6.32 × 10⁻⁶. -3 S / cm, conversion rate 51.8%.

[0050] Comparative Example 8 Compared with Comparative Example 6, the only difference is that the reaction time was adjusted to 6 hours, while the other steps and conditions were the same as those in Comparative Example 6.

[0051] The electrical conductivity of the PEDOT powder was measured to be 2.59 × 10⁻⁶. -2 S / cm, conversion rate 72%.

[0052] Comparative Example 9 Compared with Comparative Example 6, the only difference is that the reaction time was adjusted to 7 hours, while the other steps and conditions were the same as those in Comparative Example 6.

[0053] The electrical conductivity of the PEDOT powder was measured to be 7.95 × 10⁻⁶. -5 S / cm, conversion rate 56.2%.

[0054] Comparative Example 10 Compared with Comparative Example 6, the only difference is that the reaction time was adjusted to 8 hours, while the other steps and conditions were the same as those in Comparative Example 6.

[0055] The electrical conductivity of the PEDOT powder was measured to be 5.94 × 10⁻⁶. -4 S / cm, conversion rate 45.2%.

[0056] The conductivity and conversion results of the products in Comparative Examples 6-10 between 4h and 8h show that, with the extension of reaction time, the conductivity of the products reaches the order of 10 at 6h. -2 The conductivity was measured at 72% (S / cm). However, with further extension of the reaction time, the conductivity decreased by orders of magnitude at 7 and 8 hours, and the conversion rate also decreased significantly. Therefore, to obtain higher conversion and conductivity, the reaction time was controlled at 6 hours in subsequent experiments.

[0057] Example 1 (1) Preparation of a mixture of EDOT monomer and hydrochloric acid: Weigh 4.56g of concentrated hydrochloric acid (mass fraction of 36%-38%, molar ratio of HCl to EDOT monomer of about 1.5:1), 100mL of distilled water and 4.34g of EDOT monomer into a round-bottom flask, then fix the round-bottom flask in a low-temperature constant temperature reaction bath, and stir at 15℃ alcohol-water bath and 650rpm for 1h to fully disperse the EDOT monomer and obtain a mixture of EDOT monomer and hydrochloric acid.

[0058] (2) Adding ferric chloride: In a 15°C alcohol-water bath with continuous mechanical high-speed stirring at 650 rpm, 2.4 mL of ferric chloride hexahydrate aqueous solution (0.137 g / mL) was added dropwise into a round-bottom flask using a syringe over a period of 20 min.

[0059] (3) Add hydrogen peroxide dropwise: Weigh 4.08g of 30% hydrogen peroxide solution and dilute it with 50mL of distilled water. Under the conditions of a 15℃ alcohol-water bath and continuous mechanical high-speed stirring at 650rpm, slowly add the hydrogen peroxide solution dropwise into the round-bottom flask using a drip infusion set for 2.5h.

[0060] (4) Oxidative polymerization of EDOT: After adding hydrogen peroxide, the reaction was carried out for 6 hours under a 15°C alcohol-water bath and continuous mechanical high-speed stirring at 650 rpm.

[0061] (5) Washing and drying of PEDOT: After the reaction, the reaction solution was separated into solid and liquid phases using a G6 sintered glass funnel, and the PEDOT solid product was collected. Since the solid contained residual hydrogen peroxide, hydrochloric acid, small amounts of iron salts, oligomers, and unreacted monomers, the product was first washed three times with anhydrous ethanol to dissolve the unreacted monomers and oligomers. The PEDOT solid product was then transferred to a 500 mL beaker, and 200 mL of distilled water was added. The mixture was sonicated at room temperature for 30 min to fully disperse the PEDOT product and dissolve the residual hydrogen peroxide, hydrochloric acid, and iron salt impurities in the distilled water. After sonication, the PEDOT solid product was separated using a G6 sintered glass funnel. The product was washed several times with distilled water until the washing solution became neutral. After washing, the washed solid product was placed in a freeze-drying oven for 24 h (temperature -50℃). The freeze-dried PEDOT solid was then ground into a fine powder in an agate mortar to obtain the desired PEDOT powder sample.

[0062] The electrical conductivity of the PEDOT powder was measured to be 3.58 × 10⁻⁶. -2 S / cm, PEDOT conversion rate is 94.3%.

[0063] Example 2 Compared with Example 1, the only difference is that the amount of hydrochloric acid is adjusted so that the molar ratio of hydrochloric acid to EDOT is 2:1. All other steps and conditions are the same as in Example 1.

[0064] The electrical conductivity of the PEDOT powder was measured to be 3.02 × 10⁻⁶. -1 S / cm, conversion rate 97.8%.

[0065] Example 3 Compared with Example 1, the only difference is that the amount of hydrochloric acid is adjusted so that the molar ratio of hydrochloric acid to EDOT is 2.5:1. All other steps and conditions are the same as in Example 1.

[0066] The electrical conductivity of the PEDOT powder was measured to be 2.96 S / cm, and the conversion rate was 109.3%.

[0067] Example 4 Compared with Example 1, the only difference is that the amount of hydrochloric acid is adjusted so that the molar ratio of hydrochloric acid to EDOT is 3:1. All other steps and conditions are the same as in Example 1.

[0068] The electrical conductivity of the PEDOT powder was measured to be 1.79 S / cm, and the conversion rate was 104.6%.

[0069] Performance testing (1) PEDOT conductivity test method: 0.1g of PEDOT powder was poured into the tableting mold, and the pressure was gradually increased to 40MPa and held for 30min. Then the PEDOT tablet was taken out, its thickness was measured and its conductivity was tested using a four-probe resistivity tester (the four-probe tester model was Mitsubishi MCP-TP610, the test probe was Mitsubishi MCP-TP06P, and the probe calibrator was Mitsubishi RMH311).

[0070] (2) PEDOT conversion rate test method: The conversion rate calculation formula is as follows:

[0071] In the formula: To collect the quality of the products; The mass of EDOT monomer added.

[0072] The conductivity and conversion efficiency of PEDOT obtained from the above embodiments and comparative examples were statistically analyzed, and the results are shown in Table 1 below.

[0073] Table 1. Conductivity and conversion efficiency of PEDOT obtained in each embodiment and comparative example.

[0074] As shown in Table 1, the ratio of catalytic iron salt to EDOT was investigated in Comparative Examples 1-5 of this invention. It was found that when the ratio of FeCl3 to EDOT was 0.04:1, a certain yield could be achieved within 6 hours of reaction, and the conductivity reached as high as 10 at 6 hours. -2 The S / cm order of magnitude was subsequently maintained. The FeCl3:EDOT ratio was controlled at 0.04:1, with other conditions remaining the same. In Comparative Examples 6-10, the conductivity and yield of the product within a short time frame of 4-8 hours were investigated. The highest conductivity and yield were found within 6 hours, reaching 2.59 × 10⁻⁶. -2The conductivity and conversion rate of the prepared PEDOT conductive powder were 72% and HCl:cm, respectively. After determining the ratio of FeCl3 to EDOT to be 0.04:1 and the reaction time to be 6 h, Comparative Example 8 and Examples 1-4 of this invention controlled the reaction temperature to be 15 °C, the reaction time to be 6 h, the ratio of H2O2 to EDOT to be 1.2:1, and the ratio of FeCl3 to EDOT to be 0.04:1. The conductivity and conversion rate of the prepared PEDOT conductive powder showed a trend of first increasing and then decreasing with the ratio of HCl to EDOT. The conductivity and conversion rate reached the highest when the ratio of HCl to EDOT was 2.5:1, which were 2.96 S / cm and 109.3%, respectively.

[0075] Table 2. EDS elemental analysis results of PEDOT powder obtained in Example 3

[0076] Please see Figure 1 ,pass Figure 1 It can be seen that the PEDOT powder synthesized in Example 3 of this invention exhibits an irregular aggregate morphology. Furthermore, the EDS results in Table 2 show that the PEDOT powder synthesized in this invention contains chloride ion doping and possesses high purity. Moreover, since the conversion rate of this invention is calculated based on the mass of the final synthesized product and the initially added monomer, as well as the coordination doping of chloride ions, the conversion rates of Examples 3-4 exceed 100%.

[0077] In summary, compared to traditional EDOT polymerization, this invention utilizes a dual oxidation system (appropriate amount of green oxidant H2O2 + catalytic amount of iron salt), significantly reducing the amount of iron salt required. This dual oxidation system not only greatly increases the oxidation rate but also facilitates subsequent cleaning of the PEDOT product. The reaction time is reduced from over 24 hours to 6 hours, and polymerization can be carried out at low temperatures (15°C), significantly reducing energy consumption. By selecting the optimal ratio of ferric chloride to EDOT and HCl to EDOT, this invention enables polymerization at low temperatures, and the synthesized product exhibits high conductivity and high conversion rate. The method of this invention is more scientific, efficient, energy-saving, cost-effective, and environmentally friendly, producing PEDOT with higher conversion rates and better performance, and the resulting powder has better processability.

[0078] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing PEDOT powder, characterized in that, Includes the following steps: Provides a mixture of EDOT monomer and hydrochloric acid, ferric chloride solution and hydrogen peroxide solution; The mixture of EDOT monomer and hydrochloric acid was mixed with the ferric chloride solution, followed by the addition of hydrogen peroxide solution. The mixture underwent oxidative polymerization, solid-liquid separation, washing, and drying to obtain PEDOT powder. The molar ratio of hydrochloric acid to EDOT monomer is (1-3):1; The molar ratio of hydrogen peroxide to the EDOT monomer is (1.1-1.3):1; The molar ratio of ferric chloride to the EDOT monomer is (0.01-0.04):

1.

2. The method for preparing PEDOT powder according to claim 1, characterized in that, The molar ratio of hydrochloric acid to the EDOT monomer is (2-3):1; and / or, The molar ratio of ferric chloride to the EDOT monomer is (0.03-0.04):

1.

3. The method for preparing PEDOT powder according to claim 1, characterized in that, In the mixture of EDOT monomer and hydrochloric acid, the concentration of EDOT monomer is 0.2-0.4 mol / L, and the concentration of hydrochloric acid is 0.3-0.9 mol / L.

4. The method for preparing PEDOT powder according to claim 1, characterized in that, The preparation process of the mixture of EDOT monomer and hydrochloric acid includes: mixing hydrochloric acid and water, then adding EDOT monomer, and obtaining the mixture of EDOT monomer and hydrochloric acid under high-speed stirring.

5. The method for preparing PEDOT powder according to claim 1, characterized in that, The concentration of the ferric chloride solution is 0.4-0.6 mol / L.

6. The method for preparing PEDOT powder according to claim 1, characterized in that, The concentration of the hydrogen peroxide solution is 0.55-0.8 mol / L.

7. The method for preparing PEDOT powder according to claim 1, characterized in that, The process of mixing the mixture of EDOT monomer and hydrochloric acid with the ferric chloride solution includes: adding the ferric chloride solution dropwise to the mixture of EDOT monomer and hydrochloric acid; wherein, During the dropwise addition of ferric chloride solution, the temperature is 10-20℃, the time is 15-25 min, and the stirring speed is 650-800 rpm.

8. The method for preparing PEDOT powder according to claim 1, characterized in that, Hydrogen peroxide solution is added dropwise; among which... During the dropwise addition of the hydrogen peroxide solution, the temperature is 10-20℃, the time is 2-3 hours, and the stirring speed is 650-800 rpm.

9. The method for preparing PEDOT powder according to claim 1, characterized in that, During the oxidative polymerization reaction, the temperature is 10-20℃, the time is 4-8h, and the stirring speed is 650-800rpm.

10. A PEDOT powder, characterized in that, The PEDOT powder is obtained by the preparation method of PEDOT powder according to any one of claims 1-9.

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