A polyglycerol-modified pedot:pss aqueous dispersion, and a preparation method and applications thereof

Abstract

This application relates to the field of organic optoelectronic materials technology, specifically disclosing a polyglycerol-modified PEDOT:PSS aqueous dispersion, its preparation method, and its application. The PEDOT:PSS aqueous dispersion comprises the following raw materials: PEDOT:PSS aqueous dispersion, hydroxyl-terminated polyglycerol derivative, functional polar organic solvent, composite coupling agent, and deionized water. The preparation method of the PEDOT:PSS aqueous dispersion is as follows: the PEDOT:PSS aqueous dispersion is mixed with deionized water to obtain a basic dispersion; the hydroxyl-terminated polyglycerol derivative is added to the basic dispersion and stirred evenly; the functional polar organic solvent is added and stirred evenly; the composite coupling agent is added, and the pH value is adjusted to obtain the polyglycerol-modified PEDOT:PSS aqueous dispersion. This PEDOT:PSS aqueous dispersion exhibits excellent comprehensive performance, good film uniformity, good surface wettability, and high conductivity.

Description

Technical Field

[0001] This application relates to the field of organic optoelectronic materials technology, and more specifically, to a polyglycerol-modified PEDOT:PSS aqueous dispersion, its preparation method, and its application. Background Technology

[0002] Poly(3,4-ethylenedioxythiophene): Polystyrene sulfonic acid (PEDOT:PSS) is one of the most widely used conductive polymer materials. With its high visible light transmittance, excellent environmental stability and solution processability, it has become a core functional material in fields such as flexible electronics, solid-state capacitors, organic photovoltaics, and electroluminescent devices. However, commercial PEDOT:PSS aqueous dispersions have many inherent defects that severely restrict their high-end applications: First, although PSS, as a water-soluble polyelectrolyte, ensures the dispersion stability of PEDOT in water, the large amount of insulating PSS encapsulating the conductive PEDOT chains forms a core-shell structure, hindering carrier transport and resulting in low conductivity of the original PEDOT:PSS film, far lower than that of metals and inorganic conductive materials; Second, the rigid conjugated backbone and the π-π stacking effect between strong chains of PEDOT make the film brittle and have poor tensile strength, easily causing cracks when bent, destroying the conductive path, and failing to meet the mechanical requirements of flexible wearable devices; Third, the aqueous dispersion is strongly acidic, easily corroding metal electrodes and degrading organic functional layers, and is sensitive to humidity, easily agglomerating and delaminating under high temperature and high humidity environments, resulting in poor storage and use stability.

[0003] Existing modification techniques mostly employ small-molecule alcohols, glycols, ionic liquids, or surfactant doping. While these techniques can improve conductivity to some extent, they have significant limitations: small-molecule additives are volatile and their performance degrades rapidly after high-temperature treatment; ionic liquids are costly, and residual impurities affect device stability; traditional surfactants have poor compatibility with PEDOT:PSS, easily leading to phase separation. Therefore, there is an urgent need to develop a high-efficiency, low-cost polyglycerol-modified PEDOT:PSS aqueous dispersion to achieve synergistic optimization of conductivity, stability, and mechanical properties. Summary of the Invention

[0004] To address the technical problems mentioned in the background, this application provides a polyglycerol-modified PEDOT:PSS aqueous dispersion, its preparation method, and its application.

[0005] In a first aspect, this application provides a polyglycerol-modified PEDOT:PSS aqueous dispersion, employing the following technical solution: A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85-92 parts of PEDOT:PSS aqueous dispersion, 3-10 parts of hydroxyl-terminated polyglycerol derivative, 2-6 parts of functional polar organic solvent, 0.1-0.4 parts of composite coupling agent, and 3-8 parts of deionized water.

[0006] Preferably, the mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1-1.2:2.5-5.

[0007] Preferably, the preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol, modified monomers, and catalysts were added to a reaction vessel and stirred for 3-5 hours under nitrogen protection and at 50-65°C. Then, glycidyl methacrylate and polymerization inhibitors were added, the temperature was raised to 70-80°C, and the reaction was continued for 4-6 hours. After the reaction was completed, the product was purified by vacuum distillation and dried to obtain the hydroxyl-terminated polyglycerol derivative.

[0008] Preferably, the modified monomer is composed of maleic anhydride and polycaprolactone diol in a mass ratio of 1-1.8:0.5-0.8; the molecular weight of the polycaprolactone diol is 500-1000.

[0009] Preferably, the mass ratio of the polyglycerol, modified monomer, catalyst, glycidyl methacrylate and polymerization inhibitor is 100-120:20-30:0.5-2:10-15:0.1-0.5.

[0010] Preferably, the degree of polymerization of the polyglycerol is 2-8.

[0011] Preferably, the functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2-3:1-2.

[0012] Preferably, the composite coupling agent is composed of a silane coupling agent and a borate ester coupling agent in a mass ratio of 3-6:1-3.

[0013] Preferably, the silane coupling agent is one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropyltriethoxysilane.

[0014] Preferably, the borate coupling agent is one of tributylborate, trioctylborate, and trilaurylborate.

[0015] Secondly, this application provides a method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion, comprising the following steps: Mix PEDOT:PSS aqueous dispersion with deionized water and stir at 25-40℃ for 10-30 min to obtain a basic dispersion. Add terminal hydroxyl polyglycerol derivative to the basic dispersion and stir until homogeneous. Then add functional polar organic solvent and stir until homogeneous at 30-50℃. Finally, add composite coupling agent and stir at 35-55℃ for 40-80 min. Adjust the pH to 5.5-7.0 to obtain polyglycerol modified PEDOT:PSS aqueous dispersion.

[0016] Thirdly, this application provides the application of polyglycerol-modified PEDOT:PSS aqueous dispersion in the preparation of flexible transparent conductive films, hole transport layers of organic solar cells, and electrode materials for electrochromic devices.

[0017] In summary, this application has the following beneficial effects: This application utilizes a modified monomer formulated from maleic anhydride and low-molecular-weight polycaprolactone diol, and precisely controls the mass ratio of polyglycerol, modified monomer, and other raw materials, as well as the reaction conditions, to significantly improve the overall performance of polyglycerol-modified PEDOT:PSS aqueous dispersions. Specifically, the introduction of polycaprolactone diol with a specific molecular weight effectively controls the flexibility and spatial configuration of the polyglycerol chains, enhances their interfacial compatibility with the PEDOT:PSS matrix, inhibits polymer chain aggregation, and gives the dispersion superior storage stability and film uniformity. Simultaneously, the hydroxyl functional groups in the hydroxyl-terminated polyglycerol derivative can form strong interactions with the sulfonic acid groups on the PEDOT:PSS surface, optimizing charge transport channels and significantly improving surface resistance uniformity.

[0018] In this application, a combination of silane and borate ester coupling agents is used, achieving a synergistic effect compared to using a single coupling agent. The epoxy groups in the silane coupling agent can chemically react with the hydroxyl-terminated polyglycerol derivatives to form a strong chemical bond, while the borate ester coupling agent enhances the interfacial adhesion between the system and the substrate. After the two are combined, the water resistance and solvent resistance of the PEDOT:PSS aqueous dispersion are significantly enhanced. The functional polar organic solvent is a combination of dimethyl sulfoxide and ethylene glycol monomethyl ether, which can effectively regulate the swelling behavior of PEDOT:PSS, promote the uniform dispersion of polyglycerol derivatives in the dispersion system, and further improve the film-forming properties and electrical conductivity stability of the dispersion. This application achieves multiple advantages of PEDOT:PSS aqueous dispersion, namely high stability, high conductivity, and strong adhesion, through the compounding and precise selection of modified monomers, the matching of composite coupling agents, and the optimized combination of functional polar organic solvents. This provides solid technical support for its application in flexible electronic devices, solid-state capacitors, biomedical sensors, and other fields, and has significant industrial application value and market promotion prospects. Detailed Implementation

[0019] The present application will be further described in detail below with reference to the embodiments.

[0020] The PEDOT:PSS aqueous dispersion used in the embodiments and comparative examples of this application was purchased from Wuhan Linsheng Technology Co., Ltd.; tributylboronic acid ester was purchased from Hubei Xingyan New Material Technology Co., Ltd.; polyglycerol-6 and polyglycerol-10 were both purchased from Hubei Xinghengye Technology Co., Ltd.; polycaprolactone diol (molecular weight: 500) and polycaprolactone diol (molecular weight: 2000) were both purchased from Jining Fangyu Chemical Co., Ltd.

[0021] Examples 1-3 provide a polyglycerol-modified PEDOT:PSS aqueous dispersion and its preparation method.

[0022] Example 1 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85 parts of PEDOT:PSS aqueous dispersion, 3 parts of hydroxyl-terminated polyglycerol derivative, 2 parts of functional polar organic solvent, 0.1 parts of composite coupling agent, and 3 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1:2.5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2:1. The composite coupling agent is composed of γ-glycidyl etheroxypropyltrimethoxysilane and tributylboronic acid ester in a mass ratio of 3:1.

[0023] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 50°C, the mixture was stirred at 200 rpm for 3 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 70°C. The mixture was stirred at 400 rpm for another 4 hours. After the reaction was complete, the mixture was distilled under reduced pressure at 0.08 MPa and 90°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then purified by passing through a 300-meter immersion reactor while still hot. The solution was filtered through a mesh screen, and after the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered again and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 70°C and 0.08 MPa for 6 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 100:20:0.5:10:0.1. The modified monomer consisted of maleic anhydride and polycaprolactone diol in a mass ratio of 1:0.5, with a molecular weight of 500.

[0024] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 200 rpm for 10 min at 25°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 200 rpm for 10 min until homogeneous. Then, a functional polar organic solvent was added and stirred at 200 rpm for 10 min at 30°C until homogeneous. Finally, a composite coupling agent was added and stirred at 500 rpm for 40 min at 35°C. The pH was adjusted to 5.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0025] Example 2 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 88 parts of PEDOT:PSS aqueous dispersion, 7 parts of hydroxyl-terminated polyglycerol derivative, 4 parts of functional polar organic solvent, 0.3 parts of composite coupling agent, and 5 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1.1:4. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2.5:1.5. The composite coupling agent is composed of γ-glycidyl etheroxypropyltrimethoxysilane and tributyl borate in a mass ratio of 4.5:2.

[0026] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 58°C, the mixture was stirred at 300 rpm for 4 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 75°C. The mixture was stirred at 500 rpm for another 5 hours. After the reaction was complete, the mixture was distilled under reduced pressure at 0.085 MPa and 95°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then purified by passing through a 400-meter fluid filtration system while still hot. The solution was filtered through a mesh screen, and after the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered again and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 75°C and 0.09 MPa for 7 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 110:25:1.2:12:0.3. The modified monomer consisted of maleic anhydride and polycaprolactone diol in a mass ratio of 1.4:0.7, with a molecular weight of 500 for the polycaprolactone diol.

[0027] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 300 rpm for 20 min at 32°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 400 rpm for 20 min until homogeneous. A functional polar organic solvent was then added and stirred at 350 rpm for 15 min at 40°C until homogeneous. A composite coupling agent was then added and stirred at 700 rpm for 60 min at 45°C. The pH was adjusted to 6.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0028] Example 3 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 92 parts of PEDOT:PSS aqueous dispersion, 10 parts of hydroxyl-terminated polyglycerol derivative, 6 parts of functional polar organic solvent, 0.4 parts of composite coupling agent, and 8 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1.2:5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 3:2. The composite coupling agent is composed of γ-glycidyl etheroxypropyltrimethoxysilane and tributyl borate in a mass ratio of 6:3.

[0029] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 65°C, the mixture was stirred at 400 rpm for 5 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 80°C. The mixture was stirred at 600 rpm for another 6 hours. After the reaction was complete, the mixture was distilled under reduced pressure at 0.09 MPa and 100°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then purified by passing through a 50 mL aerator while hot. The solution was filtered through a 0-mesh filter. After the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered under vacuum and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 80°C and 0.1 MPa for 8 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 120:30:2:15:0.5. The modified monomer consisted of maleic anhydride and polycaprolactone diol in a mass ratio of 1.8:0.8, and the molecular weight of the polycaprolactone diol was 500.

[0030] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 400 rpm for 30 min at 40°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 500 rpm for 30 min until homogeneous. A functional polar organic solvent was then added and stirred at 500 rpm for 20 min at 50°C until homogeneous. A composite coupling agent was then added and stirred at 800 rpm for 80 min at 55°C. The pH was adjusted to 7.0 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0031] Comparative Example 1 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85 parts of PEDOT:PSS aqueous dispersion, 3 parts of hydroxyl-terminated polyglycerol derivative, 2 parts of functional polar organic solvent, 0.1 parts of composite coupling agent, and 3 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1:2.5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2:1. The composite coupling agent is composed of γ-glycidyl etheroxypropyltrimethoxysilane and tributylboronic acid ester in a mass ratio of 3:1.

[0032] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 50°C, the mixture was stirred at 200 rpm for 3 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 70°C. The mixture was stirred at 400 rpm for another 4 hours. After the reaction was completed, the mixture was distilled under reduced pressure at 0.08 MPa and 90°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to... The solution was completely dissolved at 75℃, then filtered through a 300-mesh filter while hot. After the filtrate cooled naturally to room temperature, it was allowed to stand at 0℃ to crystallize. The solution was then filtered and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 70℃ and 0.08 MPa for 6 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 100:20:0.5:10:0.1, and the modified monomer was maleic anhydride.

[0033] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 200 rpm for 10 min at 25°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 200 rpm for 10 min until homogeneous. Then, a functional polar organic solvent was added and stirred at 200 rpm for 10 min at 30°C until homogeneous. Finally, a composite coupling agent was added and stirred at 500 rpm for 40 min at 35°C. The pH was adjusted to 5.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0034] Comparative Example 2 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85 parts of PEDOT:PSS aqueous dispersion, 3 parts of hydroxyl-terminated polyglycerol derivative, 2 parts of functional polar organic solvent, 0.1 parts of composite coupling agent, and 3 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1:2.5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2:1. The composite coupling agent is composed of γ-glycidyl etheroxypropyltrimethoxysilane and tributylboronic acid ester in a mass ratio of 3:1.

[0035] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 50°C, the mixture was stirred at 200 rpm for 3 hours. Subsequently, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 70°C. The mixture was stirred at 400 rpm for another 4 hours. After the reaction was completed, the mixture was distilled under reduced pressure at 0.08 MPa and 90°C. The crude product from the reduced pressure distillation was then added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then filtered through a 300-mesh filter while still hot. After the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered under vacuum and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 70°C and 0.08 MPa for 6 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 100:20:0.5:10:0.1. The modified monomer was polycaprolactone diol with a molecular weight of 500.

[0036] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 200 rpm for 10 min at 25°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 200 rpm for 10 min until homogeneous. Then, a functional polar organic solvent was added and stirred at 200 rpm for 10 min at 30°C until homogeneous. Finally, a composite coupling agent was added and stirred at 500 rpm for 40 min at 35°C. The pH was adjusted to 5.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0037] Comparative Example 3 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85 parts of PEDOT:PSS aqueous dispersion, 3 parts of hydroxyl-terminated polyglycerol derivative, 2 parts of functional polar organic solvent, 0.1 parts of composite coupling agent, and 3 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1:2.5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2:1. The composite coupling agent is composed of γ-glycidyl etheroxypropyltrimethoxysilane and tributylboronic acid ester in a mass ratio of 3:1.

[0038] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 50°C, the mixture was stirred at 200 rpm for 3 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 70°C. The mixture was stirred at 400 rpm for another 4 hours. After the reaction was complete, the mixture was distilled under reduced pressure at 0.08 MPa and 90°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then purified by passing through a 300-meter immersion reactor while still hot. The solution was filtered through a mesh screen, and after the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered again and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 70°C and 0.08 MPa for 6 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 100:20:0.5:10:0.1. The modified monomer consisted of maleic anhydride and polycaprolactone diol in a mass ratio of 1:0.5, with a molecular weight of 2000.

[0039] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 200 rpm for 10 min at 25°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 200 rpm for 10 min until homogeneous. Then, a functional polar organic solvent was added and stirred at 200 rpm for 10 min at 30°C until homogeneous. Finally, a composite coupling agent was added and stirred at 500 rpm for 40 min at 35°C. The pH was adjusted to 5.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0040] Comparative Example 4 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85 parts of PEDOT:PSS aqueous dispersion, 3 parts of hydroxyl-terminated polyglycerol derivative, 2 parts of functional polar organic solvent, 0.1 parts of composite coupling agent, and 3 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1:2.5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2:1. The composite coupling agent is composed of γ-glycidyl etheroxypropyltrimethoxysilane and tributylboronic acid ester in a mass ratio of 3:1.

[0041] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-10, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 50°C, the mixture was stirred at 200 rpm for 3 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 70°C. The mixture was stirred at 400 rpm for another 4 hours. After the reaction was complete, the mixture was distilled under reduced pressure at 0.08 MPa and 90°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then purified by passing through a 300-meter immersion reactor while still hot. The solution was filtered through a mesh screen, and after the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered again and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 70°C and 0.08 MPa for 6 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-10, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 100:20:0.5:10:0.1. The modified monomer consisted of maleic anhydride and polycaprolactone diol in a mass ratio of 1:0.5, with a molecular weight of 500.

[0042] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 200 rpm for 10 min at 25°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 200 rpm for 10 min until homogeneous. Then, a functional polar organic solvent was added and stirred at 200 rpm for 10 min at 30°C until homogeneous. Finally, a composite coupling agent was added and stirred at 500 rpm for 40 min at 35°C. The pH was adjusted to 5.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0043] Comparative Example 5 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85 parts of PEDOT:PSS aqueous dispersion, 3 parts of hydroxyl-terminated polyglycerol derivative, 2 parts of functional polar organic solvent, 0.1 parts of coupling agent, and 3 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1:2.5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2:1. The coupling agent is γ-glycidyl etheroxypropyltrimethoxysilane.

[0044] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 50°C, the mixture was stirred at 200 rpm for 3 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 70°C. The mixture was stirred at 400 rpm for another 4 hours. After the reaction was complete, the mixture was distilled under reduced pressure at 0.08 MPa and 90°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then purified by passing through a 300-meter immersion reactor while still hot. The solution was filtered through a mesh screen, and after the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered again and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 70°C and 0.08 MPa for 6 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 100:20:0.5:10:0.1. The modified monomer consisted of maleic anhydride and polycaprolactone diol in a mass ratio of 1:0.5, with a molecular weight of 500.

[0045] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 200 rpm for 10 min at 25°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 200 rpm for 10 min until homogeneous. Then, a functional polar organic solvent was added and stirred at 200 rpm for 10 min at 30°C until homogeneous. Finally, a coupling agent was added and stirred at 500 rpm for 40 min at 35°C. The pH was adjusted to 5.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0046] Comparative Example 6 A polyglycerol-modified PEDOT:PSS aqueous dispersion comprises the following raw materials in parts by weight: 85 parts of PEDOT:PSS aqueous dispersion, 3 parts of hydroxyl-terminated polyglycerol derivative, 2 parts of functional polar organic solvent, 0.1 parts of coupling agent, and 3 parts of deionized water. The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1:2.5. The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2:1. The coupling agent is tributylboronic acid ester.

[0047] The preparation method of the hydroxyl-terminated polyglycerol derivative includes the following preparation steps: Polyglycerol-6, modified monomers, and dibutyltin dilaurate were added to a reaction vessel. Under nitrogen protection and at 50°C, the mixture was stirred at 200 rpm for 3 hours. Then, glycidyl methacrylate and hydroquinone were added, and the temperature was raised to 70°C. The mixture was stirred at 400 rpm for another 4 hours. After the reaction was complete, the mixture was distilled under reduced pressure at 0.08 MPa and 90°C. The crude product from the reduced pressure distillation was added to ethyl acetate at a feed-to-liquid ratio of 1:10 and heated to 75°C until completely dissolved. The solution was then purified by passing through a 300-meter immersion reactor while still hot. The solution was filtered through a mesh screen, and after the filtrate cooled naturally to room temperature, it was allowed to stand at 0°C to crystallize. The solution was then filtered again and the filter cake was washed with cold ethyl acetate. The product was then vacuum dried at 70°C and 0.08 MPa for 6 hours to obtain a hydroxyl-terminated polyglycerol derivative. The mass ratio of polyglycerol-6, modified monomer, dibutyltin dilaurate, glycidyl methacrylate, and hydroquinone was 100:20:0.5:10:0.1. The modified monomer consisted of maleic anhydride and polycaprolactone diol in a mass ratio of 1:0.5, with a molecular weight of 500.

[0048] A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion includes the following steps: PEDOT:PSS aqueous dispersion was mixed with deionized water and stirred at 200 rpm for 10 min at 25°C to obtain a basic dispersion. A terminal hydroxyl polyglycerol derivative was added to the basic dispersion and stirred at 200 rpm for 10 min until homogeneous. Then, a functional polar organic solvent was added and stirred at 200 rpm for 10 min at 30°C until homogeneous. Finally, a coupling agent was added and stirred at 500 rpm for 40 min at 35°C. The pH was adjusted to 5.5 with citric acid to obtain a polyglycerol-modified PEDOT:PSS aqueous dispersion.

[0049] Performance testing The performance of the polyglycerol-modified PEDOT:PSS aqueous dispersions prepared in Examples 1-3 and Comparative Examples 1-6 of this application was tested. The specific test items are as follows: The polyglycerol-modified PEDOT:PSS aqueous dispersion samples prepared in Examples 1-3 and Comparative Examples 1-6 were used to coat a clean ITO glass substrate by spin coating. The spin coating parameters were: 3000 rpm and 30 s. After the film was formed, it was placed in a vacuum drying oven and dried at 60°C for 2 h to obtain a PEDOT:PSS film with a thickness of 50±5 nm.

[0050] Volumetric conductivity: The volumetric conductivity of the PEDOT:PSS films prepared in Examples 1-3 and Comparative Examples 1-6 was tested using the four-probe method at an ambient temperature of 25°C and a relative humidity of 45%. Surface wettability: Tested according to national standard GB / T 30447-2013 "Method for measuring contact angle of nanofilms"; Water resistance: According to the national standard GB / T 1733-1993 "Determination of water resistance of paint film", the PEDOT:PSS films prepared in Examples 1-3 and Comparative Examples 1-6 were immersed in deionized water for 24 hours at room temperature, and the conductivity retention rate was measured. Moisture and heat resistance: The PEDOT:PSS films prepared in Examples 1-3 and Comparative Examples 1-6 were placed in a damp heat chamber at 60°C and 90% RH for 48 hours, and the conductivity retention rate was measured. Film uniformity: The surface morphology of PEDOT:PSS film was observed using atomic force microscopy (AFM) with a scanning range of 5μm×5μm. The root mean square roughness (Rq) of the film surface was recorded. The smaller the Rq value, the better the film uniformity. The specific test results are shown in Table 1.

[0051] Table 1 Performance parameters of polyglycerol-modified PEDOT:PSS aqueous dispersion As shown in Table 1, the polyglycerol-modified PEDOT:PSS aqueous dispersions prepared in Examples 1-3 of this application exhibit excellent comprehensive performance, good film uniformity, good surface wettability, and high conductivity. Through the synergistic effect of specific structured terminal hydroxyl polyglycerol derivatives and composite coupling agents, the film-forming properties and interfacial compatibility of the PEDOT:PSS aqueous dispersions are effectively improved, resulting in stronger practicality and reliability.

[0052] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A polyglycerol-modified PEDOT:PSS aqueous dispersion, characterized in that, The raw materials include the following parts by weight: 85-92 parts of PEDOT:PSS aqueous dispersion, 3-10 parts of hydroxyl-terminated polyglycerol derivative, 2-6 parts of functional polar organic solvent, 0.1-0.4 parts of composite coupling agent, and 3-8 parts of deionized water.

2. The polyglycerol-modified PEDOT:PSS aqueous dispersion according to claim 1, characterized in that, The mass ratio of PEDOT to PSS in the PEDOT:PSS aqueous dispersion is 1-1.2:2.5-5.

3. The polyglycerol-modified PEDOT:PSS aqueous dispersion according to claim 1, characterized in that, The preparation method of the terminal hydroxyl polyglycerol derivative includes the following preparation steps: Polyglycerol, modified monomers, and catalysts were added to a reaction vessel and stirred for 3-5 hours under nitrogen protection and at 50-65°C. Then, glycidyl methacrylate and polymerization inhibitors were added, the temperature was raised to 70-80°C, and the reaction was continued for 4-6 hours. After the reaction was completed, the product was purified by vacuum distillation and dried to obtain the hydroxyl-terminated polyglycerol derivative.

4. The polyglycerol-modified PEDOT:PSS aqueous dispersion according to claim 3, characterized in that, The modified monomer is composed of maleic anhydride and polycaprolactone diol in a mass ratio of 1-1.8:0.5-0.8; the molecular weight of the polycaprolactone diol is 500-1000.

5. The polyglycerol-modified PEDOT:PSS aqueous dispersion according to claim 3, characterized in that, The mass ratio of the polyglycerol, modified monomer, catalyst, glycidyl methacrylate and polymerization inhibitor is 100-120:20-30:0.5-2:10-15:0.1-0.

5.

6. The polyglycerol-modified PEDOT:PSS aqueous dispersion according to claim 3, characterized in that, The degree of polymerization of the polyglycerol is 2-8.

7. The polyglycerol-modified PEDOT:PSS aqueous dispersion according to claim 1, characterized in that, The functional polar organic solvent is composed of dimethyl sulfoxide and ethylene glycol monomethyl ether in a mass ratio of 2-3:1-2.

8. The polyglycerol-modified PEDOT:PSS aqueous dispersion according to claim 1, characterized in that, The composite coupling agent is composed of a silane coupling agent and a borate ester coupling agent in a mass ratio of 3-6:1-3. The silane coupling agent is one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropyltriethoxysilane. The borate ester coupling agent is one of tributylboronic acid ester, trioctylboronic acid ester, and trilaurylboronic acid ester.

9. A method for preparing a polyglycerol-modified PEDOT:PSS aqueous dispersion as described in any one of claims 1-8, characterized in that, Includes the following steps: Mix PEDOT:PSS aqueous dispersion with deionized water and stir at 25-40℃ for 10-30 min to obtain a basic dispersion. Add terminal hydroxyl polyglycerol derivative to the basic dispersion and stir until homogeneous. Then add functional polar organic solvent and stir until homogeneous at 30-50℃. Finally, add composite coupling agent and stir at 35-55℃ for 40-80 min. Adjust the pH to 5.5-7.0 to obtain polyglycerol modified PEDOT:PSS aqueous dispersion.

10. The application of a polyglycerol-modified PEDOT:PSS aqueous dispersion as described in any one of claims 1-8 in the preparation of flexible transparent conductive films, hole transport layers of organic solar cells, and electrode materials for electrochromic devices.

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