Preparation method of hydrophilic high-entropy conjugated polymer

Abstract

The invention discloses a preparation method of a hydrophilic high-entropy conjugated polymer, and relates to the technical field of high-entropy polymer materials for multifunctional photoelectric application, and the method is characterized in that a donor-acceptor (D-A) type high-entropy polymer with an irregular random sequence skeleton structure is constructed through a ternary polymerization strategy. According to the polymer, various components can be uniformly and randomly distributed in the polymer, and good balance between material solubility and interchain aggregation strength can be realized. Therefore, the method can synergistically improve the hydrophilicity and inter-batch repeatability of the irregular polymer material, promote the separation and migration of photon-generated carriers under the action of a multi-interface electric field, and improve the activity and stability of a photocatalytic reaction. The problems of poor dispersity, poor batch-to-batch repeatability and the like caused by hydrophobicity of a traditional conjugated polymer are solved, and the conjugated polymer can be widely applied to the fields of photocatalysis, perovskite solar cells, organic field effect transistors, organic electroluminescent devices and organic photovoltaic solar cells.

Description

Technical Field

[0001] The present invention relates to the technical field of high-entropy polymer materials for multifunctional optoelectronic applications, and more specifically, it relates to a preparation method of a hydrophilic high-entropy conjugated polymer. Background Art

[0002] Conjugated polymers play an important role in fields such as gas storage and separation, electrical devices, and optoelectronics due to their easy-to-design structure, multiple synthesis methods, and easily adjustable properties. However, most conjugated polymers contain fused benzene rings, which make them highly hydrophobic and limit their practical applications.

[0003] In order to improve the superior properties of conjugated polymers and expand their application scope, several strategies have been developed to improve and enhance the hydrophilicity of conjugated polymers. These strategies include using polyelectrolytes with ionic side chains, non-ionic ethylene glycol side chain modification, or adding amphiphilic surfactants or organic co-solvents, etc. However, these strategies still have problems such as high cost, complex processes, and poor effects.

[0004] Therefore, there is an urgent need to develop a preparation method of a hydrophilic conjugated polymer material with low cost and simple operation. High-entropy materials (a new type of material composed of 5 or more components or sequences combined and randomly distributed in a single-phase structure) have attracted the attention of researchers in the field of photocatalysis due to their adjustable components, unique electronic configurations, rich active sites, excellent batch-to-batch repeatability, high hydrophilicity, and entropy stability. The high-entropy polymer materials constructed by the ternary copolymerization strategy can not only achieve a good balance between material solubility and inter-chain aggregation strength, thereby synergistically improving the hydrophilicity of non-regular polymer materials, but also inhibit the recombination of electrons and holes, promote the separation and migration of photo-generated carriers through the action of multiple interfacial electric fields, thereby improving the activity and stability of photocatalytic reactions, and finally developing a high-entropy polymer semiconductor photocatalyst with ideal charge separation and transport properties, good batch-to-batch repeatability, low cost, and high hydrophilicity. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a hydrophilic high-entropy conjugated polymer. This method constructs a high-entropy polymer through a ternary copolymerization strategy, solves problems such as poor dispersibility and poor batch-to-batch repeatability caused by the hydrophobicity of traditional conjugated polymers, and can be widely used in the fields of photocatalysis, perovskite solar cells, organic field-effect transistors, organic light-emitting devices, and organic photovoltaic solar cells.

[0006] The above technical purpose of the present invention is achieved through the following technical solutions: A preparation method of a hydrophilic high-entropy conjugated polymer, the hydrophilic high-entropy conjugated polymer is a D1 / D2-A or D-A1 / A2 type hydrophilic conjugated polymer, and its molecular structural formula is shown as follows:

[0007]

[0008] The present invention is further configured as follows: First, monomers A and D are mixed with a reaction solvent in a reaction flask according to a specific molar feeding ratio. After backfilling with nitrogen three times, a catalyst is added to the reaction flask under the protection of nitrogen. Then, after backfilling with nitrogen three times again, the temperature is raised and stirred, and a reaction occurs through random copolymerization under the action of the catalyst. After the reaction is completed, the reaction solution is filtered to obtain a precipitate, and then the powder obtained by Soxhlet extraction is vacuum-dried to obtain a hydrophilic high-entropy conjugated polymer material.

[0009] The present invention is further configured as follows: When synthesizing the D1 / D2-A type hydrophilic high-entropy conjugated polymer, D:A = 2:1, and D = D1 + D2;

[0010] When synthesizing the D-A1 / A2 type hydrophilic high-entropy conjugated polymer, D:A = 1:2, and A = A1 + A2.

[0011] The present invention is further configured as follows: When the A and D monomers are halogenated aromatic hydrocarbons and organotin compounds, the Stille coupling reaction is adopted.

[0012] The present invention is further configured as follows: The catalyst for the Stille coupling reaction is tetrakis(triphenylphosphine)palladium, bis(dibenzylideneacetone)palladium, tris(dibenzylideneacetone)dipalladium, palladium acetate, or trans-bis(triphenylphosphine)palladium(II) dichloride.

[0013] The present invention is further configured as follows: When the A and D monomers are organoboron compounds and organic halogen compounds, the Suzuki coupling reaction is adopted.

[0014] The present invention is further configured as follows: The catalyst for the Suzuki coupling reaction is tetrakis(triphenylphosphine)palladium, tris(dibenzylideneacetone)dipalladium, palladium acetate, or 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride.

[0015] The present invention is further configured as follows: For the reaction of direct functionalization of the carbon-hydrogen bond (C-H) in the A and D monomers, it is a direct arylation reaction.

[0016] The present invention is further configured as follows: The catalyst for the direct arylation reaction is palladium acetate and tetrakis(triphenylphosphine)palladium.

[0017] In summary, the present invention has the following beneficial effects:

[0018] Superhydrophilicity and Dispersibility: The prepared high-entropy conjugated polymers exhibit superhydrophilicity. Compared with traditional binary conjugated polymers, their contact angles with water are significantly reduced. The diffusion of the water contact angle can be observed within 1 second for some polymers. Under the assistance of ultrasonic waves, these polymers can be uniformly dispersed in hydrophilic liquids and will not precipitate even after long-term placement. This excellent property benefits from the enhanced hydrogen bond interactions and reduced particle size due to the high-entropy structure. At the same time, the material itself has good hydrophilicity and relatively good thermal stability, which not only facilitates processing but also extends its service life. In addition, compared with other synthesis methods of hydrophilic materials, its synthesis steps are simple and are very suitable for large-scale production and applications.

[0019] Unique Structure and Batch-to-Batch Repeatability: The polymer has a highly complex structure, containing multiple constituent units (such as Figure 1 M1 - M6), which is achieved by the enhanced entropy contribution. The unique structure of this polymer endows it with superhydrophilicity and good dispersibility. At the same time, it reduces the exciton binding energy and improves the charge separation ability, further enhancing the photocatalytic performance. In addition, it shows excellent batch-to-batch repeatability during the preparation process, indicating great application potential in the large-scale synthesis and industrial manufacturing in the semiconductor field.

[0020] Excellent Photocatalytic Performance: Under visible light irradiation (λ > 420 nm), this hydrophilic high-entropy conjugated polymer exhibits excellent photocatalytic hydrogen evolution performance. As shown in the examples, by skillfully adjusting the molar ratio of two different electron acceptor units with different electron affinities, 1,4-dibromotetrafluorobenzene and 3,7-dibromodibenzo[b,d]thiophene 5,5-dioxide (4FB and DBTO), which have different π-conjugation degrees, the two different electron acceptor units are introduced into the basic skeleton of the polymer material in a random copolymerization manner. When 4FB and DBTO are copolymerized at a molar ratio of 1:1, the system shows excellent hydrogen evolution reaction (HER) activity under visible light driving, and its maximum yield can reach 189.66 mmol g-1 h-1. Under 450 nm monochromatic light irradiation, the apparent quantum yield (AQY) is significantly improved: 38.13% without a co-solvent, and it can reach 57.63% when N,N-dimethylformamide (DMF) is introduced as a co-solvent. In addition, this catalytic system has good long-term stability. The high-entropy polymer material constructed based on the ternary copolymerization strategy promotes the formation and dissociation of excitons, not only broadens and enhances light absorption but also improves the charge transport ability, having a significant positive impact on the photocatalytic performance of the polymer. Description of the Drawings

[0021] Figure 1 Structural diagrams of Py-FBDBTO-1, Py-FBDBTO-2, and Py-FBDBTO-3 in the D-A1 / A2 type hydrophilic high-entropy conjugated polymer material of the present invention.

[0022] Figure 2 For Py-FBDBTO-1, Py-FBDBTO-2 and Py-FBDBTO-3 in the D-A1 / A2 type hydrophilic high-entropy conjugated polymer material of the present invention, the infrared spectra (FT-IR ) spectra.

[0023] Figure 3 For the change of the corresponding water contact angle of Py-FBDBTO-2 and Py-FBDBTO-3 in the D-A1 / A2 type hydrophilic high-entropy conjugated polymer material of the present invention with time within 1 second.

[0024] Figure 4 For the comparison chart of the photocatalytic hydrogen production rate (HER) of the D-A1 / A2 type hydrophilic high-entropy conjugated polymer material of the present invention and the traditional D-A type polymer.

[0025] Figure 5 For the cyclic stability chart of Py-FBDBTO-2 in the D-A1 / A2 type hydrophilic high-entropy conjugated polymer material of the present invention.

[0026] Figure 6 For the apparent quantum efficiency (AQY) of Py-FBDBTO-2 in the D-A1 / A2 type hydrophilic high-entropy conjugated polymer material of the present invention at different wavelength bands. Detailed implementation manners

[0027] The following is a further detailed description of the present invention in conjunction with the attached Figures 1-6 drawings.

[0028] Example 1: A hydrophilic high-entropy conjugated polymer, the hydrophilic high-entropy conjugated polymer is a D1 / D2-A or D-A1 / A2 type hydrophilic high-entropy conjugated polymer, and its molecular structural formula is shown as follows:

[0029]

[0030] The preparation method of the above D-A1 / A2 or D1 / D2-A type hydrophilic high-entropy conjugated polymer material is specifically as follows:

[0031] First, monomers A and D are mixed with a reaction solvent in a reaction flask according to a specific molar feed ratio (when synthesizing the D1 / D2-A type hydrophilic high-entropy conjugated polymer, D:A = 2:1, D = D1 + D2; when synthesizing the D-A1 / A2 type hydrophilic high-entropy conjugated polymer, D:A = 1:2, A = A1 + A2). After backfilling with nitrogen three times, a catalyst is then added to the reaction flask under the protection of nitrogen. Then, after backfilling with nitrogen three times again, the temperature is raised and stirred, and the reaction occurs through random copolymerization under the action of the catalyst. After the reaction is completed, the reaction solution is filtered to obtain a precipitate, and the powder obtained by Soxhlet extraction is vacuum dried to obtain the D-A1 / A2 or D1 / D2-A type hydrophilic high-entropy conjugated polymer material. Depending on the selection of monomers A1, A2, D1, and D2, one of the following reaction methods is chosen:

[0032] Stille coupling reaction: The coupling reaction between aryl halides and organotin compounds; the catalysts are tetrakis(triphenylphosphine)palladium, bis(dibenzylideneacetone)palladium, tris(dibenzylideneacetone)dipalladium, palladium acetate, or trans-bis(triphenylphosphine)palladium(II) dichloride.

[0033] Suzuki coupling reaction: The coupling reaction between organoboron compounds and organic halogen compounds; the catalysts are tetrakis(triphenylphosphine)palladium, tris(dibenzylideneacetone)dipalladium, palladium acetate, 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride.

[0034] Direct arylation reaction: The reaction of direct functionalization of the carbon-hydrogen bond (C-H) in a compound, and the catalysts are palladium acetate and tetrakis(triphenylphosphine)palladium.

[0035] The D-A1 / A2 or D1 / D2-A type high-entropy conjugated polymer material prepared by the above method is characterized by tests of contact angle, optics, electrochemistry, and charge mobility, and has the characteristics of good hydrophilicity, good light absorption performance, and high charge mobility, and is widely used in the fields of photocatalysis, perovskite solar cells, organic field effect transistors, organic light-emitting devices, and organic photovoltaic solar cells.

[0036] Example 2:

[0037] Preparation of D-A1 / A2 type hydrophilic high-entropy conjugated polymers Py-FBDBTO-1, Py-FBDBTO-2, and Py-FBDBTO-3:

[0038]

[0039] As shown above, when the molar ratios of A1 and A2 are different, the ratios of x and y (where x represents 1,4-dibromotetrafluorobenzene and y represents 3,7-dibromodibenzo[b,d]thiophene 5,5-dioxide) are as follows:

[0040] Py-FBDBTO-1 x:y = 3:1

[0041] Py-FBDBTO-2 x:y = 1:1

[0042] Py-FBDBTO-3 x:y = 1:3

[0043] The synthesis steps are as follows:

[0044] (1) Synthesis of Py-FBDBTO-1

[0045] In a two-necked flask, 4FB (230.90 mg, 0.75 mmol), DBTO (93.51 mg, 0.25 mmol), pyrene (Py) (353.05 mg, 0.5 mmol) with 1,3,6,8-tetrakis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) and 50 mL of DMF were mixed. Then, after backfilling with nitrogen three times, under a nitrogen atmosphere, tetrakis(triphenylphosphine)palladium (20 mg) and an aqueous solution of anhydrous potassium carbonate (K2CO3, 2 M) were added to the flask. After that, nitrogen backfilling was carried out three more times, and finally the reaction mixture was heated under reflux at 150 °C for 48 h. After cooling to room temperature, the mixture was poured into water and the precipitate was collected by filtration. Then, Soxhlet extraction was carried out successively with methanol, tetrahydrofuran, and chloroform. The remaining polymer was dried under vacuum at 80 °C for 24 hours to obtain the purified product, which is Py-FBDBTO-1.

[0046] (2) Synthesis of Py-FBDBTO-2

[0047] In a two-necked flask, 4FB (153.94 mg, 0.50 mmol), DBTO (187.03 mg, 0.50 mmol), Py (353.05 mg, 0.5 mmol) and 50 mL of DMF were mixed. Then, after backfilling with nitrogen three times, under a nitrogen atmosphere, tetrakis(triphenylphosphine)palladium (20 mg) and an aqueous solution of anhydrous potassium carbonate (K2CO3, 2 M) were added to the flask. After that, nitrogen backfilling was carried out three more times, and finally the reaction mixture was heated under reflux at 150 °C for 48 h. After cooling to room temperature, the mixture was poured into water and the precipitate was collected by filtration. Then, Soxhlet extraction was carried out successively with methanol, tetrahydrofuran, and chloroform. The remaining polymer was dried under vacuum at 80 °C for 24 hours to obtain the purified product, which is Py-FBDBTO-2.

[0048] (3) Synthesis of Py-FBDBTO-3

[0049] In a two-necked flask, 4FB (76.97 mg, 0.25 mmol), DBTO (280.54 mg, 0.75 mmol), Py (353.05 mg, 0.5 mmol) were mixed with 50 mL of DMF. After backfilling with nitrogen three times, under a nitrogen atmosphere, tetrakis(triphenylphosphine)palladium (20 mg) and an aqueous solution of potassium carbonate (K2CO3, 2 M) were added to the flask. Then, nitrogen backfilling was carried out three more times. Finally, the reaction mixture was heated under reflux at 150 °C for 48 h. After cooling to room temperature, the mixture was poured into water, and the precipitate was collected by filtration. Then, Soxhlet extraction was carried out successively with methanol, tetrahydrofuran, and chloroform. The remaining polymer was dried under vacuum at 80 °C for 24 hours to obtain the purified product, which is Py-FBDBTO-3.

[0050] The Py-FBDBTO-2 polymer synthesized in Example 2 was subjected to photophysical and electrochemical property tests, and the D-A1 / A2 type high-entropy conjugated polymer was applied to the field of photocatalytic hydrogen production.

[0051] The results showed that the D-A type high-entropy polymer with an irregular random sequence backbone structure constructed by the ternary copolymerization strategy achieved a dynamic balance between material solubility and intermolecular aggregation strength. This characteristic not only significantly improved the dispersion stability of polymers such as Py-FBDBTO-2 in aqueous solutions, but also formed multiple dipole fields through intramolecular multicomponent synergistic effects. The spontaneous polarization field generated by this disordered structure enhanced the directional transfer rate of photoinduced carriers, specifically manifested as an excellent HER of 189.66 mmol g -1 h -1 and an AQY of 57.63% obtained at 450 nm. In addition, the randomized main-chain sequence of the high-entropy polymer produced a moderate aggregation strength. Its structural disorder reduced the photocatalytic reaction energy barrier and significantly improved the photocatalytic performance of the polymer. This mechanism increased the charge separation efficiency, which was improved compared to traditional copolymers. Moreover, the synthesis steps of this polymer material are simple, and it has excellent batch-to-batch repeatability. The hydrophilic high-entropy conjugated polymer material prepared by the described preparation method can be widely applied in the fields of photocatalysis, perovskite solar cells, organic field-effect transistors, organic light-emitting devices, and organic photovoltaic solar cells.

[0052] This specific embodiment is only an explanation of the present invention and is not a limitation thereof. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A hydrophilic high-entropy conjugated polymer, characterized in that: The hydrophilic high-entropy conjugated polymer is a D1 / D2-A or D-A1 / A2 type hydrophilic high-entropy conjugated polymer, and its molecular structural formula is as follows:

2. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 1, characterized in that: First, monomers A and D are mixed with a reaction solvent in a reaction flask according to a specific molar feed ratio. After backfilling with nitrogen three times, a catalyst is then added to the reaction flask under the protection of nitrogen. Then, after backfilling with nitrogen three times again, the temperature is raised and stirred, and the reaction occurs through random copolymerization under the action of the catalyst. After the reaction is completed, the reaction solution is filtered to obtain a precipitate, and then the powder obtained by Soxhlet extraction is vacuum dried to obtain the hydrophilic high-entropy conjugated polymer material.

3. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 2, characterized in that: When synthesizing the D1 / D2-A type hydrophilic high-entropy conjugated polymer, D:A = 2:1, D = D1 + D2; When synthesizing the D-A1 / A2 type hydrophilic high-entropy conjugated polymer, D:A = 1:2, A = A1 + A2.

4. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 2, characterized in that: When the A and D monomers are haloarenes and organotin compounds, the Stille coupling reaction is used.

5. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 4, characterized in that: The catalyst for the Stille coupling reaction is tetrakis(triphenylphosphine)palladium, bis(dibenzylideneacetone)palladium, tris(dibenzylideneacetone)dipalladium, palladium acetate, or trans-bis(triphenylphosphine)palladium(II) dichloride.

6. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 2, characterized in that: When the A and D monomers are organoboron compounds and organic halogen compounds, the Suzuki coupling reaction is used.

7. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 6, characterized in that: The catalyst for the Suzuki coupling reaction is tetrakis(triphenylphosphine)palladium, tris(dibenzylideneacetone)dipalladium, palladium acetate, 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride.

8. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 2, characterized in that: For the reaction of direct functionalization of the carbon-hydrogen bond (C-H) in the A and D monomers, it is a direct arylation reaction.

9. The preparation method of a hydrophilic high-entropy conjugated polymer according to claim 8, characterized in that: The catalyst for the direct arylation reaction is palladium acetate, tetrakis(triphenylphosphine)palladium.

Images