A pyridine ion porous organic polymer, its preparation method and application

Abstract

The present invention relates to the field of polymer materials and electrochromic technology, and specifically to a pyridine-based ionic porous organic polymer, a preparation method thereof, and applications thereof. The pyridine-based ionic porous organic polymer, a preparation method thereof, and applications thereof provided by the present invention, by introducing the color-changing gene triphenylamine, designs a pyridine-based ionic porous organic polymer with a short synthesis route, simple operation, high yield, and high ion density. The high ion density not only imparts specific solubility to the polymer, but is also more conducive to regulating the physical and chemical properties of the ionic porous organic polymer through ion replacement, enriching the performance of the ionic porous organic polymer, and making the polymer have good solubility in specific solvents, allowing for film formation through various processing methods such as spin coating or spray coating.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials and electrochromic technology, and in particular to a pyridine ion porous organic polymer, a preparation method thereof and applications thereof. Background Art

[0002] Electrochromism refers to the reversible change in a material's optical properties (including absorptivity, reflectivity, and transmittance) when driven by different voltages, manifesting itself macroscopically as a reversible change in the material's color. Electrochromism technology has broad application prospects and has already found applications in smart windows, automotive anti-glare rearview mirrors, electronic paper, and military camouflage. However, materials remain a major bottleneck limiting its application.

[0003] Ionic porous organic polymers (iPOPs) are a new class of porous organic polymers whose structural units are connected by ionic and chemical bonds, resulting in ions not only attached to the pore walls but also embedded within them. The physicochemical properties of ionic porous organic polymers can be easily tuned through ion insertion or ion replacement. They possess high ion density, high porosity, unique solubility, and synthetic versatility, and hold great potential in the field of electrochromic materials.

[0004] However, the synthesis of ionic porous organic polymers is usually complicated. The synthesis of ionic porous organic polymers requires the selection of appropriate monomers and reaction conditions to ensure highly selective ion exchange and polymerization processes. At the same time, it is also necessary to control the structure and pore properties of the polymer to obtain the desired electrochromic properties. Due to the high difficulty and high cost of preparing electrochromic materials based on ionic porous organic polymers, ionic porous organic polymers have not yet been used in the field of electrochromism in the prior art. Therefore, the design and preparation of electrochromic materials based on ionic porous organic polymers with rich color changes, high optical contrast, fast response and high cycle stability is of great significance to the development of electrochromic technology. Summary of the Invention

[0005] The present invention addresses these challenges. To achieve electrochromic properties in a polymer, the inventors introduced triphenylamine, a color-changing gene, and designed a pyridine-based ion-porous organic polymer with a short synthetic route, simple operation, high yield, and high ion density. This porous structure imparts an excellent specific surface area and high porosity, facilitating the doping and dedoping of electrolyte ions. This, when fabricated into an electrochromic film, improves the film's response time.

[0006] At the same time, the inventors found that the pyridine ion porous organic polymer has good solubility in trifluoroethanol or hexafluoroisopropanol, and can be formed into a film through various processing methods such as spin coating or spraying. The obtained pyridine ion porous organic polymer film has reversible color change, which is easy to achieve large-scale preparation and patterned display of the film, and has potential application value in the field of electrochromism.

[0007] In a first aspect of the present invention, a pyridinium ion porous organic polymer is provided. The structural formula of the pyridinium ion porous organic polymer is as shown in Formula (I):

[0008]

[0009] The pyridine-based ionic porous organic polymer provided by the present invention has a high ion density. The high ion density not only brings specific solubility to the polymer, but also is more conducive to adjusting the physical and chemical properties of the ionic porous organic polymer through ion replacement, enriching the performance of the ionic porous organic polymer, and making the polymer have good solubility in specific solvents. Films can be formed by various processing methods such as spin coating or spray coating.

[0010] A second aspect of the present invention provides a method for preparing a pyridinium ion porous organic polymer, comprising the following steps:

[0011] (1) Dissolve tri(4-bromo)triphenylamine and 4-boric acid-pyridine in a reaction solvent and perform a Suzuki coupling reaction to obtain tri(4-(pyridin-4-yl)phenyl)amine. The chemical reaction equation is as follows:

[0012]

[0013] (2) Dissolving tris(4-(pyridin-4-yl)phenyl)amine and 2,4,6-trichloro-1,3,5-triazine in a reaction solvent to undergo a coupling reaction to obtain an ionic porous organic polymer represented by formula (II); the chemical reaction equation is as follows:

[0014]

[0015] (3) The ionic porous organic polymer obtained in step (2) is subjected to ion replacement to obtain a pyridine ionic porous organic polymer having a structural formula as shown in formula (I) and a chemical reaction equation as follows:

[0016]

[0017] The pyridine ion porous organic polymer provided by the present invention has good reaction selectivity, a simple preparation method, few by-products, is easy to purify and has a high final yield.

[0018] In some embodiments of the preparation method provided by the second aspect of the present invention, in step (1), the molar ratio of tris(4-bromo)triphenylamine to 4-boric acid-pyridine is 1:6-9.

[0019] The present invention limits the ratio of the amount of the reaction raw materials, promotes the reaction, and has a high reaction yield.

[0020] In some embodiments of the preparation method provided by the second aspect of the present invention, in step (1) of the preparation method provided by the second aspect of the present invention, the reaction temperature is 80°C to 100°C.

[0021] In some embodiments of the preparation method provided in the second aspect of the present invention, in the step (2), the reaction time is 24 to 48 hours.

[0022] In some embodiments of the preparation method provided in the second aspect of the present invention, in step (3), the reaction time is at least 12 hours.

[0023] The present invention limits the reaction temperature and reaction time, ensures that the reaction can proceed smoothly, and improves the reaction yield.

[0024] A third aspect of the present invention provides an application of a pyridine ion porous organic polymer, comprising: using the pyridine ion porous organic polymer to prepare an electrochromic film.

[0025] The pyridine ion porous organic polymer provided by the present invention can be used to prepare electrochromic films with excellent performance and reversible color change. The experimental operation is simple and the polymer is soluble in organic solvents, which facilitates the subsequent large-scale preparation of electrochromic films.

[0026] The fourth aspect of the present invention provides a method for preparing an electrochromic film based on a pyridine ion porous organic polymer, comprising the following preparation steps: dissolving the pyridine ion porous organic polymer as described in the first aspect in an organic solvent to obtain a polymer solution, and spraying the polymer solution onto ITO conductive glass to form an electrochromic film.

[0027] The pyridine ion porous organic polymer provided by the present invention is a soluble polymer and can be made into an electrochromic film on ITO conductive glass by spraying, thereby realizing large-area film preparation.

[0028] In some embodiments of the preparation method provided in the fourth aspect of the present invention, the organic solvent is trifluoroethanol or hexafluoroisopropanol.

[0029] The present invention limits the reaction solvent, ensuring that the pyridine ion porous organic polymer is fully dissolved during preparation, thereby facilitating subsequent spraying.

[0030] In some embodiments of the preparation method provided in the fourth aspect of the present invention, the concentration of the polymer solution is 5-10 mg / mL.

[0031] The present invention limits the concentration of the polymer solution, avoiding the unevenness of the prepared film caused by multiple sprayings due to too low a concentration, and also avoiding the blockage of the nozzle during the preparation process due to too high a concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the hydrogen nuclear magnetic resonance spectrum of tris(4-(pyridin-4-yl)phenyl)amine in Example 1 of the present invention;

[0033] Figure 2 is a cyclic voltammetry curve of the electrochromic thin film based on pyridine ion porous organic polymer in Example 10 of the present invention;

[0034] Figure 3 is the ultraviolet-visible absorption spectrum of the electrochromic film based on the pyridinium ion porous organic polymer in Example 11 of the present invention;

[0035] Figure 4 This is an electrochromic optical contrast diagram of the electrochromic film based on pyridine ion porous organic polymer in Example 12 of the present invention. DETAILED DESCRIPTION

[0036] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is described in detail below with reference to embodiments and drawings.

[0037] Example 1: Preparation of tris(4-(pyridin-4-yl)phenyl)amine monomer

[0038] Tris(4-bromo)triphenylamine (500 mg, 1.01 mmol), 4-boronic acid-pyridine (1.12 g, 9.09 mmol), tetrabutylammonium bromide (10 mg), K2CO3 (27 mmol) and tetrakis(triphenylphosphine)palladium (1 mg) were added to a 100 mL two-necked round-bottom flask in sequence. Under N2 protection, toluene (15 mL) and tetrahydrofuran (10 mL) were added as reaction solvents, and 3 mL of deionized water was added to the reaction flask. The reaction mixture was stirred and heated under reflux at 100°C for 48 hours. After the reaction was complete, the mixture was extracted three times with dichloromethane. The extract was concentrated and dried over anhydrous sodium sulfate to remove water. The sample was mixed with coarse silica gel and purified by column chromatography using fine silica gel as the stationary phase and dichloromethane and petroleum ether as the mobile phase (dichloromethane:petroleum ether = 1:1). The eluate containing the target compound was collected, the solvent was removed by rotary evaporation, and the mixture was dried to obtain the pure product tris(4-(pyridin-4-yl)phenyl)amine in a yield of 86%. Its H NMR spectrum is shown below. Figure 1 shown.

[0039] Example 2: Screening of Preparation Conditions for Tris(4-(pyridin-4-yl)phenyl)amine Monomer

[0040] In this example, tris(4-(pyridin-4-yl)phenyl)amine monomer was prepared according to the method in Example 1, and the reaction substrate ratio and reaction temperature were further screened.

[0041] Table 1 Reaction effect changes with reaction substrate ratio and reaction temperature

[0042]

[0043] As shown in Table 1, when the molar ratio of tris(4-bromo)triphenylamine to 4-boric acid-pyridine is 1:(6-9) and the reaction temperature is 80-90° C., the reaction yield is higher.

[0044] Example 3: Preparation of pyridine-based ionic porous organic polymer

[0045] Tris(4-(pyridin-4-yl)phenyl)amine (500 mg, 1.05 mmol) and 2,4,6-trichloro-1,3,5-triazine (209.94 mg, 1.05 mmol) prepared in Example 1 and Example 2 were sequentially added to a 100 mL two-necked round-bottom flask. Under N2 protection, anhydrous toluene (20 mL) was added as the reaction solvent. The mixture was heated at reflux at 150°C for 48 hours. After the reaction was completed, the mixture was vacuum filtered, washed three times with toluene, and dried in vacuo to obtain a pure product, a pyridine ionic porous organic polymer, in a yield of 86%.

[0046] Example 4: Screening of Preparation Conditions for Pyridine Ionic Porous Organic Polymers

[0047] In this example, a pyridine ion porous organic polymer was prepared according to the method in Example 3, and the reaction time was further screened.

[0048] Table 2 Changes in reaction yield with reaction time

[0049] Serial number Reaction time (h) Reaction yield (%) 1 16 40 2 24 70 3 32 75 4 40 82 5 48 86 6 56 65

[0050] It can be seen from Table 2 that when the reaction time is controlled within 24 to 48 hours, the reaction yield is high.

[0051] Example 5: Ion replacement of porous organic polymers containing chloride ions and pyridinium ions

[0052] The pyridinium ion porous organic polymer prepared in Example 4 was dissolved in a saturated sodium hexafluorophosphate aqueous solution, stirred at room temperature for 12 hours, vacuum filtered, and washed to obtain the pyridinium ion porous organic polymer after hexafluorophosphate ion replacement.

[0053] Example 6: Screening of ion exchange conditions for porous organic polymers containing chloride ions and pyridinium ions

[0054] In this example, ion exchange was performed according to the method in Example 5, and the reaction time was further screened.

[0055] Table 3 Changes in reaction effect with reaction time

[0056] Serial number Reaction time (h) Reaction results 1 10 Incomplete ion exchange 2 12 Complete ion exchange 3 16 Complete ion exchange 4 18 Complete ion exchange 5 20 Complete ion exchange

[0057] As shown in Table 3, when the reaction time is controlled to be above 12 h, the ion replacement is complete, and at this time, all the chloride ions in the ion porous organic polymer are replaced by hexafluorophosphate ions.

[0058] Example 7: Preparation of electrochromic thin film based on pyridine ion porous organic polymer

[0059] The pyridinium ion porous organic polymer prepared in Example 6 was dissolved in trifluoroethanol at a concentration of 8 mg / ml. Ultrasonication was performed until the polymer was completely dissolved. After filtering through a nylon 66 filter, the polymer was sprayed onto an ITO conductive glass substrate. The thickness of the film measured by a step profiler was 300 nm.

[0060] Example 8: Screening of solvents for preparing electrochromic thin films based on pyridine-based porous organic polymers

[0061] In this example, an electrochromic film was prepared according to the method in Example 7, and the solvent of the pyridine ion porous organic polymer during the reaction was further screened.

[0062] Table 4 Reaction effect changes with pyridine ion porous organic polymer solvent

[0063] Serial number solvent Reaction effect 1 Trifluoroethanol Polymer dissolution 2 Hexafluoroisopropanol polymer dissolution 3 dichloromethane Polymer insoluble 4 Tetrahydrofuran Polymer insoluble

[0064] It can be seen from Table 4 that when the solvent of the pyridine-based ionic porous organic polymer is trifluoroethanol or hexafluoroisopropanol, the polymer has good solubility and is convenient for preparing thin films.

[0065] Example 9: Preparation of Electrochromic Thin Films Based on Pyridine Ionic Porous Organic Polymers and Polymer Concentration Screening

[0066] In this example, an electrochromic film was prepared according to the method in Example 7, and the concentration of the pyridine ion porous organic polymer solution was further screened during the reaction.

[0067] Table 5 Preparation effect changes with polymer solution concentration

[0068]

[0069]

[0070] As shown in Table 5, a too low polymer solution concentration results in a large number of spray layers, resulting in uneven film thickness. A too high concentration can cause the polymer to become insoluble and clog the nozzle. Therefore, the polymer solution concentration should be limited to 5-10 mg / mL to ensure smooth film preparation.

[0071] Example 10: Electrochemical Performance Test of Electrochromic Film Based on Pyridine Ionic Porous Organic Polymer

[0072] 0.387 g (0.1 mol / L) of tetrabutylammonium hexafluorophosphate was added to a 10 mL volumetric flask, and chromatographic grade dichloromethane was added to the volume. Ultrasonication was performed until the electrolyte was completely dissolved, and this was used as a blank supporting electrolyte solution. The electrochromic film based on the pyridine ion porous organic polymer prepared in Example 7 was used as the working electrode, Ag / AgCl as the reference electrode, and platinum wire as the counter electrode. The cyclic voltammetry curves of the electrochromic film at different voltages were tested. The test results are shown in FIG. Figure 2 As shown. Figure 2 It can be seen from the cyclic voltammetry curve that the electrochromic film based on pyridine ion porous organic polymer has a significant redox potential, with an oxidation potential of 1.72 V and a reduction potential of 1.26 V, and exhibits good redox reversibility.

[0073] Example 11: UV-Vis Absorption Spectrum Test of Electrochromic Film Based on Pyridine Ionic Porous Organic Polymer

[0074] 0.387 g (0.1 mol / L) of tetrabutylammonium hexafluorophosphate was added to a 10 mL volumetric flask, and chromatographic grade dichloromethane was added to the volume. Ultrasonication was performed until the electrolyte was completely dissolved, and this was used as a blank supporting electrolyte solution. The electrochromic film based on the pyridine ion porous organic polymer prepared in Example 7 was used as the working electrode, Ag / AgCl as the reference electrode, and platinum wire as the counter electrode. The ultraviolet-visible absorption spectrum of the electrochromic film at different voltages was tested. The test results are shown in FIG. Figure 3 As shown. Figure 3 From the ultraviolet-visible absorption spectrum, it can be seen that the electrochromic film has a strong absorption peak at 400nm-500nm in the neutral state, and the color appears pink. In the fully oxidized state, there are two absorption peaks at 450nm and 775nm, and the color appears yellow-green. The film shows reversible color change.

[0075] Example 12: Electrochromic Performance Test of Electrochromic Film Based on Pyridine Ionic Porous Organic Polymer

[0076] 0.387 g (0.1 mol / L) of tetrabutylammonium hexafluorophosphate was added to a 10 mL volumetric flask, and chromatographic grade dichloromethane was added to the volume. Ultrasonication was performed until the electrolyte was completely dissolved, and this was used as a blank supporting electrolyte solution. The electrochromic film based on the pyridine ion porous organic polymer prepared in Example 7 was used as the working electrode, Ag / AgCl as the reference electrode, and platinum wire as the counter electrode. The optical contrast diagram of the electrochromic film was tested, and the test results were as shown in FIG. Figure 4 As shown. Figure 4 From the optical contrast diagram, it can be seen that the coloring time of the electrochromic film at 450nm and 780nm is 8.50s and 2.85s respectively, and the fading time is 1.61s and 1.91s respectively. The optical contrast can reach 17.21% and 23.53% respectively, showing relatively excellent electrochromic performance.

[0077] The above embodiments are preferred examples of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A pyridine ion porous organic polymer, characterized in that: The structural formula of the pyridinium ion porous organic polymer is as shown in formula (I):

2. The method for preparing a pyridinium ion porous organic polymer according to claim 1, wherein: The steps include: (1) Dissolve tri(4-bromo)triphenylamine and 4-boric acid-pyridine in a reaction solvent and perform a Suzuki coupling reaction to obtain tri(4-(pyridin-4-yl)phenyl)amine. The chemical reaction equation is as follows: (2) Dissolving tris(4-(pyridin-4-yl)phenyl)amine and 2,4,6-trichloro-1,3,5-triazine in a reaction solvent to undergo a coupling reaction to obtain an ionic porous organic polymer represented by formula (II); the chemical reaction equation is as follows: (3) The ionic porous organic polymer obtained in step (2) is subjected to ion replacement to obtain a pyridine ionic porous organic polymer having a structural formula as shown in formula (I) and a chemical reaction equation as follows:

3. The method for preparing a pyridinium ion porous organic polymer according to claim 2, wherein: In the step (1), the molar ratio of tris(4-bromo)triphenylamine to 4-boric acid-pyridine is 1:6-9.

4. The method for preparing a pyridinium ion porous organic polymer according to claim 2, wherein: In the step (1), the reaction temperature is 80°C to 100°C.

5. The method for preparing a pyridinium ion porous organic polymer according to claim 2, wherein: In the step (2), the reaction time is 24 to 48 hours.

6. The method for preparing a pyridinium ion porous organic polymer according to claim 2, wherein: In the step (3), the reaction time is at least 12 hours.

7. The use of a pyridinium ion porous organic polymer according to claim 1, characterized in that: The pyridinium ion porous organic polymer is used to prepare an electrochromic film.

8. A method for preparing an electrochromic film based on a pyridine ion porous organic polymer, characterized in that: The method comprises the following preparation steps: dissolving the pyridine ion porous organic polymer according to claim 1 in an organic solvent to obtain a polymer solution, and spraying the polymer solution onto ITO conductive glass to prepare an electrochromic film.

9. The method for preparing the electrochromic film according to claim 8, characterized in that: The organic solvent is trifluoroethanol or hexafluoroisopropanol.

10. The method for preparing the electrochromic film according to claim 8, wherein: The concentration of the polymer solution is 5-10 mg / mL.

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