Fluorine-containing polythiophene conjugated polymer, preparation method therefor, and use thereof

Abstract

A fluorine-containing polythiophene conjugated polymer, a preparation method therefor, and a use thereof, relating to the technical field of photoelectric devices. The preparation method for the fluorine-containing polythiophene conjugated polymer comprises the following steps: performing constant-voltage polymerization on a precursor of the conjugated polymer to obtain a conjugated polymer, wherein a preparation method for the precursor comprises mixing 3-bromothieno[3,2-b]thiophene, 4-fluorobenzeneboronic acid, tetrakis(triphenylphosphine)palladium, sodium carbonate, tetrahydrofuran, and water, and reacting in a protective atmosphere to obtain the precursor. According to the conjugated polymer, fluorine atoms are introduced to form intermolecular hydrogen bonds with hydrogen on a benzene ring and hydrogen on a thiophene ring, so that the transmission capacity of electrons between polymer chains is enhanced, and plane geometric structures are formed in the polymer chains and between the polymer chains to enhance the planarity of a polymer skeleton; and the volume expansion and shrinkage degree of the polymer in the repeated charging and discharging process is reduced, thereby improving the cycling stability of the material in the charging and discharging process.

Description

A fluorinated polythiophene conjugated polymer and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a fluorine-containing polythiophene conjugated polymer and a preparation method and application thereof. Background Art

[0002] With the increasing depletion of fossil fuels and the growing severity of environmental crises, carbon neutrality policies have gained widespread recognition, and the development of renewable energy and related cost-effective energy storage devices has become a top priority. Supercapacitors, due to their rapid charging and discharging capabilities and high power density, are considered one of the most promising energy storage devices in clean and renewable energy systems. Due to their energy storage mechanism, supercapacitors have found widespread application in a wide range of fields, including electronics, electrical infrastructure, and new energy vehicles. However, the rapid development of smart electronics has placed new demands on supercapacitors, including flexibility, miniaturization, and multifunctionality. Electrochromic supercapacitors, which combine the characteristics of energy storage and electrochromic devices, have potential applications in new smart electronic devices, smart wearables, and military equipment.

[0003] As a key component of supercapacitors, electrode performance is crucial. To meet these requirements, electrodes must possess not only excellent electrochemical performance but also high mechanical flexibility and processability. Inorganic materials, such as WO3, TiO2, MoO3, and V2O5, have been used as active materials in electrochromic supercapacitors due to their stable and reversible redox properties. However, their high cost, single color change, long reaction time, low color change efficiency, and poor flexibility have limited their application. Compared to inorganic materials, organic materials, such as conductive polymers, offer tunable optical and electronic properties, high conductivity, good energy storage capacity, a large voltage window, and polychromism, along with excellent processability and flexibility. However, structural damage caused by volume expansion / contraction during charge-discharge cycling reduces their cycling stability. This poor cycling stability has become a key technical issue limiting the development and application of conductive polymers in electrochromic supercapacitors. Summary of the Invention

[0004] The purpose of the present invention is to provide a fluorinated polythiophene conjugated polymer and its preparation method and application, so as to solve the problem in the prior art that the conductive polymer is damaged due to volume expansion / contraction during the charge and discharge process.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a fluorinated polythiophene conjugated polymer, the structural formula of the fluorinated polythiophene conjugated polymer is as follows:

[0007]

[0008] Where n is a natural number between 2 and 100.

[0009] Preferably, in the above-mentioned fluorinated polythiophene conjugated polymer, the structural formula of the precursor of the fluorinated polythiophene conjugated polymer is as follows:

[0010]

[0011] The present invention also provides a method for preparing a fluorinated polythiophene conjugated polymer, comprising the following steps:

[0012] The precursor of the fluorinated polythiophene conjugated polymer is polymerized at a constant voltage to obtain the fluorinated polythiophene conjugated polymer.

[0013] Preferably, in the above-mentioned method for preparing a fluorinated polythiophene conjugated polymer, the method for preparing a precursor of the fluorinated polythiophene conjugated polymer comprises the following steps:

[0014] 3-bromothieno[3,2-b]thiophene, 4-fluorophenylboric acid, tetrakis(triphenylphosphine)palladium, sodium carbonate, tetrahydrofuran and water are mixed and reacted under a protective atmosphere to obtain a precursor of a fluorinated polythiophene conjugated polymer.

[0015] Preferably, in the above-mentioned method for preparing a fluorinated polythiophene conjugated polymer, the usage ratio of 3-bromothieno[3,2-b]thiophene, 4-fluorophenylboric acid, tetrakis(triphenylphosphine)palladium, sodium carbonate, tetrahydrofuran and water is 2~6mmol:4~8mmol:0.2~0.8mmol:10~15mmol:60~80mL:10~20mL.

[0016] Preferably, in the above method for preparing a fluorinated polythiophene conjugated polymer, the reaction temperature is 60-95° C., and the reaction time is 6-10 h.

[0017] Preferably, in the above method for preparing a fluorinated polythiophene conjugated polymer, the voltage of the constant voltage polymerization is 0.7-1.2V.

[0018] The present invention also provides an application of the fluorine-containing polythiophene conjugated polymer in a photoelectric device.

[0019] It can be seen from the above technical solutions that compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The conjugated polymers of the present invention can form intermolecular hydrogen bonds with hydrogen atoms on the benzene ring and hydrogen atoms on the thiophene ring by introducing fluorine atoms. Such intermolecular hydrogen bonds not only enhance the ability to transfer electrons between polymer chains, but also enhance the planarity of the polymer backbone by forming planar geometric structures within and between polymer chains. Such intermolecular and intramolecular interactions reduce the volume expansion and contraction of the polymer during repeated charge and discharge, thereby increasing the cyclic stability of the material during charge and discharge.

[0021] (2) The electrochromic-supercapacitor material for optical devices based on fluorinated polythiophene conjugated polymers prepared by the present invention has good electrochemical energy storage and cycle stability, and the preparation method is simple and controllable, which promotes the rapid processing and preparation of conjugated polymer electrode materials and their energy storage applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0023] FIG1 is a synthetic route of the precursor of the fluorinated polythiophene conjugated polymer in Example 1;

[0024] FIG2 is the LSV of the precursor of the fluorinated polythiophene conjugated polymer in Example 1;

[0025] FIG3 is a graph showing the redox stability test of the fluorinated polythiophene conjugated polymer film in Example 2;

[0026] FIG4 is a UV-visible spectrum of the fluorinated polythiophene conjugated polymer film in Example 2;

[0027] FIG5 is a time-transmittance curve of the fluorinated polythiophene conjugated polymer film in Example 2;

[0028] FIG6 is a charge-discharge curve diagram of the fluorinated polythiophene conjugated polymer film in Example 2;

[0029] FIG7 is a graph showing the cycling stability of the specific capacitance of the fluorinated polythiophene conjugated polymer film in Example 2;

[0030] FIG8 is a diagram showing the preparation process of the optical device in Example 3;

[0031] FIG9 is a schematic structural diagram of an optical device in Example 3;

[0032] FIG10 is a diagram showing the charge and discharge color change of the optical device in Example 3;

[0033] FIG11 is a constant current charge and discharge curve diagram of the optical device in Example 3;

[0034] FIG12 is a UV-visible spectrum of the optical device in Example 3;

[0035] FIG13 is a graph showing the cycling stability of the specific capacitance of the flexible device in Example 3;

[0036] FIG14 is a graph showing the cyclic stability of transmittance of the flexible device in Example 3. DETAILED DESCRIPTION

[0037] The present invention provides a fluorinated polythiophene conjugated polymer, the structural formula of the fluorinated polythiophene conjugated polymer is as follows:

[0038]

[0039] Here, n is preferably a natural number between 2 and 100, more preferably a natural number between 10 and 90, and even more preferably a natural number between 30 and 50.

[0040] In the present invention, the structural formula of the precursor of the fluorinated polythiophene conjugated polymer is as follows:

[0041] .

[0042] The present invention also provides a method for preparing a fluorinated polythiophene conjugated polymer, comprising the following steps:

[0043] The precursor of the fluorinated polythiophene conjugated polymer is polymerized at a constant voltage to obtain the fluorinated polythiophene conjugated polymer.

[0044] In the present invention, the method for preparing the precursor of the fluorinated polythiophene conjugated polymer comprises the following steps:

[0045] 3-bromothieno[3,2-b]thiophene, 4-fluorophenylboric acid, tetrakis(triphenylphosphine)palladium, sodium carbonate, tetrahydrofuran and water are mixed and reacted under a protective atmosphere to obtain a precursor of a fluorinated polythiophene conjugated polymer;

[0046] The specific process of the mixing is:

[0047] 3-Bromothieno[3,2-b]thiophene, 4-fluorophenylboric acid and tetrahydrofuran are mixed, and then sodium carbonate is dissolved in water and added to the above system. After deoxygenation, tetrakis(triphenylphosphine)palladium is added, and deoxygenation is carried out again before reaction.

[0048] In the present invention, the usage ratio of the 3-bromothieno[3,2-b]thiophene, 4-fluorophenylboric acid, tetrakis(triphenylphosphine)palladium, sodium carbonate, tetrahydrofuran and water is preferably 2~6mmol:4~8mmol:0.2~0.8mmol:10~15mmol:60~80mL:10~20mL, more preferably 3~5.5mmol:4.3~7.5mmol:0.35~0.7mmol:11~14mmol:63~78mL:12~17mL, and more preferably 3.8~5mmol:5~6.5mmol:0.42~0.65mmol:12~13mmol:65~70mL:13~15mL.

[0049] In the present invention, the protective atmosphere is preferably nitrogen.

[0050] In the present invention, the reaction temperature is preferably 60-95° C., more preferably 62-85° C., more preferably 70-80° C.; the reaction time is preferably 6-10 h, more preferably 6.5-9.5 h, more preferably 7-8 h.

[0051] In the present invention, after the reaction is completed, the process further comprises: extracting the mixture with ethyl acetate, drying with anhydrous sodium sulfate and then evaporating the solvent, and finally performing column chromatography separation to obtain a precursor of a fluorinated polythiophene conjugated polymer.

[0052] In the present invention, the specific process of the constant voltage polymerization is:

[0053] A three-electrode system was used, with ITO glass as the working electrode, platinum wire as the counter electrode, and homemade Ag / AgCl as the reference electrode. Polymerization was performed using a constant voltage in a boron trifluoride ether solution.

[0054] The method of the self-made Ag / AgCl is:

[0055] Using the constant voltage film forming method, at 6 mol·L -1 It was prepared by electrochemical deposition at a voltage of 1.5 V for 100 s in a hydrochloric acid solution; the working electrode was silver wire, and the reference electrode and counter electrode were platinum wires.

[0056] The data measured by using the homemade Ag / AgCl in the present invention are more stable and reliable, thus avoiding the problem of unstable data deviation after repeated use of purchased Ag / AgCl.

[0057] In the present invention, the voltage of the constant voltage polymerization is preferably 0.7-1.2V, more preferably 0.8-1.1V, and even more preferably 0.95-1V.

[0058] The present invention also provides an application of the fluorine-containing polythiophene conjugated polymer in a photoelectric device.

[0059] In the present invention, the method for preparing the optoelectronic device comprises the following steps:

[0060] Conjugated polymer film and poly (3,4-ethylenedioxythiophene) coated indium tin oxide PET were used as working and counter electrodes, respectively, with gel electrolyte as the ion-conducting layer. After sealing, an optical device electrochromic-supercapacitor was obtained.

[0061] The preparation method of the gel electrolyte comprises the following steps:

[0062] The product is prepared by reacting lithium perchlorate, acetonitrile, polymethyl methacrylate and propylene carbonate (weight ratio of 3.5:5.5:5.5:85.5) at 70°C for 6 hours under nitrogen protection.

[0063] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0064] Example 1

[0065] A method for preparing a precursor of a fluorinated polythiophene conjugated polymer, as shown in FIG1 , comprises the following steps:

[0066] 4.56 mmol of 3-bromothieno[3,2-b]thiophene and 6.84 mmol of 4-fluorophenylboronic acid were placed in a 250 mL two-necked flask, and then 70 mL of tetrahydrofuran was added; 13.6 mmol of sodium carbonate was dissolved in 14 mL of water and added to the above two-necked flask, deoxygenated with nitrogen for 10 minutes, and then 0.45 mmol of tetrakis(triphenylphosphine)palladium was added. The mixture was replaced with nitrogen three times and reacted at 85°C for 6 hours. After the reaction, 20 mL of ethyl acetate was added and extracted three times. The organic phase was then dried over anhydrous sodium sulfate and the solvent was evaporated using a rotary evaporator. Column chromatography was performed with petroleum ether to obtain a white solid, which was the precursor of the fluorinated polythiophene conjugated polymer.

[0067] The LSV of the fluorinated polythiophene conjugated polymer precursor prepared above in boron trifluoride etherate is shown in Figure 2. The concentration of the fluorinated polythiophene conjugated polymer precursor was 0.01 mol / L, and the scan rate was 100 mV / s. As shown in Figure 2, the initial oxidation potential of the fluorinated polythiophene conjugated polymer precursor in boron trifluoride etherate was 0.6 V, and the polymerization potential was 0.95 V.

[0068] Example 2

[0069] A method for preparing a fluorinated polythiophene conjugated polymer comprises the following steps:

[0070] The precursor of the fluorinated polythiophene conjugated polymer prepared in Example 1 was mixed with boron trifluoride etherate, where the concentration of the fluorinated polythiophene conjugated polymer precursor was 0.01 mol / L. Constant voltage polymerization was performed at 0.95 V using a three-electrode system with ITO conductive glass as a working electrode, a platinum wire as a counter electrode, and a homemade Ag / AgCl as a reference electrode to obtain a fluorinated polythiophene conjugated polymer film.

[0071] Among them, the method of making Ag / AgCl:

[0072] Using the constant voltage film forming method, at 6 mol·L -1 It was prepared by electrochemical deposition at a voltage of 1.5 V for 100 s in a hydrochloric acid solution; the working electrode was silver wire, and the reference electrode and counter electrode were platinum wires.

[0073] The redox stability test graph of the prepared fluorinated polythiophene conjugated polymer film in boron trifluoride ether (scan rate 100 mV / s) is shown in Figure 3. As shown in Figure 3, the fluorinated polythiophene conjugated polymer film exhibits excellent electrochemical stability during doping-dedoping cycles, with an electroactivity loss of less than 6% after 10,000 cycles.

[0074] The fluorinated polythiophene conjugated polymer film prepared above was heated in acetonitrile-lithium perchlorate (0.1 mol·L -1 ) is shown in Figure 4. As shown in Figure 4, the maximum absorption peaks of the conjugated polymer are around 480nm and 740nm, respectively. At a voltage of 0.5V, the conjugated polymer appears orange-red. When the applied voltage is increased to 1V, the color of the conjugated polymer changes from orange-red to blue. At this time, the absorption peak at 480nm weakens and eventually disappears, and a new absorption peak appears at 740nm due to the formation of monopoles and bipolarons.

[0075] Figure 5 shows the time-transmittance curves of the fluorinated polythiophene conjugated polymer film prepared above at different wavelengths using double-step spectral chronoamperometry with a switching time of 10 seconds. As shown in Figure 5, the optical contrast of the fluorinated polythiophene conjugated polymer film is 48% at 480 nm, 46% at 740 nm, and 56% at 1050 nm.

[0076] The charge and discharge curves of the fluorinated polythiophene conjugated polymer film prepared above at different current densities are shown in FIG6 . As shown in FIG6 , the charge and discharge curves of the fluorinated polythiophene conjugated polymer film at a current density of 1.0 A·g -1 When the specific capacitance is 116F·g-1 When the current density increases to 10.0 A·g -1 When the specific capacitance of the conjugated polymer is still maintained at 102F·g -1 , with excellent rate performance.

[0077] The specific capacitance cycle stability diagram of the fluorinated polythiophene conjugated polymer film prepared above is shown in FIG7. As shown in FIG7, after 1000 charge and discharge cycles, the specific capacitance of the fluorinated polythiophene conjugated polymer film increases from 122 F·g to 200 F·g. -1 Down to 102F·g -1 , there is still 85% capacitance retention rate.

[0078] Example 3

[0079] A method for preparing a photoelectric device, as shown in Figures 8 and 9, comprises the following steps:

[0080] Conjugated polymer film and poly (3,4-ethylenedioxythiophene) coated indium tin oxide PET were used as working and counter electrodes, respectively, with gel electrolyte as the ion-conducting layer. After sealing, an optical device electrochromic-supercapacitor was obtained.

[0081] The preparation method of the gel electrolyte comprises the following steps:

[0082] The product is prepared by reacting lithium perchlorate, acetonitrile, polymethyl methacrylate and propylene carbonate (weight ratio of 3.5:5.5:5.5:85.5) at 70°C for 6 hours under nitrogen protection.

[0083] The constant current charge and discharge curves of the optical device prepared above at different current densities are shown in FIG11. As shown in FIG11, when the current density is 1.0 A·g -1 When the specific capacitance is 22F·g -1 When the current density increases to 10.0 A·g -1 When the specific capacitance of the optical device is still maintained at 16F·g -1 , with excellent rate performance.

[0084] The UV-visible spectrum of the optical device prepared above is shown in Figure 12. As shown in Figure 12, in the UV-visible spectrum of the optical device from 0V to 1.4V, its maximum absorption peaks are around 470nm and 610nm, respectively.

[0085] The specific capacitance cycle stability diagram of the optical device prepared above is shown in FIG13. As shown in FIG13, the optical device has a specific capacitance cycle stability of 1A·g -1 When the device is charged and discharged for 600 cycles, the specific capacitance of the device is maintained at 82%.

[0086] The transmittance cycle stability diagram of the optical device prepared above is shown in Figure 14. As shown in Figure 14, the optical contrast of the device is maintained at 11% (470nm) and 15% (610nm) after 600 cycles.

[0087] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A fluorinated polythiophene conjugated polymer, characterized in that: The structural formula of the fluorinated polythiophene conjugated polymer is as follows: Wherein, n is a natural number between 2 and 100.

2. The fluorinated polythiophene conjugated polymer according to claim 1, characterized in that: The structural formula of the precursor of the fluorinated polythiophene conjugated polymer is as follows: 。 3. The method for preparing the fluorinated polythiophene conjugated polymer according to claim 1 or 2, characterized in that: The following steps are involved: The precursor of the fluorine-containing polythiophene conjugated polymer is polymerized at a constant voltage to obtain the fluorine-containing polythiophene conjugated polymer.

4. The method for preparing a fluorinated polythiophene conjugated polymer according to claim 3, characterized in that: The method for preparing the precursor of the fluorinated polythiophene conjugated polymer comprises the following steps: 3-bromothieno[3,2-b]thiophene, 4-fluorophenylboric acid, tetrakis(triphenylphosphine)palladium, sodium carbonate, tetrahydrofuran and water are mixed and reacted under a protective atmosphere to obtain a precursor of a fluorinated polythiophene conjugated polymer.

5. The method for preparing a fluorinated polythiophene conjugated polymer according to claim 4, characterized in that: The dosage ratio of the 3-bromothieno[3,2-b]thiophene, 4-fluorophenylboric acid, tetrakis(triphenylphosphine)palladium, sodium carbonate, tetrahydrofuran and water is 2-6 mmol: 4-8 mmol: 0.2-0.8 mmol: 10-15 mmol: 60-80 mL: 10-20 mL.

6. The method for preparing a fluorinated polythiophene conjugated polymer according to claim 4 or 5, characterized in that: The reaction temperature is 60-95° C., and the reaction time is 6-10 hours.

7. The method for preparing a fluorinated polythiophene conjugated polymer according to claim 6, characterized in that: The voltage of the constant voltage polymerization is 0.7~1.2V.

8. Use of the fluorinated polythiophene conjugated polymer according to claim 1 or 2 in optoelectronic devices.

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