Triphenylamine-based conjugated polymer, preparation method therefor, and use thereof

Abstract

A triphenylamine-based conjugated polymer, a preparation method therefor, and a use thereof, belonging to the technical field of photoelectric devices. The method comprises the following steps: in a protective atmosphere, immersing 3,4-ethylenedioxythiophene and n-butyllithium into tetrahydrofuran and then adding tributyltin chloride to undergo a reaction to obtain a filtrate; in a protective atmosphere, adding tris(4-bromophenyl)amine and tetrakis(triphenylphosphine)palladium to the filtrate to undergo a reaction to obtain a conjugated polymer precursor; and polymerizing the conjugated polymer precursor in boron trifluoride diethyl ether to obtain the triphenylamine-based conjugated polymer. The triphenylamine-based conjugated polymer still retains 91.1% of electrochemical activity after 6000 cycles and has excellent electrical stability. When the current density is 1 A g-1, the specific capacitance (C) is 134 F g-1, and when the current density is 10 A g-1, the specific capacitance (C) can remain at 124 F g-1. The triphenylamine-based conjugated polymer has excellent rate performance.

Description

A triphenylamine 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 triphenylamine conjugated polymer and a preparation method and application thereof. Background Art

[0002] Supercapacitors, with their advantages of long cycle life, high power density, and rapid charge and discharge, are highly competitive in the clean energy storage sector. Electrochromic-supercapacitor devices (ESDs), which combine supercapacitors with electrochromic technology, can monitor their energy storage status in real time through color changes, preventing energy loss caused by excessive charge and discharge. They are suitable for future intelligent electronic devices.

[0003] The key to developing electrochromic supercapacitors lies in the development of efficient active electrode materials. Organic materials, represented by conductive polymers, can enhance their electrochemical energy storage and electrochromic properties by designing their molecular structure. Their exceptional flexibility allows ESDs to overcome the shortcomings of traditional energy storage devices, such as high rigidity and inconvenience. As a member of the conductive polymer family, polytriphenylamine (PTPA) boasts a propeller structure that greatly enhances ion transport, resulting in a rich variety of polymer colors. Furthermore, the benzene ring is highly susceptible to modification, allowing for diverse properties depending on the type of modifying group. Unfortunately, repeated doping and dedoping of ions during multiple charge and discharge cycles causes the volume of PTPA to expand and contract, leaving the material facing the challenge of balancing electrochemical activity and stability. Therefore, the ingenious design of triphenylamine-based conjugated polymers is crucial for preparing conductive polymer electrode materials and for building high-performance ESDs. Summary of the Invention

[0004] The purpose of the present invention is to provide a triphenylamine conjugated polymer and a preparation method and application thereof.

[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 triphenylamine conjugated polymer, wherein the triphenylamine conjugated polymer is:

[0007] ;

[0008] n is 2~100.

[0009] Preferably, the precursor of the triphenylamine conjugated polymer is:

[0010] .

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

[0012] (1) Under a protective atmosphere, 3,4-ethylenedioxythiophene and n-butyl lithium are immersed in tetrahydrofuran, and then tributyltin chloride is added to react to obtain a filtrate;

[0013] (2) Under a protective atmosphere, tri(4-bromophenyl)amine and tetrakis(triphenylphosphine)palladium are added to the filtrate to react and obtain a conjugated polymer precursor;

[0014] (3) The conjugated polymer precursor is polymerized in boron trifluoride ether to obtain the triphenylamine conjugated polymer.

[0015] Preferably, the volume ratio of 3,4-ethylenedioxythiophene, n-butyllithium and tributyltin chloride in step (1) is 1-5:11-15:8-12.

[0016] Preferably, the immersion temperature in step (1) is -80 to -60°C, and the immersion time is 100 to 140 minutes.

[0017] Preferably, the reaction time in step (1) is 10 to 14 hours.

[0018] Preferably, the mass volume ratio of tri(4-bromophenyl)amine, tetrakis(triphenylphosphine)palladium and 3,4-ethylenedioxythiophene in step (2) is 3-7 g:1-5 g:1-5 mL.

[0019] Preferably, the reaction temperature in step (2) is 80-120° C., and the reaction time is 40-55 h.

[0020] Preferably, the polymerization voltage in step (3) is 0.3-0.7V.

[0021] The present invention also provides application of the triphenylamine conjugated polymer in electrochromic supercapacitors.

[0022] The present invention has the following beneficial effects:

[0023] The triphenylamine conjugated polymer provided by the present invention has the advantages of multi-color change, good stability and the like.

[0024] The present invention also provides a method for preparing the triphenylamine conjugated polymer, comprising the following steps: immersing 3,4-ethylenedioxythiophene and n-butyllithium in tetrahydrofuran under a protective atmosphere, then adding tributyltin chloride to react to obtain a filtrate; under a protective atmosphere, adding tri(4-bromophenyl)amine and tetrakis(triphenylphosphine)palladium to the filtrate to react to obtain a conjugated polymer precursor; and polymerizing the conjugated polymer precursor in boron trifluoride ether to obtain the conjugated polymer. The present invention starts from the molecular structure itself and introduces 3,4-ethylenedioxythiophene (EDOT) as a "bridge" into the polymer chain, which not only expands the conjugated structure and increases the polymerization sites, but also stabilizes the twisted propeller configuration and enhances the electrochemical energy storage characteristics; the conjugated polymer in the present invention is subjected to one-step electrochemical polymerization in a boron trifluoride ether solution to obtain a high-quality polymer film with a porous network structure. On the one hand, the strong electrophilicity of boron trifluoride ether can strongly catalyze the deprotonation of aromatic compounds on the electrode, and significantly reduce the oxidation potential of aromatic compounds, improve the dense stacking of polymer chains, and increase the performance of the polymer film. On the other hand, since boron trifluoride ether does not require the addition of other supporting electrolytes, the porous structure of the polymer can be protected to the greatest extent during the charge and discharge process, ensuring its cyclic stability. The preparation method provided by the present invention is simple in process and controllable in method, which provides ideas for the preparation of high-performance electrochromic-supercapacitor electrode materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is an infrared spectrum of a triphenylamine-based conjugated polymer precursor and a triphenylamine-based conjugated polymer prepared in Example 1;

[0026] FIG2 is a SEM image of the triphenylamine conjugated polymer prepared in Example 1;

[0027] FIG3 is a graph showing the redox stability of the triphenylamine conjugated polymer prepared in Example 1 in a boron trifluoride etherate system;

[0028] Figure 4 shows the triphenylamine conjugated polymer prepared in Example 1 in acetonitrile-Bu4NPF6 (0.1 mol·L -1 ) UV-visible spectrum of the system;

[0029] FIG5 is a time-transmittance curve of the triphenylamine conjugated polymer prepared in Example 1;

[0030] FIG6 is a charge-discharge curve of the triphenylamine conjugated polymer prepared in Example 1;

[0031] FIG7 is a flow chart for fabricating an electrochromic-supercapacitor device;

[0032] FIG8 is a schematic structural diagram of an electrochromic-supercapacitor device;

[0033] FIG9 is a diagram showing the color change of an electrochromic supercapacitor device in a charging state and a discharging state;

[0034] FIG10 is a constant current charge and discharge curve diagram of an electrochromic-supercapacitor device;

[0035] FIG11 is a UV-visible spectrum of an electrochromic-supercapacitor device;

[0036] FIG12 is a graph showing the cycling stability of an electrochromic-supercapacitor device;

[0037] FIG13 is an optical contrast image of the electrochromic-supercapacitor device after 3000 cycles. DETAILED DESCRIPTION

[0038] The present invention provides a triphenylamine conjugated polymer, wherein the triphenylamine conjugated polymer is:

[0039]

[0040] n is 2~100.

[0041] In the present invention, n is preferably 10-90, more preferably 20-80, and even more preferably 40-60.

[0042] In the present invention, the precursor of the triphenylamine conjugated polymer is:

[0043] .

[0044] The present invention also provides a method for preparing the triphenylamine conjugated polymer, comprising the following steps:

[0045] (1) Under a protective atmosphere, 3,4-ethylenedioxythiophene and n-butyl lithium are immersed in tetrahydrofuran, and then tributyltin chloride is added to react to obtain a filtrate;

[0046] (2) Under a protective atmosphere, tri(4-bromophenyl)amine and tetrakis(triphenylphosphine)palladium are added to the filtrate to react and obtain a conjugated polymer precursor;

[0047] (3) The conjugated polymer precursor is polymerized in boron trifluoride ether to obtain the triphenylamine conjugated polymer.

[0048] In the present invention, the protective atmosphere in step (1) is preferably nitrogen.

[0049] In the present invention, the volume ratio of 3,4-ethylenedioxythiophene, n-butyllithium and tributyltin chloride in step (1) is preferably 1-5:11-15:8-12, more preferably 1.5-4.5:11.5-14.5:9-11, and more preferably 2-3:12-14:9.5-10.

[0050] In the present invention, the immersion temperature in step (1) is preferably -80 to -60°C, more preferably -75 to -65°C, and more preferably -72 to -62°C. The immersion time is preferably 100 to 140 min, more preferably 110 to 130 min, and more preferably 115 to 125 min.

[0051] In the present invention, tetrahydrofuran is used as the reaction environment to ensure the progress of the reaction.

[0052] In the present invention, the method of adding tributyltin chloride in step (1) is preferably dropwise addition.

[0053] In the present invention, the reaction time in step (1) is preferably 10 to 14 hours, more preferably 11 to 13 hours, and even more preferably 11.5 to 12.5 hours.

[0054] In the present invention, after the reaction time in step (1) is reached, the filtrate is obtained by filtering and rotary evaporation.

[0055] In the present invention, the protective atmosphere in step (2) is preferably nitrogen.

[0056] In the present invention, the mass volume ratio of tri(4-bromophenyl)amine, tetrakis(triphenylphosphine)palladium and 3,4-ethylenedioxythiophene in step (2) is preferably 3-7 g:1-5 g:1-5 mL, more preferably 4-6 g:2-4 g:2-4 mL, and more preferably 4.5-5.5 g:2.5-3.5 g:2.5-3.5 mL.

[0057] In the present invention, the reaction in step (2) is carried out under reflux.

[0058] In the present invention, the reaction temperature in step (2) is preferably 80-120°C, more preferably 90-110°C, more preferably 95-105°C, and the reaction time is preferably 40-55h, more preferably 45-50h, more preferably 47-48h.

[0059] In the present invention, after the reaction in step (2) is completed, the conjugated polymer precursor is obtained by cooling, filtering, drying and purification.

[0060] In the present invention, the target temperature of the cooling is preferably 15-30°C, more preferably 18-27°C, and even more preferably 20-25°C.

[0061] In the present invention, the process of generating a conjugated polymer precursor is:

[0062] .

[0063] In the present invention, a conjugated polymer precursor is obtained and then placed in boron trifluoride ether to obtain a mixed solution, and the mixed solution is subjected to electrochemical polymerization to obtain a triphenylamine conjugated polymer. The concentration of the mixed solution is preferably 0.05 to 0.15 mol L -1 , more preferably 0.08~0.12mol L -1 , more preferably 0.09 to 0.11 mol L -1 .

[0064] In the present invention, the electrochemical polymerization is preferably a three-electrode system, wherein ITO glass is used as the working electrode, Ag / AgCl is used as the reference electrode, and platinum wire is used as the counter electrode.

[0065] In the present invention, the polymerization voltage in step (3) is preferably 0.3-0.7 V, more preferably 0.4-0.6 V, and even more preferably 0.45-0.55 V.

[0066] In the present invention, the process of electrochemical polymerization is:

[0067] .

[0068] The present invention also provides application of the triphenylamine conjugated polymer in electrochromic supercapacitors.

[0069] In the present invention, unless otherwise specified, the raw materials required for preparation are all commercially available products well known to those skilled in the art.

[0070] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0071] Example 1

[0072] Under nitrogen atmosphere, the temperature was lowered to -78°C, 3 mL of 3,4-ethylenedioxythiophene and 12.3 mL of n-butyllithium were immersed in tetrahydrofuran for 120 minutes, and then 10.29 mL of tributyltin chloride was added dropwise. The mixture was reacted for 12 hours, filtered, and rotary evaporated to obtain a filtrate.

[0073] Under a nitrogen atmosphere, 4.924 g of tris(4-bromophenyl)amine and 3.23 g of tetrakis(triphenylphosphine)palladium were added to the filtrate, refluxed at 100° C. for 48 h, and then cooled to 25° C., filtered, dried, and purified to obtain a conjugated polymer precursor.

[0074] The conjugated polymer precursor was placed in boron trifluoride ether, and electrochemical polymerization was carried out at a polymerization voltage of 0.5 V using ITO glass as a working electrode, Ag / AgCl as a reference electrode, and a platinum wire as a counter electrode to obtain a triphenylamine conjugated polymer.

[0075] The triphenylamine-based conjugated polymer precursor and triphenylamine-based conjugated polymer obtained in this example were structurally characterized by infrared spectroscopy. The results are shown in FIG1 . FIG1 shows that the triphenylamine-based conjugated polymer precursor and triphenylamine-based conjugated polymer were successfully prepared.

[0076] The triphenylamine conjugated polymer obtained in this example was observed by electron scanning microscopy. The specific structure is shown in FIG2 . FIG2 shows that the introduction of 3,4-ethylenedioxythiophene stabilizes the propeller configuration of triphenylamine, making the polymer film porous.

[0077] At a scan rate of 100 mVs -1 The redox stability of the triphenylamine conjugated polymer in a boron trifluoride ether system was tested under the conditions of 1 0.5 % and 2 0.6 % respectively. The results are shown in FIG3 . As can be seen from FIG3 , the triphenylamine conjugated polymer provided by the present invention still maintains 91.1% of its electrochemical activity after 6000 cycles, indicating that the conjugated structure in the present invention does improve the electrical stability of the film.

[0078] The triphenylamine conjugated polymer obtained in this example was reacted with acetonitrile-Bu4NPF6 (0.1 mol·L -1 The UV-visible spectrum of a triphenylamine-based conjugated polymer was tested in a 2.5-μm CMOS system. The results are shown in Figure 4. Figure 4 shows that the maximum absorption peaks of the triphenylamine-based conjugated polymer provided by the present invention are around 450 nm and 660 nm, respectively. In the neutral state, the polymer film exhibits two absorption peaks at 450 nm and 660 nm. When the voltage is -0.2 V, the film appears yellow. When the voltage is increased to 0.2 V, the film turns cyan; when the voltage is increased to 0.7 V, the color changes to blue; and when the voltage is increased to 1.1 V, the film turns bluish-purple.

[0079] At different wavelengths, the time-transmittance curves of triphenylamine conjugated polymers with a switching time of 10 s were recorded using the double-step energy spectrum chronoamperometry method. The results are shown in Figure 5. It can be seen from Figure 5 that the optical contrast of triphenylamine conjugated polymers at 450 nm is 33%, and the optical contrast at 660 nm is 20%.

[0080] 1 A g -1 , 2 A g -1 , 5A g -1 , 8 A g -1 and 10 A g -1 The charge-discharge curves of triphenylamine conjugated polymers were tested at a current density of 1 A g -1 When the specific capacitance (C) is 134 F g -1 When the current density increases to 10 A g -1 When the specific capacitance of triphenylamine conjugated polymers is maintained at 124 F g -1 , with excellent rate performance.

[0081] Fabrication of electrochromic-supercapacitor devices:

[0082] Double-sided tape was applied around two 2 cm × 1.5 cm ITO-PET sheets; electrochemical polymerization was performed on two pieces of glass to obtain the triphenylamine conjugated polymer and PEDOT film; a gel electrolyte was injected; the double-sided tape was removed and the two sheets were glued together; and the electrochromic-supercapacitor device was obtained after sealing with vulcanized silicone rubber at room temperature and drying. The specific process is shown in FIG7 , and the schematic diagram of the device structure is shown in FIG8 .

[0083] The color change diagrams of the electrochromic-supercapacitor device in the charging and discharging states are shown in Figure 9.

[0084] 1 A g -1 , 2 A g -1 , 5A g -1 , 8 A g -1 and 10 A g -1 The constant current charge and discharge curve of the device is tested at a current density of 1 A g -1 When the specific capacitance is 19 F g -1 When the current density increases to 10A g -1 The specific capacitance of the device can still be maintained at 13 F g -1 , with excellent rate performance.

[0085] The UV-visible spectrum of the electrochromic-supercapacitor device was tested at 0~1.2 V, and the results are shown in Figure 11. As can be seen from Figure 11, its maximum absorption peaks are around 430 nm, 525 nm, and 1050 nm, respectively.

[0086] At a current density of 1 A g -1Under the conditions of , the cycle stability of the electrochromic-supercapacitor device was tested, and the results are shown in Figure 12. It can be seen from Figure 12 that the specific capacitance of the device remains 87.1% after 1500 cycles.

[0087] The optical contrast of the electrochromic-supercapacitor device after 3000 cycles was tested, and the results are shown in FIG13 . As can be seen from FIG13 , the optical contrast of the device after 3000 cycles remains at 10.5% (430 nm), 7.5% (525 nm), and 12% (1050 nm), respectively.

[0088] Example 2

[0089] Under nitrogen atmosphere, the temperature was lowered to -80°C, 1 mL of 3,4-ethylenedioxythiophene and 11 mL of n-butyllithium were immersed in tetrahydrofuran for 120 minutes, 8 mL of tributyltin chloride was added dropwise, and the mixture was reacted for 12 hours. The mixture was then filtered and subjected to rotary evaporation to obtain a filtrate.

[0090] Under a nitrogen atmosphere, 3 g of tris(4-bromophenyl)amine and 1 g of tetrakis(triphenylphosphine)palladium were added to the filtrate, refluxed at 100° C. for 48 h, and then cooled to 25° C., filtered, dried, and purified to obtain a conjugated polymer precursor.

[0091] The conjugated polymer precursor was placed in boron trifluoride ether, and electrochemical polymerization was carried out at a polymerization voltage of 0.5 V using ITO glass as a working electrode, Ag / AgCl as a reference electrode, and a platinum wire as a counter electrode to obtain a triphenylamine conjugated polymer.

[0092] Example 3

[0093] Under nitrogen atmosphere, the temperature was lowered to -60°C, 5 mL of 3,4-ethylenedioxythiophene and 15 mL of n-butyllithium were immersed in tetrahydrofuran for 120 minutes, 12 mL of tributyltin chloride was added dropwise, and the mixture was reacted for 12 hours. The mixture was filtered and subjected to rotary evaporation to obtain a filtrate.

[0094] Under a nitrogen atmosphere, 7 g of tris(4-bromophenyl)amine and 5 g of tetrakis(triphenylphosphine)palladium were added to the filtrate, refluxed at 100° C. for 48 h, and then cooled to 25° C., filtered, dried, and purified to obtain a conjugated polymer precursor.

[0095] The conjugated polymer precursor was placed in boron trifluoride ether, and electrochemical polymerization was carried out at a polymerization voltage of 0.5 V using ITO glass as a working electrode, Ag / AgCl as a reference electrode, and a platinum wire as a counter electrode to obtain a triphenylamine conjugated polymer.

[0096] As can be seen from the above examples, the present invention provides a triphenylamine conjugated polymer with advantages such as multi-color change and good stability. The present invention starts from the molecular structure itself, not only expanding the conjugated structure to increase the polymerization site, but also stabilizing the twisted propeller configuration and enhancing the electrochemical energy storage properties; after 6000 cycles, it still maintains 91.1% of the electrochemical activity and has excellent electrical stability. -1 When the specific capacitance (C) is 134 F g -1 When the current density increases to 10 A g -1 When the specific capacitance of triphenylamine conjugated polymers is maintained at 124 F g -1 , with excellent rate performance.

[0097] 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 triphenylamine conjugated polymer, characterized in that: The triphenylamine conjugated polymer is: n is 2~100.

2. The triphenylamine conjugated polymer according to claim 1, characterized in that: The precursor of the triphenylamine conjugated polymer is:

3. The method for preparing the triphenylamine conjugated polymer according to claim 1 or 2, characterized in that: It includes the following steps: (1) Under a protective atmosphere, 3,4-ethylenedioxythiophene and n-butyl lithium are immersed in tetrahydrofuran, and then tributyltin chloride is added to react to obtain a filtrate; (2) under a protective atmosphere, adding tri(4-bromophenyl)amine and tetrakis(triphenylphosphine)palladium to the filtrate to react and obtain a conjugated polymer precursor; (3) The conjugated polymer precursor is polymerized in boron trifluoride ether to obtain the triphenylamine conjugated polymer.

4. The method for preparing a triphenylamine conjugated polymer according to claim 3, characterized in that: The volume ratio of 3,4-ethylenedioxythiophene, n-butyl lithium and tributyltin chloride in step (1) is 1-5:11-15:8-12.

5. The method for preparing a triphenylamine conjugated polymer according to claim 4, characterized in that: The immersion temperature in step (1) is -80 to -60°C, and the immersion time is 100 to 140 minutes.

6. The method for preparing a triphenylamine conjugated polymer according to claim 4 or 5, characterized in that: The reaction time in step (1) is 10 to 14 hours.

7. The method for preparing a triphenylamine conjugated polymer according to claim 6, characterized in that: The mass volume ratio of tri(4-bromophenyl)amine, tetrakis(triphenylphosphine)palladium and 3,4-ethylenedioxythiophene in step (2) is 3-7 g:1-5 g:1-5 mL.

8. The method for preparing a triphenylamine conjugated polymer according to claim 7, characterized in that: The reaction temperature in step (2) is 80-120° C., and the reaction time is 40-55 h.

9. The method for preparing a triphenylamine conjugated polymer according to claim 7 or 8, characterized in that: The polymerization voltage in step (3) is 0.3-0.7V.

10. Use of the triphenylamine conjugated polymer according to claim 1 or 2 in an electrochromic supercapacitor.

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