WO2015127861A1

WO2015127861A1 - Anion exchange membrane with in-situ power regulation optical switch and preparation method

Info

Publication number: WO2015127861A1
Application number: PCT/CN2015/072780
Authority: WO
Inventors: 李存璞; 谢晓峰; 王树博; 邓长生
Original assignee: 清华大学
Priority date: 2014-02-28
Filing date: 2015-02-11
Publication date: 2015-09-03
Also published as: CN103887535B; CN103887535A

Abstract

Disclosed are an anion exchange membrane with an in-situ power regulation optical switch and a preparation method, belonging to the field of new energy. Decafluorobenzene oxadiazole and diallyl bisphenol A are selected as polymerization monomers, N-bromosuccinimide is selected as a brominating agent, and diarylethene containing a nitrogen pendant group is selected as an ion exchange group, so as to synthesize the anion exchange membrane with the in-situ power regulation optical switch. The anion exchange membrane is stable in physical properties, excellent in alkali resistance and high in ion exchange capacity, and a linear chain structure of the anion exchange membrane can be reversibly adjusted under the effect of ultraviolet light/visible light, thus ionic conductance and mechanical properties are synchronously regulated. The process is simple, practical and high in efficiency, a breakthrough is made for the original complex functionalization steps, a good balance is achieved between the service life and the structural stability of the anion exchange membrane, and the anion exchange membrane is particularly suitable for all-vanadium flow batteries and fuel battery systems that have a wide operating power window.

Description

Anion exchange membrane with in-situ power regulating optical switch and preparation method thereof

Technical field

The invention belongs to the field of new energy materials, and particularly relates to an anion exchange membrane with an in-situ power regulating optical switch, in particular to an anion exchange membrane for an all vanadium redox flow battery or a proton exchange membrane fuel cell.

Background technique

The anion exchange membrane is one of the core materials of an all-vanadium redox flow battery or a proton exchange membrane fuel cell. The hydroxide ions are exchanged through the ion exchange membrane to ensure the charge balance between the cathode and the anode, so that the battery can be continuously discharged. With the rapid development of new energy power generation technology, high performance, high stability anion exchange membrane has become a key topic of various research units.

There are many reports on the preparation of ion exchange membranes using polystyrene or a mixture thereof as a skeleton and a quaternary ammonium salt as a reactive functional group. However, quaternary ammonium salts are easily decomposed, chemical stability, especially alkali resistance, and chemical and physical stability are difficult to meet commercial needs. A substance having a certain aromaticity such as imidazolyl has a strong alkali resistance. Studies have shown that a larger conjugated system can provide a more stable anion structure and maintain a higher ion exchange rate, but the larger conjugate structure is too rigid and the mechanical properties of the film will decrease. Longer fat branches increase the flexibility of the anion exchange membrane and thus improve mechanical properties. How to properly balance the two requirements of high ionic conductivity and long life has become the main point of many studies.

Summary of the invention

In view of this, it is indeed necessary to provide an anion exchange membrane having a high ionic conductivity and a long lifetime and capable of in-situ power-regulating optical switches and a preparation method thereof.

An anion exchange membrane with an in-situ power conditioning optical switch, the structural formula of the anion exchange membrane with an in-situ power conditioning optical switch is:

Wherein R is a branched chain, a diarylene crosslinking group having a nitrogen-containing pendant group, and n is the number of repeating units in the amphoteric ion exchange membrane.

A method for preparing an anion exchange membrane having an in-situ power-regulating optical switch, comprising: S1: using decafluorobenzene oxadiazole and diallyl bisphenol A as monomers, and selecting dimethylacetamide as a solvent, selecting Potassium fluoride as a catalyst, after reaction at room temperature, adding excess deionized water to obtain a base polymer; S2: using N-bromosuccinimide as a brominating reagent, 1,2-dichloroethane as a solvent, The base polymer is completely dissolved in the 1,2-dichloroethane, heated to 75-95 degrees Celsius, and then refluxed to add 4-10 mmol of the N-bromosuccinimide, and 0.02 g to 0.08 g of initiator. Azobisisobutyronitrile, the reaction solution is poured into an excess of the deionized water to obtain the brominated polymer; and S3: the brominated polymer is completely dissolved in dimethylformamide, and added 4 to 10 mmol of diarylene, after stirring at room temperature, excess methyl bromide was added, and poured onto a glass plate to form a film to obtain an anion exchange membrane having an in-situ power-regulating optical switch.

Compared with the prior art, the anion exchange membrane with the in-situ power-regulating optical switch of the present invention and the preparation method have the following beneficial effects: under the condition that the electric system requires higher power, the anion exchange membrane is irradiated by ultraviolet rays, and the diarylene cross-linking The linked group is converted into a closed-loop state, forming a large conjugated system with the connected functionalized groups, providing a strong ionic conductivity, thereby improving the battery power; when the power system is running smoothly, the required battery output power is higher. When low, the anion exchange membrane is irradiated with visible light, and the diarylene is partially converted into an open-ring state. At this time, the cross-linking group is converted into a highly flexible aliphatic chain, and the mechanical properties are improved, and the long operating life can be maintained. The prepared anion exchange membrane has the property of light control power, the preparation method is simple and easy to operate, and the cost is low, and at the same time, it can provide a stable structure or a strong ionic conductivity and output power on demand, and is suitable for industrial production and application. .

DRAWINGS

FIG. 1 is a schematic diagram of a method for preparing an anion exchange membrane with an in-situ power conditioning optical switch according to an embodiment of the present invention.

2 is a schematic view showing a preparation method of dipyridyldiarylene according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a method for preparing an anion exchange membrane of an in-situ power-regulating optical switch having a dipyridyldiarylene according to an embodiment of the present invention.

4 is a schematic view showing the operation of a dipyridyl diarylene optical switch portion in an anion exchange membrane with an in-situ power-regulating optical switch according to an embodiment of the present invention.

FIG. 5 is a comparison diagram of conductivity after anion exchange film of an in-situ power-regulating optical switch having a dipyridyldiarylene provided by an embodiment of the present invention by ultraviolet irradiation/visible light irradiation.

The invention will be further illustrated by the following detailed description in conjunction with the accompanying drawings.

detailed description

The anion exchange membrane with the in-situ power-regulating optical switch and the preparation method provided by the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides an anion exchange membrane with an in-situ power-regulating optical switch, and the structural formula of the anion exchange membrane with an in-situ power-regulating optical switch is:

The structural adjustment of the diarylene crosslinking group is carried out by ultraviolet or visible light, thereby realizing the reversible adjustment of the size of the ion exchange group conjugated system and the flexibility of the crosslinking group. Specifically, after the ultraviolet irradiation, the diarylene crosslinking group is converted into a ring-closed state to form a large conjugated system with the attached functionalized group, and the anion exchange membrane is further irradiated with visible light. The diarylene crosslinking group is partially converted to an open ring state, at which time the diarylene crosslinking group is converted to a flexible aliphatic chain.

Wherein the molecule of the diarylene crosslinking group includes at least one of pyridine diarylene, imidazole diarylene and derivatives thereof. In the embodiment of the present invention, the molecular structure of the diarylene crosslinking group is dipyridyl diarylene:

Specifically, when the anion exchange membrane is irradiated by ultraviolet rays, the dipyridyldiarylene crosslinking group is converted into a closed-loop state, and the structural formula of the anion exchange membrane having the in-situ power-regulating optical switch is:

When the ion exchange membrane is irradiated by visible light, the dipyridyldiarylene crosslinking group is converted into an open ring state, and the structural formula of the anion exchange membrane having the in-situ power-regulating optical switch is:

Referring to FIG. 1, the present invention provides a method for preparing an anion exchange membrane having an in-situ power conditioning optical switch, comprising the following steps:

S1: using decafluorobenzene oxadiazole and diallyl bisphenol A as monomers, selecting dimethylacetamide as a solvent, selecting potassium fluoride as a catalyst, and reacting at room temperature, adding excess deionized water to obtain a base polymerization. Object

S2: using N-bromosuccinimide as a brominating reagent, 1,2-dichloroethane as a solvent, completely dissolving the base polymer in the 1,2-dichloroethane, and heating to After refluxing at 75-95 degrees Celsius, 4-10 mmol of the N-bromosuccinimide is added, and 0.02 g to 0.08 g of initiator couple Nitrogen diisobutyronitrile, after the reaction is refluxed, the reaction liquid is poured into the excess of the deionized water to obtain the brominated polymer;

S3: completely dissolving the brominated polymer into dimethylformamide, adding 4-10 mmol of diarylene, stirring at room temperature, adding excess methyl bromide, pouring onto a glass plate to form a film to obtain an in-situ power-regulating optical switch. Anion exchange membrane.

Specifically, in S1, the base polymer is prepared by mixing 2 to 5 mmol of the decafluorobenzene oxadiazole and 2 to 5 mmol of the diallyl bisphenol A into a first container. Further, 10 to 16 mmol of the potassium fluoride and 20 to 30 mL of the dimethylacetamide are further added, and the mixture is reacted at room temperature for 7 to 9 hours, and the base polymer is obtained by adding an excess of the deionized water.

Specifically, in S3, the diarylene is a dipyridyldiarylene. Referring to FIG. 2, the preparation method of the dipyridyldiarylene includes:

S30: 25 g of glutaryl chloride was added to 200 ml of dichloromethane, 48 g of excess anhydrous aluminum trichloride was added, and after stirring at 0 ° C for half an hour, 32.3 ml of 5-chloro-2 was added dropwise to a second container. - a solution of methylthiophene in methylene chloride, maintaining the temperature for a further 8 hours, then allowing the temperature to naturally rise to room temperature, quenching with 50 ml of ice water, and recrystallizing twice with a 95% aqueous ethanol solution;

S31: Under nitrogen protection, 7.8 g of zinc powder was placed in 150 ml of purified tetrahydrofuran, and 4.33 ml of titanium tetrachloride was injected under an ice bath, stirred uniformly, and heated under reflux for 1 hour, and then kept in the dark for 24 hours. 100 ml of the tetrahydrofuran solution of the above target product was added dropwise to the second vessel. After the reaction was continued for 24 hours, the reaction was terminated by adding 40 ml of a 40% potassium carbonate solution, and the tetrahydrofuran was removed by distillation under reduced pressure, and then extracted with ethyl acetate. Drying over anhydrous magnesium sulfate overnight, then the crude product was recrystallized from the 95% aqueous ethanol;

S32: 0.54 g of chlorodiarylene, 0.4 g of p-hydroxymethylbenzeneboronic acid was dissolved in 20 ml of tetrahydrofuran, 20 ml of an aqueous solution containing 0.7 g of sodium carbonate was added, and the mixture was heated under reflux, and 0.2 g of tetrakis(triphenylphosphine)palladium was added thereto. 15 hours;

S33: The obtained crude product was separated by column chromatography, eluting with petroleum ether/ethyl acetate gradient to give dipyridyldiarylene.

Referring to FIG. 3, the technical solution of the present invention will be further described below with reference to an embodiment of a method for preparing an anion exchange membrane in which a dipyridyldiarylene is used as a crosslinking group.

Example 1

1) Using decafluorobenzene oxadiazole and diallyl bisphenol A as monomers, selecting dimethylacetamide as a solvent, selecting potassium fluoride as a catalyst; after reacting at room temperature, adding excess deionized water to obtain a base polymerization The basic preparation process of the base polymer is: mixing 3 mmol of decafluorobenzene oxadiazole and 3 mmol of diallyl bisphenol A into a three-necked flask, and then adding 12.00 mmol of potassium fluoride and 20 mL of dimethylacetamide. , reacting at room temperature for 8 hours, adding excess deionized water to obtain a base polymer;

2) using N-bromosuccinimide as a brominating reagent and 1,2-dichloroethane as a solvent, completely dissolving the above base polymer in 1,2-dichloroethane and heating to about 85 ° C. After refluxing, 6 mmol of N-bromosuccinimide was added, and 0.02 g of the initiator azobisisobutyronitrile was refluxed for 3 hours, and the reaction liquid was poured into excess deionized water to obtain a brominated polymer;

3) 25 g of glutaryl chloride was added to 200 ml of dichloromethane, 48 g of excess anhydrous aluminum trichloride was added, and after stirring at 0 ° C for half an hour, 32.3 ml of 5-chloro-2- was slowly added dropwise to the flask. After a solution of methylthiophene in dichloromethane, the reaction was continued (unchanged temperature) for 8 hours, the temperature was naturally raised to room temperature, and the reaction was quenched by adding 50 ml of ice water, and the obtained solid was recrystallized twice with a 95% aqueous ethanol solution. Under nitrogen protection, 7.8 g of zinc powder was placed in 150 ml of purified tetrahydrofuran, and 4.33 ml of titanium tetrachloride was injected under ice bath. After stirring, the mixture was heated and refluxed for 1 hour, and then kept in the dark for 24 hours. 100 ml of the tetrahydrofuran solution of the above target product was added dropwise to the flask. After the reaction was continued for 24 hours, the reaction was terminated by adding 40 ml of a 40% potassium carbonate solution, and the tetrahydrofuran was removed by distillation under reduced pressure, and then extracted with ethyl acetate. The magnesium was dried overnight and the crude product was recrystallized from a 95% aqueous solution of ethanol. 0.54 g (1.65 mmol) of chlorodiarylene, 0.4 g (3.29 mmol) of p-hydroxymethylbenzeneboronic acid was dissolved in 20 ml of tetrahydrofuran, and 20 ml of an aqueous solution containing 0.7 g of sodium carbonate was added thereto, and the mixture was heated under reflux to add tetrakis(triphenylphosphine). Palladium 0.2 g (3% mol/mol) and refluxed for 15 hours. The obtained crude product is separated by column chromatography, and washed with petroleum ether/ethyl acetate gradient to obtain dipyridyldiarylene;

3) Dissolving the brominated polymer into dimethylformamide, adding 6 mmol of dipyridyldiarylene at room temperature for 10 hours, adding excess methyl bromide, pouring onto a glass plate and casting at 60 ° C to form a pyridyl group. Anion exchange membrane for in situ optical switching.

Example 2

1) 2.5 mmol of decafluorobenzene oxadiazole and 2.5 mmol of diallyl bisphenol A were mixed, added to a three-necked flask, and then 11.00 mmol of potassium fluoride and 25 mL of dimethylacetamide were added, and reacted at room temperature for 7.5 hours. Adding excess deionized water to obtain a base polymer;

2) using N-bromosuccinimide as a brominating reagent and 1,2-dichloroethane as a solvent, completely dissolving the above base polymer in 1,2-dichloroethane and heating to about 80 ° C. After refluxing, 5 mmol of N-bromosuccinimide was added, and 0.05 g of the initiator azobisisobutyronitrile was refluxed for 3 hours, and the reaction solution was poured into excess deionized water to obtain a brominated polymer;

3) Dissolving the brominated polymer into dimethylformamide, adding 5 mmol of the dipyridyldiarylene obtained in Example 1 at room temperature for 10 hours, adding excess methyl bromide, pouring onto a glass plate and casting at 60 ° C to form a film. An anion exchange membrane with a pyridyl-based in situ optical switch was obtained.

Example 3

1) 4.5 mmol of decafluorobenzene oxadiazole and 4.5 mmol of diallyl bisphenol A were mixed, added to a three-necked flask, and further added 15.00 mmol of potassium fluoride and 26 mL of dimethylacetamide, and reacted at room temperature for 9 hours. Adding excess deionized water to obtain a base polymer;

2) using N-bromosuccinimide as a brominating reagent and 1,2-dichloroethane as a solvent, completely dissolving the above base polymer in 1,2-dichloroethane and heating to about 90 ° C. After refluxing, 9 mmol of N-bromosuccinimide was added, and 0.1 g of the initiator benzoyl peroxide was added, and the reaction was refluxed for 3 hours, and the reaction solution was poured into excess deionized water to obtain a brominated polymer.

3) Dissolving the brominated polymer into dimethylformamide, adding 9 mmol of the dipyridyldiarylene obtained in Example 1 at room temperature for 10 hours, adding excess methyl bromide, pouring onto a glass plate and casting at 60 degrees Celsius to form a film. An anion exchange membrane with a pyridyl-based in situ optical switch was obtained.

Figure 4 is a schematic view of the dipyridyl diarylene optical switch portion (where the wavy line indicates the main chain of the anion exchange membrane), and the dipyridyldiarylene crosslink group light after the ultraviolet light is irradiated to the anion exchange membrane The switch portion becomes a closed loop structure, and a large conjugate system is formed (as shown by curve 2 in Fig. 5), and the film is increased in rigidity to provide a more stable pyridinium cation. After the anion exchange membrane is irradiated with visible light, the optical switch portion of the dipyridyldiarylene crosslinking group becomes an open-loop structure, and the large conjugate system disappears, but the formation of the flexible chain provides a more stable mechanical structure. The ionic conductivity of the anion exchange membrane of the closed-loop structure (shown as curve 1 in Figure 5) is compared with the ionic conductivity of the anion exchange membrane of the open-loop structure (as shown by curve 2 in Figure 5). Exchange membranes provide higher ionic conductivity. The light control switch process is reversible. The physical properties of the closed-loop state and the open-loop state of the anion exchange membrane of an in-situ power-regulating optical switch having a dipyridyldiarylene are shown in Table 1.

Table 1 Comparison of the properties of pyridyl diarylene anion exchange membrane after UV/visible irradiation

It can be clearly seen from Table 1 that the open-loop state of the anion exchange membrane of the in-situ power-regulating optical switch having dipyridyldiarylene has higher toughness and better structural stability than the closed-loop state.

The anion exchange membrane with the in-situ power-regulating optical switch of the invention and the preparation method have the following beneficial effects: when the electric system requires higher power, the anionic exchange membrane is irradiated by ultraviolet rays, and the diarylene crosslinking group is converted into a closed loop State, forming a large conjugate system with the functionalized groups attached, providing strong ionic conductivity, thereby increasing battery power; when the power system is running smoothly, the required battery output power is low, and visible light irradiation is used. The anion exchange membrane converts the diarylene into an open-ring state. At this time, the cross-linking group is converted into a highly flexible aliphatic chain, and the mechanical properties are improved, and the long operating life can be maintained. The prepared anion exchange membrane has the property of light control power, the preparation method is simple and easy to operate, and the cost is low, and at the same time, it can provide a stable structure or a strong ionic conductivity and output power on demand, and is suitable for industrial production and application. .

In addition, those skilled in the art can make other changes in the spirit of the present invention. Of course, the changes made in accordance with the spirit of the present invention should be included in the scope of the present invention.

Claims

An anion exchange membrane with an in-situ power conditioning optical switch, characterized in that the structural formula of the anion exchange membrane with an in-situ power conditioning optical switch is:

Wherein R is a branched chain, a diarylene crosslinking group having a nitrogen-containing pendant group, and n is the number of repeating units in the amphoteric ion exchange membrane.
The anion exchange membrane with an in-situ power-modulated optical switch according to claim 1, wherein the anion exchange membrane is converted into a closed-loop state after being irradiated by ultraviolet rays, and is connected thereto. The functionalized group forms a large conjugated system, and after the anion exchange membrane is further irradiated with visible light, the diarylene crosslinking group is partially converted into an open ring state, at which time the diarylene crosslinking group is converted into Flexible fatty chain.
The anion exchange membrane with an in-situ power conditioning optical switch according to claim 1, wherein the molecule of the diarylene crosslinking group comprises at least at least a pyridine diarylene, an imidazolium diene and a derivative thereof. One.
The anion exchange membrane with an in-situ power-modulating optical switch according to claim 1, wherein the molecule of the diarylene crosslinking group is a dipyridyldiarylene, and the anion exchange membrane is irradiated by ultraviolet rays. The dipyridyldiarylene crosslinking group is converted into a closed loop state. At this time, the structural formula of the anion exchange membrane having the in-situ power regulating optical switch is:
The anion exchange membrane with an in-situ power-modulating optical switch according to claim 1, wherein the molecule of the diarylene crosslinking group is a dipyridyldiarylene, and the anion exchange membrane is irradiated by visible light. The dipyridyldiarylene crosslinking group is converted into an open ring state, and the structural formula of the anion exchange membrane having the in-situ power conditioning optical switch is:
A method for preparing an anion exchange membrane having an in-situ power conditioning optical switch, comprising:

S1: using decafluorobenzene oxadiazole and diallyl bisphenol A as monomers, selecting dimethylacetamide as a solvent, selecting potassium fluoride as a catalyst, and reacting at room temperature, adding excess deionized water to obtain a base polymerization. Object

S2: using N-bromosuccinimide as a brominating reagent, 1,2-dichloroethane as a solvent, completely dissolving the base polymer in the 1,2-dichloroethane, and heating to After refluxing at 75-95 degrees Celsius, 4-10 mmol of the N-bromosuccinimide is added, and 0.02 g-0.08 g of the initiator azobisisobutyronitrile is reacted, and the reaction solution is poured into an excess of the deionized solution. Water to obtain the brominated polymer;

S3: completely dissolving the brominated polymer into dimethylformamide, adding 4-10 mmol of diarylene, stirring at room temperature, adding excess methyl bromide, pouring onto a glass plate to form a film to obtain an in-situ power-regulating optical switch. Anion exchange membrane.
The method for preparing an anion exchange membrane having an in-situ power-regulating optical switch according to claim 5, wherein the preparation process of the base polymer is: 2 to 5 mmol of the decafluorobenzene oxadiazole and 2 ～5 mmol of the diallyl bisphenol A is mixed, added to a first container, and then 10 to 16 mmol of the potassium fluoride and 20 to 30 mL of the dimethylacetamide are added, and reacted at room temperature for 7 to 9 hours. The base polymer is obtained by adding an excess of the deionized water.
Preparation method of anion exchange membrane with in-situ power conditioning optical switch according to claim 5 The method is characterized in that the preparation method of the dipyridyldiarylene comprises:

S30: 25 g of glutaryl chloride was added to 200 ml of dichloromethane, 48 g of excess anhydrous aluminum trichloride was added, and after stirring at 0 ° C for half an hour, 32.3 ml of 5-chloro-2 was added dropwise to a second container. - a solution of methylthiophene in methylene chloride, maintaining the temperature for a further 8 hours, then allowing the temperature to naturally rise to room temperature, quenching with 50 ml of ice water, and recrystallizing twice with a 95% aqueous ethanol solution;

S31: Under nitrogen protection, 7.8 g of zinc powder was placed in 150 ml of purified tetrahydrofuran, and 4.33 ml of titanium tetrachloride was injected under an ice bath, stirred uniformly, and heated under reflux for 1 hour, and then kept in the dark for 24 hours. 100 ml of a tetrahydrofuran solution of the above target product was added dropwise to the second vessel. After the reaction was continued for 24 hours, the reaction was terminated by adding 40 ml of a 40% potassium carbonate solution, and the tetrahydrofuran was removed by evaporation under reduced pressure, and then extracted with ethyl acetate. The organic phase was dried over anhydrous magnesium sulfate overnight, then the crude material was recrystall

S32: 0.54 g of chlorodiarylene, 0.4 g of p-hydroxymethylbenzeneboronic acid was dissolved in 20 ml of tetrahydrofuran, 20 ml of an aqueous solution containing 0.7 g of sodium carbonate was added, and the mixture was heated under reflux, and 0.2 g of tetrakis(triphenylphosphine)palladium was added thereto. 15 hours;

S33: The obtained crude product was separated by column chromatography, eluting with petroleum ether/ethyl acetate gradient to give dipyridyldiarylene.