Anion exchange membrane as well as preparation method and application thereof

Abstract

The invention relates to the technical field of ion exchange, in particular to an anion exchange membrane as well as a preparation method and application thereof, a quaternary ammonium salt type anion exchange membrane can be modified through corona treatment without changing the molecular structure and the preparation process of a polymer, the operation is simple and easy to implement, the cost is low, and the method is suitable for industrial production. The performance of the anion exchange membrane can be effectively improved. The preparation method comprises the following steps: providing a quaternary ammonium salt type anion exchange membrane; and performing corona treatment on the quaternary ammonium salt type anion-exchange membrane by adopting gas plasma so as to modify the quaternary ammonium salt type anion-exchange membrane, thereby preparing the anion-exchange membrane.

Description

Technical Field

[0001] The present application relates to the technical field of ion exchange, and in particular to an anion exchange membrane and a preparation method and application thereof. Background Art

[0002] In recent years, with the large-scale development and application of renewable energy, people's demand for safe and efficient storage and consumption of green electricity has been increasing day by day.

[0003] Water electrolysis is a continuous and efficient energy conversion technology that can achieve long-term storage from green electricity to green hydrogen. Among water electrolysis technologies, alkaline electrolyzer technology has been widely used due to its high durability and low cost. However, due to the loose and porous structure of its diaphragm, hydrogen permeation in the electrolyzer is serious, and there is a problem of poor safety in the low load range.

[0004] Anion exchange membranes can selectively pass hydroxide ions while blocking hydrogen and oxygen produced by the cathode and anode to ensure the continuity and safety of the water electrolysis process. Therefore, anion exchange membrane materials are required to have good hydrophilicity and durability. Among them, quaternary ammonium salt functional groups are usually used as hydrophilic groups of anion exchange membranes to conduct hydroxide. However, due to their susceptibility to hydroxide attack, a large number of studies in recent years have been conducted around improving the stability of hydrophilic groups, such as polymer monomer design, modification, cross-linking and organic-inorganic composite methods. However, the above methods based on changing the molecular structure of polymers and preparation processes have the disadvantages of long cycles, high costs and complex processes, and are difficult to meet the requirements of industrial continuity, high efficiency and low cost. Summary of the invention

[0005] Based on this, some embodiments of the present application provide an anion exchange membrane and a preparation method and application thereof. The quaternary ammonium salt anion exchange membrane can be modified by corona treatment without changing the polymer molecular structure and preparation process. The operation is simple and easy, the cost is low, and the hydrophilicity and durability of the anion exchange membrane can be effectively improved.

[0006] In a first aspect, a method for preparing an anion exchange membrane is provided, comprising:

[0007] Provide quaternary ammonium salt anion exchange membrane;

[0008] The quaternary ammonium salt type anion exchange membrane is subjected to corona treatment by using gas plasma to modify the quaternary ammonium salt type anion exchange membrane and prepare the anion exchange membrane.

[0009] Optionally, the corona treatment is performed in an oxygen-containing atmosphere or an inert gas atmosphere, and the gas plasma is oxygen-containing gas plasma or inert gas plasma.

[0010] Optionally, the gas used in the oxygen-containing atmosphere is air, oxygen, or a mixture of oxygen and an inert gas;

[0011] The inert gas used in the inert gas atmosphere includes at least one of nitrogen and argon.

[0012] Optionally, the quaternary ammonium salt anion exchange membrane is subjected to corona treatment by gas plasma to modify the quaternary ammonium salt anion exchange membrane, and the anion exchange membrane is prepared, comprising:

[0013] In an oxygen-containing atmosphere or an inert gas atmosphere, a radio frequency power source is used to energize the oxygen-containing gas or the inert gas to excite oxygen-containing gas plasma or inert gas plasma, and the oxygen-containing gas plasma or the inert gas plasma is used to perform corona discharge on the quaternary ammonium salt type anion exchange membrane to modify the quaternary ammonium salt type anion exchange membrane.

[0014] Optionally, the output power of the RF power supply is 1.8 kW to 2.0 kW, and the power-on time is 30 s to 60 s.

[0015] Optionally, the corona treatment is carried out in a vacuum chamber, in an oxygen-containing atmosphere or an inert gas atmosphere, a radio frequency power supply is used to energize the oxygen-containing gas or the inert gas to excite the oxygen-containing gas plasma or the inert gas plasma, and the quaternary ammonium salt anion exchange membrane is subjected to corona discharge using the oxygen-containing gas plasma or the inert gas plasma to modify the quaternary ammonium salt anion exchange membrane. The preparation method further comprises:

[0016] The air in the vacuum chamber is replaced by an oxygen-containing gas or an inert gas, and the oxygen-containing gas or the inert gas is introduced into the vacuum chamber at a flow rate of 50 sccm to 200 sccm, and the pressure in the vacuum chamber is maintained at 0.1 kPa to 10 kPa;

[0017] After preparing the anion exchange membrane, the preparation method further comprises:

[0018] The anion exchange membrane is kept in the vacuum chamber for 0.5 min to 5 min.

[0019] Optionally, the general structural formula of the quaternary ammonium salt anion exchange membrane is as shown in the following formula (I):

[0020] (I);

[0021] A segment is represented by , segment B is represented by , X represents the molar number of segment A when the sum of the molar numbers of segment A and segment B is 100 mol, and Ar is selected from divalent diphenyl or divalent terphenyl;

[0022] Optionally, the molar percentage of quaternary ammonium ions in the quaternary ammonium salt anion exchange membrane is 50% to 100%.

[0023] Optionally, when the gas plasma is an oxygen-containing gas plasma, the conductivity of the anion exchange membrane is greater than or equal to 21.0 mS / cm, and the contact angle is less than or equal to 75°;

[0024] When the gas plasma is an inert gas plasma, the conductivity of the anion exchange membrane is greater than or equal to 21.2 mS / cm, and the contact angle is less than or equal to 76.5°.

[0025] In a second aspect, an anion exchange membrane is provided, wherein the anion exchange membrane is prepared by the preparation method described in the first aspect.

[0026] In a third aspect, a method for producing hydrogen by electrolysis of water is provided.

[0027] Compared with the related art, this application has the following beneficial effects:

[0028] The quaternary ammonium salt anion exchange membrane is subjected to corona treatment by gas plasma, and the surface of the quaternary ammonium salt anion exchange membrane can be physically or chemically modified, so that the performance of the quaternary ammonium salt anion exchange membrane can be improved, such as improving its hydrophilicity and durability. The operation is simple and easy, the cost is low, and the demand for industrial production can be met. The problem that the method based on changing the molecular structure of the polymer and the preparation process in the related art has the disadvantages of long cycle, high cost and complex process, and is difficult to meet the requirements of industrial continuity, high efficiency and low cost is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a process for preparing an ion exchange membrane provided in an embodiment of the present application;

[0030] Figure 2 This is a comparison chart of the alkali resistance test results of the anion exchange membrane provided in Example 1 and Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0033] The present application will be further described in detail below in conjunction with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly understood.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0035] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0036] In the present application, reference to a numerical range includes both endpoints of the numerical range unless otherwise specified.

[0037] In this application, when it comes to percentage concentration, unless otherwise specified, it refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0038] In this application, when it comes to temperature parameters, unless otherwise specified, both constant temperature treatment and treatment within a certain temperature range are permitted. The constant temperature treatment allows the temperature to fluctuate within the precision range controlled by the instrument.

[0039] In view of the fact that the methods based on changing the molecular structure of polymers and the preparation process in the related art have the disadvantages of long cycle, high cost and complex process, and are difficult to meet the requirements of industrial continuous, high efficiency and low cost, the specific implementation methods of the present application are described as follows:

[0040] In a first aspect, some embodiments of the present application provide a method for preparing an anion exchange membrane, such as Figure 1 As shown, including:

[0041] S11), providing a quaternary ammonium salt anion exchange membrane;

[0042] S12), using gas plasma to perform corona treatment on the quaternary ammonium salt type anion exchange membrane to modify the quaternary ammonium salt type anion exchange membrane and prepare the anion exchange membrane.

[0043] Among them, the quaternary ammonium salt anion exchange membrane is a polymer membrane material containing cationic groups (such as quaternary ammonium salt groups) and mobile anions (such as hydroxide ions). These cationic groups are connected to the polymer backbone through chemical bonds to form ion exchange sites. Mobile anions can migrate between these sites under the action of an electric field to achieve ion conduction function and have good hydroxide ion selectivity.

[0044] Corona treatment utilizes the corona discharge phenomenon to physically and chemically modify the surface of quaternary ammonium salt anion exchange membrane to improve the performance of the quaternary ammonium salt anion exchange membrane.

[0045] Corona discharge is a gas discharge phenomenon. When the electric field strength on the electrode surface reaches a certain critical value, the gas near the electrode ionizes and emits light, thereby generating gas plasma.

[0046] The gas plasma contains a large number of active particles such as high-energy electrons, ions, free radicals and excited molecules. These active particles collide with molecules on the surface of the quaternary ammonium salt anion exchange membrane and can react with the CH bonds on the surface of the quaternary ammonium salt anion exchange membrane, thereby introducing cross-linkable groups or hydrophilic groups on the surface of the quaternary ammonium salt anion exchange membrane, or physically modifying the surface of the quaternary ammonium salt anion exchange membrane to improve its surface roughness and promote group reconstruction, thereby improving the hydrophilicity and durability of the quaternary ammonium salt anion exchange membrane.

[0047] In the preparation method of the anion exchange membrane provided in the embodiment of the present application, the quaternary ammonium salt anion exchange membrane is subjected to corona treatment by gas plasma, and the surface of the quaternary ammonium salt anion exchange membrane can be physically or chemically modified, thereby improving the performance of the quaternary ammonium salt anion exchange membrane, such as improving its hydrophilicity and durability. The operation is simple and easy, low in cost, and can meet the needs of industrial production. It solves the problem that the methods based on changing the molecular structure of the polymer and the preparation process in the related art have the disadvantages of long cycle, high cost and complex process, and are difficult to meet the requirements of industrial continuity, high efficiency and low cost.

[0048] In some embodiments, the general structural formula of the quaternary ammonium salt anion exchange membrane is as shown in the following formula (I): (I);

[0049] A segment is represented by , segment B is represented by , X represents the molar number of segment A when the sum of the molar numbers of segment A and segment B is 100 mol, and Ar is selected from divalent diphenyl or divalent terphenyl.

[0050] In these embodiments, the quaternary ammonium salt group in this quaternary ammonium salt type anion exchange membrane is connected on a relatively stable carbon skeleton, helps to improve its alkaline stability, can better resist the nucleophilic attack of hydroxide ion, thereby can slow down the degradation rate of quaternary ammonium salt group, and then make this quaternary ammonium salt type anion exchange membrane can keep higher ion exchange capacity and specific conductivity under long-time alkaline operating condition.Simultaneously, because the piperidine structure of the six-membered ring in this quaternary ammonium salt type anion exchange membrane itself has certain rigidity and stability, therefore, this quaternary ammonium salt type anion exchange membrane has good thermal stability.In addition, this quaternary ammonium salt type anion exchange membrane can form relatively orderly ion channel in preparation process, can improve ion conduction efficiency.

[0051] In some embodiments, the corona treatment is performed in an oxygen-containing atmosphere or an inert gas atmosphere, wherein when the corona treatment is performed in an oxygen-containing atmosphere, the gas plasma is an oxygen-containing gas plasma, and when the power treatment is performed in an inert gas atmosphere, the gas plasma is an inert gas plasma.

[0052] Through research, it is found that: when the corona treatment is carried out in an oxygen-containing atmosphere, the oxygen-containing gas plasma can react with the CH bonds on the surface of the quaternary ammonium salt anion exchange membrane, oxidizing them into hydrophilic groups such as hydroxyl groups, thereby improving the hydrophilicity of the quaternary ammonium salt anion exchange membrane; at the same time, the oxygen-containing gas plasma can also change the chemical structure of the surface of the quaternary ammonium salt anion exchange membrane, thereby exposing more ion exchange sites and improving the ion exchange capacity. From a microscopic perspective, the energy of the oxygen-containing plasma can cause the molecular chains on the surface of the quaternary ammonium salt anion exchange membrane to break and reorganize, thereby improving its microstructure and improving the hydrophilicity and durability of the quaternary ammonium salt anion exchange membrane.

[0053] When the corona treatment is carried out in an inert gas atmosphere, the high-energy particles in the inert gas plasma can physically collide with the impurities on the surface of the quaternary ammonium salt anion exchange membrane, thereby cleaning the surface of the quaternary ammonium salt anion exchange membrane and changing the surface tension; at the same time, the high-energy particles can also break the molecular bonds on the surface of the quaternary ammonium salt anion exchange membrane, generate some active sites, and improve the reaction activity; from a microscopic perspective, the inert gas plasma can also induce the rearrangement of the molecular chains on the surface of the quaternary ammonium salt anion exchange membrane, improve the uniformity of the pore size distribution, and thus improve its ion selectivity, and the cross-linking reaction induced by the inert gas plasma can form a more stable chemical bond network, thereby improving its own hydrophilicity and durability.

[0054] In some embodiments, the gas used in the oxygen-containing atmosphere is air, oxygen, or a mixed gas of oxygen and an inert gas; the inert gas used in the inert gas atmosphere includes at least one of nitrogen and argon.

[0055] In these embodiments, when the gas that this oxygen-containing atmosphere adopts is air, the quaternary ammonium salt group in the quaternary ammonium salt type anion exchange membrane can react with moisture and oxygen in the air, promote the interaction between the quaternary ammonium salt group, and impel the quaternary ammonium salt group on the quaternary ammonium salt type anion exchange membrane surface to form hydrogen bond or further crosslink.When the gas that this oxygen-containing atmosphere adopts is oxygen, oxygen can react with some organic group generation oxidation reaction in the quaternary ammonium salt type anion exchange membrane, thereby promote surface crosslinking, improve the durability and the hydrophilicity of quaternary ammonium salt type anion exchange membrane.When the gas that this oxygen-containing atmosphere adopts is the mixed gas of oxygen and inert gas, adopt oxygen and inert gas plasma to improve the hydrophilicity, durability and the electrical conductivity of quaternary ammonium salt type anion exchange membrane equally.When the gas that this inert gas atmosphere adopts is at least one in nitrogen and argon, the performance of this quaternary ammonium salt type anion exchange membrane itself can be kept, reduce the influence of impurities, and can improve the reactivity of this quaternary ammonium salt type anion exchange membrane, improve its hydrophilicity, durability and electrical conductivity.

[0056] In some embodiments, the method for preparing the quaternary ammonium salt anion exchange membrane may include:

[0057] S111), using N-methyl-4-piperidone, 2,2,2-trifluoroacetophenone and diphenyl or terphenyl to synthesize neutral poly (aryl piperidine) polymer (PAP-N), wherein when the biphenyl is diphenyl, its reaction equation is shown in the following formula (II), recorded as PB-N-60, and when the biphenyl is terphenyl, its reaction equation is shown in the following formula (III), recorded as PT-N-75:

[0058] (II);

[0059] (III);

[0060] S112), synthesizing poly(arylpiperidinium) (PAP) by Menshutkin reaction with PAP-N and iodomethane, wherein when the biphenyl is diphenyl, the reaction equation is shown in the following formula (IV), and the poly(arylpiperidinium) is denoted as PAP-BP, and when the biphenyl is terphenyl, the reaction equation is shown in the following formula (V), and the poly(arylpiperidinium) is denoted as PAP-TP:

[0061] (IV);

[0062] (V);

[0063] S113), dissolving PAP-BP or PAP-TP in a solvent and casting it into a membrane on a clean glass plate to obtain an iodine salt type anion exchange membrane, which can be peeled off from the glass plate when in contact with water, and the peeled iodine salt type anion exchange membrane is treated by alkali immersion to prepare the quaternary ammonium salt type anion exchange membrane in the hydroxide form, when the biphenyl is diphenyl, the reaction equation is shown in the following formula (VI), when the biphenyl is terphenyl, the reaction equation is shown in the following formula (VII):

[0064] (VI);

[0065] (VII)

[0066] In these embodiments, the quaternary ammonium salt anion exchange membrane can be prepared by adopting the above steps.

[0067] Wherein, in the above S111), x is the molar number of N-methyl-4-piperidone when the diphenyl or terphenyl is 100 mol, and correspondingly, the molar number of 2,2,2-trifluoroacetophenone is equal to the remainder (100-x) mol; N-methyl-4-piperidone, 2,2,2-trifluoroacetophenone and diphenyl or terphenyl can be reacted at 0°C~25°C for 6h~24h in the presence of trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TFSA); after the reaction is completed, in order to remove the residual acid in the product as completely as possible, the solid product can be soaked in an alkaline solution for a certain period of time.

[0068] In the above S112), when iodomethane is introduced to synthesize poly(arylpiperidinium) (PAP), on the one hand, the amount of quaternary ammonium salt groups introduced and their uniform distribution on the molecular chain can be evaluated by measuring the iodide content, so that the ion exchange capacity and conductivity of the quaternary ammonium salt anion exchange membrane can be evaluated. On the other hand, it can be verified whether the reaction is completely carried out to ensure that the quaternary ammonium salt groups are successfully introduced. The specific method of introducing iodomethane is as follows:

[0069] Suspend PB-N-60 or PT-N-75 in DMSO, quickly add methyl iodide thereto, stir for 12h~48h at room temperature (such as 25℃~50℃) in the dark, filter, wash and dry to obtain poly(arylpiperidinium).

[0070] In some embodiments, the molar percentage of quaternary ammonium ions in the quaternary ammonium salt anion exchange membrane is 50% to 100%.

[0071] In these embodiments, the molar percentage of quaternary ammonium ions in the quaternary ammonium salt type anion exchange membrane measured by hydrogen nuclear magnetic spectrum is 50% to 100%, indicating that the quaternary ammonium salt groups are introduced relatively completely into the quaternary ammonium salt type anion exchange membrane.

[0072] In S113), PAP-BP or PAP-TP can be dissolved in DMSO to cast a membrane on a clean glass plate. After the iodine salt type anion exchange membrane is stripped, the stripped iodine salt type anion exchange membrane can be immersed in 1M KOH solution at 80° C. to achieve ion exchange, and the number of immersions is 5 times, each time for 2 hours; then, the residual KOH can be removed by washing and soaking in deionized water to obtain a quaternary ammonium salt type anion exchange membrane in a hydroxide form, and the quaternary ammonium salt type anion exchange membrane in a hydroxide form is measured by X-ray fluorescence (XRF), and I - The mole percentage is less than 1%.

[0073] In some embodiments, a quaternary ammonium salt anion exchange membrane is subjected to corona treatment using gas plasma to modify the quaternary ammonium salt anion exchange membrane to prepare the anion exchange membrane, comprising:

[0074] In an oxygen-containing atmosphere or an inert gas atmosphere, a radio frequency power source is used to energize the oxygen-containing gas or the inert gas to excite oxygen-containing gas plasma or inert gas plasma, and the oxygen-containing gas plasma or inert gas plasma is used to perform corona discharge on the quaternary ammonium salt type anion exchange membrane to modify the quaternary ammonium salt type anion exchange membrane.

[0075] In some embodiments, the output power of the RF power supply is 1.8 kW to 2.0 kW, and the power-on time is 30 s to 60 s.

[0076] In some embodiments, the corona treatment is performed in a vacuum chamber, in an oxygen-containing atmosphere or an inert gas atmosphere, a radio frequency power source is used to energize the oxygen-containing gas or the inert gas to excite the oxygen-containing gas plasma or the inert gas plasma, and the quaternary ammonium salt anion exchange membrane is subjected to corona discharge by using the oxygen-containing gas plasma or the inert gas plasma to modify the quaternary ammonium salt anion exchange membrane. The preparation method further comprises:

[0077] The air in the vacuum chamber is replaced by oxygen-containing gas or inert gas, and oxygen-containing gas or inert gas is introduced into the vacuum chamber at a flow rate of 50 sccm to 200 sccm, so that the gas pressure in the vacuum chamber is maintained at 0.1 kPa to 10 kPa.

[0078] In these embodiments, the corona treatment of the quaternary ammonium salt type anion exchange membrane can be carried out in an oxygen-containing atmosphere or an inert gas atmosphere without being disturbed by other gas plasmas.

[0079] In some embodiments, after preparing the anion exchange membrane, the preparation method further comprises:

[0080] The anion exchange membrane is kept in the vacuum chamber for 0.5 min to 5 min.

[0081] In these embodiments, after the anion exchange membrane is prepared, the anion exchange membrane is kept in a vacuum chamber for 0.5 min to 5 min, and oxygen-containing gas or inert gas is introduced to promote heat dissipation of the anion exchange membrane, thereby ensuring that the structure of the anion exchange membrane is less affected by heat.

[0082] In some embodiments, when the gas plasma is an oxygen-containing gas plasma, the conductivity of the anion exchange membrane is greater than or equal to 21.0 mS / cm, and the contact angle is less than or equal to 75°;

[0083] When the gas plasma is an inert gas plasma, the conductivity of the anion exchange membrane is greater than or equal to 21.2 mS / cm, and the contact angle is less than or equal to 76.5°.

[0084] In these embodiments, by using different plasmas to perform corona treatment on the quaternary ammonium salt type anion exchange membrane, the quaternary ammonium salt type anion exchange membrane can be modified to different degrees, thereby obtaining anion exchange membranes with different durability, hydrophilicity and conductivity.

[0085] In some embodiments, the anion exchange membrane has a thickness of 5 μm to 100 μm.

[0086] In a second aspect, some embodiments of the present application provide an anion exchange membrane, which is prepared by the preparation method described in the first aspect.

[0087] Compared with the anion exchange membrane before modification, the conductivity, mechanical strength and hydrophilicity of the anion exchange membrane can be improved, thereby improving the performance of the anion exchange membrane.

[0088] In a third aspect, some embodiments of the present application provide an application of an anion exchange membrane as described in the second aspect in hydrogen production by water electrolysis.

[0089] The electrolyte used in the electrolysis of water to produce hydrogen can be an alkaline electrolyte, and the anion exchange membrane has excellent mechanical properties and high hydroxide ion conductivity, which can meet the growing demand for the use of anion exchange membranes.

[0090] The above introduces the specific implementation methods of the present application. In order to objectively illustrate the technical effects produced by the present application, the following examples and comparative examples will be used for description.

[0091] In the following examples and comparative examples, all raw materials can be purchased in commercial form, and in order to maintain the reliability of the experiment, the raw materials used in the following examples and comparative examples have the same physical and chemical parameters or are processed in the same way.

[0092] Example 1

[0093] Embodiment 1 provides an anion exchange membrane, and the preparation method of the anion exchange membrane is as follows:

[0094] (1) Preparation of quaternary ammonium salt anion exchange membrane:

[0095] N-methyl-4-piperidone (6.7895 g, 60 mmol), 2,2,2-trifluoroacetophenone (6.9648 g, 40 mmol) and biphenyl (15.4210 g, 100 mmol) were dissolved in dichloromethane (68 ml), and then trifluoroacetic acid (TFA, 4.6 ml) and trifluoromethanesulfonic acid (TFSA, 68.4 ml) were slowly added dropwise at 0°C, and then the reaction was continued at this temperature for 24 hours to obtain a viscous brown solution. The obtained viscous brown solution was slowly poured into an ethanol aqueous solution to precipitate the product, and after filtering and washing with water, the solid product was immersed in 1 M K2CO3 at 50°C for 12 hours. Finally, after filtering and washing with water, it was vacuum dried at 60°C to obtain a white fiber polymer PB-N-60, and the yield of the polymer PB-N-60 was 95%. The preparation method of the polymer PB-N-60 is represented by the reaction equation as follows:

[0096]

[0097] 1.0 g of PB-N-60 was suspended in DMSO (20 ml), placed in a 50 ml single-necked flask equipped with a magnetic bar, methyl iodide (1 ml) was quickly added, and the solution was stirred at room temperature for 12 h. Then, the resulting viscous yellow solution was added dropwise to ether to obtain a yellow precipitate. The yellow precipitate was filtered, washed with ether, and then vacuum dried at 60°C to obtain a yellow solid product. The yield of the yellow solid product was 99.8%. The yellow solid product (1.0 g) was dissolved in DMSO (30 ml) and cast on a clean glass plate at 120°C for 2 h to prepare a quaternary ammonium salt anion exchange membrane in the form of iodide. The quaternary ammonium salt anion exchange membrane in the form of iodide was peeled off from the glass plate when in contact with deionized water. The peeled quaternary ammonium salt anion exchange membrane in the form of iodide was soaked in a 1M KOH solution at 80°C for 5 times, each time for 2 h. Subsequently, the soaked quaternary ammonium salt anion exchange membrane was soaked in deionized water for 48 h to remove residual KOH, and a quaternary ammonium salt anion exchange membrane in the form of hydroxide (0.5 g) was obtained. The iodine content in the quaternary ammonium salt anion exchange membrane in the form of hydroxide was tested by X-ray fluorescence (XRF), and the molar percentage of iodine was less than 1%. Among them, the preparation method of the quaternary ammonium salt anion exchange membrane in the form of hydroxide is expressed by the reaction equation as follows:

[0098]

[0099] (2) The quaternary ammonium salt anion exchange membrane in the form of hydroxide is dried and fixed on a rotating sample holder. The vacuum chamber is evacuated and air is introduced into the chamber at a flow rate of 100 sccm. The air pressure in the chamber is maintained at 0.5 kPa. Then, the radio frequency power supply is started with a transmission power of 1.8 kW to perform corona treatment on the quaternary ammonium salt anion exchange membrane in the form of hydroxide. The radio frequency power supply is turned off after 30 seconds and maintained for 1 minute while continuing to introduce air to cool the quaternary ammonium salt anion exchange membrane in the form of hydroxide.

[0100] Example 2

[0101] The method for preparing the anion exchange membrane in Example 2 is substantially the same as the method for preparing the anion exchange membrane in Example 1, except that:

[0102] In step (2), the output power of the RF power supply is 2.0 kW.

[0103] Example 3

[0104] The method for preparing the anion exchange membrane in Example 3 is substantially the same as the method for preparing the anion exchange membrane in Example 1, except that:

[0105] In step (2), the output power of the RF power supply is 2.0 kW, and the corona treatment time is 60 s.

[0106] Example 4

[0107] The method for preparing the anion exchange membrane in Example 4 is substantially the same as the method for preparing the anion exchange membrane in Example 1, except that:

[0108] In step (2), the air is replaced with oxygen.

[0109] Example 5

[0110] The method for preparing the anion exchange membrane in Example 5 is substantially the same as the method for preparing the anion exchange membrane in Example 4, except that:

[0111] In step (2), the corona treatment time is 60s.

[0112] Example 6

[0113] The method for preparing the anion exchange membrane in Example 6 is substantially the same as the method for preparing the anion exchange membrane in Example 4, except that:

[0114] In step (2), the output power of the RF power supply is 2.0 kW.

[0115] Example 7

[0116] The method for preparing the anion exchange membrane in Example 7 is substantially the same as the method for preparing the anion exchange membrane in Example 4, except that:

[0117] In step (2), the output power of the RF power supply is 2.0 kW, and the corona treatment time is 60 s.

[0118] Example 8

[0119] The method for preparing the anion exchange membrane in Example 8 is substantially the same as the method for preparing the anion exchange membrane in Example 1, except that:

[0120] In step (2), the air is replaced with nitrogen.

[0121] Example 9

[0122] The method for preparing the anion exchange membrane in Example 9 is substantially the same as the method for preparing the anion exchange membrane in Example 8, except that:

[0123] In step (2), the corona treatment time is 60s.

[0124] Example 10

[0125] The method for preparing the anion exchange membrane in Example 10 is substantially the same as the method for preparing the anion exchange membrane in Example 8, except that:

[0126] In step (2), the output power of the RF power supply is 2.0 kW.

[0127] Embodiment 11

[0128] The method for preparing the anion exchange membrane in Example 11 is substantially the same as the method for preparing the anion exchange membrane in Example 8, except that:

[0129] In step (2), the output power of the RF power supply is 2.0 kW, and the corona treatment time is 60 s.

[0130] Example 12

[0131] The method for preparing the anion exchange membrane in Example 12 is substantially the same as the method for preparing the anion exchange membrane in Example 1, except that:

[0132] In step (2), the air is replaced with argon.

[0133] Embodiment 13

[0134] The method for preparing the anion exchange membrane in Example 13 is substantially the same as the method for preparing the anion exchange membrane in Example 12, except that:

[0135] In step (2), the corona treatment time is 60s.

[0136] Embodiment 14

[0137] The method for preparing the anion exchange membrane in Example 14 is substantially the same as the method for preparing the anion exchange membrane in Example 12, except that:

[0138] In step (2), the output power of the RF power supply is 2.0 kW.

[0139] Embodiment 15

[0140] The method for preparing the anion exchange membrane in Example 15 is substantially the same as the method for preparing the anion exchange membrane in Example 12, except that:

[0141] In step (2), the output power of the RF power supply is 2.0 kW, and the corona treatment time is 60 s.

[0142] Example 16

[0143] The method for preparing the anion exchange membrane in Example 16 is substantially the same as the method for preparing the anion exchange membrane in Example 1, except that:

[0144] In step (2), the air is replaced with a mixed gas of argon and oxygen in a volume ratio of 1:1.

[0145] Comparative Example 1

[0146] The preparation method of the anion exchange membrane in Comparative Example 1 is substantially the same as the preparation method of the anion exchange membrane in Example 1, except that:

[0147] Remove step (2).

[0148] Test Case

[0149] The conductivity of the anion exchange membranes provided in Examples 1 to 16 and Comparative Example 1 was tested using a Gamry electrochemical workstation Reference 3000 impedance analyzer. The test results are shown in Table 1 below.

[0150] The specific test method is as follows:

[0151] The anion exchange membranes provided in Examples 1 to 16 and Comparative Example 1 were immersed in a 1M KOH aqueous solution for 24 hours, and then cut into a circle with a diameter of 3.5 cm. The initial conductivity of the circular sample was measured using a Gamry electrochemical workstation Reference 3000 impedance analyzer at room temperature of 25°C.

[0152] 2. The contact angles of the anion exchange membranes provided in Examples 1 to 16 and Comparative Example 1 were tested using a contact angle meter (JY-PHC). The test results are shown in Table 1 below.

[0153] The specific test method is as follows:

[0154] The anion exchange membrane provided in Examples 1 to 16 and Comparative Example 1 is fixed on the sample stage of the contact angle measuring instrument, and the camera and light source are adjusted to ensure that the surface of the anion exchange membrane is clearly visible. A small drop of water (1 μL) is added to the surface of the anion exchange membrane as a test liquid using a syringe, and the shape of the drop is immediately captured by the camera, and the contact angle formed by the drop and the sample surface is measured using the instrument software, and the result of each measurement is recorded, and the average value is obtained by multiple measurements at different positions. At the same time, the discreteness of the measured values ​​of the contact angles of the anion exchange membranes provided in Examples 1 to 16 and Comparative Example 1 at different positions is statistically analyzed to obtain the standard deviation of the measured values ​​of the contact angles of the anion exchange membranes provided in Examples 1 to 16 and Comparative Example 1. The standard deviation is the square root of the variance, and the variance is the average of the squares of the difference between each measured value and the average value. The larger the standard deviation, the more dispersed the measured values ​​are, and the difference between the measurement results at various locations is large. On the contrary, it means that the difference between the measurement results at various locations is small, and the membrane performance is relatively uniform.

[0155] Table 1

[0156]

[0157] In Table 1, the contact angles are expressed in the form of mean value ± standard deviation.

[0158] As shown in Table 1, compared with Comparative Example 1, the contact angle of Embodiment 1~16 is all reduced, and the specific conductivity of Embodiment 1~16 is all lifted to varying degrees, which shows that the hydrophilicity and specific conductivity of the quaternary ammonium salt anion exchange membrane can be improved to a certain extent by carrying out corona treatment to the quaternary ammonium salt anion exchange membrane. When particularly passing into oxygen-containing gases such as air and oxygen and carrying out corona treatment, hydrophilicity is improved more obviously, and when passing into inert gas and carrying out power supply treatment, specific conductivity is improved more obviously; and when passing into a mixed gas of oxygen and argon, compared with passing into oxygen alone, hydrophilicity and electrical conductivity are all reduced, compared with passing into argon alone, hydrophilicity is improved to a certain extent, and specific conductivity changes little, indicating that when passing into oxygen, the hydrophilicity and electrical conductivity of the quaternary ammonium salt anion exchange membrane are greatly improved.

[0159] In addition, through comparison, it was found that for different gases, the improvement of the hydrophilicity and conductivity of the quaternary ammonium salt anion exchange membrane varies with the output power of the RF power supply and the corona time.

[0160] 3. The alkali resistance of the anion exchange membranes provided in Example 1 and Comparative Example 1 was tested, and the test method was as follows:

[0161] The anion exchange membrane was cut into 2.95*2.95cm squares and soaked in 1 M KOH solution for 24h. The nickel foam and Pt / C carbon cloth were used as cathodes, and the Ni / Fe catalyst nickel foam was used as anode. They were cut into squares of (length) 3.0×(width) 3.0 cm. The cut square anion exchange membrane, cathode and anode, together with the polytetrafluoroethylene insulating gasket, were assembled into a battery. The flow field area of ​​a single battery was 9 cm 2 , connect the positive and negative electrodes of the battery, and circulate 1M KOH aqueous solution as the electrolyte through the electrolytic cell at 60 ml / min. When the temperature reaches 55°C, 2 Activate for half an hour at a current density of , increase the current to 7.2A, record the corresponding voltage, continue to operate, and record the voltage change until the anion exchange membrane fails. The test results are as follows Figure 2 shown.

[0162] Depend on Figure 2 It can be seen that the voltage of the anion exchange membrane provided in Comparative Example 1 increased significantly after running for 600 hours, causing the anion exchange membrane to fail, while the anion exchange membrane provided in Example 1 did not fail after running for 700 hours, indicating that the anion exchange membrane provided in Example 1 has strong durability.

[0163] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0164] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for preparing an anion exchange membrane, characterized in that: include: Provide quaternary ammonium salt anion exchange membrane; The quaternary ammonium salt type anion exchange membrane is subjected to corona treatment by using gas plasma to modify the quaternary ammonium salt type anion exchange membrane and prepare the anion exchange membrane.

2. The method for preparing an anion exchange membrane according to claim 1, characterized in that: The corona treatment is performed in an oxygen-containing atmosphere or an inert gas atmosphere, and the gas plasma is an oxygen-containing gas plasma or an inert gas plasma.

3. The method for preparing an ion exchange membrane according to claim 2, characterized in that: The gas used in the oxygen-containing atmosphere is air, oxygen, or a mixture of oxygen and an inert gas; The inert gas used in the inert gas atmosphere includes at least one of nitrogen and argon.

4. The method for preparing an anion exchange membrane according to claim 1, characterized in that: The quaternary ammonium salt anion exchange membrane is subjected to corona treatment by using gas plasma to modify the quaternary ammonium salt anion exchange membrane to prepare the anion exchange membrane, comprising: In an oxygen-containing atmosphere or an inert gas atmosphere, a radio frequency power source is used to energize the oxygen-containing gas or the inert gas to excite oxygen-containing gas plasma or inert gas plasma, and the oxygen-containing gas plasma or the inert gas plasma is used to perform corona discharge on the quaternary ammonium salt type anion exchange membrane to modify the quaternary ammonium salt type anion exchange membrane.

5. The method for preparing an anion exchange membrane according to claim 4, characterized in that: The output power of the radio frequency power supply is 1.8 kW to 2.0 kW, and the power-on time is 30 s to 60 s.

6. The method for preparing an anion exchange membrane according to claim 4, characterized in that: The corona treatment is carried out in a vacuum chamber, in an oxygen-containing atmosphere or an inert gas atmosphere, a radio frequency power source is used to energize the oxygen-containing gas or the inert gas to excite the oxygen-containing gas plasma or the inert gas plasma, and the quaternary ammonium salt anion exchange membrane is subjected to corona discharge by using the oxygen-containing gas plasma or the inert gas plasma to modify the quaternary ammonium salt anion exchange membrane. The preparation method further comprises: The air in the vacuum chamber is replaced by an oxygen-containing gas or an inert gas, and the oxygen-containing gas or the inert gas is introduced into the vacuum chamber at a flow rate of 50 sccm to 200 sccm, and the pressure in the vacuum chamber is maintained at 0.1 kPa to 10 kPa; After preparing the anion exchange membrane, the preparation method further comprises: The anion exchange membrane is kept in the vacuum chamber for 0.5 min to 5 min.

7. The method for preparing an anion exchange membrane according to claim 1, characterized in that: The general structural formula of the quaternary ammonium salt anion exchange membrane is shown in the following formula (I): （I）； A segment is represented by , segment B is represented by , x represents the molar number of segment A when the sum of the molar numbers of segment A and segment B is 100 mol, and Ar is selected from divalent diphenyl or divalent terphenyl; Optionally, the molar percentage of quaternary ammonium ions in the quaternary ammonium salt anion exchange membrane is 50% to 100%.

8. The method for preparing an anion exchange membrane according to any one of claims 1 to 7, characterized in that: In the case where the gas plasma is an oxygen-containing gas plasma, the conductivity of the anion exchange membrane is greater than or equal to 21.0 mS / cm, and the contact angle is less than or equal to 75°; When the gas plasma is an inert gas plasma, the conductivity of the anion exchange membrane is greater than or equal to 21.2 mS / cm, and the contact angle is less than or equal to 76.5°.

9. An anion exchange membrane, characterized in that The anion exchange membrane is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the anion exchange membrane as claimed in claim 9 in producing hydrogen by electrolysis of water.

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