KR102170555B1 - Anion-exchange membranes and preparation method thereof - Google Patents

Abstract

The present invention relates to an anion exchange membrane and a method of manufacturing the same. More specifically, it relates to an anion exchange membrane capable of selectively permeating monovalent ions and simultaneously blocking protons, and a method of manufacturing the same.

Description

Anion exchange membrane and its manufacturing method {ANION-EXCHANGE MEMBRANES AND PREPARATION METHOD THEREOF}

The present invention relates to an anion exchange membrane and a method of manufacturing the same. More specifically, it relates to an anion exchange membrane capable of selectively permeating monovalent ions and simultaneously blocking protons, and a method of manufacturing the same.

The ion exchange membrane contains a fixed charge on a polymer matrix. It is divided into an anion exchange membrane that selectively separates anions and a cation exchange membrane that selectively separates cations. Ion exchange membranes are actively used in electrodialysis, diffusion dialysis, water splitting electrodialysis, and capacitive deionization for desalting and concentrating solutions containing ions. In addition, recently, it has been used as an electrolyte for various energy conversion processes such as reverse electrodialysis, redox flow cells, and fuel cells.

In general, the ion exchange membrane should have low electrical resistance and excellent ion selective permeability. In particular, while the demand for a membrane having high selective permeability for a specific ion is increasing, there is a need to develop an ion exchange membrane that can satisfy this.

On the other hand, the anion exchange membrane basically has selective permeability to anions, but exhibits high permeability to hydrogen ions called protons (protons). These protons have much higher mobility than general cations in aqueous solutions. For example, it exhibits about 7 times higher mobility when compared to sodium cations.

Protons are smaller than other cations and move through the mechanisms of Grotthuss and Vehicles, and thus promote diffusion of protons through water molecules as a medium and have high mobility.

In the diffusion dialysis process for acid recovery, the high proton permeability of the anion exchange membrane is used as a separation mechanism, but in general, proton permeation in the anion exchange membrane causes a problem of reducing the separation efficiency of the process.

Therefore, there is a need to develop an anion exchange membrane having proton blocking properties that can prevent the permeation of protons. In addition, development of an anion exchange membrane having excellent selective permeability to monovalent ions is required to improve separation efficiency in various processes.

Korean Patent Registration No. 10-1137313 (2012.04.10)

An object of the present invention is to provide a method for producing an anion exchange membrane having excellent monovalent ion selective permeability and excellent proton blocking properties, and an anion exchange membrane prepared therefrom.

In addition, an object of the present invention is to provide an anion exchange membrane having a low moisture content and capable of suppressing swelling.

In addition, an object of the present invention is to provide an anion exchange membrane capable of remarkably lowering electrical resistance and maximizing ion exchange capacity.

In one aspect of the present invention, a porous polymer substrate is impregnated with a monomer mixture containing a styrene monomer, a vinyl monomer substituted with a quaternary ammonium salt, a crosslinking agent and an initiator, and then polymerized to prepare a base membrane filled with pores of the substrate. And

It relates to a method for manufacturing an anion exchange membrane comprising the step of forming an ionomer layer on the base membrane by coating the base membrane filled with the pores with an ionomer solution of a halogenated phenylene oxide polymer and an amine compound and drying.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the vinyl-based monomer substituted with the quaternary ammonium salt may be a vinylbenzene substituted with the quaternary ammonium salt.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the halogenated phenylene oxide polymer may be benzyl brominated polyphenylene oxide.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the amine compound may include one or more selected from primary, secondary, and tertiary amines.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the ionomer solution may have a molar ratio of a halogenated phenylene oxide-based polymer and an amine compound of 1:0.25 to 1:1.25.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the crosslinking agent is divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3- Butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, triethylene glycol diacrylate, tricyclodecanedi It may be any one or more selected from the group consisting of methanol diacrylate, trimethylolpropane trimethacrylate, and trimethylol triacrylate.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the step of forming the ionomer layer may further include graphene oxide in the ionomer solution.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, in the forming of the ionomer layer, the base layer filled with the pores is coated with an ionomer solution containing a halogenated phenylene oxide polymer, an amine compound, and graphene oxide. Thus, the ionomer layer may be formed and then impregnated with an aqueous glutaraldehyde solution may be further included.

Furthermore, after the process of impregnating the glutaraldehyde aqueous solution, the base film may be further included in impregnating the aqueous diamine solution. At this time, the diamine aqueous solution may include at least one selected from hexamethylenediamine, tetramethylenediamine, 2,4-dimethylhexamethylenediamine, dodeca methylenediamine, isophoronediamine, and p-cyclohexylenediamine.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the polymerization may be carried out by photocrosslinking or thermal crosslinking.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the porous polymer substrate may have a thickness of 1 to 50 μm and a porosity of 40 to 80%.

In the method of manufacturing an anion exchange membrane according to an embodiment of the present invention, the porous polymer substrate may be any one selected from a film, a sheet, and a nonwoven fabric.

Another aspect of the present invention is a pore-filling base film in which a polymer derived from a vinyl-based monomer substituted with a styrene-based monomer and a quaternary ammonium salt is filled in the pores on a porous polymer substrate, and a halogenated phenylene oxide-based polymer formed on the pore-filled base film, and It relates to an anion exchange membrane comprising an ionomer layer containing an amine compound.

Another aspect of the present invention relates to an electrochemical device comprising an anion exchange membrane.

The anion exchange membrane of the present invention has a low moisture content, can adequately suppress swelling, and has the effect of implementing excellent proton blocking properties by significantly lowering the hydrogen ion permeability.

At the same time, the selective transmittance for monovalent ions has a remarkably improved effect.

In addition, since the thickness can be significantly reduced compared to the conventional commercial film, not only the device is compact, but also the electrical resistance is drastically reduced, as well as the device compaction is possible. In addition, it has a high ion exchange capacity and can be applied to various electrochemical devices.

Hereinafter, a method of manufacturing an anion exchange membrane of the present invention and an anion exchange membrane manufactured therefrom will be described in detail with reference to the accompanying drawings. The present invention can be better understood by the following examples. The following examples are for illustrative purposes of the present invention, and are not intended to limit the scope of protection defined by the appended claims. In this case, the technical terms and scientific terms used have meanings commonly understood by those of ordinary skill in the technical field to which this invention belongs, unless otherwise defined.

The inventors of the present invention have noted that the anion exchange membrane generally has high hydrogen ion permeability, and has recognized that such high hydrogen ion permeability has a problem in reducing the separation efficiency of the process. Therefore, while researching on a method to increase the selectivity for monovalent ions in order to adjust the hydrogen ion permeation characteristics to increase the separation efficiency and further increase the separation efficiency in various processes, the pores are filled with ionomers. By forming an ionomer layer containing a halogenated phenylene oxide polymer and an amine compound on a porous substrate, it was found that an anion exchange membrane capable of improving the selective permeability of monovalent ions as well as proton blocking properties can be prepared. The invention was completed. In addition, the anion exchange membrane according to the present invention has a thin thickness and excellent mechanical strength, which is advantageous for device miniaturization, and has a low electrical resistance and high ion exchange capacity, so that the application range to various electrochemical devices can be expanded. Have.

In one aspect of the present invention, a porous polymer substrate is impregnated with a monomer mixture containing a styrene monomer, a vinyl monomer substituted with a quaternary ammonium salt, a crosslinking agent and an initiator, and then polymerized to prepare a base membrane filled with pores of the substrate. And

And forming an ionomer layer on the base film by coating and drying the base film filled with the pores with an ionomer solution of a halogenated phenylene oxide polymer and an amine compound.

The step of preparing the base membrane filled with the pores includes impregnating a porous polymer base material in a monomer mixture containing a styrene-based monomer, a vinyl-based monomer substituted with a quaternary ammonium salt, a crosslinking agent, and an initiator so that the monomer mixture penetrates into the pores, and then the monomer It is a process that allows the polymerization of In this case, the impregnation process may be performed by impregnating the porous polymer substrate in the monomer mixture for 5 minutes or more, specifically 10 minutes or more, but is not limited thereto.

The monomer mixture contains a vinyl-based monomer substituted with a quaternary ammonium salt. The vinyl-based monomer substituted with the quaternary ammonium salt may be used without limitation as long as it contains a functional group capable of performing anion exchange after polymerization. As a non-limiting example, the quaternary ammonium salt may be substituted vinylbenzene, specifically (vinylbenzyl)tri(C1-C8)alkylammonium chloride, more specifically (vinylbenzyl)trimethylammonium chloride ((vinylbenzyl)trimethylammonium chloride, VBTMAC), but is not necessarily limited thereto.

The vinyl-based monomer substituted with the quaternary ammonium salt may be included in a monomer mixture of 20 to 60% by weight, specifically 30 to 50% by weight, and more specifically 35 to 45% by weight, but this is only a non-limiting example and the numerical range Is not limited to

The type of the styrenic monomer is not greatly limited, but as non-limiting examples, styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, chlorostyrene, bromostyrene, fluorostyrene, ethylstyrene , N,N-diethylaminostyrene may be any one or more selected from the group consisting of, but is not necessarily limited thereto.

The styrene-based monomer may be included in 20 to 60% by weight, specifically 30 to 50% by weight, and more specifically 35 to 45% by weight in the monomer mixture, but this is a non-limiting example and is not limited to the numerical range.

When the content of the vinyl-based monomer substituted with the styrene-based monomer and the quaternary ammonium salt in the monomer mixture satisfies the above range, excellent ion exchange performance can be achieved, and durability and mechanical strength can be improved at the same time as high ion selective permeability. It has a characteristic, but this is only a non-limiting example, and is not limited to the numerical range.

The styrene-based monomer and the vinyl-based monomer in which the quaternary ammonium salt is substituted in the monomer mixture are not significantly limited in molar ratio, but may be 1:0.5 to 1:2.0, specifically 1:1 to 1.5. The ion exchange capacity, moisture content, and electrical resistance characteristics are excellent in the above range, but this is only a non-limiting example and is not limited to the above numerical range.

The monomer mixture contains a solvent. In this case, the solvent may be used without limitation as long as it can dissolve the monomers, and ethanol may be mentioned as a specific and non-limiting example, but is not limited thereto. The content of the solvent is not greatly limited, but may be 5 to 30% by weight, specifically 8 to 25% by weight.

The crosslinking agent may be used without large limitation as long as it performs polymerization of a styrene-based monomer and a vinyl-based monomer substituted with a quaternary ammonium salt, and can be crosslinked. Specifically, two or more acrylate groups, methacrylate groups, vinyl groups, and the like may be exemplified at the terminal, but are not necessarily limited thereto.

In a more specific and non-limiting example, the crosslinking agent is divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1 ,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, triethylene glycol diacrylate, tricyclodecane dimethanol diacrylate, trimethylol It may be one or two or more selected from propane trimethacrylate, trimethylol triacrylate, etc., but is not limited thereto.

The crosslinking agent may be a crosslinking agent mixture in which two or more components are mixed in terms of controlling a distance between polymer chains and a free volume. When the crosslinking reaction is carried out by including a high content of a crosslinking agent having a relatively large molecular weight, the distance between the polymer chains can be increased, which has a property of lowering the membrane electrical resistance (MER). Accordingly, it is possible to control the electrical resistance of the membrane as well as the ion selectivity by controlling the components and the content of the crosslinking agent mixture. In one embodiment, the crosslinking agent mixture is divinylbenzene (DVB), ethylene glycol dimethacrylate (EGDMA), 1,3-butanediol dimethacrylate (1,3-butanediol dimethacrylate, BDDMA). ) And 1,6-hexanediol dimethacrylate (1,6-hexanediol dimethacrylate, HDDMA) may be mixed, but is not limited thereto. At this time, the content of the components in the crosslinking agent mixture can be controlled depending on the physical properties of the desired film, but preferably, the content of divinylbenzene is more effective in achieving the desired properties of the present invention when it is contained 2 to 5 times more than other components. to be.

The content of the crosslinking agent is not greatly limited, but may be included in 1 to 30% by weight, specifically 5 to 25% by weight, and more specifically 10 to 20% by weight, of the total weight in the monomer mixture, but is not necessarily limited thereto. .

The initiator is not largely limited as long as it can initiate the polymerization reaction of the monomers penetrating the pores in the porous polymer substrate, and examples include benzophenone and benzoylperoxide, but are limited thereto. It doesn't work. The initiator may be 0.01 to 5% by weight, specifically 0.1 to 4% by weight in the monomer mixture, but is not limited thereto.

A process of polymerizing the monomer mixture that has penetrated the pores in the porous polymer substrate is performed. In this case, polymerization may be performed by light or heat, but is not limited thereto. As a specific example, it may be carried out by photocrosslinking, and at this time, the photopolymerization conditions may be carried out in a conventional manner within a range that does not impair the object of the present invention.

Before the polymerization, a process of removing the excess monomer may be performed. As a specific and non-limiting example, the excess monomer may be removed by removing the excess monomer by interposing a porous polymer substrate in which a monomer mixture is filled in the pores between two release films and rolling in close contact with each other, but is not limited thereto. .

The porous polymer substrate on which the polymerization has been completed, that is, the base membrane filled with pores prepared by polymerization, can have a thinner thickness than that of a conventional ion exchange membrane, thereby reducing electrical resistance. In addition, since it does not require a separate process for introducing an anion exchanger, the process is simplified and mass production is easy.

In the present invention, the porous polymer substrate may be used without limitation if it contains pores so that polymerization can be performed after the monomer mixture is filled. As a specific and non-limiting example, it may be a film, sheet, nonwoven fabric, etc., but is not limited thereto.

Preferably, the porous polymer substrate may be a film, and may be used without limitation as long as it has a thickness and pores that facilitate passage of ions. As a specific and non-limiting example, the porous polymer substrate may have an average pore diameter of 0.05 to 1 μm, specifically 0.1 to 0.5 μm, but is not limited thereto. In addition, the porous polymer substrate may have a thickness of 1 to 50 μm, specifically 2 to 30 μm, and a porosity of 40 to 80%, specifically 45 to 75%. In the above range, it is possible to implement high ion exchange performance while preventing the mechanical properties of the anion exchange membrane from deteriorating, and has an effect of reducing the burden of increasing electrical resistance as the thickness increases.

The porous polymer substrate may be used without much limitation as long as it is a material capable of supporting an anion exchange membrane, but non-limiting examples include polyolefin such as polyethylene or polyvinylidene fluoride, but are not limited thereto.

After the step of preparing a base layer filled with pores, the base layer filled with pores is coated with an ionomer solution containing a halogenated phenylene oxide polymer and an amine compound and dried to form an ionomer layer on the base layer. do. By including the combination of the base membrane filled with the pores and the ionomer layer through this process, proton permeability can be suppressed, and the selective permeability for monovalent ions can be remarkably improved.

Furthermore, it is possible to minimize the content of the anion-exchangeable compound in the ionomer layer, and to prevent the ion exchange performance from significantly deteriorating despite reducing the thickness, thereby accelerating the swelling of the ionomer layer, unlike the swelling pattern in the base membrane in the ion exchange process. Can be suppressed. In addition, hydrogen ion permeation characteristics can be controlled, and selective permeability for monovalent ions can be remarkably increased.

The ionomer solution contains a halogenated phenylene oxide polymer and an amine compound.

The ionomer solution may be in a state in which its constituents form an anion-exchangeable functional group while forming an ionomer layer, or a state in which anion-exchangeable functional group is already formed in the mixed solution, or both. In this case, the amine compound may include any one or more selected from primary, secondary, and tertiary amines. Specific and non-limiting examples include primary amines such as methylamine, ethylamine, monoisopropylamine, n-butylamine, sec-butylamine, isobutylamine, t-butylamine, and pentylamine; Secondary classes such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, methylethylamine, methylpropylamine, methylisopropylamine, methylbutylamine, and methylisobutylamine Amine; Tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, dimethylethylamine, methyldiethylamine, and methyldipropylamine; and the like, but are not limited thereto.

The method of forming an ionomer layer by impregnating a base membrane filled with pores in the ionomer solution of the present invention completely solves the problem of thin and uniform coating due to the low solubility of the conventional ion exchange polymer, and has a great technological advance.

The halogenated phenylene oxide polymer may be a benzyl brominated polyphenylene oxide. Specifically, polydimethylphenylene oxide (poly(2,6-dimethyl)phenylene oxide) (PPO) may be mentioned, but the present invention is not limited thereto.

The halogenated phenylene oxide polymer is intended to introduce an anion exchange group using the introduced halogen functional group, and a halogenated ion exchange polymer or a commercially available one may be used. As the halogenation conditions, the reaction temperature, the reaction time, the stirring conditions, or the halogen element used are not greatly limited, but may be adjusted according to the size and performance of the film to be produced. Halogen elements include, but are not limited to, fluorine, chlorine, bromine, and iodine. As a specific example, the halogenated polymer may be brominated polydimethylphenylene oxide, but is not limited thereto.

The ionomer solution may have a molar ratio of a halogenated phenylene oxide-based polymer and an amine compound of 1:0.25 to 1:1.25. It has a low moisture content in the above range and is effective in lowering the proton transmittance, but this is only a non-limiting example and is not limited to the numerical range.

According to an aspect of the present invention, the ionomer solution may further include graphene oxide (GO). The graphene oxide is more effective in that it can lower the hydrophilicity of the film surface and secure mechanical property stability. In addition, it has an advantageous characteristic in that it can have high ion exchange performance while reducing the thickness of the ionomer layer.

The graphene oxide content in the ionomer solution is not significantly limited, but may be 0.5 to 10% by weight, specifically 1 to 5% by weight based on the total weight of the ionomer solution, but this is only a non-limiting example and the numerical range Is not limited to

According to one aspect of the present invention, the ionomer layer forming step is more preferably coated with an ionomer solution containing a halogenated phenylene oxide polymer, an amine compound, and graphene oxide to the base film filled with the pores, thereby forming the ionomer layer. After forming, it may further include impregnating the glutaraldehyde aqueous solution. This is more effective in terms of implementing a low moisture content and a synergistic effect of mechanical properties of the membrane by significantly lowering the hydrophilicity of the ionomer layer by inducing crosslinking with glutaraldehyde using the carboxy group in the graphene oxide molecule. In addition, proton permeability can be significantly lowered, and monovalent ion selective permeability can be remarkably improved.

In this case, the base film filled with pores in which the ionomer layer is formed may be impregnated with the ionomer solution and may be in a wet state. Alternatively, some or all of them may be dried, but in order to increase crosslinking efficiency in a post process, it is preferable to be in a swollen state.

The glutaraldehyde aqueous solution may further include an acid catalyst. The acid catalyst is not largely limited as long as it can accelerate the crosslinking reaction, but hydrochloric acid may be mentioned as an example, and its content may be adjusted within a range that does not inhibit the achievement of the desired physical properties.

According to an aspect of the present invention, the ionomer layer forming step is more preferably coated by impregnating and coating the base film filled with the pores in an ionomer solution containing a halogenated phenylene oxide polymer, an amine compound, and graphene oxide. After forming the layer, it may further include impregnating the glutaraldehyde aqueous solution to crosslink or treat, and then impregnate the diamine aqueous solution to crosslink or treat, and then dry. This improves the physical stability of the ionomer layer as well as further increases the degree of crosslinking, thereby suppressing the swelling of the membrane in the ion exchange process, and is more effective in terms of implementing the synergistic effect of the proton blocking property and the monovalent ion selective permeation property.

At this time, the base film filled with the pores may be wet before being impregnated with the coating object, or may be partially or completely dried, but it is preferable that the base film is swollen in order to increase the crosslinking efficiency in the subsequent process. Do.

The diamine aqueous solution may include any one or more selected from hexamethylenediamine, tetramethylenediamine, 2,4-dimethylhexamethylenediamine, dodeca methylenediamine, isophoronediamine and p-cyclohexylenediamine, but must be Not limited.

Another aspect of the present invention may relate to an anion exchange membrane manufactured by the method for manufacturing an anion exchange membrane described above. Specifically, a pore-filled base membrane filled with a polymer derived from a vinyl-based monomer substituted with a styrene-based monomer and a quaternary ammonium salt in the pores on a porous polymer substrate, and a halogenated phenylene oxide-based polymer and an amine compound formed on the pore-filled base membrane. It is to provide an anion exchange membrane comprising the containing ionomer layer.

The anion exchange membrane has a low moisture content and can be thinner than a commercial membrane, so that electrical resistance can be significantly lowered, and proton blocking and monovalent ion selective transmission characteristics are excellent.

The anion exchange membrane according to an embodiment of the present invention has a monovalent ion selective permeability of 1.5 or more, specifically 1.8, and more specifically 2.0 or more, and has excellent monovalent ion selective transmission characteristics. Accordingly, when the anion exchange membrane is applied to the reverse electrodialysis process, it has the effect of generating power with higher efficiency.

Another aspect of the present invention relates to an electrochemical device comprising the anion exchange membrane. The electrochemical device is not limited if it is a device that performs a chemical reaction or an electrical reaction in the device including the anion exchange membrane according to the present invention. As a specific and non-limiting example, the electrochemical device according to an embodiment of the present invention may be a battery or a water treatment facility, but the present invention is not limited thereto.

Hereinafter, an example of an anion exchange membrane according to the present invention will be described. This is presented as a preferred embodiment to aid understanding, the following examples are only an illustration of the present invention, and the scope of the present invention is not limited to the following examples.

(Example 1)

As a porous polymer substrate, a 25 μm thick porous polyethylene (PE) film (HiporeTM, Asahi Kesei) was used. After washing the porous polymer substrate with acetone, vacuum drying at 60° C. for 1 hour, then mixing 35% by weight of styrene, 35% by weight of vinylbenzyltrimethyl ammonium chloride, 18% of crosslinking agent, 1% by weight of benzophenone and the remaining amount of ethanol One monomer mixture was impregnated for 20 minutes. In this case, a crosslinking agent mixture of divinylbenzene, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate and 1,6-hexanediol dimethacrylate is used as the crosslinking agent, and each component in the crosslinking agent mixture The content of was set to a weight ratio of 55:15:15:15. Thereafter, the porous polymer substrate impregnated with the monomer mixture was taken out, placed between two release films, laminated, and then polymerized by irradiating light for 15 minutes using a 1 KW UV lamp, and then separated from the release film to fill the pores of the substrate. Was obtained.

The obtained base membrane was brominated (brominated) polydimethylphenylene oxide (PPO) in dimethylformamide containing 5% by weight of trimethylamine (45wt% in H2O) compared to PPO The ionomer layer (thickness 4 μm) was formed on the base film by impregnating the ionomo solution in a 0.5 molar ratio and dip coating. This was dried at room temperature (20°C) for 12 hours and then dried in a 40°C vacuum oven for 6 hours to prepare an anion exchange membrane.

(Example 2)

The same method as in Example 1, except that an aqueous dispersion of graphene oxide (containing 4% by weight of graphene oxide) in the ionomo solution was further included so that the content in the solution was 1% by weight. To prepare an anion exchange membrane.

(Example 3)

An anion exchange membrane was prepared in the same manner as in Example 2, except that the content of the graphene oxide aqueous dispersion in Example 2 was changed to be 3% by weight in the ionomo solution.

(Example 4)

An anion exchange membrane was prepared in the same manner as in Example 2, except that the content of the graphene oxide aqueous dispersion in Example 2 was changed to be 5% by weight in the ionomo solution.

(Example 5)

As a porous polymer substrate, a 25 μm thick porous polyethylene (PE) film (HiporeTM, Asahi Kesei) was used. After washing the porous polymer substrate with acetone, vacuum drying at 60° C. for 1 hour, then mixing 35% by weight of styrene, 35% by weight of vinylbenzyltrimethyl ammonium chloride, 18% of crosslinking agent, 1% by weight of benzophenone and the remaining amount of ethanol One monomer mixture was impregnated for 20 minutes. In this case, a crosslinking agent mixture of divinylbenzene, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate and 1,6-hexanediol dimethacrylate is used as the crosslinking agent, and each component in the crosslinking agent mixture The content of was set to a weight ratio of 55:15:15:15. Thereafter, the porous polymer substrate impregnated with the monomer mixture was taken out, placed between two release films, laminated, and then polymerized by irradiating light for 15 minutes using a 1 KW UV lamp, and then separated from the release film to fill the pores of the substrate. Was obtained.

The obtained base membrane was brominated (brominated) polydimethylphenylene oxide (PPO) in dimethylformamide containing 5% by weight of trimethylamine (45wt% in H2O) compared to PPO It was added at a 0.5 molar ratio and impregnated in an ionomo solution containing graphene oxide aqueous dispersion (containing 4% by weight of graphene oxide) so that the total content in the solution was 5% by weight, followed by dip coating to form an ionomer layer on the base membrane. Formed. Thereafter, the film on which the ionomer layer was formed on the base film was impregnated with a glutaaldehyde aqueous solution mixed with a glutaaldehyde and an aqueous hydrochloric acid solution (hydrochloric acid content of 32% by weight) to perform dip coating. At this time, the amounts of glutaaldehyde and hydrochloric acid were adjusted to be 1% by weight and 0.02% by weight, respectively, based on the total weight of the ionomer solution. Then, after drying for 12 hours at room temperature (20 ℃), and then dried for 6 hours in a vacuum oven at 40 ℃ to prepare a final anion exchange membrane.

(Example 6)

As a porous polymer substrate, a 25 μm thick porous polyethylene (PE) film (HiporeTM, Asahi Kesei) was used. After washing the porous polymer substrate with acetone, vacuum drying at 60° C. for 1 hour, then mixing 35% by weight of styrene, 35% by weight of vinylbenzyltrimethyl ammonium chloride, 18% of crosslinking agent, 1% by weight of benzophenone and the remaining amount of ethanol One monomer mixture was impregnated for 20 minutes. In this case, a crosslinking agent mixture of divinylbenzene, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate and 1,6-hexanediol dimethacrylate is used as the crosslinking agent, and each component in the crosslinking agent mixture The content of was set to a weight ratio of 55:15:15:15. Thereafter, the porous polymer substrate impregnated with the monomer mixture was taken out, placed between two release films, laminated, and then polymerized by irradiating light for 15 minutes using a 1 KW UV lamp, and then separated from the release film to fill the pores of the substrate. Was obtained.

The obtained base membrane was brominated (brominated) polydimethylphenylene oxide (PPO) in dimethylformamide containing 5% by weight of trimethylamine (45wt% in H2O) compared to PPO It was added at a 0.5 molar ratio and impregnated in an ionomo solution containing graphene oxide aqueous dispersion (containing 4% by weight of graphene oxide) so that the total content in the solution was 5% by weight, followed by dip coating to form an ionomer layer on the base membrane. Formed. Thereafter, the film on which the ionomer layer was formed on the base film was impregnated with a glutaaldehyde aqueous solution mixed with a glutaaldehyde and an aqueous hydrochloric acid solution (hydrochloric acid content of 32% by weight) to perform dip coating. At this time, the amounts of glutaaldehyde and hydrochloric acid were adjusted to be 1% by weight and 0.02% by weight, respectively, based on the total weight of the ionomer solution. Next, the film after the dip coating was dried for 12 hours at room temperature (20° C.) and then dried in a vacuum oven at 40° C. for 6 hours to prepare a final anion exchange membrane.

The film on which the ionomer layer was formed on the base film prepared in the same manner as in Example 4 was impregnated in an aqueous glutaraldehyde solution mixed with glutaaldehyde and an aqueous hydrochloric acid solution (hydrochloric acid content of 32% by weight) to perform dip coating and then at room temperature ( 20°C) for 12 hours, and then dried in a 40°C vacuum oven for 6 hours. Thereafter, dip coating was performed by impregnating the aqueous solution of hexamethylenediamine. At this time, the content of hexamethylenediamine in the aqueous hexamethylenediamine solution was 1% by weight based on the total weight of the ionomer solution. Next, after drying at room temperature (20°C) for 12 hours, it was dried in a vacuum oven at 40°C for 6 hours to prepare a final anion exchange membrane.

(Comparative Example 1)

Astom's ACM membrane, a commercial anion exchange membrane, was used as a control.

(evaluation)

The prepared anion exchange membranes according to Examples 1 to 6 and the commercial anion exchange membranes of Comparative Example 1 were tested according to the following evaluation items, and the results are shown in Table 1 below.

(1) Ion exchange capacity

The ion-exchange capacity (IEC) of the anion exchange membrane was measured by conventional acid-base titration, and was calculated by the following equation 1.

[Equation 1]

은 건조된 멤브레인의 질량이고,

는 적정용액의 농도이고

는 적정을 위해 사용된 용액의 부피이다. In Equation 1

Is the mass of the dried membrane,

Is the concentration of the titration solution

Is the volume of solution used for titration.

(2) moisture content

)와 건조 무게 (

)를 측정하여 다음 식 2에 의해 산출되었다. Water uptake (WU) is the wet weight of the membrane (

) And dry weight (

) Was measured and calculated by the following equation 2.

[Equation 2]

(3) membrane electrical resistance

The membrane electrical resistance (MER) was calculated by measuring the AC impedance. After the anion exchange membrane was impregnated with 0.5 M NaCl electrolyte solution, electric resistance was measured by connecting a 2-point probe clip cell and a potentiostat/galvanostat including an impedance analyzer, and the MER was calculated from Equation 3 below.

[Equation 3]

MER = (R ₁ -R ₂ ) × Area

In Equation 3, R ₁ is the sum of electrolyte and membrane resistance, R ₂ is the resistance of the electrolyte solution, and Area is the effective area of the membrane and electrode.

(4) ion transport water

)는 2-compartment diffusion cell을 이용한 emf 방법으로 측정되며, 다음 식 4 및 5에 의하여 산출되었다. Ion transport water (transport number,

) Is measured by the emf method using a 2-compartment diffusion cell, and was calculated by the following equations 4 and 5.

[Equation 4]

[Equation 5]

은 측정된 셀 전위,

은 기체상수,

는 절대온도,

는 Faraday 상수이며,

과

는 NaCl 용액의 농도로 각각 1 mM과 5 mM으로 실험하였다. 셀 전위는 한 쌍의 Ag/AgCl 전극을 디지털 전압계에 연결하여 측정하였다. In the above formula

Is the measured cell potential,

Silver gas constant,

Is the absolute temperature,

Is the Faraday constant,

and

Was tested at 1 mM and 5 mM, respectively, with the concentration of NaCl solution. The cell potential was measured by connecting a pair of Ag/AgCl electrodes to a digital voltmeter.

(5) Hydrogen ion permeability

It was measured using the same 2-compartment cell as the ion transport water measurement. The feed compartment was filled with 4 M HCl aqueous solution, and the permeate compartment was filled with distilled water to check the HCl concentration change over time in the permeate compartment. The permeability of hydrogen ions (acids) through the membrane was calculated from Equation 6 below.

[Equation 6]

과

은 각각 feed(I)와 permeate(II) compartment에서의 산의 농도이고

는 feed compartment에서의 산의 초기 농도이다.

는 막의 유효면적이고,

는 시간,

과

는 각각 feed(I)와 permeate(II) compartment의 부피이며

는 양 compartment의 부피비 (

) 이다. In the above equation

and

Is the concentration of acid in the feed(I) and permeate(II) compartments, respectively

Is the initial concentration of acid in the feed compartment.

Is the effective area of the membrane,

Is the time,

and

Is the volume of the feed(I) and permeate(II) compartments, respectively

Is the volume ratio of both compartments (

) to be.

(6) Selective permeability of monovalent ions

)를 산정하였다. In order to evaluate the selective permeability of the ion exchange membrane to monovalent ions, SO ₄ ^2- ions and Cl ^- ions were selected as reference materials, and mixed solutions having different concentration ratios of the two ions were prepared in 5 ratios. At this time, the concentration ratio of chloride and sulfate ions in the solution was adjusted to [Cl ^- ]:[SO ₄ ^2- ] = 5:1, 5:2, 5:3, 5:4, and 5:5, respectively. The ion exchange membrane was impregnated with the prepared solution at room temperature for 12 hours or longer so that the concentration of substituted ions inside the membrane reached an equilibrium state. After washing the surface with distilled water 2-3 times to remove the excess solution on the membrane surface, immerse each membrane in an electrolyte solution (0.1 M NaNO ₃ , 10 mL) for 12 hours or longer to remove the ions inside the membrane from the external solution. To be replaced. And the chloride and sulfate ion concentrations of the substituted solution were quantitatively analyzed using ion chromatography. Substituting the measured concentration of ions into the following equation (7), the selective permeability coefficient (

) Was calculated.

[Equation 7]

는 막 상에서의 농도비이고,

는 용액 상에서의 농도비를 나타낸다.In the above equation

Is the concentration ratio on the membrane,

Represents the concentration ratio in the solution.

[Table 1]

Analysis result of anion exchange membrane

As can be seen in Table 1, Examples according to the present invention exhibited higher ion exchange performance and lower moisture content compared to Comparative Example 1. This indicates that the anion exchange membrane according to the embodiment suppresses excessive swelling by including a pore-filled basement membrane. In addition, compared to Comparative Example 1, it exhibited a low electrical resistance of about 1/20 due to the thin film thickness.

In particular, in Examples 2 to 4, the hydrogen ion permeability according to the ionomer layer containing graphene oxide could be significantly lowered, and a low moisture content could be maintained even when a large number of hydrophilic functional groups of the graphene oxide were included. At the same time, the monovalent ion selective transmittance was remarkably improved. In Example 5, by crosslinking graphene oxide in the ionomer layer using glutaaldehyde, it was possible to improve physical stability and further lower the moisture content of the film. In addition, the permeability of hydrogen ions was significantly reduced, and further, the selective transmittance of monovalent ions was remarkably improved. In addition, Example 6 showed the effect of further improving the monovalent ion selectivity and reduction of hydrogen ion permeability compared to Example 5 by crosslinking including diamine.

Although a preferred embodiment of the present invention has been described above, it is clear that the present invention can use various changes, modifications, and equivalents, and that the above embodiment can be appropriately modified and applied in the same manner. Therefore, the above description does not define the scope of the present invention determined by the limits of the following claims.

Claims (14)

Impregnating a porous polymer substrate in a monomer mixture containing a styrene monomer, a vinyl monomer substituted with a quaternary ammonium salt, a crosslinking agent and an initiator, and polymerizing to prepare a base membrane filled with the pores of the substrate; and
Coating the base film filled with the pores with an ionomer solution containing a halogenated phenylene oxide polymer, an amine compound and graphene oxide, and drying to form an ionomer layer on the base film,
The step of forming the ionomer layer further comprises impregnating the base membrane on which the ionomer layer is formed in an aqueous glutaraldehyde solution. The method of claim 1,
The vinyl-based monomer substituted with the quaternary ammonium salt is a vinylbenzene substituted with the quaternary ammonium salt. The method of claim 1,
The halogenated phenylene oxide-based polymer is a benzyl brominated polyphenylene oxide method for producing an anion exchange membrane. The method of claim 1,
The amine compound is a method of manufacturing an anion exchange membrane comprising at least one selected from primary, secondary and tertiary amines. The method of claim 1,
The ionomer solution is a method for producing an anion exchange membrane in which the molar ratio of the halogenated phenylene oxide-based polymer and the amine compound is 1:0.25 to 1:1.25. The method of claim 1,
The crosslinking agent is divinylbenzene, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate , Neopentyl glycol dimethacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, triethylene glycol diacrylate, tricyclodecane dimethanol diacrylate, trimethylolpropane trimethacrylate and trimethyloltri A method for producing an anion exchange membrane of any one or more selected from the group consisting of acrylates. delete delete The method of claim 1,
In the ionomer layer forming step, any one or more selected from hexamethylenediamine, tetramethylenediamine, 2,4-dimethylhexamethylenediamine, dodeca methylenediamine, isophoronediamine, and p-cyclohexylenediamine in the base film on which the ionomer layer is formed. A method for producing an anion exchange membrane further comprising impregnating the aqueous diamine solution containing. The method of claim 1,
The polymerization is a method of manufacturing an anion exchange membrane in which photo-crosslinking or thermal crosslinking is performed. The method of claim 1,
The porous polymer substrate has a thickness of 1 to 50 μm and a porosity of 40 to 80% of an anion exchange membrane. The method of claim 1,
The porous polymer substrate is any one selected from a film, a sheet, and a nonwoven fabric method of manufacturing an anion exchange membrane. A pore-filled base membrane filled with a polymer derived from a vinyl-based monomer substituted with a styrene-based monomer and a quaternary ammonium salt in the pores on a porous polymer substrate, and
And an ionomer layer comprising a halogenated phenylene oxide-based polymer, an amine compound, and graphene oxide formed on the pore-filled base layer, wherein the ionomer layer is crosslinked with glutaaldehyde. An electrochemical device comprising the anion exchange membrane of claim 13.