KR20170032874A - Ion exchange membrane and method for manufacturing thereof - Google Patents

Abstract

A method for manufacturing an ion-exchange membrane is provided. According to an embodiment of the present invention, the method for manufacturing the ion-exchange membrane comprises a step of manufacturing a fiber mat, by electrospinning a mixed spinning solution containing a supporting component and an ion exchangeable component. According to the step of the present invention, controlling the factors, such as the film thickness, the electric conductivity, the mechanical strength, the diameter/the ratio of the pores, and others, in accordance with a use of the ion exchange membrane, is easily done in manufacturing processes, and simplifies the manufacturing processes. The ion-exchange membrane prepared through the processes has excellent mechanical strength and durability, and at the same time, can be utilized as a general-purpose ion-exchange membrane, having large ion-exchange capacity and small electric resistance and a small diffusion coefficient.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion exchange membrane,

The present invention relates to an ion exchange membrane, and more particularly, to an ion exchange membrane which is realized through a simplified manufacturing process and a shortened manufacturing time, and has excellent mechanical strength and durability, An ion exchange membrane having a small coefficient and a manufacturing method thereof.

The ion exchange resin is a synthetic resin having ion exchange ability. In 1935, B. A. Adams and F. L. Holmes of the United Kingdom found that a resin that condensed polyvalent phenol and formaldehyde and a resin that condensed m-phenylenediamine and formaldehyde exchanged ions. It was found that this resin can remove various ions in the water, and then it started to be systematically studied and industrialized in Germany and the United States. During World War II, it was used in water purification, copper and ammonia recovery in artificial dog factory, and in the United States, it was used to classify fission product, uranium element, and trace element. In addition, purification of various materials (amino acids, antibiotics, etc.) was facilitated by the ion exchange resin, and the ion exchange membrane was developed and became more important in terms of electrochemistry. Currently, ion exchange membranes are widely used in fields such as fuel cells, redox flow cells, electrodialysis, desalination, ultrapure water and wastewater treatment. In particular, it has attracted worldwide attention due to its reduced use of fossil fuels and clean technology for producing environmentally friendly new and renewable energy. Due to the rapid increase in the use of electronic products such as small notebooks and mobile phones, research on ion exchange membranes, which is a core material thereof, has been actively carried out in accordance with the necessity of development of high-capacity battery and high capacity battery.

On the other hand, a typical ion exchange membrane is often provided with a separate support for improving mechanical properties. Specifically, a sheet-like ion exchange resin layer may be provided on one side of the support. The material of the support and the ion exchange resin layer There is a problem that peeling and separation frequently occur between interlayer interfaces due to compatibility and the like, and thus ion exchange ability and / or mechanical properties are remarkably deteriorated. Further, there has been a problem in that it is very difficult to control the composition of the ion-exchange membrane in accordance with its application, for example, the thickness, the electrical conductivity, the mechanical strength, and the diameter /

Accordingly, it is easy to change the structure and physical properties of the ion exchange membrane in accordance with the intended application, and at the same time, the ion exchange membrane produced has excellent mechanical strength and durability, and at the same time has a high ion exchange capacity, And ion exchange membranes such as the above-mentioned ion exchange membranes.

Korean Patent Laid-Open Publication No. 2014-0036609

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a method for manufacturing an ion exchange membrane, which can easily control the factors such as the thickness, electrical conductivity, mechanical strength, It is an object of the present invention to provide a method of manufacturing an ion exchange membrane in which a fabrication process is greatly simplified.

Another object of the present invention is to provide a general-purpose ion exchange membrane having high mechanical strength and physical / chemical durability, high ion exchange capacity, and low electrical resistance and diffusion coefficient.

In order to solve the above-mentioned problems, the present invention provides (1) a process for producing an ion exchange membrane comprising: (1) preparing a fiber mat by electrospunning a spinning solution containing a supporting component and an ion exchangeable component.

According to an embodiment of the present invention, the support component may be selected from the group consisting of polyimides, polyamic acid, polycarprolactone, polyetherimide, nylon, polyaramid Polybenzyl-glutamate, polyphenyleneterephthalamide, polyaniline, polyacrylonitrile, polyethylene oxide, polystyrene, cellulose, polyvinylpyrrolidone, polyvinylpyrrolidone, Poly (methyl methacrylate), poly (methyl methacrylate), polylactic acid (PLA), polyglycolic acid (PGA), polylactic-co-glycolic acid, poly { (PEOT / PBT), polyphosphoester (PPE), polyphosphazene (PPA), polyanhydride (PA), polyorthoesters {poly (POE), poly (propylene fumarate) -diacrylate (PPF-DA), polyvinyl alcohol, polyester, polyurethane, polyvinyl chloride, polytetrafluoroethylene (PTFE), polytetrafluoroethylene (PTFE), polyethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE), and polychlorotrifluoroethylene Ethylene (PCTFE), poly (styrene-co-maleic anhydride), and the like.

In addition, the ion-exchangeable component may be a cationic ion-exchangeable component or an anionic ion-exchangeable component.

Also, the spinning solution may contain 20 to 80 parts by weight of an ion exchangeable component with respect to 100 parts by weight of the supporting component.

In addition, after the step (1), (2) applying heat and pressure to the fiber mat to adjust porosity and pore size.

Further, the melting point of the support component contained in the fiber mat may be lower than the melting point of the ion-exchangeable component.

The present invention also provides an ion exchange membrane comprising a fiber mat comprising a first fiber comprising a support component and an ion exchangeable component.

According to one embodiment of the present invention, the fiber mat may further comprise a second fiber comprising a support component and a third fiber comprising an ion exchangeable component.

In addition, the fiber mat may include a web area of a three-dimensional network structure formed by fusing fibers.

In addition, the average diameter of the fibers included in the fiber mat may be 0.1 to 100 탆, the average pore size of the island fiber mat may be 0.1 to 10 탆, and the thickness of the fiber mat may be 0.1 to 200 탆.

At this time, the ion exchange membrane may be a liquid filter or an air filter.

The present invention also relates to a fiber mat comprising a third fiber comprising an ion exchangeable component; And a support for supporting the third fibers by filling spaces between the fibers in the fiber mat.

According to an embodiment of the present invention, the ion exchange membrane may be used for a liquid filter, an air filter, a capacitive deionization (CDI), an electrodialysis (ED) or a battery separator.

Hereinafter, terms used in the present invention will be described.

The term "surface portion " of the mat as used in the present invention means a region corresponding to a thickness of 15% or less of the total thickness of the mat from the mat surface.

The term "mat" as used in the present invention means a state in which electrospun fibers are accumulated, wherein the mat is formed by bending and intertwining a single strand of fibers several times, And may be included in a "mat" when a portion of the fiber is melted to include a fibrous portion, even if it includes a non-fibrous portion.

According to the present invention, it is possible to easily adjust electrical conductivity, mechanical strength, pore, etc. in accordance with the required characteristics of the ion exchange membrane, and owing to the omission of the ion exchange solution filling process, The productivity can be remarkably increased. In addition, the ion exchange membrane produced by manifesting the effect of significantly increasing the filling property of the ion exchangeable component inside the support has excellent mechanical strength and durability, at the same time, has a high ion exchange capacity and a small electric resistance and diffusion coefficient Accordingly, it can be widely applied to separation membranes in the field of batteries, desalination systems such as CDI / ED and materials for various filters, and may be more suitable for battery separator applications.

1 is a schematic view illustrating a process of manufacturing an ion exchange membrane according to an embodiment of the present invention,
2 is a sectional schematic view of the ion exchange membrane manufactured through FIG. 1, and FIG.
FIG. 3 is a schematic view showing a partial enlargement of fibers and fibers in the ion exchange membrane according to FIG. 2;

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

1, a spinning solution in which a support component and an ion exchangeable component are mixed is electrospun through a plurality of electrospinning tips 10, An integrated fiber mat 21 to 25 can be produced.

The spinning solution includes a support component and an ion exchangeable component, and the spinning solution may be a melt mixed / fused with a support component and an ion exchange component, or a dissolving solution in which the components are dissolved by a solvent. The spinning solution may contain 20 to 80 parts by weight, more preferably 30 to 60 parts by weight, of the ion exchangeable component with respect to 100 parts by weight of the supporting component. If the ion-exchangeable component is contained in an amount of less than 20 parts by weight, the ion exchange capacity may be significantly deteriorated. When the ion-exchangeable component is contained in an amount exceeding 80 parts by weight, .

The above-mentioned support component may be used without limitation in the case of a compound used as a component of a support in a conventional ion exchange membrane, but it is preferable to use a polyimide, a polyamic acid, a polycarprolactone, Polyetherimide, polyetherimide, nylon, polyaramid, polybenzyl-glutamate, polyphenyleneterephthalamide, polyaniline, polyacrylonitrile, polyethylene oxide polyethylene oxide, polystyrene, cellulose, polymethylmethacrylate, polylactic acid (PLA), polyglycolic acid (PGA), polylactic-co-glycolic acid , Poly {poly (ethylene oxide) terephthalate-co-butylene terephthalate} (PEOT / PBT), polyphosphoester PPE), polyphosphazene (PPA), polyanhydride (PA), polyorthoester (POE), poly (propylene fumarate) - polyacrylate diacrylate, PPF-DA, polyvinyl alcohol, polyester, polyurethane, polyvinyl chloride, polytetrafluoroethylene (PTFE), polyethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (1) selected from the group consisting of polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE) and polychlorotrifluoroethylene (PCTFE) and poly (styrene-co-maleic anhydride) It can be more than a species. However, the present invention is not limited thereto and the components can be changed depending on the use of the ion exchange membrane.

When the support component contains at least two kinds of support components, for example, polyvinylidene fluoride (PVDF) as the heat resistant support component and polyacrylonitrile (PAN) as the adhesive support component (or swelling support component) ), And it is preferable to mix the respective components in the weight ratio range of 8: 2 to 5: 5.

When the mixing ratio of the heat resistant support component and the adhesive support component is less than 5: 5 by weight, the heat resistance is low and the high temperature property is not obtained. When the mixing ratio is more than 8: 2 by weight, the strength is lowered and radial trouble is generated.

The heat-resistant supporting component may be a resin which can be dissolved in an organic solvent for electrospinning and has a melting point of 180 or more, for example, polyacrylonitrile (PAN), polyamide, polyimide, polyamideimide, poly Aromatic polyesters such as polyethylene terephthalate, polyethylene terephthalate and the like, polytetrafluoroethylene, polydiphenoxaphospazene, poly {bis [(isophthalamide)], polysulfone, polyether ketone, polyethylene terephthalate, Poly (2-methoxyethoxy) phosphazene], polyurethane copolymers including polyurethane and polyether urethane, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, etc. .

The swelling support component is a resin which swells in an electrolyte solution and can be formed by ultrafine fibers by electrospinning. Examples of the swelling support component include polyvinylidene fluoride (PVDF), poly (vinylidene fluoride-co-hexafluoropropylene) , Polyethylene glycol derivatives including polyfluoro polymers, polyvinyl chloride or polyvinylidene chloride and copolymers thereof and polyethylene glycol dialkyl ethers and polyethylene glycol dialkyl esters, poly (oxymethylene-oligo-oxyethylene), poly (Polyvinylpyrrolidone-vinyl acetate), polystyrene and polystyrene acrylonitrile copolymers, polyacrylonitrile methyl methacrylate copolymers, polyvinyl acetates, poly (vinyl pyrrolidone-vinyl acetate) Acrylonitrile copolymer, poly Methyl methacrylate, polymethyl methacrylate copolymer, and mixtures thereof

Next, the ion-exchangeable component may be a cationic ion-exchangeable component or an anionic ion-exchangeable component, and a cation exchange membrane or anion exchange membrane may be implemented depending on the polarity of the selected ion.

The cationic ion-exchangeable component may be a quaternary ammonium salt (-NH ₃ ), a primary to tertiary amine (-NH ₂ , -NHR, -NR ₂ ), a quaternary phosphonium group (-PR ₄ ) (-SR < ₃ >), and the like.

In addition, the anionic ion-exchangeable component may be a sulfonic acid group (-SO ₃ H), a carboxyl group (-COOH), a phosphonic group (-PO ₃ H ₂ ), a phosphonic group (-HPO ₂ H) -AsO ₃ H ₂ ), and a selinonic group (-SeO ₃ H), and specific examples thereof include polysulfone, polyisocyanurine and the like.

The cationic or anionic ion-exchangeable component is a crosslinking reaction functional group, which is a hydroxyl group (-OH) capable of performing a crosslinking reaction by an ester bond, an amine group (-NH ₂ , -NH-, -NR-, -NR ₂ ) And a carboxylic acid group (-COOH), an isocyanate functional group capable of forming an epoxy group or a urethane bond, etc., or a polymer compound having a condensation polymerization type crosslinking reaction functional group capable of undergoing a crosslinking reaction by addition polymerization The polymer resin may be present in the form of a solution in the form of a solution dissolved in an organic solvent. Specific examples thereof include polystyrene, polysulfone, polyisocyanurate, polyamide, polyester , Polyimide, polyether, polyethylene, polytetrafluoroethylene, polyglycidyl methacrylate, and mixtures thereof. You can use the water.

Next, when the spinning solution is a dissolving solution, it may further include a solvent. The solvent may be used without limitation in the case of a solvent used in a conventional electrospinning spinning solution. However, solubility in a supporting component and an ion exchangeable component This excellent solvent is preferable. In addition, the solvent is preferable for a solvent which can be vaporized easily, and the solvent is not particularly limited because the solvent can be selected depending on the kind of support component and ion-exchangeable component which are specifically selected. However, it is preferable to use at least one selected from the group consisting of gamma -butyrolactone, cyclohexanone, 3-hexanone, 3-heptanone, 3-octanone, N-methylpyrrolidone, dimethylacetamide, dimethylsulfoxide, acetic acid, , A single solvent selected from the group consisting of acetone, chloroform, dichloromethane, trichlorethylene, ethanol, methanol, n-hexane and dimethylformamide, or a mixed solvent of these two solvents may be used. The two-component type mixed solvent may be a two-component type mixed solvent in which a high boiling point solvent and a low boiling point solvent are mixed. The mixing ratio between the two-component type mixed solvent and the total supporting component is preferably set to about 8: 2 by weight, But is not limited thereto.

In consideration of the fact that the solvent may not be volatilized well depending on the kind of the support component when the single solvent is used, the pre-air drying zone after the spinning process (pre-air drying zone) The process of controlling the amount of solvent and moisture remaining on the surface of the fiber mat can be further roughened.

The spinning liquid described in step (1) according to the present invention can be put into a conventional electrospinning apparatus. The electrospinning device may be a device for wet spinning or dry spinning depending on the specific type of components contained in the spinning solution selected.

For example, the spinning solution may be fed into the feeder of the electrospinning device and conveyed to the nozzle section through a pump unit such as a known syringe pump. The nozzle unit may include a nozzle and a connection unit connecting the nozzle to the supply unit. However, the nozzle can be formed by connecting the nozzle with the supply part without the connection part, so that the specific configuration of the nozzle part is not particularly limited in the present invention, and the configuration of the nozzle part included in the general electrospinning device can be selected and changed.

The diameter of the nozzle of the nozzle unit may be selected in consideration of the basis weight, porosity, pore diameter, mechanical strength, etc. of the target fiber mat, and is not particularly limited in the present invention. In addition, the cross-sectional shape of the nozzle may be various shapes such as circular, elliptical, and polygonal, and the cross-sectional shape of the nozzle may be a cross-sectional shape of a conventional electrospinning nozzle such as a single nozzle, a double nozzle or a triple nozzle. In addition, the nozzle unit may include a plurality of nozzles according to the purpose, and the diameter of each of the plurality of nozzles may be different, and the present invention does not limit the specific shape, size, and number of the nozzles. In addition, the material of the nozzle may be a material of a nozzle used for ordinary electrospinning, and preferably, it may be an electrically conductive metal material, but is not limited thereto.

A portion of the nozzle portion may be connected to be in electrical communication with an electric field forming portion, e.g., a high voltage device, to form an electric field for electrospinning. The electric field forming unit forms a jet of the spinning solution from the nozzle unit to the collector. The electric field forming unit is configured to form an electric field between a nozzle tip of the nozzle unit and an imaginary point passing straight through the nozzle tip and the collector And the configuration of the electric field forming portion provided in the conventional electrospinning device can be selected, and thus the present invention is not particularly limited thereto. However, the electric field forming unit may include a current collecting plate and a high voltage generating unit, the current collecting plate may be grounded, and the high voltage generating unit may be electrically connected to the nozzle unit.

If wet electrospinning is performed, the collector may further include a coagulation bath. The coagulating bath may include an external coagulating liquid for coagulating the jet of the spinning solution into a fiber shape. As the external coagulating solution, water, an organic solvent and the like can be used without any restriction, the present invention is not particularly limited as to the specific kind, and examples thereof include hexane, benzene, ethanol, methanol, , Butanol, dimethylformamide, tetrahydrofuran and the like, but is not limited thereto.

The air gap, which is a vertical distance between the nozzle tip of the nozzle unit and the surface of the external coagulating solution of the collector or the coagulation bath, may be 0 to 50 cm, but is not limited thereto.

The ion exchange membrane produced by the above-described production method comprises a first fiber comprising a support component and an ion exchangeable component.

One of the fibers forming the fiber mat may be spun in a state containing both a support component and an ion exchange component, but a part of the fibers included in the fiber mat may be separated due to phase separation between the components during the spinning process, Since one strand of fibers can be formed for each component, the fiber mat may further include at least one of a second fiber including a supporting component and a third fiber including an ion-exchangeable component, The ion exchange membrane may include both the first fibers 21a / 22b, the second fibers 21a, and the third fibers 22b.

The fiber mat may include a web region having a three-dimensional network structure formed by fusing fibers. As shown in FIG. 3, the second fibers 21a and the other second fibers 22a may be formed of a non- A part of the surface of the second fiber 21a is fusion bonded (B ₁ ), and a part of the surface of the second fiber 21a and the third fiber 21b is fused (B ₂ ) to form a three-dimensional network structure. Also, although not shown in Fig. 3, fusion between the first fiber, the second fiber, or the third fiber, which includes both the support component and the ion exchangeable component, may occur.

The fusion does not only mean a partial melting of the fibers through a separate warming process. Specifically, in the process of electrospinning, the solvent contained in the spinning solution is usually radiated irrespective of the electrospinning method and then vaporized in the air. In the case of wet electrospinning, the solvent remaining in an amount not vaporized is dissolved in the external coagulating solution Solvents present in the spunbonded fibers that have not been completely vaporized and / or dissolved can induce attachment of contact points or contact surfaces when contact occurs between the fibers.

When the three-dimensional network structure is formed in the fiber mat, stable pore structure formation between the fibers and mechanical strength of the fiber mat can be improved, so that the desired properties of the present invention can be realized more easily.

On the other hand, the average diameter of the fibers included in the fiber mat may be 0.1 to 100 탆. If the diameter of the fiber is less than 0.1 mu m, the mechanical strength is weak and it is difficult to form a stable pore structure, so that it may be unsuitable for some applications, for example, filters, and radioactivity may be lowered. In addition, if the diameter exceeds 100 탆, heat / pressure is applied through step (2) described later depending on the application, so that melting of the supporting component is not easy when the supporting component in the fiber is melted, The porosity may not be easily controlled. However, the diameter of the fiber is not limited to the range of the diameter of the fiber, and the fiber diameter range may be changed depending on the application in which the ion exchange membrane is used.

The average pore diameter of the fiber mat may be 0.1 to 10 mu m. If the average pore size is less than 0.1 탆, there is a problem that the flow rate is significantly reduced in the filter application, and when the average pore size is more than 10 탆, the filtration efficiency is deteriorated in the filter application. However, the average pore diameter is not limited to the average pore diameter, and the average pore diameter may be changed depending on the application in which the ion exchange membrane is used.

In addition, the thickness of the fiber mat may be 0.1 to 200 탆, but is not limited thereto, and the thickness may be changed depending on the application.

On the other hand, the fiber mats can be controlled in pore size and thickness depending on the intended use of the ion exchange membrane through the step (2) described below, and the heat applied at a temperature higher than the melting point of the support component is a part of the monosaccharide Or all of them may be melted to affect the pore size and porosity of the fiber mat.

Specifically, the heat applied to the fiber mat may have a temperature of 60 to 180 and a pressure of 2 psi or less, but it may vary depending on the specific application of the ion exchange membrane, the specific component of the support component and the ion exchange component .

Further, in the case of an ion exchange membrane in which the use of the ion exchange membrane is a liquid filter or an air filter, the heat and / or pressure applied may be low even if the step (2) is omitted or the step (2) 2) The execution time of the step may be short. In addition, even if the same filter is used, the specific heat / pressure / execution time may vary depending on the size of the target material to be filtered.

On the other hand, even if the above-mentioned step (2) is not carried out, as shown in Fig. 2, the pore / pore diameter can be controlled by adjusting the diameter of the plurality of spinning nozzles 11 to 15 and / It is possible to realize the fiber mat 20 in which the different mats 21 to 25 are laminated, and through this, an ion exchange membrane having a gradient of pore size and / or porosity from one surface portion to the other surface portion of the fiber mat can be realized .

In another embodiment of the present invention, the melting point of the material of the supporting fibers included in the supporting fiber mat may be lower than the melting point of the material of the ion exchange fiber included in the ion exchange fiber mat, The heat and pressure exerted through the step may melt at least some of the support components through which interfiber fusing within the fiber mat and / or pores in the fiber mat may be filled with molten support components.

Accordingly, the ion exchange membrane according to one embodiment of the present invention is embodied to include a fiber mat comprising fibers comprising an ion exchangeable component and a support for supporting the fibers by filling the space between the fibers in the fiber mat.

The fiber forming the fiber mat may contain the ion-exchangeable component as a subject of the fiber-forming component as the support component is melted by heat / pressure, and may include an unmelted support component in the case of some fibers. The supporting member is formed by melting the supporting component contained in the first fiber or the supporting fiber contained in the second fiber among the fibers included in the fiber mat manufactured through the step (1), thereby filling the space between the fibers in the fiber mat The porosity and pore size can be controlled and the bonding between the fibers, the ion exchangeable component of which is the subject, can be increased to further enhance the mechanical strength.

The porosity and pore size of the fiber mat may vary depending on the heat / pressure and the melting point of the support component through the step (2). The porosity of the ion exchange membrane prepared in step (2) Can be made suitable for use in capacitive deionization (CDI) or electrodialysis (ED).

Further, the non-porous ion exchange membrane having a porosity of 5% or less, more preferably 3% or less, still more preferably 1% or less, still more preferably 0% of porosity may be used as a fuel cell or a redox flow cell And further satisfies the mechanical properties and electrical properties required by the battery separator. Therefore, the separator can be suitably used as a battery separator.

Meanwhile, in order to supplement mechanical strength, the ion exchange membrane according to one preferred embodiment of the present invention may further include a separate support member such as a nonwoven fabric on one side of the ion exchange membrane. The supporting member may be, for example, a non-woven fabric made of a double structure PP / PE fiber or a nonwoven fabric made of polyethylene terephthalate (PET), a nonwoven fabric made of cellulose fibers And the basis weight and thickness of the nonwoven fabric may be changed according to the purpose, and the present invention is not particularly limited thereto.

The inorganic material may be selected from the group consisting of nickel (Ni), copper (Cu), stainless steel (SUS), titanium (Ti), chromium (Cr) At least one metal selected from among Mn, Fe, Co, Zn, Mo, W, Ag, Au and Al, Oxides thereof, and the like.

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

≪ Example 1 >

12 g of polyvinylidene fluoride (Kynar 761) as a support component was dissolved in 88 g of a mixture of dimethylacetamide and acetone at a weight ratio of 90:10 using a magnetic bar at a temperature of 60 for 6 hours to prepare a first mixed solution . Next, 12 g of an anion exchange resin APS (PolyStyrene: VinylBenzeneChloride: MethylMethacrylate = 1: 1: 2) resin as an ion exchangeable component was dissolved in 88 g of dimethylacetamide at a temperature of 60 for 6 hours using a magnetic bar to form a second mixed solution . Then, the first mixed solution and the second mixed solution were mixed again and stirred to prepare a spinning solution. The ion exchangeable component was mixed in an amount of 50 parts by weight based on 100 parts by weight of the support component. The spinning solution thus prepared was put into a solution tank of the electrospinning device and discharged at 15 / / min / hole. At this time, the temperature of the radiation section was maintained at 28, the humidity was maintained at 45%, and the distance between the collector and the radiation nozzle tip was set to 25 cm.

Using a high voltage generator, a voltage of 45 kV or more was applied to a spin nozzle pack and an air pressure of 0.05 MPa was applied per spin pack nozzle, and the fiber mat was produced by spinning as shown in Fig. Thereafter, a calendering process was performed by applying heat and pressure at 140 and 1 kgf / cm 2 to dry the solvent and moisture remaining in the fiber mat, thereby obtaining an ion exchange membrane having a total thickness of 95 탆 and a porosity of 65% .

≪ Examples 2 to 5 >

The ion exchange membranes as shown in Table 1 below were prepared by changing the content of the support component and the ion exchangeable component of the spinning solution as shown in Table 1

≪ Comparative Example 1 &

The same procedure as in Example 1 was carried out except that no supporting component was added to the spinning solution.

≪ Comparative Example 2 &

12 g of polyvinylidene fluoride (Kynar 761, manufactured by Arkema) was used as a support fiber forming component in a weight ratio of dimethylacetamide and acetone of 90:10, and 88 g of a magnetic bar was used at 60 ° C. for 6 hours To prepare a spinning solution. The spinning solution was poured into a solution tank of the electrospinning device and discharged at a rate of 15 / / min / hole. At this time, the temperature of the radiation section was maintained at 28 ° C, the humidity was maintained at 45%, and the distance between the collector and the spinneret tip was set to 25 cm. A support fiber mat having a thickness of 100 탆 was produced by applying a voltage of 45 kV or higher to the spin nozzle pack using a high voltage generator and applying an air pressure of 0.05 MPa per spin pack nozzle. Then, to dry the solvent and water remaining on the fiber mat, calendering process was performed by applying heat and pressure at 140 and 1 kgf / cm 2 to prepare a support film having a total thickness of 95 탆. Subsequently, 8 g of an anion exchange resin, APS (PolyStyrene: VinylBenzeneChloride: MethylMethacrylate = 1: 1: 2) resin, was dissolved in 92 g of dimethylacetamide at a temperature of 60 ° C. for 6 hours using a magnetic bar and immersed in the mixed solution for 1 hour And dried at a temperature of 80 ° C to prepare an ion exchange membrane as shown in Table 1 below.

<Experimental Example>

The following properties of the ion exchange membranes prepared in Examples and Comparative Examples were evaluated and shown in Table 1 below.

1. Dimensional Change (%)

The dimensional change of the membrane was measured to evaluate the mechanical strength of the ion exchange membrane. The volume of the wet film (V _wet ) was measured after immersing the specifically prepared film in distilled water for 24 hours, and the wet film was vacuum dried again for 120 to 24 hours to measure the volume (V _dry ). These measured values were substituted into the following formula 1 to calculate the degree of dimensional change.

[Formula 1]

Dimensional change (%) = (V _wet - V _dry ) × 100 / V _dry

The larger the dimensional change, the less the mechanical strength and the durability are not as good.

2. Sacrifice

SEM photographs were taken at a magnification of 2000 times with respect to the surface of the fiber mat, and the total number of fibers and the number of beads were counted on the photographed image, and the formality was calculated according to the following formula 2.

[Formula 2]

3. Membrane performance of redox flow battery

After the surface area within a cell located in the center of the ion exchange membrane 30㎝ ^2, wherein the ion exchange membrane by both the electrodes on both sides of carbon felt (GF020, JMTG) pair, graphite plate (Graphite plate) pair, collector plate couple and the end plate ( (WBCS 3000, WonAtech), a pump, a positive electrode electrolyte tank connected to one region of the cell divided by the ion exchange membrane, and a negative electrode electrolyte tank connected to the other region of the cell A redox flow cell was prepared. At this time, the positive electrode electrolyte tank was filled with 40 ml of a solution containing 2.0 M of sulfuric acid and 1.0 M of vanadium oxysulfate, and the negative electrode electrolyte tank was filled with 40 ml of a solution containing 2.0 M of sulfuric acid and 1.0 M of V3 +.

Charging proceeded to 1.5V with current density maintained at 60mA / cm &lt; ² &gt; and discharging progressed to 1.0V at the same current density to measure charge / discharge cycle performance.

At this time, the energy efficiency in each cycle was calculated according to the following Equation 3 by measuring the change in voltage with time in each cycle, and the remaining energy efficiency was calculated based on the energy efficiency of Embodiment 1 at 10 charge / discharge cycles The energy efficiency was relatively expressed at 10 charge / discharge cycles of the example and the comparative example. In addition, a cycle in which the energy efficiency decreased by 2% in comparison with the energy efficiency in the first cycle of each example / comparative example is also shown.

 [Formula 3]

(Energy efficiency, energy efficiency, Id: discharge current amount, Ic: charge current amount, V: discharge voltage, VC: charge voltage, t: charge time or discharge time)

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Spray solution Support component content (parts by weight) 100 100 100 100 100 0 100 Ion exchangeable component content (parts by weight) 50 10 25 75 90 100 0 Ion exchange membrane Dimensional change (%) 9 2 4 12 25 68 One Sacrifice (%) 99 100 100 96 78 76 100 Energy efficiency (%) 100 46 78 106 110 25 109 When the energy efficiency is reduced by 2%, the number of cycles (times) 716 902 705 658 493 14 730

As can be seen from Table 1,

In Comparative Example 1 in which the ion exchange membrane was produced only through the ion exchange fiber, the durability was not good due to the remarkable dimensional change compared with the Examples, and the energy efficiency in the 10 charge / discharge cycles was 25% And the energy efficiency can not be maintained for a long period of time.

On the other hand, Comparative Example 2, which is a conventional ion exchange membrane packed with ion exchange solution in the supporting membrane, has somewhat superior physical properties compared to Example 1, but since the immersion time is separately required, Example 1 is more excellent in terms of productivity Can be confirmed.

It can also be seen that, in Examples 2 and 5, in which the content of the ion exchangeable component in the spinning solution is excessive or excessive, all the physical properties are hardly satisfied at the same time as in Example 1.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

10: Electrospinning tips 20: Textile mat

Claims (14)

(1) preparing a fiber mat by electrospunning a spinning solution mixed with a supporting component and an ion exchangeable component. The method according to claim 1,
The support component may be selected from the group consisting of polyimides, polyamic acid, polycarprolactone, polyetherimide, nylon, polyaramid, polybenzyl-glutamate Polyphenyleneterephthalamide, polyaniline, polyacrylonitrile, polyethylene oxide, polystyrene, cellulose, polymethylmethacrylate, polymethylmethacrylate, polymethylmethacrylate, Poly (ethylene oxide) terephthalate-co-butylene terephthalate} (PEOT / PBT), polyglycolic acid (PGA), polylactic acid- , Polyphosphoester (PPE), polyphosphazene (PPA), polyanhydride (PA), polyorthoester (POE), poly Poly (propylene fumarate) -diacrylate (PPF-DA), polyvinyl alcohol, polyester, polyurethane, polyvinyl chloride, polytetrafluoroethylene (PTFE) (ETFE), polyvinylidene fluoride (PVDF), ethylene chlorotrifluoroethylene (ECTFE) and polychlorotrifluoroethylene (PCTFE), and poly (ethylene terephthalate) Styrene-co-maleic anhydride). &Lt; / RTI &gt; The method according to claim 1,
Wherein the ion-exchangeable component is a cationic ion-exchangeable component or an anionic ion-exchangeable component. The method according to claim 1,
Wherein the spinning solution comprises 20 to 80 parts by weight of an ion exchangeable component with respect to 100 parts by weight of the support component. 2. The method of claim 1, wherein after step (1)
(2) adding at least one of heat and pressure to the fiber mat to adjust porosity and pore size. 6. The method of claim 5,
Wherein the melting point of the support component contained in the fiber mat is lower than the melting point of the ion-exchangeable component. A fiber mat comprising a first fiber comprising a support component and an ion exchangeable component. 8. The method of claim 7,
Wherein the fiber mat further comprises a second fiber comprising a support component and a third fiber comprising an ion exchangeable component. 8. The method of claim 7,
Wherein the fiber mat comprises a web region of a three-dimensional network structure formed by fusing fibers. 8. The method of claim 7,
Wherein the fibers have an average diameter of 0.1 to 100 占 퐉. 8. The method of claim 7,
Wherein the fiber mat has an average pore size of 0.1 to 10 占 퐉. 8. The method of claim 7,
Wherein the thickness of the fiber mat is 0.1 to 200 占 퐉. A fiber mat comprising a third fiber comprising an ion exchangeable component; And
And a support body for supporting the third fibers by filling spaces between the fibers in the fiber mat. 14. The method according to any one of claims 7 to 13,
The ion exchange membrane may be a liquid filter, an air filter, a capacitive deionization (CDI), an electrodialysis (ED) or an ion exchange membrane for a battery separator.

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