KR20180001915A - Ion exchange membrane having flow channel laminated bipolar electrodes and method thereof - Google Patents

Abstract

The present invention relates to a particle electrode coated with a flow path-integrated ion exchange membrane, a production method thereof, and a capacitive deionization (CDI) module using the same. The particle electrode of the present invention exhibits excellent adsorption efficiency and durability without bending of electrodes, enables easy production of stack-type modules, and does not require additional spacers to form flow paths during the assembly of CDI modules, thereby ensuring simple and automatized module assembly.

Description

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a bipolar electrode having a flow-integrated ion exchange membrane and a method for manufacturing the same,

The present invention relates to a bipolar electrode coated with an ion exchange membrane that can be used in capacitive deionization desalination.

Deionization techniques to remove ions dissolved in fluids are very important for the production of domestic or industrial water. For example, if drinking water contains heavy metals, nitrate nitrogen, fluoride ions, etc., it can have a serious health effect. In the case of industrial water, the use of boiler water containing hard material can cause scale in the heat exchanger of the boiler, which may reduce the efficiency of the process. In addition, in the electronic and pharmaceutical industries, deionized water, in which ions are completely removed, can be one of the main factors in determining the performance of a product. Desalination technology is used in various industrial fields.

In general, the ion exchange method using an ion exchange resin is mainly used as a method for desalting. The ion exchange method is capable of effectively separating ionic materials, but there is a disadvantage that an acid, a base or a salt waste solution may be generated in the regeneration of the resin after the ion exchange is completed. In addition to the ion exchange method, a membrane technique such as a reverse osmosis membrane method and an electrodialysis method is used, but there are various drawbacks such as reduction of efficiency due to fouling of the membrane and necessity of treatment of a contaminated membrane.

In recent years, a storage type desalination technology capable of improving the disadvantages of the existing desalination techniques has been developed. The electrolytic desalination technique utilizes the ion attraction reaction by electric attraction in the electric double layer formed on the electrode surface when the electric potential is applied to the electrode, which is advantageous in that the energy consumption is very low as compared with other desalination techniques.

Electrolytic desalination technology includes an ion selective electrode using a cation or anion ion exchange membrane having ion selectivity for improving the adsorption efficiency of the electrode. However, when the storage desalination module is assembled, it is necessary to insert a spacer that can flow fluid between the electrodes, so that the assembling process is complicated and automation is difficult, which may lead to a decrease in productivity and an increase in manufacturing cost. In order to solve this problem, a method of directly coating an ion exchange material on both sides of the electrode and forming or patterning a flow path has been proposed. However, when making a depolarizing depolarization electrode, a cation exchange solution and an anion exchange solution having different polarities It is necessary to coat each of them, so that a curling phenomenon may occur when the electrode is manufactured in a continuous process, resulting in breakage and a difficulty in stacking. Korean Patent No. 10-1410642 discloses a method for producing a desalting electrode that does not require a spacer by artificially forming a flow path in an ion exchange membrane. However, a process for forming a flow path pattern is separately required, and there are difficulties in continuous process, difficulty in pattern maintenance in the continuous desalination process, and the like.

Korean Patent No. 10-1410642

The present invention relates to a bipolar elctrodes having a channel integrated type ion exchange membrane on both surfaces of which electrodes are not required to form a channel and a method for manufacturing the same, And to provide new technologies that simplify and automate the assembly process of capacitive deionization (CDI) modules.

The present invention relates to a cation exchange membrane having an anion exchange group and an anion exchange group prepared by coating a cation exchange solution prepared by dissolving a polymer resin having a cation exchange group in an organic solvent, An anion exchange membrane prepared by coating an anion exchange solution prepared by dissolving a polymer resin in an organic solvent on a woven or nonwoven fabric, followed by drying, a cation exchange membrane, and an anion exchange membrane attached to different surfaces of the electrode, Electrode.

The present invention relates to a process for preparing a cation exchange solution and an anion exchange solution by dissolving a polymer resin having a cation exchange group and an anion exchange group in an organic solvent to prepare a cation exchange solution and anion exchange solution, The method comprising the steps of: preparing an integral cation exchange membrane and an anion exchange membrane; and attaching the cation exchange membrane and the anion exchange membrane to different surfaces of the carbon electrode, respectively.

Since the channel-integrated ion-exchange membrane of the present invention is formed in accordance with the structure of the support in the course of manufacturing the ion-exchange membrane, a process for forming the channel is not particularly required. The cation exchange membrane and the anion exchange membrane of the present invention are stable in shape without causing a curling phenomenon of the electrode even when they are attached to both surfaces of the electrode, and stacking is easy. Also, it is possible to assemble a capacitive deionization (CDI) electrode module without using a spacer, so that module assembly is simple, and productivity and manufacturing cost can be reduced through automation. In addition, since the ion selective solution is not coated on the electrode, there is no decrease in the adsorption site, so that the adsorption removal efficiency of the ion can be enhanced, and the support of the ion exchange membrane is bonded to the electrode surface.

Fig. 1 shows the surface ((A)) and the cross section ((B)) of the channel-integrated ion exchange membrane.
Fig. 2 shows the surface ((A)) and the cross section ((B)) of the channel-integrated separator.
3 shows the surface ((A)) and the cross section ((B)) of the coating type electrostatic desalination electrode.
FIG. 4 is a graph showing a TDS (total dissolved solid) change curve (A) and a salt removal rate ((B)) of a desalting cell containing a coating type electrostatic desalting electrode, a flow path integral type desalination electrode and a commercial membrane, )).
5 is a photograph of a bipolar electrode manufactured by attaching ion exchange membranes having different polarities to both surfaces of a carbon electrode.
6 is a picture of a bipolar electrode prepared by coating an ion exchange solution of different polarity on both sides of a carbon electrode.
7 is a photograph of an electrode prepared by coating an ion exchange solution of the same polarity on both sides of a carbon electrode.

Hereinafter, the present invention will be described in detail. The terms used in the present specification should be construed as generally understood by a person having ordinary skill in the art unless otherwise defined. It is to be understood that the drawings and embodiments are not intended to limit the scope of the present invention, which is not intended to limit the scope of the present invention. It is not.

The present invention relates to a channel integrated type desalination bi-polar electrode having a channel-integrated ion exchange membrane including a channel through which a fluid including ions flows, and a method for manufacturing the same.

The channel integral-type desalting bi-polar electrode of the present invention is characterized in that a cation exchange solution prepared by dissolving a polymer resin having a cation exchange group in an organic solvent is coated on a woven fabric or a nonwoven fabric and then dried, Anion exchange membrane, anion exchange membrane and anion exchange membrane prepared by coating an anion exchange solution prepared by dissolving a polymer resin having an anion exchange group in an organic solvent on a woven fabric or a nonwoven fabric and drying the same, Depleted bi-polar electrode.

The ion exchange membrane according to the desalted bipolar electrode of the present invention is formed by coating an ion exchange solution prepared by dissolving a polymer resin having a cation exchange group or an anion exchange group in a woven or nonwoven fabric as a support in an organic solvent And is then dried to form a flow path through which a fluid containing ions flows. In the ion exchange membrane of the present invention, a polymer solution having an ion exchange function group may be coated or impregnated on a woven or nonwoven substrate, followed by evaporation and drying, thereby forming a flow path in the course of manufacturing the ion exchange membrane.

The channel-integrated ion-exchange membrane of the present invention can be produced by using a woven fabric or a nonwoven fabric as a support and, depending on the kind of the support, the cation-selective or anion-selective solution in the support or the thickness of the coating layer formed by the solution, Can be different in shape and depth. By laminating the thus formed channel-integrated ion exchange membrane on the surface of the electrode, it is possible to manufacture a bi-polar electrode which is excellent in adsorption efficiency and durability, has no warping phenomenon, can maintain a stable shape, and can be easily stacked. Furthermore, since a channel integral type desalination (CDI) electrode module having ion selectivity can be easily produced without the need for spacers, productivity can be improved through automation.

In the present invention, the woven or nonwoven fabric is a support for coating or impregnating an ion exchange solution, and may be a polyamide series, a polyethylene series, a polypropylene series, a cellulose series, an acrylic series polyacrylic series, polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyester series and natural fibers. However, the present invention is not limited thereto.

The thickness of the support is in the range of 10 to 10,000 占 퐉, preferably 50 to 1,000 占 퐉, but is not limited thereto and can be adjusted according to the module to be manufactured.

In the present invention, the ion exchange solution coated or impregnated on the support may be prepared by dissolving a polymer resin having a cation exchange group or an anion exchange group in an organic solvent.

The cation exchanger includes sulfonic acid group (-SO ₃ H), carboxyl group (-COOH), phosphonic group (-PO ₃ H ₂ ), phosphonic group (-HPO ₂ H), asonic group (-AsO ₃ H ₂ ) But is not limited to, at least one cation-exchange group selected from the group consisting of a serinonucleotide (-SeO ₃ H).

Anion exchangers include quaternary ammonium salts (-NH ₃ ), primary amines (-NH ₂ ), secondary amines (-NHR), tertiary amines (-NR ₂ ), quaternary phosphonium groups (-PR ₄ ) (-SR < ₃ >), but is not limited thereto.

The ion exchange solution can be prepared by dissolving a polymer resin having a cation or anion exchanger in an organic solvent, and is not limited as long as it is a polymer having a functional group capable of ion exchange. For example, a polymer ionomer having an ion exchanger and dissolved in an organic solvent to be present as a solution may be a polymer ionomer such as polystyrene, polysulfone, polyisocyanurate, polyamide, polyphenylene oxide, polyphenylene sulfide, polyester, polyimide, Any one or a mixture of two or more selected from the group consisting of polyether, polyethylene, polytetrafluoroethylene and polyglycidyl methacrylate can be used.

The organic solvent may be selected depending on the type of polymer having a cation or anion exchanger, and is not limited as long as it is a solvent capable of dissolving a polymeric ionomer. For example, any one or a mixture of two or more selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone acetone, chloroform, dichloromethane, trichlorethylene, ethanol, methanol, have.

The thickness of the coating layer in the channel-integrated ion exchange membrane formed by coating or impregnating the supporter with an ion exchange solution and drying it is 0.1 to 200 μm, preferably 5 to 30 μm, but it is not limited to this and can be controlled according to a module to be manufactured. However, when the thickness of the ion exchange membrane is 0.1 탆 or less, the resistance of the ion exchange membrane is low, but the selectivity is low, and the desorption efficiency may be low. When the thickness is 200 탆 or more, the selectivity is good. However, There is a need.

The flow-through integral ion exchange membrane has a moisture content of 5 to 70%, preferably 10 to 50%. If the moisture content is less than 5%, the desalination efficiency may be lowered due to the high membrane resistance. If the water content exceeds 70%, the desalination efficiency due to the channeling phenomenon in the water may be lowered.

The channel-integrated ion exchange membrane of the present invention can be attached to an electrode to produce a charge storage type desalination electrode having ion selectivity. The cation exchange membrane and the anion exchange membrane of the present invention may be attached to different surfaces of the electrode to produce bipolar electrodes, thereby making a stacked module free from warpage. Generally, when preparing a bipolar electrode according to the conventional method, the ion exchange solution of different polarity is coated on both sides of the bipolar electrode. Since the physical properties of the polymer used for preparing the ion exchange solution having different polarity are different, . Further, in the continuous manufacturing process, there are frequent breaks during production, and it is very difficult to manufacture the stacked module. However, the bipolar electrode of the present invention can solve such existing problems.

The ion exchange membrane of the present invention can be used for manufacturing a bi-polar electrode membrane having ion exchange membranes of different polarities, and also for ion exchange (ion exchange) You can attach a membrane or attach an ion exchange membrane with a different polarity.

Since the flow path is formed in the ion exchange membrane of the desalination electrode having the channel integrated ion exchange membrane of the present invention, a CDI (capacitive deionization) module can be assembled without using a separate spacer. The assembly type of the module is free of monopolar or biomolecules, and the ion exchange membrane can be suitably attached to the electrode according to the desired assembly form.

The channel-integrated ion exchange membrane of the present invention is produced by dissolving a polymer resin having a cation-exchange group or anion-exchange group in an organic solvent to prepare an ion-exchange solution, coating the ion- . The desalted bipolar electrode of the present invention can be produced with the thus prepared ion exchange membrane. More specifically, it is possible to prepare a cation exchange solution and an anion exchange solution by dissolving a polymer resin having a cation exchange group and an anion exchange group of the present invention in an organic solvent, a step of coating a cation exchange solution and an anion exchange solution on woven or non- Followed by drying to prepare an oil-in-line type cation exchange membrane and anion exchange membrane, and attaching the cation exchange membrane and the anion exchange membrane to different surfaces of the carbon electrode, respectively.

When the ion exchange solution is coated on a support, a support is placed on a release film that is not dissolved in a solvent, the ion exchange solution is coated on the support, evaporated and dried, and the release film is removed to produce a channel-integrated ion exchange membrane. The channel-integrated ion exchange membrane thus prepared is distinguished from a surface on which a coating layer on which ions are exchanged is formed based on a support and a surface on which a coating layer is not formed.

When preparing a desalting electrode, a surface of the ion exchange membrane on which no coating layer is formed is adhered to the electrode. Since the ion selective solution is not coated on the electrode, the adsorption site of the electrode due to the coating is not reduced, so that the adsorption and removal efficiency of the electrode can be enhanced. Since the support surface on which the coating layer is not formed adheres to the electrode, the durability of the electrode surface can also be improved. In addition, a warp phenomenon does not occur in the production of the desalting electrode, and the manufacture of the stacked module is also easy.

In the production method of the present invention, the content of the polymer having an ion exchange function, which is a solid content in the production of the cation or anion exchange solution, is 1 to 30% by weight, preferably 3 to 10% by weight. If the solid content is less than 1 wt%, the concentration of the cation or anion exchange solution is very low, so that the evaporation time of the solvent may be prolonged and the thickness of the anion exchange membrane may be thinned. If the solid content exceeds 30% by weight, the concentration of the anion exchange solution increases, which makes it difficult to coat, to control the thickness and to secure the passage, and thus to produce a channel-integrated ion exchange membrane.

In the manufacturing method of the present invention, when the ion exchange solution is coated, a woven or nonwoven fabric, which is the support of the ion exchange membrane, is coated on the release film, and the ion exchange membrane is sufficiently dried to produce an ion exchange membrane. At this time, since the evaporation amount of the solvent is determined according to the concentration of the coating ion exchange solution, the thickness of the ion exchange membrane and the depth of the flow path can be controlled. The release film on which the support is placed is preferably a polymer film having hydrophobic properties. It is preferable that no thermal deformation occurs during drying, and any polymer film that can be easily separated from the ion exchange membrane layer after formation of the ion exchange membrane can be used without limitation. For example, in the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), polyacrylate, polymethylmethacrylate (PMMA), ethylene vinyl acetate copolymer (EVA) and Teflon Any one selected can be used.

In the production process of the present invention, the coating can be coated by any one of casting, spraying, dip coating, knife coating, doctor blade and spin coating, and the coating method is not particularly limited.

After the production of the channel-integrated ion exchange membrane according to the present invention, a step of attaching an ion exchange membrane to the carbon electrode can be further performed to manufacture a charge storage type desalination electrode.

When the ion exchange membrane is attached to the carbon electrode, it is possible to use a porous nonionic adhesive or a pressure-sensitive adhesive which can be coated with an ion exchange solution of the same polarity as the ion exchange membrane or can pass both positive and negative ions. In this case, the ion exchange solution refers to the cation exchange solution and the anion exchange solution used for coating the support, and it is preferable to use a cation exchange solution to attach the cation exchange membrane to the carbon electrode and use anion exchange solution to attach the anion exchange membrane Do. Porous nonionic adhesives and pressure sensitive adhesives can generally be used without any particular restriction on adhesives or pressure sensitive adhesives capable of attaching ion exchange membranes to carbon electrodes. For example, adhesives such as hot melt (CoPA, CoPES, TPU, PE, PP, EVA, Fatty acid PA, Reactive Hotmelt) adhesives, water dispersion (natural rubber, vinyl acetate, latex, acrylic, EVA) A hot-melt adhesive which can use both an adhesive agent such as a solvent-based adhesive, a silicone-based adhesive agent, an epoxy-based adhesive agent and a bonding agent in which a synthetic resin or a rubber is dissolved can be used and easily fused by heat without a drying step desirable.

When the ion exchange membrane is attached to the carbon electrode, a press capable of heating can be used for pressing the smooth surface of the surface of the carbon electrode and the supporter of the channel-integrated ion exchange membrane on the side where the coating layer is not formed and attaching it to increase the adhesive force. There is no limitation as long as it is possible to form a coating, a spray, an electrospinning, and a porous web of a coating method of an adhesive and apply the coating to a carbon electrode. It is preferable that the adhesive is applied by pressing and heating at a melting temperature equal to or higher than the glass transition temperature (Tg) of the adhesive so that the smooth part where the coating layer of the ion exchange membrane is not formed is facing, Can be used without.

In the present invention, the carbon electrode to which the ion exchange membrane is attached includes a step of dissolving the polymer resin in an organic solvent or preparing a binder solution with an aqueous dispersion polymer solution, adding an electrode active material to the binder solution to prepare a slurry or kneading for calendering forming a carbon electrode by applying a slurry to a current collector or by calibrating a paste to form a carbon electrode by attaching a carbon sheet to the current collector, and pressing the carbon electrode to have a predetermined thickness . ≪ / RTI >

The polymer resin solution in the step of producing the polymeric binder solution in the carbon electrode manufacturing method means a polymer resin capable of mixing with an active material to produce an electrode. The polymer resin solution is not limited as long as it is dissolved in an organic solvent or in a state of an aqueous dispersion emulsion solution. . (PVDF), poly (vinylidene fluoride), poly (vinylidene fluoride), poly (vinylidene fluoride), poly (SBR), polytetrafluoroethylene (PTFE), polyurethane (PU), and the like can be used. The weight average molecular weight of the polymer resin is from 10,000 to 4,000,000, preferably from 100,000 to 1,500,000. When the polymer resin having such a range is used, the viscosity of the electrode slurry and the property of bonding the electrode active material are excellent, but are not limited thereto.

In the preparation of the polymeric binder solution of the carbon electrode, the organic solvent may be selected depending on the kind of the polymer resin. Examples of the organic solvent in which the polymer resin is dissolved include a solvent selected from the group consisting of dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidoneacetone, chloroform, dichloromethane, trichlorethylene, ethanol, methanol, Or a mixture of two or more thereof may be used, but is not limited thereto.

In the production of the polymeric binder solution in the carbon electrode manufacturing method, the content of the polymer used as a binder with respect to the solid carbon content is 1 to 30% by weight, preferably 3 to 10% by weight. If the solids content is less than 1% by weight or more than 30% by weight, the viscosity of the polymer solution may be too low or too high to produce an electrode slurry thereafter, or it may not be easy to prepare a dough to make a carbon sheet by calendering have.

The process of adding the electrode active material to the polymeric binder solution in the carbon electrode manufacturing method can further improve the specific surface area and storage capacity of the electrode by adding an electrode active material having a high specific surface area. Further, a conductive material may be further added to further improve the electrical conductivity of the electrode.

The electrode active material is an activated carbon material having a high specific surface area, and may be activated carbon powder, activated carbon fiber, carbon nanotube, carbon aerogels or a mixture thereof. It may be preferable to use the powder as a powder. As the metal oxide series material, RuO ₂ , Ni (OH) ₂ , MnO ₂ , PbO ₂ , TiO ₂ or a mixture thereof can be used.

The electrode active material can be used by adjusting the particle size or the content range according to the desired physical properties in the electrode module. The average particle size of the electrode active material may be 10 μm or less, preferably 10 nm to 10 μm, to increase the specific surface area and storage capacity of the electrode. The electrode active material may be used in an amount of 600 to 900 parts by weight based on 20 parts by weight of the ion exchange functional group-containing polymer material, thereby producing an electrode having good ion selectivity and high storage capacity.

The conductive material that can be added together with the electrode active material can be used without restriction as long as the material has low electrical resistance. For example, conductive carbon black such as acetylene black, Ketjen black, XCF carbon, SRF carbon and the like can be used. Conductive materials can also be used by controlling the particle size or the content range of the electrode module according to the desired physical properties. The average particle diameter of the conductive material is 1 占 퐉 or less, preferably 10 nm to 1 占 퐉, and the electrical conductivity of the electrode can be increased. It is preferable that the content of the conductive material is in the range of 1 to 10 parts by weight based on 100 parts by weight of the electrode active material to enhance the electric conductivity and the storage capacity of the electrode.

The electrode active material and the polymer binder solution are mixed to prepare a slurry or uniformly mixed to make a kneaded mass.

When the electrode active material and the polymeric binder solution are homogeneously mixed and kneaded to make a kneaded mass, the respective components may be sequentially metered and kneaded using a pressure dispersion kneader. The kneading temperature and time may be determined according to the kind of the binder. The raw materials such as the electrode active material and the binder are first kneaded dry, then the binder solution is kneaded, and the binder mixture is impregnated with a liquid binder. At this time, the temperature of the kneader is raised to the kneading temperature. When the temperature is elevated to a temperature not lower than the softening point of the binder, the viscosity of the binder becomes too high and mixing becomes difficult. If the heating temperature is too high, the kneading mass for the galvanizing process is not well formed by the decomposition of the binder, and if it is too low, the kneading time becomes longer. The kneader is preferably a type having a stirring blade or a roll kneader, but is not limited thereto as long as it can be kneaded uniformly. The amount of the feedstock to be added to the kneading machine is usually 10 vol% or more, preferably 15 to 50 vol%, relative to the volume of the mixer. The kneading time is from 5 minutes to 5 hours, preferably from 30 to 120 minutes, until a time when a large viscosity change occurs. The obtained kneaded product may be used for calendering as it is, and it is preferable to provide the kneaded product in a predetermined size so as to be easily handled. The molding method is not particularly limited as long as the shape can be maintained.

When the slurry is applied to the current collector in the method of manufacturing the carbon electrode, it is preferable to use a current collector having excellent conductivity so that the electric field can be uniformly distributed on the electrode surface when current is supplied to the electrode manufactured through the power supply device Do. For example, a sheet, a thin film, or a plain-mesh network form including aluminum, nickel, copper, titanium, iron, stainless steel, graphite or a mixture thereof may be used. The coating method is not particularly limited and it can be applied by spraying, dip coating, knife casting, doctor blade, spin coating or the like. When the coating thickness is in the range of 50 to 300 μm, it is preferable to increase the desalination efficiency while reducing the electrical resistance of the electrode Do. If necessary, the slurry applying method can be repeated one or more times to produce an electrode having a desired specific thickness.

When calendaring kneaded kneaded material among the carbon electrode manufacturing methods, the roll surface temperature of the calender is determined according to the kind of the binder. The preferred temperature is below the melting temperature of the binder above the glass transition temperature. When the temperature of the calender roll surface is higher than the melting temperature, softening of the resin becomes active, the sheet on the roll surface becomes sticky, the tension is weakened during the roll production, and the sheet is cut off. . ≪ / RTI > On the other hand, if the roll surface temperature of the caliper is lower than the glass transition temperature, the resin is not softened and the surface of the sheet becomes uneven, and it may be difficult to produce a sheet having a thickness of 200 탆 or less.

The surface temperature of the roll press when the electrode active material sheet is pressed onto the current collector by a roll press may be different depending on the type of the binder. The glass transition temperature is preferably higher than the glass transition temperature of the binder and lower than the melting temperature, and more preferably 20 ° C higher than the glass transition temperature.

When the carbon electrode is pressed to have a certain thickness in the carbon electrode manufacturing method, it may further include a step of pressing if necessary for the flatness of the electrode surface. When compressing, it is preferable that the compressibility is compressed to about 0 to 30% of the thickness of the produced carbon electrode. When the compression ratio exceeds 30%, the density of the electrode surface and the electrode active material is improved, but it becomes hard and brittle, and therefore, it may be difficult to handle. More preferably, the compressibility is 1 to 25%, the surface of the electrode is uniform, and the density of the electrode active material can be made sufficiently, and the reproducibility of the electrode characteristics is excellent.

According to one embodiment of the present invention, the condensate desalting electrode of the present invention can be produced according to a specific embodiment as follows. (a) dissolving a polymer resin having a cation exchanger or anion exchanger in an organic solvent to prepare a cation or anion exchange solution, (b) impregnating the support with a cation and an anion exchange solution, and evaporating and drying to obtain an oil- (C) dissolving the polymer resin in an organic solvent or preparing a binder solution with an aqueous dispersion polymer solution, (d) adding an electrode active material to the binder solution to prepare a slurry or calendering (E) applying a slurry to a current collector to form a carbon electrode or calendering the dough to attach a carbon sheet to the current collector to form a carbon electrode, (f) (G) a step of pressing the carbon monoxide type ion exchange membrane of step (b) above and the carbon electrode paste of step (f) It is having an on-selectivity can be produced by steps of creating a capacitive electrode desalting. A capacitive deionization (CDI) electrode module can be manufactured using the thus-prepared capacitive desalination electrode.

Hereinafter, a more specific embodiment of the present invention will be described. The following examples are intended to illustrate the present invention and are not to be construed as limiting thereof.

Ion exchange membrane  How to measure characteristics

1. Ion exchange capacity

To determine the ion exchange capacity, ion exchange capacity was measured by acid base titration using 1 N NaOH aqueous solution and 1 N HCl aqueous solution by the following equation. In the case of the anion exchange membrane, the order of NaOH and HCl was changed.

IEC: Ion exchange capacity (meq / g)

IEC (meq / g) = (VHCl x NHCl) -5 (VNaOH x NNaOH) / Weight of sample (g)

VHCl: volume of HCl (ml), VNaOH: volume of NaOH (ml)

Concentration of NHCl: HCl (N), concentration of NNaOH: concentration of NaOH (N)

2. Membrane Resistance

A 2-compartment cell was used to measure the electrical resistance of the ion exchange resin membrane. The membrane was cut into a certain size (5 × 5 cm) and inserted into an electrochemical cell. The electrical resistance was measured in a 0.1 M NaCl solution (R1), and the membrane was removed. The resistance of the electrolyte solution was measured (R2) ER) was obtained.

Film resistance (Ω · m ² ) = (R 1 - R 2) · A

R: resistance (Ω), A: area (m ² )

3. Moisture content

The ion-exchange resin membrane was cut to a certain size (5 × 5 cm), immersed in a 0.1 M NaCl solution, swollen sufficiently, and free water removed from the surface of the ion exchange membrane was weighed using an MX-50 moisture analyzer And water content (WC) was calculated by the following equation.

WC (%) = (Wwet - Wdry) / Wdry x 100

WC: Water content (%),

Wwet: the film weight (g) in the initial wet state,

Wdry: weight after drying (g)

4. Method for measuring cross-section of ion-exchange membrane

The thickness of the ion exchange membrane and the depth of the flow path were measured by a scanning electron microscope (SEM).

[ Example  One]

Channel type cation selective electrode was prepared.

Example  1-1. Preparation of cation exchange solution

10 g of PPO (polyphenylene oxide) and 90 g of chloroform were dissolved in a round bottomed flask, and 2.5 g of chlorosulfonic acid (CSA) was added thereto, followed by reaction at 60 ° C for 5 hours. The reaction product was precipitated in ice water, washed and dried in a vacuum oven at 80 ° C., and then dissolved in dimethylacetamide (DMAc) and reprecipitated in methanol. The reaction was repeated three times to remove residual sulfuric acid and dried to give sulfonated PPO PPO; SPPO) were prepared. The dried sulfonated PPO was put into DMAc to prepare a cation exchange solution having a solid content of 10% by weight.

Example  1-2. Euro integrated type Cation exchange membrane  Produce

The cation exchange membranes were prepared by fixing four corners of a woven fabric (120 mesh, polyamide) support having a thickness of 100 mu m on a PET film (SK chemical) having a thickness of 100 mu m and attaching the cation exchange solution prepared in Example 1-1 to a doctor And then dried at 50 ° C. for 5 hours at 80 ° C. for 3 hours and then at 50 ° C. for 1 hour at room temperature and then dried at 50 ° C. for 10 hours to completely dry the PET film. To prepare a cation exchange membrane having a channel structure.

Example  1-3. Carbon electrode  Produce

0.4 g of polyvinylidene diprolide (PVdF, Aldrich, Mw = 1,800, 000) and 40 g of dimethylacetamide were mixed to prepare a polymer solution. To the polymer solution was added activated carbon powder (P-60, Surface area = 1600 m 2 / g) were mixed to prepare an electrode slurry. The prepared slurry was coated on a conductive graphite sheet (thickness: 130 탆, Orient Carbon Co., Cat. No. F02511C) with a doctor blade so that the coating layer had a thickness of 200 탆 and then dried at 70 캜 And dried for 30 minutes to prepare a carbon electrode.

Example  1-4. Euro integrated type  Preparation of cation selective electrode

A hot-melt adhesive web (10 g / m 2, Chemtec Korea) was placed between the smooth portion of the channel-integrated cation exchange membrane prepared in Example 1-2 and the carbon electrode prepared in Example 1-3, and pressed at 0.2 kgf for 1 minute at 120 DEG C in a hot pressor to prepare a channel integrated anode having cationic selectivity.

[ Example  2]

Channel integrated anion selective electrode was prepared.

Example  2-1. Preparation of anion exchange solution

12.0 g of polyphenylene oxide (PPO) and 88.0 g of chlorobenzene were dissolved in a round-bottomed four-necked flask, and 4.4 g of CMME (chloromethyl methyl ether) was added. The mixture was reacted at 130 ° C. for 3 hours, cooled to room temperature, , And the compound was dissolved in NMP (1-Methyl-2-pyrrolidinone), reacted with 1.5 mol of TMA (trimethyl ammonium chloride) at room temperature, precipitated with methanol, and vacuum-dried at room temperature. The synthesized anion exchange resin was put into NMP to prepare an anion exchange solution having a solid content of 10% by weight.

Example  2-2. Euro integrated type Anion exchange membrane  Produce

The anion exchange membranes were prepared by fixing four corners of a woven fabric (120 mesh, polyamide) support having a thickness of 100 mu m on a 100 mu m thick PET film (SK Chemical), placing the anion exchange solution prepared in Example 2-1 at 200 mu m And then dried at 50 ° C. for 5 hours at 80 ° C. for 3 hours and then at 50 ° C. for 1 hour at room temperature and then dried at 50 ° C. for 10 hours to completely dry the PET film. Thereby preparing an oil-in-line type anion exchange membrane.

Example  2-3. Carbon electrode  Produce

0.4 g of polyvinylidene diprolide (PVdF, Aldrich, Mw = 1,800, 000) and 40 g of dimethylacetamide were mixed to prepare a polymer solution. To the polymer solution was added activated carbon powder (P-60, Surface area = 1600 m 2 / g) were mixed to prepare an electrode slurry. The prepared slurry was coated on a conductive graphite sheet (thickness: 130 탆, Orient Carbon Co., Cat. No. F02511C) with a doctor blade so that the coating layer had a thickness of 200 탆 and then dried at 70 캜 And dried for 30 minutes to prepare a carbon electrode.

Example  2-4. Euro integrated type  Manufacture of anion selective electrode

A hot-melt adhesive web (10 g / m ² , manufactured by KEMITEK CORPORATION) was placed between the smooth portion of the channel-integrated anion exchange membrane prepared in Example 2-2 and the carbon electrode prepared in Example 2-3, And pressed at 0.2 kgf for 1 minute at 120 DEG C in a hot pressor to prepare an anode integrated with flow path having anion selectivity.

[ Comparative Example  One]

A coated electrode having a carbon electrode coated with a cation exchange solution was prepared in Comparative Example 1.

The cation exchange solution prepared in Example 1-1 was coated with a doctor blade so as to form a coating layer of about 20 탆 on the carbon electrode prepared in Example 1-3 and dried at 80 캜 for 1 hour to form a negative electrode having a cation- .

[ Comparative Example  2]

A coated electrode having a carbon electrode coated with an anion exchange solution was prepared in Comparative Example 2.

The cation exchange solution prepared in Example 2-1 was coated on the carbon electrode prepared in Example 2-3 with a doctor blade so as to form a coating layer having a thickness of about 20 탆 and dried at 80 캜 for 1 hour to form a positive electrode having an anion- .

[ Comparative Example  3]

A commercial cation exchange membrane electrode was prepared in Comparative Example 3.

A hot-melt adhesive web (10 g / m 2, Chemtec Korea) was placed between a commercially available cation exchange membrane (CMX, Astom) and the carbon electrode prepared in Example 1-3 and hot- At 120 [deg.] C for 1 minute at 0.2 kgf to prepare a channel integrated anode having cationic selectivity.

[ Comparative Example  4]

A commercial anion exchange membrane electrode was prepared as Comparative Example 4.

A hot-melt adhesive web (10 g / m 2, Chemtec Korea) was placed between the commercial anion exchange membrane (AMX, Astom) and the carbon electrode prepared in Example 2-3, At 120 DEG C for 1 minute at 0.2 kgf to prepare an integrated positive electrode having anion selectivity.

[ Example  3]

(FIGS. 1 to 3) and characteristics (Table 1) of the ion exchange membranes prepared in Examples 1 and 2 and Comparative Examples 1 to 4 were compared. FIG. 1 shows the channel-integrated ion exchange membrane prepared in Example 1-2, FIG. 2 shows the channel-integrated desalination electrode prepared in Example 2-2, and FIG. A scanning electron microscope photograph is shown.

[Table 1]

[ Example  4]

A desalting electrode cell was prepared from the electrodes prepared in Examples 1 and 2 and Comparative Examples 1 to 4, and the desalting characteristics were evaluated.

A channel-integrated desalination electrode cell was prepared using the electrode prepared in Example 1 as a negative electrode and the electrode prepared in Example 2 as a positive electrode. The electrode prepared in Comparative Example 1 was used as a cathode and the electrode prepared in Comparative Example 2 was used as an anode to prepare a desalting electrode cell of a coated electrode. The membrane prepared in Comparative Example 3 was used as a negative electrode and the electrode prepared in Comparative Example 4 was used as an anode to prepare a membrane desalting electrode cell. After cutting the Euro-integrated electrode or coated electrode 10 x 10 cm ² , the flow-channel type was mounted between the anode and the cathode with no spacer, and the coating electrode was designed to prevent the two electrodes from contacting each other between the anode and the cathode, And a spacer (120 mesh, polyamide) having a thickness of 100 mu m was mounted. A 1 cm hole was drilled in the center of the electrode to allow the solution to pass through the spacer at the slope of the electrode and to escape to the center. A 15 x 15 cm ² acrylic plate was placed on the outside of the anode and the cathode and fixed with a bolt to form a single cell for depolarization.

A 250 mg / L NaCl solution was supplied at a rate of 30 mL / min while the electrode potential was constantly applied at 1.5 V. The total dissolved solid (TDS) of the effluent was measured and the desalting efficiency was analyzed. After the adsorption for 3 minutes, the electrode potential was operated for 1 minute by short circuit and 50 seconds by reversing the reverse potential for 10 seconds. The cell desalting test was conducted and the results are shown in FIG. 4 as the TDS change curve and the salt removal rate (%).

It was confirmed that the coating type electrode had the highest desorption efficiency of 85% and the integral type electrode had the removal efficiency of 84% of the coated type electrode. When the commercial type ion exchange membrane was used, it showed the lowest removal efficiency of 81% I could. In this way, it is possible to assemble the cell without using the spacer when using the integral electrode, and it is confirmed that the cell has a high removal efficiency similar to that of the coated electrode. Also, it is difficult to stack thin and lightweight spacers, so that the assembling process of the module stack is complicated. As a result, it is possible to assemble the module stack without using the spacer, which is very simple. Therefore, through the production of the integrated ion exchange membrane, it was possible to produce a channel integrated type desalination electrode having ion selectivity, and it is also confirmed that the desalination efficiency of these electrodes is higher than that of the case of using a commercial ion exchange membrane.

[ Example  5]

The ion exchange membranes prepared in Examples 1-2 and 2-2 were attached to both surfaces of the carbon electrode prepared in Examples 1-3 or 1-4, and ion exchange membranes of different polarities were attached to both surfaces of the electrode, . The attachment method was according to Examples 1-4 or 2-4. The manufactured bipolar electrode is suitable for making an industrial high-capacity module (Fig. 5) since it is a bipolar electrode having a polarity different on both sides, since it can perform a roll-to-roll continuous production process without warping.

The ion exchange solution prepared in Examples 1-1 and 2-1 was coated on both surfaces of the carbon electrode prepared in Examples 1-3 or 1-4 to form electrodes of the same polarity and electrodes of the same polarity . The coating method was coated according to Comparative Example 1 or 2. As a result, in the case of a bipolar electrode prepared by coating with a different ion exchange solution on both sides of the carbon electrode, the characteristics of the ion exchange solution were different, and the electrode was warped to one side. This phenomenon occurred in the roll- The intermediate portion is broken due to the bending phenomenon of the electrode in the process (FIG. 6). When the same ion exchange solution is coated on both sides of the carbon electrode, it is possible to produce the roll-to-roll without bending the electrode. However, in order to make an industrial large-capacity module, it is necessary to manufacture a double electrode type electrode (FIG.

Claims (8)

A monolithic cation exchange membrane prepared by coating a cation exchange solution prepared by dissolving a polymer resin having a cation exchange group in an organic solvent on a woven or nonwoven fabric followed by drying;
An anion exchange membrane prepared by coating an anion exchange solution prepared by dissolving a polymer resin having an anion exchange group in an organic solvent on a woven fabric or a nonwoven fabric followed by drying;
And the cation exchange membrane and the anion exchange membrane are attached to different surfaces of the electrode, respectively.
The method according to claim 1,
The woven or nonwoven fabric may be a polyamide series, a polyethylene series, a polypropylene series, a cellulose series, a polyacryl series, a polyvinyl chloride (PVC), a polyvinyl Wherein the electrode is formed of a polymer selected from the group consisting of alcohol (PVA), polyester series, and natural fibers.
The method according to claim 1,
The cation exchanger includes a sulfonic acid group (-SO ₃ H), a carboxyl group (-COOH), a phosphonic group (-PO ₃ H ₂ ), a phosphonic group (-HPO ₂ H), an acidic group (-AsO ₃ H ₂ ) And at least one cation-exchange group selected from the group consisting of a celinonilic group (-SeO ₃ H).
The method according to claim 1,
The anion exchanger is a quaternary ammonium (-NH _3), 1 primary amine (-NH _{2), 2} amine (-NHR), 3 tertiary amine (-NR _2), quaternary phosphonium umgi (-PR ₄₎ and And a tertiary sulfonium group (-SR < ₃ >).
A capacitive deionization (CDI) electrode module comprising at least one desalting electrode according to any one of claims 1 to 5.
Dissolving a polymer resin having a cation exchanger and an anion exchanger in an organic solvent to prepare a cation exchange solution and an anion exchange solution;
Preparing a cation exchange membrane and an anion exchange membrane by coating a cation exchange solution and an anion exchange solution on a woven or nonwoven fabric of a support and then drying; And
Attaching the cation exchange membrane and the anion exchange membrane to different surfaces of the carbon electrode, respectively;
Wherein the electrolytic dehydrogenated bipolar electrode is formed of a mixture of water and an organic solvent.
The method according to claim 6,
Wherein the desalted bipolar electrode has a solid content of 1 to 30 wt% when the ion exchange solution is prepared.
8. The method of claim 7,
Wherein the thickness of the coating layer formed by coating the ion exchange solution is 0.1 to 200 mu m.

Images