KR101254653B1 - Method for preparing carbon electrode coated an anion exchanging polymer - Google Patents

Abstract

The present invention relates to a method for producing a carbon electrode coated with an anion exchange polymer and an electroadsorption desalination method, which produces a polymer coated on a carbon electrode and used as a charge barrier, and a carbon electrode coated with the polymer solution. The present invention relates to the application of capacitive deionization (CDI) method. The produced polymer contains quaternary ammonium functional groups, which plays an excellent role as a charge wall and contributes to the improvement of the electrosorption desalination performance. Electrodesorption desalination of the carbon electrode coated with the polymer is effective in producing pure water by softening soft water or purifying water by removing ions dissolved in water.

Description

Method for preparing carbon electrode coated an anion exchanging polymer

With the improvement of quality of life and the development of industrialization, the consumption of water treated water is increasing, and the quality of polluted water affected by the environment is required. Water softeners are used to convert hard water into sweet water by removing various impurities such as hardness components (calcium and magnesium) and water dissolved metal ions (iron, lead, aluminum, manganese, chromium, mercury, cadmium, etc.) in water. have. Conventional water purifiers and water softeners use ion exchange resins, adsorbents or separators, and electrodialysis. The electrosorption desorption method (capacitive deionization, hereinafter abbreviated as "CDI") of the present invention is a cation and anion dissolved in water. It is a technology to electrically remove / desorption by removing and adsorbing to the other electrode, it can be used for softening water of high hardness and manufacturing pure water for industrial use, and also for water purifier used for drinking water. In addition, pollutants such as nitrate nitrogen and fluoride ions are present in groundwater depending on agricultural and fishing areas. These pollutants are known to be harmful to the human body. To be used for drinking water and living water, the pollutants must be removed below the standards of the relevant authorities. In this case, CDI technology is used to electrically adsorb and desorb the carbon electrode by applying a low potential. It is possible to remove the ions in the water.

This CDI method uses a carbon electrode to apply a potential of 1 to 2 V to remove the ionic material by adsorbing the ionic material in the water by the opposite electrode. Since the electrode is easily regenerated and regenerated, there is no fear of secondary contamination of waste liquid generation, as in the case of using ion exchange resin, and it is a new water treatment technology that consumes less energy than other ion removal technologies. It has the advantage of easy maintenance and is promising as next generation dissolved ion removal technology.

Conventional ion exchange resins, adsorption, electrodialysis, reverse osmosis, and evaporation are commonly used to remove ionic substances dissolved in water. However, the ion exchange resin method has a disadvantage in that waste liquid is generated using acid, base or sodium chloride by periodic regeneration of the resin, and the reverse osmosis method requires a high pressure higher than the osmotic pressure. On the other hand, the evaporation method also requires a lot of operating costs due to high energy consumption, which is not suitable for small water softening or water treatment.

CDI technology, a new dissolved ion removal technology, manufactured carbon electrodes made of porous activated carbon by the researchers of the University of Oklahoma (DD Caudle et al, Electrochemical demineralization of water with carbon electrodes, Research Report, Oklahoma University Research Institute, 1966) in the 1960s. It started with desalination studies. Later, in the 1990s, carbon aerogel electrodes at the Lawrence Livermore National Laboratory (LLNL) National Laboratory (JC Farmer et al, J. Electrochem. Soc., 143 (1) (1996) 159-169, US Patent 5,425,858 (1995)). As a result, advanced researches such as developing a CDI process have been conducted, and researches to improve capacitance of forming an electric double layer by increasing the specific surface area of a porous carbon electrode have been made.

Much of the CDI research focuses on carbon electrode efficiency by studying carbon electrode specific surface area and pore size formation for effective electrical double layer formation. Republic of Korea Patent Publication No. 10-2005-0075811 (Invention name: carbon-porous support composite electrode and a method for manufacturing the same) Electrodesorption desalination (CDI The technique used as an electrode for apparatus is described. Efforts have been made to improve CDI performance in various ways, such as by increasing the specific surface area of porous carbon electrodes, or in the form of composite electrodes in which other materials with large capacitances have been added. There was a limit to improving CDI performance.

However, the MCDI (membrane capacitive deionization) method using an ion exchange membrane on the surface of the carbon electrode of the CDI process was developed to improve the efficiency of removing ionic substances in water. When the ion exchange membrane is used together with the carbon electrode as a charge barrier, the ion adsorption and desorption of the ions can be facilitated, thereby contributing to the improvement of the total dissolved solids (TDS) removal efficiency. Currently, commercial ion exchange membranes used in electrodialysis processes are applied to MCDI process, but they are not only used for each other but also are too expensive. Using them together has many difficulties in increasing TDS removal efficiency and lowering manufacturing costs. In addition, the MCDI method is a form in which a carbon electrode and an ion exchange membrane are simply attached and connected to each other, and thus an interface resistance is generated between the carbon electrode and the ion exchange membrane, thereby limiting the improvement of the CDI efficiency.

One embodiment of the present invention is to provide a method for producing a carbon electrode coated with an anion exchange polymer using a separate ion exchange membrane or does not need to perform a separate process for producing an ion exchange membrane.

In one embodiment of the present invention to provide a method for producing a carbon electrode coated with an anion exchange polymer that can improve the CDI performance by reducing the interface resistance between the electrode and the polymer (ion exchange membrane) as the charge wall.

In one embodiment of the present invention to provide a method for producing a carbon electrode coated with an anion-exchangeable polymer that can thin the thickness of the polymer layer.

In one embodiment of the present invention, a polymer is obtained by polymerizing at least one monomer selected from an acrylate monomer or a styrene monomer and a vinylbenzyl chloride monomer; Obtained polymer and trialkylamine Reacting to obtain a polymer having an anion exchange group; And it provides a method for producing a carbon electrode coated with an anion exchange polymer comprising the step of coating a polymer having an anion exchanger on the surface of the carbon electrode.

In the method for producing a carbon electrode coated with an anion exchange polymer according to an embodiment of the present invention, the acrylate monomers are C ₁ ~ C ₁₂ alkyl methacrylate, 2-ethoxyethyl methacrylate, 2-part Methoxyethyl methacrylate, ethylene glycol methyl ester acrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, 2- (methylthio) ethyl methacrylate, hexafluoroisopropyl acrylate, trifluor At least one selected from roethyl methacrylate, pentafluoropropyl methacrylate, heptafluorobutyl methacrylate, octafluoropentyl methacrylate, tetrafluoropropyl methacrylate and hexafluorobutyl methacrylate. Can be used.

In the method for producing a carbon electrode coated with an anion exchange polymer according to an embodiment of the present invention, the styrene monomers are styrene, α-methylstyrene, methyl styrene, bromostyrene, chlorostyrene, nitrostyrene, trifluoromethyl At least one of styrene and chloroα-methylstyrene can be selected and used.

In the method for producing a carbon electrode coated with an anion exchange polymer according to an embodiment of the present invention, a crosslinking agent is used in the step of obtaining a polymer, and the crosslinking agent is divinylbenzene, ethylene glycol di (meth) acrylate, butanediol di ( One or more of metha) acrylate and hexanediol di (meth) acrylate can be selected and used.

In the method for producing a carbon electrode coated with an anion exchange polymer according to an embodiment of the present invention, trialkylamine is trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine and tri One or more types can be selected and used out of octylamine.

In the method for producing a carbon electrode coated with an anion exchange polymer according to an embodiment of the present invention, vinylbenzyl chloride in the step of polymerizing the polymer may be used to 10 to 50% by weight of the total monomer content.

In the carbon electrode manufacturing method coated with an anion exchange polymer according to an embodiment of the present invention, in the step of preparing a polymer having an anion exchange group, trialkylamine can be used within 10% by weight relative to the polymer weight, trialkylamine The organic solvent may be diluted to a concentration of 5% by weight or less.

In the method for producing a carbon electrode coated with an anion exchange polymer according to an embodiment of the present invention, the anion exchange group may be a quaternary ammonium functional group.

In the carbon electrode manufacturing method coated with an anion exchange polymer according to an embodiment of the present invention, after coating the polymer having an anion exchange group on the surface of the carbon electrode, it may include the step of drying at 70 to 80 ℃. .

In the carbon electrode manufacturing method coated with an anion exchange polymer according to an embodiment of the present invention, the polymerization in the step of obtaining a polymer may be a bulk polymerization or a solution polymerization.

In another embodiment of the present invention is an anion exchange polymer comprising a side chain consisting of a benzyl group containing a quaternary ammonium functional group in the acrylate-based polymer backbone and has an anion exchange polymer layer having a thickness of several to tens of micrometers It provides a carbon electrode.

Another embodiment of the present invention provides an electrochemical cell including a carbon electrode having an anion exchange polymer layer according to the embodiments.

According to the present invention, by directly coating the surface of the carbon electrode with an ion-exchangeable polymer material which is a charge wall in manufacturing the carbon electrode for CDI water treatment, the interface resistance that may occur between the charge wall and the electrode can be reduced, thereby contributing to the improvement of the CDI performance. In addition, it is possible to reduce the electrode manufacturing cost as well as increase the water treatment efficiency, and the polymer having a quaternary ammonium functional group has an anion exchange function, and the integral carbon electrode coated with this functional polymer in the CDI technology process is a commercial ion. There is no need to use an exchange membrane or to prepare a separate ion exchange membrane, and the carbon electrode formed of a thin polymer layer can significantly reduce the thickness of the charge wall used in place of the ion exchange membrane. Up to 1/10 of commercial ion exchange membranes are possible.

1 is a process chart of a method for producing a carbon electrode coated with an anion exchange polymer according to an embodiment of the present invention.
Figure 2 is an NMR analysis of the methyl methacrylate-styrene-vinylbenzylchloride copolymer (Poly (MMA-Styrene-VBC)) obtained in accordance with an embodiment of the present invention.

This invention will be described in more detail.

In one embodiment of the present invention, a method of fabricating an integrated carbon electrode in which the ion exchange polymer is coated directly on the surface of the carbon electrode in the final step of the carbon electrode production without using a commercial ion exchange membrane as a charge wall in manufacturing the carbon electrode for CDI. To provide.

Specifically, the method for producing a carbon electrode according to an embodiment of the present invention comprises the steps of: polymerizing at least one monomer selected from an acrylate monomer or a styrene monomer and a vinyl benzyl chloride monomer to obtain a polymer; Obtained polymer and trialkylamine Reacting to obtain a polymer having an anion exchange group; And coating a polymer having an anion exchange group on the surface of the carbon electrode.

Hereinafter, each step will be described in detail. In FIG. 1, acrylate-based monomers, styrene-based monomers, and vinylbenzyl chloride are applied as monomers, copolymerized by applying a crosslinking agent to prepare a polymer, and the polymer reacts with trialkylamine. The process of preparing a coated carbon electrode by oxidizing and then preparing a coating solution from the obtained polymer and coating on the surface of the carbon electrode is shown.

(1) Polymer production by polymerization method

The polymer used in the preparation of the anion exchange coating solution of the present invention may be a combination of an acrylate monomer or a styrene monomer, and a vinylbenzyl chloride monomer, and may be polymerized using a crosslinking agent.

One example of a method of polymerization using such monomer combinations is block polymerization, in which a monomer and an initiator are reacted without using a solvent; The solution polymerization method etc. which mix and react a monomer and an initiator on a predetermined amount of solvent can be applied. In both polymerization reactions, radical polymerization may be carried out using an initiator such as a peroxide or an azo compound.

Acrylate monomers that can be used are C ₁ ~ C ₁₂ (CH ₂ = C (CH ₃ or H) COOC _n H _2n-1 ), alkyl methacrylate, 2-ethoxyethyl methacrylate (CH ₂ = C (CH ₃ orH) COO (CH ₂ ) ₂ OC ₂ H ₅ ), 2-butoxyethyl Methacrylate (CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ O (CH ₂ ) ₃ CH ₃ ), ethylene glycol methyl ester acrylate (CH ₂ = CHCOO (CH ₂ ) ₂ OCH ₃ ), cyclohexyl Methacrylate (CH ₂ = C (CH ₃ ) COOC ₆ H ₁₁ ), benzyl methacrylate (CH ₂ = C (CH ₃ ) COOCH ₂ C ₆ H ₅ ), phenyl methacrylate (CH ₂ = C (CH ₃ ) COOC ₆ H ₅ ), 2- (methylthio) ethyl methacrylate (CH ₂ = C (CH ₃ ) COO (CH ₂ ) ₂ SCH ₃ ), hexafluoroisopropyl acrylate (CH ₂ = CHCOOCH ( CF ₃ ) ₂ ), trifluoroethyl methacrylate (CH ₂ = C (CH ₃ ) COOCH ₂ CF ₃ ), pentafluoropropyl methacrylate (CH ₂ = C (CH ₃ ) COOCH ₂ (CF ₃ ) F ₂ ), heptafluorobutyl methacrylate (CH ₂ = C (CH ₃ ) COOCH ₂ CF ₂ CF ₂ CF ₃ ), octafluoropentyl methacrylate (CH ₂ = C (CH ₃ ) COOCH ₂ ( CF ₂ ) ₇ CHF ₂ ), tetrafluoropropyl methacrylate (CH ₂ = C (CH ₃ ) COOCH ₂ CF ₂ CHF ₂ ), hexafluorobutyl methacrylate (CH ₂ = C (CH ₃ ) COOCH ₂ CF ₂ CHF (CF ₃₎₎ and the like, can be selected to one or more of the foregoing.

Styrene monomers include styrene (C ₆ H ₅ CH = CH ₂ ), α-methylstyrene (C ₆ H ₅ C (CH ₃ ) = CH ₂ ), methyl styrene (CH ₃ C ₆ H ₄ CH = CH ₂ ) , Bromostyrene (BrC ₆ H ₄ CH = CH ₂ ), chlorostyrene (ClC ₆ H ₄ CH = CH ₂ ), nitrostyrene (NO ₂ C ₆ H ₄ CH = CH ₂ ), trifluoromethylstyrene (CF ₃ C ₆ H ₄ CH = CH ₂ ), chloroα-methylstyrene (ClC ₆ H ₄ C (CH ₃ ) = CH ₂ ), and the like, and one or more of these may be selected and used.

As the crosslinking agent, divinylbenzene (CH _{2 =} CHC ₆ H ₄ CH = CH ₂ ), ethylene glycol di (meth) acrylate (CH ₂ = C (HorCH ₃ ) COO (CH ₂ ) ₂ COOC (HorCH ₃ ) = CH ₂ ), butanediol di (meth) acrylate (C (H or CH 3) = CH ₂ COO (CH ₂ ) ₄ COOC (HorCH ₃ ) = CH ₂ ), hexanediol di (meth) acrylate (C (H or CH) ₃ ) = CH ₂ COO (CH ₂ ) ₆ COOC (HorCH ₃ ) CH ₂ ), and the like. One or more of these may be selected and used.

In a specific embodiment of the present invention, methyl methacrylate is selected from the acrylate monomers, styrene is selected from the styrene monomers as a monomer, and the crosslinking agent is divinylbenzene, and benzoyl peroxide is used as an initiator.

The monomer mixture for the polymerization reaction can be selected from 2 to 4 types, for example, a combination of methyl methacrylate (MMA) and vinyl benzyl chloride (VBC) or a combination of styrene and vinyl benzyl chloride. Can be. And methylmethacrylate, styrene and vinylbenzylchloride may be a combination of three monomer mixtures.

The proportion of vinylbenzylchloride used for amination to impart anion exchange functionality in the monomer mixture is preferably 50% by weight or less when mixed with other monomers in terms of avoiding excessive chlorinated functional groups which cause excessive swelling in water. can do. Excess chlorinated functional groups, i.e., excess vinylbenzene chloride, in the polymer may be involved in the amination reaction, causing excessive swelling in water.

As the crosslinking agent, divinylbenzene is added in an amount of 0.1% by weight or less of the sum of these monomers, and when the crosslinking agent exceeds 0.1% by weight, the crosslinking is too much, and the polymerized polymer may not be dissolved in an organic solvent such as dimethylacetamide. The initiator may polymerize within a range of 1% by weight or less of the sum of the monomers, and in order to maintain an appropriate molecular weight, it may be preferable to use 0.2 to 0.5% by weight of the sum of the monomers. The monomers and the initiator are put in a round flask to maintain a nitrogen atmosphere, and the temperature is maintained at 60 to 100 ° C, preferably 70 to 80 ° C, and stirred for 5 to 8 hours to form an oligomer. After keeping constant at a temperature of 70 to 80 ° C. for 5 to 12 hours, the reaction is further heated at 90 to 100 ° C. for 2 to 5 hours. The obtained polymer is dissolved in dimethylacetamide or tetrahydrofuran, precipitated in methanol and filtered. The filtered polymer copolymer is vacuum dried for 12 to 24 hours in an oven at 50 to 60 ℃.

In another embodiment, solution polymerization is performed, and in one specific embodiment, solution polymerization uses methylmethacrylate, styrene, vinylbenzyl chloride and divinylbenzene as a crosslinking agent in a tetrahydrofuran solvent. As in the bulk polymerization, two to four kinds of monomer mixtures can be used. As an initiator, 1,2'azobis (2-methylpropionitrile, AIBN) is used. The solid content percentage of the reactants is 30% by weight or less and nitrogen in the reaction. The inert atmosphere is maintained using, etc. After nitrogen purge, the polymerization is carried out for 8 to 12 hours at a temperature of 70 to 80 ° C. The obtained polymer solution is precipitated in methanol and the obtained polymer is 12 to 12 in a 50 to 60 ° C. vacuum oven. Dry for 24 hours.

(2) Amination and Polymer Coating Solution

The polymer obtained in (1) is dissolved in an organic solvent and subjected to an amination reaction at room temperature with trialkylamine.

Examples of the organic solvent that can be used at this time include dimethylacetamide, dimethylformamide, N-methylpyrrolidone and the like, but is not limited thereto.

As trialkylamine, trimethylamine ((CH ₃ ) ₃ N), triethylamine ((C ₂ H ₅ ) ₃ N), tripropylamine ((CH ₃ CH ₂ CH ₂ ) ₃ N), tributylamine ( (CH ₃ (CH ₂ ) ₃ ) ₃ N), tripentylamine ((C ₅ H ₁₁ ) ₃ N), trihexylamine ((CH ₃ (CH ₂ ) ₅ ) ₃ N), trioctylamine ((CH ₃ (CH ₂ ) ₇ ) ₃ N), and one or more of these can be selected and used.

The weight ratio of the trimethylamine to the polymer is 10% by weight or less to perform the amination reaction. Preferably it is 6 weight% or less. If the content of trimethylamine is too high, the amination reaction may be excessive, resulting in a high swelling ratio of the aminated polymer, which may adversely affect the life of the coating electrode.

In the amination reaction, the polymer is dissolved in dimethylacetamide to prepare a coating solution, which may be up to 25% by weight depending on the solubility of the polymer. It is preferable to appropriately adjust the solid content in the solution in consideration of the electrode surface coating property of the viscous coating solution.

It is preferable that the trimethylamine is diluted in the above organic solvent rather than used at a high concentration so that the concentration thereof is 5% by weight or less. If the concentration of the trimethylamine dilution solution is too high, the amination may not be uniformly aminated and the aminated polymer may be dissolved in water.

The resulting polymer is an acrylate-based having a side chain of a benzyl group having an anionic exchange group at the terminal, an example of which may be represented by the following formula (1) or (2).

Formula 1 may be a result obtained by amination of a polymer obtained by using methyl methacrylate and vinyl benzyl chloride as a monomer with trimethylamine, and Formula 2 may be methyl methacrylate, styrene and vinyl benzyl as monomers. It may be a result obtained by performing an amination reaction of a polymer obtained using chloride with trimethylamine.

Formula 1

In Formula 1, m is an integer of 65 to 262, n is an integer of 400 to 1,600.

(2)

In Formula 1, m is an integer of 65 to 283, n is an integer of 300 to 1293, o is an integer of 96 to 415.

(3) Preparation of carbon electrode coated with polymer

The prepared polymer coating solution is poured onto the surface of the carbon electrode and coated by casting using a blade or a knife. Depending on the viscosity and the solids content in the polymer solution, the thickness of the coating layer on the surface of the carbon electrode can be adjusted within the range of several to several tens of micrometers. When casting on the surface of the carbon electrode, a thin nylon net can be used to increase the durability of the coating layer as necessary. The electrode coated with the aminated polymer solution was dried for 3 hours in a dryer preheated to 70 to 80 ° C. to finally obtain an electrode coated with an anion exchange polymer. The coated electrode is stored in water at room temperature.

The carbon electrode thus obtained is an anion exchange polymer having a side chain made of a benzyl group containing a quaternary ammonium functional group in the acrylate polymer main chain, and a carbon electrode having an anion exchange polymer layer having a thickness of several to several tens of micrometers. to be.

(4) Application of electrosorption deionization (CDI) method

Electrosorption deionization is a technique for removing ions dissolved in water by applying an electric potential to a carbon electrode. In this method, a carbon electrode coated with ion-exchangeable polymer is placed on both ends, and a spacer is formed at the center so that when water flows into the flow path, when a relatively low potential of 2V or less is applied, cations are adsorbed on the cathode and the anode Anion is adsorbed on to remove ions in water. When the reverse potential is applied to the carbon electrode for regeneration of the electrode, the adsorbed ions are desorbed so that secondary pollution through regeneration such as an ion exchange resin does not occur.

The coating electrode obtained according to the present invention can be mounted on a CDI cell and electrosorption deionization can be performed. The electrosorption deionized unit cell is composed of a cathode and an anode, and the electrode is coated with an anion exchange polymer. As the spacer between the cathode and the anode, a nylon net (thickness of 90 mu m) may be used. The effective area of the electrode is 10 ㅧ 10 cm 2. The feedstock used in the electrosorption deionization method is a total dissolved solids (TDS) 200 ppm aqueous sodium chloride (NaCl) solution and is introduced into the unit cell at a flow rate of 30 ml / min using a pump. . Connect to the charging / discharging system (WEIS510, One Artec) and charge it periodically with 1.5 V potential applied (charge) for 3 minutes, reverse potential (discharge) for 1 minute (1.5 V), and 1 minute idle time (0 V). • discharge was carried out. As a result of this charge and discharge, the chloride and sodium ions in the water are removed by the principle of electrosorption and desorption, thereby reducing the TDS value. Install a TDS meter in the runoff area to monitor the TDS change.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1

Methyl methacrylate (MMA), styrene (Styrene) and vinyl benzyl chloride (VBC) monomers are mixed in a 6: 2: 2 weight ratio, and benzoyl peroxide, an initiator, is added 0.2% by weight of the monomer weight sum at 80 ° C under nitrogen atmosphere. , Was stirred for 6 hours. The reacted oligomer was maintained at 80 ° C. for 12 hours, heated at 100 ° C. for 5 hours, and cooled to room temperature. The obtained polymer was dissolved in dimethylacetamide and precipitated in methanol. The filtered polymer was dried in a vacuum drier at 60 ° C. for 24 hours.

The obtained poly (MMA-Styrene-VBC) copolymer polymer had a yield of 60% by weight and a molecular weight (M _w ) of 211,000. The NMR analysis results thereof are as shown in FIG. 2.

In the amination reaction step, trimethylamine was used so as to be 5% by weight relative to the polymer, and diluted to a concentration of 3% or less in dimethylacetamide. The organic solvent concentration was adjusted so that the solids content in the solution was 17, 19, 21 wt%, respectively. The polymer prepared was dissolved in a solution of trimethylamine diluted in dimethylacetamide, and then stirred at room temperature for 24 hours.

The anion-exchangeable polymer coating solution thus obtained was cast on the surface of the carbon electrode, and a thin nylon net was used during casting as needed. The carbon electrode cast with the coating solution was dried in a dryer preheated at 80 ° C. for 3 hours to prepare a carbon electrode finally coated with a functional polymer.

The thickness of the polymer coating layer was 5 ~ 10 ㎛.

As a result of CDI test with the prepared polymer coated carbon electrode, TDS removal rate was obtained as shown in Table 1. The removal rate of TDS also increased with the solids content in the coating solution, and the removal rate was over 78%.

Coating material Percentage of trimethylamine relative to polymer (% by weight) Solid content in coating solution
(weight%)  TDS removal rate (%) Poly (MMA-Styrene-VBC)
5 17 78 5 19 82 5 21 86

[Example 2]

In the same manner as in Example 1, a methyl methacrylate-styrene-vinylbenzyl chloride monomer was prepared to prepare a copolymer, and 4% by weight of trimethylamine was used, and the solid content in the solution was 21% by weight. After the privatization reaction, a polymer-coated electrode was prepared with the obtained coating solution. The thickness of the polymer coating layer was 7 ~ 8 ㎛.

The CDI test showed a TDS removal rate of 84%.

[Example 3]

Polymerization was carried out in the same manner as in Example 1 except that polymerization was carried out by adding divinylbenzene as a crosslinking agent to polymerize the polymer. At this time, divinylbenzene was used so that 0.1 weight% of three monomer weight sums of methyl methacrylate, styrene, and vinyl benzyl chloride were used.

In the amination reaction step, trimethylamine was used at 4% by weight relative to the copolymerized polymer. Solid content of the coating solution was 21% by weight.

A carbon electrode coated with a poly (MMA-Styrene-VBC-DVB) polymer was prepared, and the thickness of the polymer coating layer was 7 to 8 μm.

As a result of CDI experiment, TDS removal rate was 86%.

Example 4

A copolymer polymer was prepared in the same manner as in Example 1 except that only methyl methacrylate and vinyl benzyl chloride were used in a 8: 2 weight ratio as the polymer polymerization monomer.

In the amination reaction step, trimethylamine was used to 5 wt% relative to the polymer content, and the solid content in the coating solution was 21 wt%. Anion exchange polymer coated carbon electrode was prepared using the prepared solution, and the thickness of the polymer coating layer was 7 to 8 μm.

The CDI test showed that the TDS removal rate was 89%.

[Example 5]

Polymer polymerization using monomers of methyl methacrylate, styrene, vinylbenzyl chloride and divinylbenzene as a crosslinking agent as a monomer was solution-polymerized in a tetrahydrofuran solvent. The reaction solvent was used as 70% by weight of the reaction solution. The ratio between monomers of methyl methacrylate, styrene and vinyl benzyl chloride is 6: 2: 2 (g), divinylbenzene is 0.05% by weight of the three monomers, and initiator is used so that AIBN is 0.3% by weight of the reaction monomers. It was. The solution was polymerized for 10 hours at a temperature of 80 ° C. under a nitrogen atmosphere, and then precipitated in methanol. The yield of copolymerized polymer obtained in the polymerization reaction was 12.5%.

After the amination reaction in the same manner as in Example to obtain a coating solution to prepare a carbon electrode, the thickness of the polymer coating layer was 7 ~ 8 ㎛.

As a result of the CDI test, the same TDS removal rate as that obtained by the bulk polymerization was obtained.

Comparative Example 1

The CDS test using only a carbon electrode without a commercial ion exchange membrane showed a TDS removal rate of 55%.

Comparative Example 2

TDS removal rate of 75% was CDI tested using a carbon electrode using a commercial ion exchange membrane (Neo Septa, Japan, AMX, 150 µm thick).

Table 2 summarizes the results of the CDI test applying the carbon electrodes of Comparative Examples 1 and 2 and the CDI test applying the carbon electrode obtained from Example 3 of the present invention.

Comparative Example 1 Comparative Example 2 Example 3 electrode When using only carbon electrode ^* Carbon electrode using only commercial ion exchange ^** Carbon Electrode Coated with Ionic Polymer TDS removal rate (%) 55 75 86

* Carbon electrode: Siontech

** Commercial ion exchange membrane: Neocepta, AMX, Japan

As described above, the anion exchange polymer was prepared according to the present invention, and the carbon electrode coated with the functional polymer was applied to the CDI test, and showed excellent TDS removal rate. This can replace the expensive ion-exchange membranes used in the past and show that the manufacturing cost can be much lower in terms of CDI cell manufacturing cost.

Claims (14)

Polymerizing at least one monomer selected from an acrylate monomer or a styrene monomer and a vinylbenzyl chloride monomer to obtain a polymer;
Reacting the obtained polymer with trialkylamine to obtain a polymer having an anion exchange group; And
Coating a polymer having an anion exchanger on the surface of the carbon electrode,
The trialkylamine is a carbon electrode manufacturing method coated with an anion-exchange polymer that is used 4 to 5% by weight of the polymer.
The method of claim 1,
As the acrylate monomer, C ₁ to C ₁₂ alkyl methacrylate, 2-ethoxyethyl methacrylate, 2-butoxyethyl methacrylate, ethylene glycol methyl ester acrylate, cyclohexyl methacrylate, benzyl meta Acrylate, phenyl methacrylate, 2- (methylthio) ethyl methacrylate, hexafluoroisopropyl acrylate, trifluoroethyl methacrylate, pentafluoropropyl methacrylate, heptafluorobutyl methacrylate A method for producing a carbon electrode coated with an anion exchange polymer using at least one selected from octafluoropentyl methacrylate, tetrafluoropropyl methacrylate and hexafluorobutyl methacrylate.
The method of claim 1,
As the styrene monomer, an anion exchange polymer used by selecting one or more of styrene, α-methylstyrene, methylstyrene, bromostyrene, chlorostyrene, nitrostyrene, trifluoromethylstyrene, and chloroα-methylstyrene. Coated carbon electrode manufacturing method.
The method of claim 1,
A crosslinking agent is used in the step of obtaining a polymer, and at least one selected from divinylbenzene, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate and hexanediol di (meth) acrylate is used. Method for producing a carbon electrode coated with an anion exchange polymer.
The method of claim 1,
As the trialkylamine, carbon electrode coated with an anion exchange polymer using at least one selected from trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine and trioctylamine Way.
The method of claim 1,
Method of producing a carbon electrode coated with an anion exchange polymer using a vinyl benzyl chloride 10 to 50% by weight of the total monomer content in the step of polymerizing the polymer.
delete The method of claim 1,
A method of preparing a carbon electrode coated with an anion exchange polymer, wherein trialkylamine is diluted in an organic solvent at a concentration within 5% by weight in the step of preparing a polymer having an anion exchange group.
The method of claim 1,
Anion exchanger is a method of producing a carbon electrode coated with an anion exchange polymer which is a quaternary ammonium functional group.
The method of claim 1,
After coating a polymer having an anion exchanger on the surface of the carbon electrode, a method for producing a carbon electrode coated with an anion exchange polymer comprising the step of drying at 70 to 80 ℃.
The method of claim 1,
In the step of obtaining a polymer, the polymerization is a method of producing a carbon electrode coated with an anion-exchange polymer which is bulk polymerization or solution polymerization.
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