Monovalent selective cation exchange membrane

Abstract

To provide a monovalent selective cation exchange membrane, a monovalent selective cation exchange membrane support, a method for producing a monovalent selective cation exchange membrane, a water treatment system using an ion exchange membrane, and a method of facilitating water treatment using an electrochemical separation device.SOLUTION: A monovalent selective ion exchange membrane includes a polymeric microporous substrate, a cross-linked ion-transferring polymeric layer on a surface of the substrate, and a charged functionalizing layer covalently bound to the ion-transferring layer. A method of producing a monovalent selective cation exchange membrane includes: chemically adsorbing a styrene intermediate layer to the cross-linked ion-transferring polymeric layer on a surface of the polymeric microporous substrate; chlorosulfonating the styrene intermediate layer to attach a chlorosulfonyl group layer; aminating the sulfonyl group layer to attach an amine group layer; and functionalizing the amine group layer with a charged compound layer to produce the cation exchange membrane.SELECTED DRAWING: Figure 2

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application was filed on September 27, 2018 under 35 U.S.C. § 119 entitled “Comparative Application of a Novel Component.” "Valence-Selective Cation Exchange Membranes" U.S. Provisional Application No. 62 / 737,373, filed September 2, 2018. U.S. Provisional Application No. 62 / 2010, entitled “Cation Exchange Membranes by UV-Initiated Polymerization,” filed on the 5th. 736,176, and a patent application submitted on June 14, 2019 entitled "Replacement by UV Photopolymerization" This application claims priority to U.S. Provisional Application No. 62 / 861,608, entitled "Membrane Preparation," each of which is incorporated herein by reference in its entirety. is incorporated herein by reference in its entirety for all purposes. [Technical field]

[0002] Aspects and embodiments disclosed herein generally relate to ion exchange membranes, and more specifically to , relates to monovalent selective ion exchange membranes. Summary of the Invention

[0003] According to one embodiment, a monovalent selective ion exchange membrane is provided. The monovalent selective ion exchange membrane comprises: The polymeric microporous substrate may include a monovalent selective ion exchange membrane. The monovalent selective ion exchange membrane may include a crosslinked ion transport polymer layer. The polymer layer may include a charged functionalization layer covalently bonded to the polymer layer.

[0004] In some embodiments, the membrane may have a total thickness of about 20 μm to about 155 μm. It may have a total thickness of about 25 μm to about 55 μm.

[0005] The monovalent selective ion exchange membrane can be a cation exchange membrane. The charged functionalized layer can be a positively charged It may be a functionalized layer.

[0006] In some embodiments, the positively charged functionalized layer comprises a sulfonic acid group, a carboxylic acid group, , quaternary ammonium, and tertiary amines hydrolyzed to positively charged ammonium The compound may comprise at least one of the groups.

[0007] The monovalent selective membrane can be an anion exchange membrane. The charged functionalization layer can be a negatively charged functionalization layer. It may be a coating layer.

[0008] A monoselective ion exchange membrane may have a counterion permselectivity of at least 100%.

[0009] The monovalent selective ion exchange membrane has an initial selectivity of 8-12 times Na / Ca (ppm) at room temperature. It is possible.

[0010] The monovalent selective membrane has a resistance of about 5 Ω-cm 2 The resistance may be less than 100 .mu.m.

[0011] The polymer microporous substrates are made of high density polyethylene (HDPE) and ultra-high molecular weight polyethylene. The material may include at least one of the following:

[0012] According to another aspect, a monoselective cation exchange membrane support is provided. The monoselective cation exchange membrane support may comprise a polymeric microporous substrate. The substrate may include a crosslinked ion transport polymer layer on a surface of the substrate. The exchange membrane support comprises an intermediate layer containing amine groups covalently bonded to a crosslinked ion transport polymer layer. may include.

[0013] In some embodiments, the intermediate layer may include primary or secondary amine groups. .

[0014] The intermediate layer may include polyethyleneimine (PEI).

[0015] The intermediate layer may comprise branched PEI having a molecular weight of at least 600 g / mol.

[0016] The intermediate layer is covalently bonded to the crosslinked ion transport polymer layer by styrene groups. This is also fine.

[0017] The styrene group is chemically bonded to chlorosulfonated divinylbenzene (DVB). Good too.

[0018] According to another aspect, a method for producing a monovalent selective cation exchange membrane is provided. The styrene intermediate layer is a crosslinked ion transport polymer layer on the surface of a polymeric microporous substrate. The method may include chemically adsorbing the styrene interlayer onto a chlorosulfonated This may include attaching a sulfonyl chloride base layer to the surface of a polymeric microporous substrate. The method involves amminating a sulfonyl group to attach an amine group to the surface of a polymeric microporous substrate. The method may include functionalizing the amine-based layer with a layer of a charged compound to provide a monovalent selection. The method may include fabricating a selective cation exchange membrane.

[0019] In some embodiments, the method comprises: The method may include chemically adsorbing styrene DVB onto the ion transport polymer layer.

[0020] This method involves chlorosulfonating styrene DVB with chlorosulfonic acid (ClSO3H). This may include attaching a ClSO2 group to the styrene DVB.

[0021] The method can include amminating ClSO2 with PEI.

[0022] This method uses branched PEI with a molecular weight of at least 600 g / mol and ClSO2. This may include aminating.

[0023] The method can include functionalizing an amine-based layer with positively charged groups.

[0024] The method may include functionalizing an amine sublayer with positively charged ammonium.

[0025] The method comprises the steps of: preparing a polymeric microporous substrate by subjecting an ionogenic monomer, a multifunctional monomer and a polymerized and further immersing the layer in a solution containing an initiator to produce a crosslinked ion transport polymer layer. It may include.

[0026] According to another aspect, a water treatment system is provided. The water treatment system includes: The water treatment system may include a surface of a cation exchange membrane that is fluidly connected to a source of water to be treated. At least one monovalent selective cation exchange membrane having a charged functionalized layer covalently bonded to its surface. The water treatment system may include an electrochemical separation device including a water treatment system. The system may include a treated water outlet connected to the

[0027] In some embodiments, the water source to be treated is 2+ and Mg 2+ Selected from It may contain at least one hardness ion.

[0028] In some embodiments, the charge functionalized layer may include sulfonic acid groups, carboxylic acid groups, quaternary Ammonium, and of the tertiary amine groups hydrolyzed to positively charged ammonium The functionalized layer may be a positively charged layer comprising at least one of

[0029] In some embodiments, the charged functionalization layer is formed by a chemically adsorbed branched PEI layer. The cation exchange membrane may be covalently bonded to the surface of the cation exchange membrane.

[0030] According to another aspect, a method is provided for facilitating water treatment using an electrochemical separation device. This method involves the formation of a monovalent selective cation exchange membrane having a charged functionalized layer covalently bonded to the surface of the membrane. The method may include providing an ion exchange membrane having a monovalent selective ion exchange property in an electrochemical separation device. The method may include instructing a user to install the cation exchange membrane.

[0031] In some embodiments, the method further comprises: 2+ and M. g 2+ in fluid communication with a source of water to be treated that contains at least one hardness ion selected from The method may include instructing the user to

[0032] The method comprises preparing a polymeric microporous substrate having an amine-based layer covalently bonded to the surface of the polymeric microporous substrate. The method may include providing a monovalent selective cation exchange membrane support having a porous substrate. The system encourages users to functionalize an amine-based layer with a layer of charged compounds to produce a cation exchange membrane. It may further include instructing.

[0033] According to yet another aspect, a monovalent selective cation exchange membrane is provided. The cation exchange membrane comprises: , a polymeric microporous substrate and a positively charged functionalization agent covalently bonded to the surface of the polymeric microporous substrate. The monovalent selective cation exchange membrane can have a Na / Ca ratio of 8 to 12 ppm at room temperature. ) may have an initial selectivity.

[0034] Monoselective cation exchange membranes showed a 4-8-fold increase in affinity after 400 days in 0.5M NaCl at room temperature. It may have Na / Ca (ppm) selectivity.

[0035] The monovalent selective cation exchange membrane has an initial selectivity of 10 to 40 times Na / Ca (molar) at 80°C. It may have the following characteristics.

[0036] Monovalent selective cation exchange membranes showed 3-6 times the capacity after 30 days in 0.5M NaCl at 80°C. It may have Na / Ca (molar) selectivity.

[0037] The present disclosure relates to any one or more of the above aspects and / or embodiments in any combination. and in combination with any one or more of the embodiments described in the detailed description and any examples. The combination is intended.

[0038] The accompanying drawings are not intended to be drawn to scale. Each identical or nearly identical component illustrated in the various figures is represented by a like numeral. For clarity, not every component may be labeled in every drawing. [Brief description of the drawings]

[0039] [Figure 1] FIG. 1 is a representation of the chemical structure of a polyethyleneimine (PEI) molecule showing the primary (-NH), secondary (-NH-), and tertiary amine groups. [Diagram 2] FIG. 2 is a representation of the formation of ionic bonds by physisorption between the primary or secondary amines of PEI and the sulfonic acid groups of the cation exchange membrane surface, according to one embodiment. [Diagram 3] FIG. 3 is a representation of the formation of covalent bonds by chemisorption between primary or secondary amines of PEI and chlorosulfonic acid (ClSO3H), according to one embodiment, which occurs as a two-step process. [Figure 4]4A and 4B are graphs of the concentrations of Ca2+ and Na+ in the dilute stream over time for water treatment with a conventional membrane and an alternative conventional membrane, respectively. [Diagram 5] FIG. 5 is a graph of Ca2+ and Na+ concentrations in a dilute stream over time for water treatment with a monovalent selective ion exchange membrane, according to one embodiment. [Figure 6] 6A and 6B are graphs of ion concentrations and sodium absorption rate (SAR) values ​​for experimental groundwater treated with a monovalent selective ion exchange membrane according to one embodiment, and a conventional cation exchange membrane, respectively. [Figure 7] FIG. 7 is a graph of ion concentrations in experimental seawater treated with a monovalent selective ion exchange membrane, according to one embodiment. [Figure 8] FIG. 8 is a graph of univalent transport selectivity over time for water treatment with a univalent selective ion exchange membrane, according to one embodiment. [Figure 9] FIG. 9 is a schematic diagram of the membrane selectivity experimental setup. [Figure 10] FIGURE 10A is a graph showing the concentration of target cations in a dilute stream desalted by a monovalent selective cation exchange membrane according to one embodiment; FIGURE 10B is a graph showing the concentration of target cations in a dilute stream desalted by a conventional cation exchange membrane; FIGURE 10C is a graph showing the concentration of target cations in a dilute stream produced by a monovalent selective cation exchange membrane according to one embodiment; and FIGURE 10D is a graph showing the concentration of target cations in a dilute stream produced by a conventional cation exchange membrane. [Figure 11]11A and 11B are graphs of the concentration of selected ions in the concentrating compartment using a monoselective anion exchange membrane for treating seawater at an applied current density of 300 A / m2, according to one embodiment, and FIG. [Figure 12] Figure 12A is a graph showing lifetime selectivity (stability) at 80° C. for a conventional / commercially available univalent selective membrane and a univalent selective membrane disclosed herein, according to one embodiment. Figure 12B is a graph showing lifetime selectivity (stability) at room temperature for a conventional / commercially available univalent selective membrane and a univalent selective membrane disclosed herein, according to one embodiment. Detailed Description of the Invention

[0040] Embodiments disclosed herein include ion exchange membranes and processes for their manufacture. The electrodialysis (ED) membranes described herein generally have low resistance and high permselectivity. These properties make them ideal for water desalination applications, especially seawater desalination. Their properties make them very effective in the treatment of irrigation water, especially in sodium absorption. The ion implantation methods described herein can be very effective in adjusting the SAR values. The ion exchange membrane is preferably a mixture of one or more monofunctional ionogenic monomers, optionally a neutral monomer, at least Both can be produced by polymerizing a single polyfunctional monomer within the pores of a porous substrate. can.

[0041] Ion exchange membranes are typically used to transport cations or anions under electrical or chemical potential. Ion exchange membranes are made of polymeric materials that make up the majority of the membrane. The material may have either negatively or positively charged groups attached to it. The counterion for each group is usually Cation exchange membranes function as a membrane between fixed negative charges and mobile positive charges. Anion exchange membranes have fixed positively charged groups and mobile The properties of the ion exchange membrane depend on the amount, species, and / or type of immobilized ionic groups. These membranes can be engineered to resist strong acids, strong They can be described as base, weak acid, or weak base membranes. Strong acid cation exchange membranes are usually Weak acid membranes usually have fixed charged groups. The quaternary and tertiary positively charged ammonium salts have carboxylic acid groups that form the , can generate fixed positively charged groups in strong and weak base anion exchange membranes. do.

[0042] Ion exchange membranes are used for the desalination of water by electrodialysis (ED), as a power source for reverse electrodialysis, and or as a separator in a fuel cell. The treatment system can be a desalination system, a power generation system, or an electrodialysis reverse system. , or a desalination system, a power generation system, or an electrodialysis reversal system. Applications include the recovery of metal ions in the electroplating and metal finishing industries, as well as in food and In other embodiments, the water treatment systems disclosed herein include applications in the food and beverage industries. The system may be a metal ion recovery system or a food and beverage processing system, and may include a metal ion recovery system or a food and beverage processing system.

[0043] In certain exemplary embodiments, the ion exchange membranes disclosed herein are used in groundwater treatment and The water treatment system disclosed herein can be used in a wide variety of applications, including agricultural and / or water treatment environments. It may be or may include a groundwater treatment system. The water treatment system shown may be an agricultural irrigation runoff treatment system or an agricultural irrigation runoff treatment system. The method may include treating groundwater. The method may include treating agricultural water runoff.

[0044] Electrodialysis is generally carried out by passing a mixture of anion and cation selective membranes under the driving force of a direct current voltage. It desalinates water by transferring ions and some charged organic matter through the ED device. The device comprises electrically conductive, substantially water-impermeable, anion-selective electrodes disposed as opposing walls of the cell. Adjacent cells usually form a cell pair. A stack may contain many, sometimes hundreds, of cell pairs. Each membrane stack typically has a DC (direct current) anode at one end and a DC cathode at the other end. The electrons can migrate toward the electrode of opposite charge.

[0045] A cell pair contains two types of cells: dilute cells and concentrated cells. Each type of cell is , which may be defined by opposing membranes. One exemplary cell pair is a coaxial cell forming two cells. The membrane may include one cation transport membrane wall and two anion transport membrane walls. The ion transport membrane and the cation transport membrane form a dilute cell, and the cation transport membrane and the second anion transport membrane The transport membrane forms a concentrate cell. In a dilute cell, the cations are usually transported through the positive ions facing the anode. The ion transport membrane is transported through the concentration cell by the anion transport membrane in the direction facing the cathode. Similarly, anions may be transported through the dilute cell facing the cathode. It passes through the membrane but is stopped by the adjacent pair of cation transport membranes facing the anode. In this way, the salt in the dilute cell can be removed. In some cases, positive ions may enter from one direction and negative ions from the opposite direction. The streams can be arranged so that the dilute and concentrated streams are kept separate. Thus, a desalinated water stream can be produced from the dilute stream.

[0046] Lack of irrigation water of sufficient quality has a negative impact on crop yields and reduced demand for crop varieties. You may need to choose a method to reduce the amount of water you use by using techniques such as drip irrigation. New irrigation methods are also unsustainable because salts and impurities accumulate in the soil from the water used for irrigation. Soil salinity can lead to conditions where most water is lost through crops and evaporation. Because of the use of chlorine in water, concentrations can rise much higher than in irrigation water. and soil conditions with insufficient raw water or insufficient rainfall to leach the soil are the cause of irrigation problems. This can lead to soil salinity four to five times higher than the water itself. Furthermore, the soil is relatively shallow and impermeable. If the soil consists of high salinity groundwater, irrigation water can raise the water table. When the water reaches the root level of crops, it can harm crop growth. Water splashing from the soil surface can damage leafy crops. In addition, saline water drains from the fields. When water is irrigated, trace impurities in the soil, such as selenium or boron, or fertilizer use salts, such as nitrates, are released. Residual pollutants from these uses can contaminate wastewater, making safe wastewater management difficult.

[0047] When crops are irrigated, yield can be affected by the total dissolved salts (TDS) concentration. TDS is generally It usually correlates with the conductivity value. For example, the conductivity value of 1 mS / cm is about 500 to 70 0 ppm TDS. Many plants benefit from low TDS irrigation water. For example, beans, carrots and strawberries benefit from irrigation with water with a conductivity of less than 1 mS / cm. Other plants can tolerate irrigation water with a conductivity of about 5 mS / cm. In addition, controlling the SAR value at a certain TDS and conductivity has an impact on soil cohesion and efficient water infiltration. For example, irrigation water with a conductivity below 1 mS / cm may have poor soil structure and may be ineffective in maintaining soil structure. Irrigation water with a conductivity of 2-3 mS / cm can benefit from a SAR value of more than 3. It can benefit from a SAR value of 10.

[0048] The need for irrigation water is driven by both drinking water for humans and contaminant-free water for livestock and wildlife. Therefore, agricultural regions need combined sources of irrigation and drinking water. The membranes described herein can be used to treat agricultural irrigation water. In particular, the membranes described herein improve the TDS, conductivity, and SAR values ​​of agricultural irrigation water. In some embodiments, the membranes described herein can be used to control The membranes described herein can provide water having a conductivity of less than 1 mS / cm. , between 2 and 3 mS / cm, between 3 and 5 mS / cm, or greater than 5 mS / cm (e.g. The membranes described herein can provide water with a conductivity of 3.5-5.0 mS / cm. The membranes described herein may provide water having an SAR value greater than 1.0, e.g., between 3 and 5. may provide water having an SAR value of greater than 5, for example between 5 and 10. The membrane can provide water having an SAR value of about 10 or more, for example, between 10 and 12. Cut.

[0049] A monovalent or univalent selective membrane transports mainly univalent ions. Monovalent selective membranes can separate ions based on charge and / or size. Monovalent cation transport membranes are capable of distinguishing between monovalent and divalent ions. For example, ions with a +1 charge, such as sodium and potassium, and ions with a larger positive charge Charged ions, such as magnesium and calcium, can be distinguished. Thus, the monovalent selective cation exchange membranes described herein are capable of selectively ionizing calcium and magnesium ions. While blocking the transport of divalent ions such as ammonium ions, it also blocks the transport of sodium and potassium ions. Similarly, monovalent anion selective membranes can selectively transport any one ion. Ions with a -1 charge, such as chloride, bromide, and nitrate, are converted to ions with a larger negative charge. Thus, the monovalent anion exchange membranes described herein can separate ions from ions. While blocking the transport of divalent ions such as sulfate ions, it also blocks the transport of chloride ions and nitrate ions. It is possible to selectively transport singly charged ions of

[0050] The ion exchange membranes disclosed herein are used to process brackish water and wastewater desalination. ED is generally considered too expensive for seawater use, but The ion exchange membrane disclosed in the article can be effectively used for desalination of seawater. The most efficient seawater desalination is at 1Ω-cm 2 Less than, for example, 0.8 Ω-cm 2 Less than or 0 .5 Ω-cm 2The ion exchange membrane disclosed herein can be carried out with a membrane resistance of less than 100 μm. The membrane may also have an ion selectivity of greater than 90%, e.g., greater than 95%, or greater than 98%. Moreover, the ion exchange membranes disclosed herein can provide a permeability that is comparable to that of conventional ion exchange membranes. have a longer service life and greater physical strength and chemical durability than ion exchange membranes Finally, the ion exchange membranes disclosed herein can be produced at relatively low cost. do.

[0051] As a result, the ion exchange membranes disclosed herein can be used in reverse electrodialysis (RED). RED uses the free energy generated by mixing two aqueous solutions with different salt concentrations. Generally, the greater the difference in salinity, the greater the power generation. The water treatment system disclosed herein may be a RED system. The methods disclosed herein may include a solar cell or a RED system for generating electrical power. It can be used for this purpose.

[0052] The ion exchange membranes disclosed herein can be used as polymer electrolyte membranes (PEMs). The PEM acts as both the electrolyte and the separator, transporting hydrogen from the anode. A type of inductor that can prevent direct physical mixing of the inductor and the oxygen supplied to the cathode. The PEM is an ion exchange membrane. The PEM is a membrane that is bound to or is part of the polymer that makes up the PEM. The protons are usually attached to a fixed negatively charged group, such as a sulfonic acid group. They move through membranes by jumping from one charge to another and penetrating the membrane.

[0053] The membranes disclosed herein generally comprise an ion exchange membrane support and an ion exchange membrane support. The ion exchange membrane support may include a polymeric microporous substrate. and a cross-linked ion transport polymer layer on the surface of the substrate. The membrane support may further include an amine-based layer covalently bonded to the crosslinked ion transport polymer layer.

[0054] The membranes described herein generally exhibit good mechanical strength. It is manufactured to withstand the stresses of the continuous membrane manufacturing process and may appear after a period of operation. Sealed into the final membrane-retaining device or module without obvious or hidden damage Furthermore, the mechanical strength may be sufficient to provide high dimensional stability. The membranes are generally cleaned, disinfected, and sanitized while functioning as a desalination device. or exhibit minimal variation in dimensions during the antifouling regime or during shipping or storage. For example, high dimensional stability against changes in the ionic content or temperature of the fluid in contact with the membrane. may be provided, so that during operation, the distance between the membrane pairs, which may lead to current inefficiencies, The dimensional changes during electrodialysis induce stresses in the constrained membrane. This can lead to membrane defects and reduced performance and is generally best avoided. can.

[0055] The membranes described herein can exhibit low resistance. Generally, low resistance is required for desalination. Less electrical energy is required, lowering operational costs. Specific membrane resistance is often measured in Ω-cm. Another engineering scale is Ω-cm 2 The resistance is determined by the capacitance of a known area The resistance can be measured by a resistance test process using a cell having two electrodes. The electrodes are usually platinum or black graphite. The resistance between the electrodes is then measured. A membrane sample of known area can be placed between the electrodes in an electrolyte solution. The electrodes do not touch the membrane. Then measure the resistance again with the membrane in place. Then, By subtracting the electrolyte resistance without the membrane from the test results with the membrane in place, Thus, the membrane resistance can be estimated.

[0056] The resistance was also measured in a cell with two well-stirred chambers separated by a membrane. The current can be measured by determining the voltage vs. current curve across the membrane using a calomel electrode. The slope of the potential drop versus current curve changes as the voltage is changed. It is obtained by measuring the current.

[0057] Electrochemical impedance can also be calculated. In this method, an alternating current is applied across the membrane. Single-frequency measurements can provide data related to the electrochemical properties of the membrane. By using the frequency and amplitude variations, detailed structural information can be obtained. do.

[0058] The membranes described herein can have high counterion permselectivity. Permselectivity is generally determined by: It can refer to the relative transport of counterions to co-ions during electrodialysis. In the case of ion exchange membranes, only positively charged ions pass through the membrane, resulting in a 1.0 or 100% exchange of ions. Permselectivity is achieved by separating solutions of different concentrations of monovalent salts through a membrane. It can be found by measuring the overall potential.

[0059] The ion exchange membranes disclosed herein may have reduced water permeation. The permeation of the dilute stream through the membrane defect under the driving force of the osmotic pressure difference between the dilute and concentrated streams increases the efficiency Water infiltration reduces the current efficiency and productivity of purified water by removing pure water. The high concentration difference between the concentrate (brine) side of the membrane and the pure water side of the membrane usually results in an osmotically driven Water loss can be particularly severe in seawater electrodialysis using thin membranes to increase power. Membrane defects increase water loss as high osmotic pressure forces pure water through such defects. , which can be particularly detrimental to operation since they tend to increase power consumption.

[0060] The membranes disclosed herein generally allow high permeability of cations and low osmotic flux. As used herein, apparent counterion permselectivity refers to the amount of counterion ( The traditional measurement parameter is the ratio of the transport rates of a positive ion (cation) and a negative ion (co-ion). The ion rejection rate is not shown. In certain embodiments, the membranes disclosed herein are It can be engineered to control ion permeability.

[0061] The permeability of cations depends on the structure of the ion (molecular size and total charge) and the microstructure of the membrane. If the membrane is designed to have relatively small pores, the membrane The microstructure of the membrane can retard counterion permeability. As it passes through the membrane, it is as if it is passing through a tunnel slightly larger than the diameter of the membrane. This can be interpreted as meaning that the membrane encounters high resistance from interactions with the material. Relatively low, and counterion permeability pathways tend to be reduced. By balancing the content of hydrophilic monomers and the amount and nature of cross-linking monomers, The water content and effective pore size can be manipulated. The crosslinking monomers can be hydrophobic or hydrophilic. A user may choose to be a normer.

[0062] The membranes disclosed herein generally may include an ion exchange membrane support. The support includes a polymeric microporous substrate and a crosslinked ion transport polymer layer on a surface of the substrate. The membrane support can be prepared by selecting a suitable porous substrate and applying a cross-linked ion transport polymer to the surface of the substrate. The present invention can be manufactured by a process that includes incorporating a thin-film layer.

[0063] The microporous membrane substrate may be made of polyolefin, polyvinylidene fluoride, or other polymers. One exemplary class of substrates includes thin polyolefin films. An exemplary class of substrates is fabricated from high density polyethylene (HDPE). A common class of substrates is made from ultra-high molecular weight polyethylene (UHMWPE). The substrate is made of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, or poly The substrate may comprise a microporous membrane of vinylidene fluoride. The substrate is generally less than about 155 μm, e.g. It may have a thickness of less than about 55 μm or less than about 25 μm.

[0064] Exemplary microporous membrane materials include, for example, those disclosed herein, which are incorporated by reference in their entirety for all purposes. As disclosed in U.S. Pat. No. 8,703,831, which is incorporated herein by reference, very thin ions are Exemplary ion exchange membranes include those having a diameter of 12 to 100 μm, For example, it may have a thickness of 25 to 32 μm. Thinner membranes allow for effective penetration across the majority of the membrane. It allows for a fast chlorosulfonation reaction, which is described in more detail below. A 5-minute chlorosulfonation reaction may be sufficient to complete the chlorosulfonation. Thus, the method described herein is effective in chlorosulfonating a large portion of the membrane in about 5 minutes. This may include carrying out an efficient chlorosulfonation reaction.

[0065] Additionally, certain exemplary microporous membrane materials are used to provide stability against aggressive chemicals. For example, HDPE membrane substrates are generally stable to ClSO3H. Materials such as polypropylene may not be stable enough to ClSO3H. be.

[0066] Embodiments of the substrate membrane may have a porosity of greater than about 45%, for example, greater than about 60%. In certain embodiments, the substrate membrane may have a porosity of greater than about 70%. 0.05 μm to about 10 μm, for example, about 0.1 μm to about 1.0 μm, or about 0.1 μm to It may have a nominal pore size of about 0.2 μm.

[0067] The membrane support can be fabricated by saturating the monomer solution within the pores of the substrate. The monomer solution is polymerized from the functional monomer, crosslinker, and polymerization initiator in the pores. In certain embodiments, the functional monomer may be Ionogenic monomers, such as monofunctional ionogenic monomers and polyfunctional monomers; For example, it may include a crosslinking agent. As used herein, the term ionogenic monomer may generally refer to a monomeric species to which at least one charged group is covalently attached. As will be explained in more detail, the charged groups may be positively or negatively charged. A functional monomer generally refers to a monomer that has a single site for carrying out a polymerization reaction. Multifunctional monomers generally have multiple polymerization reaction sites and therefore can form networks. It may refer to a monomer capable of forming a polymer that is polymerized or crosslinked.

[0068] The process of polymerizing a cross-linked ion transport polymer layer within the pores of the substrate is carried out using a monofunctional ionogen The process involves saturating the substrate with a solution containing the monomer, the multifunctional monomer, and the polymerization initiator. This process leaves the porous volume saturated with solution and initiates polymerization. Optionally, the polymerization may include removing excess solution from the surface of the substrate. In the absence of all oxygen, by application of heat, ultraviolet (UV) light, or ionizing radiation The process can begin with the formation of cross-linked interfacial grafts that substantially completely fill the pores of the substrate. It may be possible to incorporate an on-transport polymer layer.

[0069] Thus, in certain embodiments, the membrane support comprises one or more ionogenic monomers, neutral The polymerizable monomer may be produced by polymerization of a neutral monomer and a suitable crosslinker monomer. The mers are hydroxyethyl acrylate and hydroxymethyl methacrylate. Other neutral monomers are within the scope of this disclosure. Ionogenic monomers can be used to prepare cation exchange membranes or Alternatively, the catalyst may be selected to produce an anion exchange membrane.

[0070] Representative, but not limited to, monomers containing negatively charged groups include However, sulfonated acrylic monomers suitable for providing cation exchange capacity, e.g., 2- Sulfoethyl methacrylate (2-SEM), 2-propyl acrylic acid, 2-acrylic acid Amido-2-methylpropanesulfonic acid (AMPS), sulfonated glycidyl methacrylate 3-Sulfopropyl methacrylate, 1-allyloxy-2-hydroxypropyl sulphonate Other exemplary monomers include acrylic acid and methacrylic acid. styrene sulfonate or its salts, sodium styrene sulfonate, styrene sulfonic acid, sulfonate Sodium vinylbenzyl chloride 1-allyloxy-2-hydroxypropyl sulfonate nate, 4-vinylbenzoic acid, trichloroacrylic acid, vinyl phosphate and vinyl sulfonate The preferred monomer is 2-sulfoethyl methacrylate (2-SEM), sulfonic acid. Ethylenesulfonic acid and its salts, and 2-acrylamido-2-methylpropanesulfur and ampicillin-containing polysaccharides (AMPS).

[0071] The cation exchange membrane embodiments described herein have a resistance of about 1.0 Ω-cm 2 Less than, e.g., about 0.5 Ω-cm 2 Certain embodiments of the cation exchange membranes described herein may have a resistivity of less than 100 nm. Embodiments may have a permselectivity of greater than about 95%, for example, greater than about 99%. In some embodiments, the ionogenic monomer for the preparation of the cation exchange membrane is 2-sulfuric acid. Ethyl methacrylate (2-SEM or 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or 2-sulfoethyl methacrylate (2-S May contain EM or 2-acrylamido-2-methylpropanesulfonic acid (AMPS) One exemplary crosslinker is ethylene glycol dimethacrylate. Genoyl monomers and crosslinkers are within the scope of the present disclosure.

[0072] Representative, but not limited to, monomers containing positively charged groups include Methacrylamidopropyltrimethylammonium chloride, trimethylammonium ethyl methacrylate, quaternary salts of polyamines and vinyl aromatic halides, e.g. For example, 1,4-diazabicyclo[2,2,2]octanedi(vinylbenzyl chloride), ( 1,4-Diazabicyclo[2,2,2]octane (DABCO) and piperazine divinyl chloride or the reaction of cyclic ethers, polyamines, and alkyl halides. Quaternary salts formed by the reaction of, for example, iodoethyl dimethyl ethylenediamino 2-hydroxyethyl Glycidyl methacrylate (GMA) is N,N-dihydroxypropyl methacrylate. Quaternary formed by reacting with methylethylenediamine and ethyl iodide ammonium salt), and vinylbenzyltrimethylammonium chloride. Other exemplary monomers for anion exchange membranes include trimethylammonium ethyl methacrylate, Cryl chloride, 3-(acrylamidopropyl)trimethylammonium chloride, N ,N,N',N',N"-Pentamethyldiethylenetriaminedi(vinylbenzyl chloride Do(N,N,N',N',N"-pentamethyldiethylenetriamine and vinylbenzyl chloride quaternary salt of glycidyl chloride), glycidyl methacrylate / trimethylamine, or glycidyl Includes methacrylate / N,N-dimethylethylenediamine reaction products.

[0073] The anion exchange membrane embodiments described herein have a resistance of about 1.0 Ω-cm 2 Less than, e.g., about 0.5 Ω-cm 2 In certain embodiments, the anions described herein may have a resistivity of less than 100 nm. The ion exchange membrane may have a permselectivity of greater than about 90%, for example, greater than about 95%. In some embodiments, the ionogenic monomer for producing the anion exchange membrane is ethylene. Trimethylammonium ethyl methacrylate crosslinked with ethylene glycol dimethacrylate glycidyl methacrylate crosslinked with ethylene glycol dimethacrylate N,N,N',N',N"-dimethylethylenediamine reaction products and N,N,N',N',N"- Formed by polymerization of pentamethyldiethylenetriaminedi(vinylbenzyl chloride) Crosslinked ion transport polymer (N,N,N',N',N"-pentamethyldiethylenetriamine) amine and vinylbenzyl chloride) or 1,4-diazabicyclo[2,2,2] Octanedi(vinylbenzyl chloride)(1,4-diazabicyclo[2,2,2]octanedi The quaternary salt of diphenyl ether (DABCO) and vinylbenzyl chloride may be or may contain It can be seen.

[0074] Multifunctional monomers containing one or more ionic groups can be used. Examples include Monomers such as 1,4-divinylbenzene-3-sulfonic acid or its salts are not The degree of crosslinking can range from 2% to 60%. Suitable polyfunctional monomers for providing crosslinking with monomers containing charged groups include, but are not limited to, Examples include, but are not limited to, ethylene glycol dimethacrylate, 1, 3-Butanediol dimethacrylate, 1,3-Butanediol diacrylate, 1,4 -Butanediol dimethacrylate, 1,4-Butanediol diacrylate, 1,6- Hexanediol diacrylate, pentaerythritol triacrylate, tetraethyl Diethylene glycol dimethacrylate, divinylbenzene, trimethylolpropane triacrylate acrylate, isophorone diisocyanate, glycidyl methacrylate, trimethylol propionate Propane trimethacrylate, ethoxylated (n) bisphenol A di(meth)acrylate (n=1.5, 2, 4, 6, 10, 30), ethoxylated (n) trimethylolpropane Tri(meth)acrylate (n=3,6,9,10,15,20), propoxylated ( n) Trimethylolpropane triacrylate (n=3,6), vinylbenzyl chloride , glycidyl methacrylate, and the like.

[0075] The polymerization initiator may be a free radical polymerization initiator. Initiators include, for example, benzoyl peroxide (BPO), ammonium persulfate, 2,2'-azobenzenesulfonate, AIBN, 2,2'-azobis(2-methylpropionyl) 2,2'-Azobis[2-(2-imidazolin-2yl)propane] dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane], and and dimethyl 2,2'-azobis(2-methylpropionate).

[0076] The pore filling or saturation process of the substrate is carried out at a slightly higher temperature to reduce the solubility of air. In other embodiments, the pore or saturation process of the substrate can be carried out at high temperatures (e.g., >40° C.). The scanning can be performed after gentle vacuum treatment of the substrate sample submerged in the compounded solution. The substrate sample is pre-soaked and then placed on a polyester or similar sheet and covered with The immersed and covered substrate can be smoothed to remove any air bubbles. Yes, you can. Layer several pre-soaked sections together and then apply polyester or similar sheeting. The adhesive can be placed on the tray, covered with a cover sheet, and smoothed to remove any air bubbles.

[0077] The immersed substrates are then heated in an oven at a temperature and for the required time to initiate complete polymerization. The immersed substrate may be heated to a temperature and pressure sufficient to initiate and complete polymerization. It can be placed on a heated surface for the required time. Alternative methods for initiating the polymerization reaction UV light or ionizing radiation such as gamma rays or electron beam radiation can be used. The wire can be used to initiate the polymerization reaction.

[0078] The continuous pilot or production process involves saturating the porous substrate, initiating and completing the polymerization. This includes completing the process and washing or leaching non-polymerized species from the now formed film. The membrane can be optionally dried. Conditioning with salt solution involves placing a tank of salt solution in through or by dipping rolls of wound membrane or into modules This can be done in a continuous dipping process, such as after manufacturing.

[0079] If the monomer solution is formulated in a solvent that wets the substrate, the process involves removing the substrate from the roll to the monomer. by feeding the polymer compound into a tank and wiping off excess solution through it. The dipped substrate is a plastic sheet delivered from a roll. It is assembled between two layers of and sandwiched between two rolls to remove air and make a smooth Multi-layer assemblies can be produced. One exemplary sheet material is polyethylene terephthalate. The sheet material is a terephthalate film. Other sheet materials can be used. The polymer is passed through an oven or over heated rolls to initiate and complete polymerization. One alternative method is to pass the saturated sheet through an oven blanketed with inert gas. An inert gas may be suitable for use with high boiling point solvents.

[0080] UV light initiation with a suitable polymerization initiator can be used. This method initiates the polymerization. and exposing the assembly to UV light of sufficient intensity and for the required time to complete the For example, the three-layer assembly described may include a UV light source on one or both sides of the web. through a tunnel or other process device having an inlet and an outlet for the substrate web, With high boiling point formulations, the method can be carried out in an inert gas atmosphere. This can be done.

[0081] The cover sheet can be removed after polymerization. The membrane formed is then washed and , which may optionally be dried.

[0082] Organic solvents can be used as reactant carriers. One useful class of solvents is biphenyls. A polar aprotic solvent. Some examples of suitable solvents include dimethylacetamide, Dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide or - Organic solvents include ionic, triamide, acetonitrile, and acetone. It can be used to solvate monomers that contain groups and monomers that are not water soluble. One exemplary solvent is N-methylpyrrolidone. Other solvents that can be used are N-methylpyrrolidone, propanol and dipropylene glycol. In certain embodiments, alcohols, For example, diols such as isopropanol, butanol, various glycols, or glycerols. Similar hydroxy-containing solvents such as polyols such as ethyl alcohols can be used. Solvents are within the scope of this disclosure. The solvents discussed may be used alone or in combination. Some solvents are used with water to increase the solubility of ion-containing organic compounds. It is possible.

[0083] The monomer mixture is selected to engineer a crosslinked copolymer having a desired balance of properties. For example, water-soluble and / or swellable ionogenic monomers can be used to form membranes. When combined with a non-water-swellable comonomer, the high degree of ionic groups and reduced swelling in water are achieved. Such ion exchange membranes can be used for desalination. In particular, the exemplary copolymers have better physical strength in water and can be used in water immersion. There may be little dimensional change during use due to changes in ion content or temperature changes. Thus, an exemplary ion exchange membrane has suitable mechanical strength, e.g., for seawater electrodialysis, It can exhibit low electrical resistance and high counterion permselectivity.

[0084] The ion exchange membranes disclosed herein comprise a crosslinked ion transport polymer layer having a band gap covalently bonded thereto. It may include an electrically functionalized layer.

[0085] Many ion exchange membranes are multivalently selective. Multivalent ion selective membranes are membranes that transport multivalent ions. For example, the common cations used in ED may be selected from ion exchange membranes. The exchange membrane allows for faster transport of multivalent ions than monovalent ions. Transport usually occurs when ions with a higher charge experience a higher electric force while moving under the same electric field. This occurs because of attraction by

[0086] The ion exchange membranes disclosed herein may be monovalent selective membranes. By controlling charge factors such as surface depletion conditions, membrane hydrophobicity, degree of cross-linking, and membrane intrinsic charge conditions, Thus, it is possible to design to select singly charged ions over multiply charged ions. For example, The change in cross-linking degree and hydrophilicity of the cation exchange membrane makes the low water condition in the membrane unfavorable for multivalent ions. This can result in a significant retardation of multiply charged ions versus singly charged ions.

[0087] The monovalent selective membranes disclosed herein may have engineered surface modifications. The surface modification of the membrane is achieved by providing charged molecules on the membrane surface, resulting in a higher valence charge. The monovalent cation exchange membrane has a surface that is positively selective. For example, a strong acid cation exchange membrane may have sulfonic acid groups as the charged groups. Weak acid membranes can be functionalized with carboxylic acid groups that constitute fixed charged groups. Quaternary and tertiary positively charged ammonium salts can be used to form strong bases and The membrane can be functionalized with positively charged groups of weakly basic anion exchange membranes. Ion exchange membranes may have negatively charged molecules on their surfaces.

[0088] Furthermore, the strength of the surface charge repellency can be manipulated by controlling the charge distribution on the surface of the membrane. The strength of the charge repellent is usually determined by the number of charged molecules provided on the surface. In simple terms, the electric field strength in an ion exchange membrane is determined by dq / dx. is defined as where q is the number or concentration of charges and x is the depth along the ion transport.

[0089] Thus, in some embodiments, the charged functionalized layer formed on the surface of the membrane is a monovalent imid. While providing a stronger barrier or a much larger dq / dx value for highly charged ions compared to ions, The monolayer may be selected to have substantially no effect on the on-transport resistance. may not have a significant effect on the overall conductance of the membrane. In some cases, this may not have a significant effect on the transport of water molecules by the ion beam.

[0090] The cross-linked ion transport polymer layer of the ion exchange membrane support has an intermediate layer covalently bonded to the polymer layer. The intermediate layer can be functionalized by reacting it with a charge-functionalizing layer. In embodiments, the intermediate layer can be a molecule that includes an amine group. During the intermediate reaction, the amine group reacts with water. The intermediate layer is a surface-adsorbed polyether ether (PAH) bond that can be exchanged with ammonium to form four covalent bonds. Various primary, secondary and tertiary amines can be used to provide polyvalent amines, including polyethylenimine (PEI). It can provide significant selectivity for ions. The PEI molecular structure is shown in FIG.

[0091] As mentioned above, the charge functionalization layer can be selected to be a single layer. The functionalization layer can be a monolayer on the surface of the ion exchange membrane. The penetration of the functionalization layer into the bulk of the membrane can be may react with the charged ion transport layer, resulting in a loss of the membrane's permselectivity. Thus, the intermediate layer is coated with a cross-linked polymer without substantially penetrating the pores of the membrane. The nanoparticles may have a size sufficient to bind to the surface of a coated microporous polymer membrane. For example, The intermediate layer is of a size sufficient to substantially inhibit penetration through the micropores of the polymer substrate. may have:

[0092] The intermediate layer is selected to have a size larger than the pores of the microporous polymer substrate. Thus, in some embodiments, the intermediate layer has a thickness of at least 100 g / mo. The intermediate layer may comprise a molecule having a molecular weight of at least 600 g / mol. A molecular weight of at least 1,000 g / mol, for example at least 10,000 g / mol The intermediate layer may include molecules having a molecular weight of at least 40,000 g / mol, e.g. having a molecular weight of at least 50,000 g / mol or at least 60,000 g / mol The intermediate layer may include molecules having a molecular weight of at least 70,000 g / mol and at least 80,0 The intermediate layer may include molecules having a molecular weight of 60,000 g / mol to 10,000 g / mol. In an exemplary embodiment, the medium may include a molecule having a molecular weight of 120,000 g / mol. The intermediate layer may comprise branched PEI. Branched PEI has a molecular weight as described herein. possible.

[0093] Conventionally, PEI can be coated onto the surface of a cation exchange molecule by physical adsorption. Briefly, the physical adsorption of PEI ions onto the cross-linked polymer layer is shown in Figure 2. However, ionic bonds are generally not stable, so Molecules with charged faces may dissolve in water, resulting in a loss of selectivity.

[0094] The method disclosed herein involves forming a cross-linked ion transport polymer layer on the intermediate layer by chemical adsorption. Chemisorption generally involves attaching an intermediate layer to a surface of the substrate by covalent bonding. This may include chemically adsorbing the intermediate layer to the polymer layer so as to The ion exchange membrane supports disclosed herein may have an intermediate layer covalently attached thereto. Covalent bonds can improve the surface stability of ion exchange membranes. In some embodiments, the ion exchange membrane may be The device may have an operational life of more than 150 days, for example more than 400 days at room temperature. The ion exchange membrane may have an operational life of 2 years or more or 3 years or more in room temperature use. In general, the ion exchange membrane may have an operational life of more than 30 days at 80°C.

[0095] The intermediate layer may include a linking group configured to covalently bond the intermediate layer to the crosslinked ion transport polymer layer. The linking group may be selected to enhance stability. For example, the linking group may have It is selected to provide a bond that is sufficiently stable to withstand the organic compounds in the water being treated. In particular, the linking group may be substituted with benzyne, toluene, ethylbenzene, and It may be sufficiently stable to withstand organic contaminants such as ethylenediaminetetraacetate and xylene. The ion exchange membrane disclosed in the document is capable of removing organic pollutants from produced water, groundwater, brackish water, salt water, and seawater. It can be used to treat wastewater containing contaminants. The wastewater can be, for example, about 100 to 200 ml of water. In certain embodiments, the wastewater may contain, for example, about 100 to 1000 ppm TDS. 400ppm TDS, about 400-600ppm TDS, or about 600-1000ppm May contain pm TDS.

[0096] The monovalent selective cation exchange membranes disclosed herein contain at least one hardness ion. For example, the water to be treated may be used to treat water that contains at least one positively charged In certain embodiments, the water to be treated may contain Ca2 + and M. g2+ In addition, the present invention may include at least one hardness ion selected from the group consisting of The monovalent selective cation exchange membranes used in this process are known to cause damage to soil when using water with high sodium content. May cause damage to the soil, but magnesium and calcium are beneficial. Can be used.

[0097] In an exemplary embodiment, the linking group may be a styrene group. The chemisorption onto the bridge polymer layer is achieved by plasma grafting an amine interlayer onto its surface. and

[0098] The chemisorption of the intermediate layer can be carried out in a multi-step process. In one exemplary embodiment, As shown in Figure 3, the amine group reacts with sulfonyl chloride to provide a stable Briefly, the method for producing an ion exchange membrane is to form immobilized amine groups on a styrene-based polymer. The method may include covalently bonding the styrene layer to the crosslinked polymer layer to form the first intermediate layer. The styrene layer may contain sulfonyl chloride groups. The reaction bonds the styrene layer to the bulk of the substrate. For example, the reaction may be carried out for a period of time sufficient to cause the styrene layer to infiltrate into the pores of the substrate. A sufficient time may be used, particularly when the substrate is less than about 155 μm, e.g. In embodiments having a thickness of less than about 25 μm, this may be on the order of a few hours. The reaction may be carried out in less than about 10 hours. The reaction may be carried out in about 1-2 hours, about 2-5 hours, about 3-6 hours, The procedure can be carried out for about 4 to 7 hours.

[0099] In an exemplary embodiment, the styrene layer may include divinylbenzene (DVB). In such an embodiment, the method comprises attaching a sulfonyl chloride group to the DVB styrene layer. In order to bond the sulfonyl chloride group to the DVB styrene layer, this method may further include The method can include polymerizing and chlorosulfonating DVB. In an exemplary embodiment, Chlorosulfonation is the process of generating concentrated sulfuric acid or chlorosulfonic acid (ClSO3H) on DVB. This can be achieved by smoking. Chlorosulfonic acid can be hydrolyzed with caustic solution. In such an exemplary embodiment, the chlorosulfonation reaction can be carried out using ClS The O2 group is attached to DVB.

[0100] The chlorosulfonation reaction can be carried out for a sufficient amount of time to penetrate the majority of the substrate. The time sufficient for the chlorosulfonation reaction can be on the order of a few hours. The chlorosulfonation reaction can be carried out in less than about 10 hours. It can be performed in about 1-2 hours, about 2-5 hours, about 3-6 hours, or about 4-7 hours. Cut.

[0101] The method for producing the ion exchange membrane is to amplify the sulfonyl chloride groups of the first intermediate layer with an amine-based layer. and nitrifying the amine-containing groups to produce chemically immobilized amine-containing groups on the surface of the membrane support. The amine groups may include primary or secondary amines. Chemically immobilized amine groups are Generally, functionalizable amines can be used to design charged molecules. Furthermore, the amine groups can be selected based on the ability to penetrate the pores of the substrate. While being qualitatively inhibited, the amination reaction may be of sufficient size to bind to the outer surface of the substrate. The reaction can be carried out overnight. For example, the amination reaction can be carried out for about 10 to 18 hours. The chemically immobilized amine-containing group can be PEI or branched PEI, as described above. do.

[0102] The method comprises reacting the surface intermediate layer with a charged functionalized layer to form an ion exchange membrane support. For example, the method may include functionalizing a charged functional group by attaching a chemically immobilized amine. Any of the above-mentioned charged functionalized molecules may be attached to the membrane support. In certain embodiments, for example, to produce a cation exchange membrane, The method includes hydrolyzing PEI with a sulfonic acid group, e.g., a sulfonyl hydroxide. The prepared cation exchange membrane generally comprises a band gap covalently bonded to the ion exchange membrane support. Covalent bonding, as previously mentioned, will result in a more functionalized layer of the ion exchange membrane in use. It can provide excellent selectivity and stability.

[0103] The monoselective ion exchange membranes disclosed herein have at least 100% counterion selectivity. For example, the monovalent selective ion exchange membranes disclosed herein may have a permeability of about 100 The present invention may have a counterion permselectivity of between about 100% and 103%. The monovalent selective ion exchange membrane disclosed in the document has a Na / Ca ratio of 8 to 12 times at room temperature. The monoselective membranes disclosed herein may have an initial selectivity of about 7 Ω-cm. 2 Less than, e.g. For example, about 5 Ω-cm 2 Less than 2 to 7 Ω-cm 2 Between 3 and 5 Ω-cm 2 Between It may have a resistivity.

[0104] The function and advantages of these and other embodiments will be better understood from the following examples. These examples are intended to be illustrative in nature and are not intended to limit the scope of the invention. is not considered to be EXAMPLES

[0105] Example 1: Preparation of a cation exchange membrane test coupon The following experimental method was used to prepare small coupons for resistivity and counterion permselectivity testing. A 43 mm diameter coupon of porous membrane substrate was prepared to investigate the formulation and process effects. A rather large disk (50 mm diameter or A 105 mm aluminum weigh boat was used to cut the The coupons were sandwiched between two polyester film discs. is.

[0106] First, a template was created by thoroughly wetting a substrate coupon with the monomer solution. The combined solution was added to the aluminum boat and mixed until the porous support was saturated. The polyester film disk on which the substrate coupon is layered is then immersed in the solution. The saturated support was then removed from the monomer solution and a piece of polyester Remove any air bubbles by using a convenient tool, such as a small glass rod, to remove the bubbles. The pompom is removed from the coupon by smoothing or squeezing it, or by hand. A second polyester disc is then layered on top of the first coupon, sealing the coupon and the bottom and the top polyester film layer was smoothed to have complete surface contact between the A second porous substrate is then layered onto the top polyester film and saturated, smoothed, and Repeat the process to add a top layer of polyester film and two coupons and three protective poles. A multi-layer sandwich of polyester film layers was obtained. In a typical experimental run, 10 or more There is a multi-layer sandwich of saturated substrate coupon layers. If necessary, the edges of the aluminum boat The disk / coupon assembly was held in place by crimping.

[0107] The sample including the boat and coupon assembly was placed in an oven at 80 °C for up to 30 min. The bag was then removed, cooled, and the reacted cation exchange membrane coupons were then washed with 0.5N Place in NaCl solution at 40℃ to 50℃ for at least 30 minutes, and then soak in NaCl for up to 18 hours. It turned out to be enough.

[0108] The method described was suitable for preparing cation exchange membrane test coupons.

[0109] Example 2: Monovalent selectivity of cation exchange membranes To evaluate the selectivity between monovalent and multivalent ions, 0.15M NaCl and 0. A solution containing 15 CaCl2 was used to supply the dilute compartment. The electrodes were supplied with 0.30M KNO3 solution. The dilute stream had a total volume of about 75 ml. The concentrated stream (0.3M KNO3) was , 1000 ml of solution to ensure negligible concentration increase. Typically, 3 hours 7cm in the experiment time 2 A salt rejection of 25% could be reached at 70 mA for the membrane sample. Cut.

[0110] The current density is 100A / m 2 All three streams were 200m apart. The dilute stream was circulated by three peristaltic pumps with a nominal pumping speed of 1000 L / min. Samples were taken for ion chromatography (IC) analysis. The volume of the sample was 100.0 μl and diluted to 50 ml for analysis. Usually, 4 to 6 samples were The removal of samples did not affect the total amount of dilute stream. In most cases, the small concentration difference between the concentrated and dilute streams Water loss was minimal due to the addition of water to the sample. No volume adjustment was required for the IC analysis samples.

[0111] Conventional cation exchange membrane Figures 4A-4B show the results of the experiments using two conventional membranes, as described in the experimental procedures above. Ca in dilute stream over time of desalination (sec) 2+ and Na + Molar amount of ions (mol / The graph shows the Ca / Na selectivity (mol / L). 2+ and Na + The molar transport ratio between these two is about 2 for conventional cation exchange membranes. , mainly due to charge effects. 2+ Since the charge of the ion is large, Na + twist However, as the slope of the line indicates, Ca 2+ Ion and Na + Both ions were steadily removed.

[0112] Monovalent selective cation exchange membrane Prepared by the methods disclosed herein (e.g., as described in Example 5 below). In addition, a monovalent selective cation exchange membrane having PEI with a molecular weight of 600 g / mol was prepared by the above method. The results are shown in the graph in Figure 5. 2+ / Na + Selection The selective permeability was 11. 2+ compared to the unmodified conventional membranes mentioned above. , transport was delayed by 22-fold. Thus, the monovalent selective cation exchange membrane described herein , providing increased permselectivity compared to conventional cation exchange membranes.

[0113] Example 3: Preparation of membrane test coupons Porous polyethylene (PE) film (thickness 24 or 34 μm) is wrapped in styrene (ST) / Divinylbenzene (DVB) / N-methyl-2-pyrrolidone (NMP) solution 0.01 The membrane was prepared by soaking for ~4 hours. The polymerization initiator was added to the mixture, and the ST:DVB:NMP The composition of the solution was 7:1:2 (by mass). A PE film was saturated with the solution and two Mylar films were The solution was placed between the Mylar sheets. Air bubbles between the Mylar sheets were removed. After long-term exposure, To avoid the "white area" caused by evaporation of the solution, more solution was added. The film was then cooled to about 80-90°C. The membrane was heated to 4 °C for 1-4 hours. Typical membrane dimensions for such experiments are 4 x 15 in. .

[0114] The membranes so prepared were cut into 1.5 inch disk coupons. , ClSO3H / CH3Cl solution with a ClSO3H:CH3Cl composition of 1:2 (by volume) The membrane was then removed from the solution and rinsed with NMP and methanol. The rinsed membrane is then dried with a napkin and is ready for further processing and testing. It was deemed that there was.

[0115] The resistivity of such films is typically 2500 Ω-cm 2 There is no selective permeability. The resistance was beyond the measurement of the instrument.

[0116] Example 4: Preparation of cation exchange membranes from the membrane test coupons of Example 3 The membrane test coupons of Example 3 were processed to produce cation exchange membrane test coupons.

[0117] After drying with a napkin, the membrane was placed in a 1N NaOH solution for about 15 minutes. It was removed from the solution, rinsed with water, and adjusted with 0.5M NaCl solution.

[0118] The membrane has a resistance of 1.8 to 3 Ω-cm 2 The selective permeability of the counter ion is 101% to 104%. there were.

[0119] Example 5: Surface modification of the cation exchange membrane test coupons of Example 4 The cation exchange membrane test coupons of Example 4 were functionalized to produce monovalent and multivalent selective cation exchange membranes. A membrane exchange test coupon was prepared.

[0120] After drying with a napkin, the membrane was placed in a PEI aqueous solution overnight (approximately 15 hours). The membrane was removed from the PEI solution and rinsed with water. The film was immersed in 1N NaOH solution for 15 to 22 minutes to convert most of the SO2Cl groups on the substrate into SO Complete conversion to 3Na was confirmed.

[0121] The membrane surface was modified with PEI polymer molecules and various tests were carried out. 7 Ω-cm 2 The selective permeability of the counter ions was 100% to 103%.

[0122] Example 6: Groundwater remediation A typical groundwater sample has 800 ppm Na. + , 250 ppm Ca 2+ , 50 ppm Mg 2+ In reality, groundwater contains the three major cations. There is a large variation. The compositions tested here were average values.

[0123] The sample groundwater was treated with the monovalent selective cation exchange membrane described in Example 5 and the method described in Example 3. The results are shown in the graphs in Figures 6A and 6B. + , Ca 2+ , and Mg 2+ The concentration of ions was measured. The sodium adsorption ratio (SAR) was also measured. SAR is an important indicator of the water hardness requirements for water used for irrigation.

[0124] In short, the results show that the monovalent selective membrane of Example 5 can reduce the SAR value of the treated water to 3. In comparison, the cation exchange membrane of Example 3 removes all ions and only multivalent ions. Thus, the monovalent selective membranes described herein increase the SAR value by removing ions. , which may reduce the SAR value of the treated groundwater.

[0125] Example 7: Seawater treatment A monoselective cation exchange membrane as described in Example 5 was used to filter seawater for hardness removal. was processed. The removal of hardness in seawater is a process that is used in many processes such as the production of hypochlorite, the extraction of oil, and the production of table salt. The results are shown in Figure 7. Specifically, in the dilute stream Mg over time 2+ , Ca 2+ , and Na + The change in ion concentration is shown in the graph in Figure 7. Simply put, Mg 2+ and Ca 2+ The concentration of Na remains relatively constant. + ion Therefore, the monovalent selective membranes described herein can be used to reduce the concentration of N a + The ion concentration can be reduced.

[0126] Example 8: Stability of monoselective cation exchange membranes The monovalent selective cation exchange membrane of Example 5 was immersed in 0.5M NaCl solution at room temperature. A conventional cation exchange membrane with adsorbed PEI was also tested. Figure 8 shows the membrane permeability over time. In brief, after 150 days of immersion, the monovalent selective membrane exhibited a change in the permeability of Na + Ion pair Ca 2+ It has a permselectivity for ions greater than 9. Monovalent selective membranes are It has higher selectivity than conventional products on the market and also shows significant stability over time. Therefore, the monovalent selective membrane has better selectivity and longer service life than conventional membranes, and can be used for a long period of time. It is stable after use.

[0127] Example 9: Monovalent selective cation membrane performance investigation The performance of the monovalent selective cation membrane was evaluated using a 7 cm 2 Experiments using membrane coupons with a surface area of The selectivity was investigated under laboratory conditions using a lab ED module containing a dilute and concentrated compartment. The solutions in these compartments were determined using an anodized fluoride filter (shown in FIG. 9). The electrolyte K2SO4 circulates between the cathode and cathode compartments, and the peristaltic porosity The dilute stream had a total volume of about 75 ml and its ion The composition was monitored by ion chromatography (IC). The cations used in the test Both cation-exchange and anion-exchange membranes have high co-ion rejection with preferential transport of 98% of the counterion. The current density was selected to avoid operating above the current limit.

[0128] Synthetic groundwater composition (800 ppm Na + , 260 ppm Ca 2+ , 76 ppm M g2+ ) is used, 30A / m 2 Selection of monovalent selective cation exchange membrane at current density of Figures 10A and 10B show the concentration of target cations in the dilute compartment over time. Figure 10B shows the concentration of ions that are reduced by passing through a nonselective membrane. Figure 10A shows the concentration of all cations in the ion exchange membrane, whereas Figure 10B shows the concentration of only the cations in the ion exchange membrane. Interpreted + Figures 10C and 10D show the time course of the rarefaction compartments. The concentrations of the target cations in the samples are given in mol / L.

[0129] Experiments will also demonstrate the recovery of sea salt. The dilution compartment contains the major ions (17 000ppm Cl - , 2800 ppm SO4 2- , 9000ppm Na + , 120 0 ppm Mg 2+ , and 300 ppm Ca 2+ ) in the initial solution. and 11B are monovalent selective anion exchange membranes and 300A / m 2 With an applied current density of The concentration of selected ions in the concentration compartment was measured using a monovalent selective cation exchange membrane. The blue boxes represent the concentrations of major ions in the original seawater.

[0130] The graphs show the chloride (Figure 11A) versus sulfate (Figure 11B) in the concentrated compartment over time. The increase in the concentration of sodium (Figure 11B) relative to calcium and monovalent ions is clearly shown. The combination of selective anion and cation exchange membranes uses an ED process with both membranes. The applicability of the method to recover sea salt from seawater has been demonstrated. Combine a pair of active membrane cells to generate a specifically targeted ion composition in the EDR product water It is possible.

[0131] Initial selectivity and solubility of conventional / commercially available monovalent selective membranes and the monovalent selective membranes disclosed herein A comparison of life span selectivity (stability) is shown in Figures 12A and 12B. Selectivity is measured as a function of calcium ion concentration, either on the parts per million (ppm) or molar (M) concentration scale. The change in sodium ion concentration is expressed as the ratio of change in sodium ion concentration to the temperature.

[0132] Conventional / commercial membranes were fabricated by a method involving physical adsorption of PEI. The membrane selectivity is shown as a function of immersion time in 0.5M NaCl solution at a temperature of 0°C. The results are , the temperature correction previously derived from experiments in an Arrhenius plot with a slope of 2.5 / 10°C. As shown in the accelerated test, the monovalent cation selection method disclosed herein The loss of selectivity with the porous membrane is significantly reduced over time compared to conventional membranes. By extrapolating the lifetime from high temperature to normal operating temperature (as shown in FIG. 12B), Therefore, the acceptable life of the monovalent selective cation exchange membrane disclosed herein is approximately 100% selective for divalent cations. It is determined by the high selectivity of the monovalent cations.

[0133] Example 10: Use of monoselective cation exchange membranes How the monovalent selective cation exchange membranes disclosed herein are used in water treatment systems Examples of how it can be used are described in the examples below. The water quality of the EDR product and rejects is Using in-house finite element analysis (FEA) projection software for monoselective cation exchange membranes The scaling index (SI) of the reject water was calculated using the PHREEQC solution. software (a C++ program designed to perform a variety of aqueous geochemical calculations) A computer program written in a programming language is used to measure the EDR results at various times. The results were calculated using a non-selective EDR installation and a FEA model. The data was compared with field data.

[0134] Application 1: Minimization of industrial water brine Many industrial applications use reverse osmosis (RO) to produce low salinity water. O systems are limited by low recovery rates due to potential scale formation, but brine disposal can be a costly part of the overall process. can be used to treat the brine, achieving discharge limits and significantly reducing disposal costs.

[0135] One comparative application site had a reject stream TDS of 2297 mg / L The RO is operated at 75% recovery rate. Without further treatment, 25% of the total feed flow would be The adoption of non-selective EDR eliminates this problem. The line can be reduced to 5.7% of the feed flow rate. The monovalent selective cation exchange membrane is Increase recovery rate of EDR process from 82% to 90% before risk of CO3 scale precipitation By increasing the Table 1 shows the results of field tests and modeling of the monovalent selective cation exchange membranes for the streams. The major ion concentrations and SI of CaCO3 at maximum EDR recovery are shown.

[0136] [Table 1]

[0137] Application 2: Discharge of generated water The processes used to harvest oil and gas create challenges in dealing with environmental emissions. In some cases, the EDR system generates “produced water.” Desalination is the main component of the treatment process. The sample water was tested at a produced water facility, which is a component of the NIRS. It is water that contains a high concentration of silica.

[0138] The EDR pilot study reduced TDS to 8587 mg / L in the first step of the two-step process. From 100 mg / L to 2107 mg / L, it showed an instantaneous recovery of 88%, but the BaSO4 scale Higher recoveries could not be achieved due to the possibility of the formation of monovalent cations. By applying the selectivity from the ion exchange membrane, the system operates at an expected recovery rate of 98%. The same TDS reduction can be achieved from 97% recovery. Table 2 shows the predicted product yield with 97% recovery. and concentrate stream analysis are shown.

[0139] [Table 2]

[0140] Application 3: Agricultural desalination There is a need to consider alternative supplies of brackish water quality to reduce the pressure on freshwater sources for agricultural use. Some crops, such as barley and cotton, are more tolerant of saline conditions, but many are poorly suited to constant brackish water. When used, it generally results in salt accumulation in the soil, which is not properly leached by adding fresh water, adversely affecting yields. Salt-sensitive crops, including fruit trees, require even more care and are often , desalting will be necessary.

[0141] In addition to overall salinity, cation concentrations can have various effects on soil structural stability. This effect is due to the sodium adsorption ratio (SAR) and the cation ratio of structural stability (CR). The effect of these parameters on agricultural yields can be expressed as and salinity, the lower the SAR or CROSS value, the more stable the soil usually is. The formulas for SAR and CROSS are shown below.

number

[0142] The monovalent selective cation exchange membrane EDR is more selective for sodium and calcium than for calcium and magnesium. As a result, it can reduce TDS and have low SA for agricultural applications. In particular, monovalent selective cation exchange membrane EDR may be suitable for maintaining the R value. , with low energy and no additional process steps, as is required for many crops Maintains low SAR values ​​across the range of TDS concentrations.

[0143] The sample brackish feedwater was analyzed using a non-selective EDR and a monovalent selective EDR with the same product TDS. The product ion concentrations are shown in Table 3. The AR value is 0.16 compared to 6.59 for the non-selective process.

[0144] [Table 3]

[0145] Therefore, the monovalent selective cation exchange membranes disclosed herein are suitable for the treatment of industrial brine water. It is suitable for applications such as mining, produced water discharge, and agricultural desalination.

[0146] The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the term "plurality" means two or more items. "include," "contains," "carry," "have," "includes," and "contain" The term "includes" refers to any open form, whether in a written description or in a claim. It is a formula term, i.e. it means "including but not limited to." Therefore, the use of such terms shall include, but is not limited to, the items listed thereafter and equivalents thereof, as well as any other terms that may be used herein. In relation to claims, the terms "consisting of" and "comprising" are used to mean the inclusion of additional items. Only the transition phrase "qualitatively" is used as a closed or semi-closed transition phrase, respectively. The use of "first," "second," and "third" in a claim to modify a claim element is Ordinary use of terms such as "common" and "common" does not, in and of itself, constitute a claim element's assertion of superiority over another claim element. means the priority, ranking, or order in which the steps of a method or the temporal order in which the steps of a method are performed However, in order to distinguish between claim elements, certain claim elements may be designated with specific names. Only as a label to distinguish it from other elements with the same name (other than using ordinal terms) Used.

[0147] Having thus described several aspects of at least one embodiment, various modifications, alterations, and variations thereon may be made. It should be understood that modifications and improvements will readily occur to those skilled in the art. Any feature described in any one of the embodiments may be included in or may be combined with any feature of any other embodiment. Such alterations, modifications, and improvements are intended to be part of this disclosure. are contemplated and are intended to be within the scope of the present invention. The illustrations and drawings are merely examples.

[0148] Those skilled in the art will recognize that the parameters and configurations described herein are exemplary and that the actual parameters and configurations may vary. The meters and / or configurations will depend on the particular application in which the disclosed methods and materials are used. Those skilled in the art will also understand that they will be able to routinely derive equivalents to the specific embodiments disclosed. It should be possible to recognize or confirm using only simple experimentation.

Claims

1. A method for producing a monovalent selective cation exchange membrane, The styrene intermediate layer is chemically adsorbed onto a crosslinked ion transport polymer layer on the surface of a polymer microporous substrate, The styrene intermediate layer is chlorosulfonated to deposit a sulfonyl chloride base layer onto the surface of the polymer microporous substrate, The sulfonyl group layer is aminated to deposit the amine group layer onto the surface of the polymer microporous substrate, The amine group layer is functionalized with a charged compound layer to produce the monovalent selective cation exchange membrane, A method for producing a monovalent selective cation exchange membrane containing [a specific compound / component].

2. The method according to claim 1, comprising chemically adsorbing styrenedivinylbenzene onto the crosslinked ion transport polymer layer on the surface of a polymer microporous substrate.

3. The styrenedivinylbenzene is converted to chlorosulfonic acid (ClSO) ３ Chlorosulfonation with H) and ClSO ２ The method according to claim 2, comprising bonding a group to styrene DVB.

4. The aforementioned ClSO ２ The method according to claim 3, comprising amination with polyethyleneimine.

5. The branched polyethyleneimine having a molecular weight of at least 600 is the ClSO ２ The method according to claim 4, comprising amination.

6. The method according to claim 1, comprising functionalizing the amine layer with a positively charged group.

7. The method according to claim 6, comprising functionalizing the amine group with positively charged ammonium.

8. The method according to claim 1, further comprising immersing the polymer microporous substrate in a solution containing an ionogen monomer, a polyfunctional monomer, and a polymerization initiator to produce the crosslinked ion transport polymer layer.

9. Water sources to be treated; An electrochemical separation apparatus comprising at least one monovalent selective cation exchange membrane having a charge-functionalized layer covalently bonded to the surface of the cation exchange membrane, which is fluidly connected to the water source to be treated; and The treated water outlet is fluidly connected to the electrochemical separation device. A water treatment system, including a water treatment system.

10. The water source to be treated is Ca ２＋ and Mg ２＋ The water treatment system according to claim 9, comprising at least one hardness ion selected from the following.

11. The water treatment system according to claim 9, wherein the charged functionalized layer is a positively charged functionalized layer comprising at least one of a sulfonic acid group, a carboxylic acid group, a quaternary ammonium group, and a tertiary amine group hydrolyzed to a positively charged ammonium group.

12. The water treatment system according to claim 11, wherein the electrostatically functionalized layer is covalently bonded to the surface of the cation exchange membrane by a chemically adsorbed branched polyethyleneimine layer.

13. A method for facilitating water treatment using an electrochemical separation apparatus, To prepare a monovalent selective cation exchange membrane having a charge-functionalized layer covalently bonded to the surface of the cation exchange membrane, Instructing the user to attach the monovalent selective cation exchange membrane to the electrochemical separation apparatus, A method for facilitating water treatment using an electrochemical separation apparatus, including the use of such apparatus.

14. The electrochemical separation apparatus Ca ２＋ and Mg ２＋ The method according to claim 13, comprising instructing the user to fluidly connect to a water source to be treated that contains at least one hardness ion selected from.

15. To provide the aforementioned monovalent selective cation exchange membrane, To prepare a monovalent selective cation exchange membrane support having a polymer microporous substrate having an amine base layer covalently bonded to the surface of the polymer microporous substrate, The user is instructed to produce the cation exchange membrane by functionalizing the amine group layer with a charged compound layer, The method according to claim 13, including the method described in claim 13.

16. A monovalent selective cation exchange membrane, The material comprises a polymer microporous substrate and a positively charged functionalized layer covalently bonded to the surface of the polymer microporous substrate. The monovalent selective cation exchange membrane is a monovalent selective cation exchange membrane having an initial selectivity of 8 to 12 times Na / Ca (pm) at room temperature.

17. A monovalent selective cation exchange membrane according to claim 16, having a 4 to 8 times Na / Ca (ppm) selectivity after 400 days in 0.5 M NaCl at room temperature.

18. A monovalent selective cation exchange membrane according to claim 16, having an initial selectivity of 10 to 40 times Na / Ca (moles) at 80°C.

19. The monovalent selective cation exchange membrane according to claim 18, which has a 3 to 6 times Na / Ca (mol) selectivity after 30 days with 0.5 M NaCl at 80°C.

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