Device and process for functionalizing and ion exchange of polymer membranes

Abstract

Device for treating an ion-conducting polymer membrane, comprising: (a) a housing configured to hold a liquid treatment solution for ion exchange or quaternization of the membrane, wherein the membrane is an ion-conducting membrane selected from anion exchange membranes, cation exchange membranes and proton exchange membranes, each having an ion exchange capacity of 0.5 to 5.0 mEq / g dry polymer; (b) at least one support element positioned in relation to the polymer membrane, the support element being configured such that at least one surface of the membrane is in contact with the liquid treatment solution containing a reactive or ionic species; and (c) at least one inlet and one outlet designed to allow circulation, refilling or exchange of the liquid treatment solution within the housing; wherein: the liquid treatment solution contains an ionic species suitable for ion exchange or a reactive species suitable for quaternization; and The device is configured to perform ion exchange or quaternization by bringing the membrane into contact with the liquid treatment solution.

Description

Technical field

[0001] The present disclosure relates to a device and a process for treating polymer membranes, including functionalization and ion exchange. background

[0002] Ion exchange membranes are used in a variety of electrochemical systems, such as water electrolyzers, fuel cells, redox flow batteries, and electrodialysis units. These membranes include anion exchange membranes (AEMs), cation exchange membranes (CEMs), and proton exchange membranes (PEMs). Each type contains fixed ion groups in a polymer matrix and mobile counterions that move across the membrane to complete an electrochemical cycle. For example, AEMs comprise polymers with positively charged groups that conduct anions and repel cations; CEMs comprise polymers with negatively charged groups that conduct cations and repel anions; and PEMs comprise acidic polymers that conduct protons.

[0003] Conventional methods for fabricating ion-conducting membranes, such as anion exchange membranes (AEMs), often leave halide counterions—typically chloride or bromide—in the cast or functionalized polymer after polymerization or quaternization. These halides can accelerate the corrosion of metallic components in electrochemical devices, impair catalytic activity, and reduce the long-term stability of membranes. After quaternization, the membranes may also contain bromide or tosylate counterions, which must be converted to more stable hydroxide or carbonate forms to achieve the desired performance characteristics. Previous approaches have not been entirely successful in uniformly and completely removing or replacing these ions throughout the membrane structure.

[0004] There is a need for a device and a process that can perform these membrane treatment steps in a consistent and scalable manner. Brief description

[0005] The disclosure relates to a method for treating a membrane to exchange halide ions in the membrane for hydroxide or carbonate ions. By performing such a treatment, such as ion exchange prior to MEA fabrication, the formation of corrosive halide salts in the electrochemical stack is avoided, thus improving durability and reliability. The disclosure also provides apparatus and system designs that enable batch or continuous processing of long membrane rolls on an industrial scale.

[0006] In one aspect, the device comprises a housing for a membrane structure with a spacer between adjacent membrane layers. The spacer allows a fluid flow and provides openings for a treatment solution, e.g., a metal hydroxide or carbonate solution, which is in contact with the membrane surfaces facing the device for a sufficient time to replace halide ions with hydroxide or carbonate ions.

[0007] In embodiments, the membrane structure incorporates a spiral configuration and the spacer allows the solution to flow from a first axial end of the membrane structure and a second axial end of the membrane structure.

[0008] In embodiments, providing the membrane structure involves arranging the spacer along a flat surface of the membrane and wrapping the membrane with the spacer arranged on the flat surface of the membrane around a tube.

[0009] In embodiments, bringing the membrane structure into contact with the solution involves positioning the membrane structure with the spiral configuration within a housing filled with the solution.

[0010] In some embodiments, bringing the membrane structure into contact with the solution involves positioning the membrane structure within a housing, with its axial ends facing opposite end faces of the housing, and pumping the solution through the housing to allow axial flow of the solution through the membrane structure. In some embodiments, the pressure of the solution within the housing is maintained at a specific level.

[0011] According to another aspect of the disclosure, a device for treating polymer membranes is disclosed. The device includes a membrane to be treated and at least one spacer that contacts the membrane surface. The spacer is arranged to define a gap or channel through which a solution can come into contact with the membrane surface, thereby enabling ion exchange or ion conversion. The device includes a housing containing the membrane, the spacer, and the solution.

[0012] In some embodiments, the device also includes a pump that is fluidically connected to the housing to pump the solution inside the housing. In certain cases, the pump is kept below a specific pressure.

[0013] According to a further aspect of the disclosure, a membrane treatment system is disclosed. The membrane treatment system includes a housing containing a membrane structure (membrane and spacers) and a pump that circulates a solution through the housing to enable ion exchange between the membrane and the solution.

[0014] In embodiments, the membrane treatment system also includes a salt trap located downstream of the device and configured to remove salt from a solution-salt mixture exiting the housing. In embodiments, the membrane treatment system also includes a filter located downstream or upstream of the pump to filter the solution supplied to the device.

[0015] In embodiments, the membrane treatment system includes a plurality of devices arranged in a series or parallel configuration.

[0016] In some embodiments, the membrane is an anion exchange membrane. Description of drawings Fig. Figure 1 shows a perspective top view of an assembly with a membrane structure arranged spirally around a tube. Fig. Figure 2 shows a perspective side view of the assembly of Fig. 1, wherein the layers of spacers are shown arranged between the layers of the membrane, with a solution moving between the layers of the membrane. Fig. Figure 3 shows an arrangement for forming the membrane structure of Fig. 1 consisting of a coil of a cast membrane and a coil of the spacer. Fig.Figure 4 shows a spacer with a mesh structure arranged on a surface of the membrane and shows a variety of openings in the mesh structure. Fig. Figure 5 shows an assembly with a membrane structure having layers of webs of spacers extending along the edges of the membrane and between the layers of the membrane. Fig. Figure 6 shows a side view of part of the membrane structure of Fig. 5. Fig. Figure 7 shows a sectional view of the assembly, illustrating the arrangement of the membrane and the two webs in the membrane structure of Fig. 5 illustrates. Fig. Figure 8 shows a perspective side view of the belt of the membrane structure of Fig. 5. Fig. Figure 9 shows a system for treating a membrane with a solution, e.g. to facilitate the treatment of the membrane with the solution. Fig.Figure 10 shows an embodiment of a membrane structure, wherein the membrane and the spacer are wound around a solid shaft. Fig. Figure 11 shows another embodiment of a membrane structure, wherein the membrane and the spacer are wrapped around a perforated tube. Fig. Figure 12 shows a schematic cross-sectional representation of a membrane structure illustrating circumferential flow between adjacent membrane layers. Fig. Figure 13 shows an alternative system in which the membrane structure is arranged in a configuration rolled up around several rolls. Description

[0017] The following terms have the following meanings:

[0018] "Anion exchange membrane (AEM)" refers to a polymer membrane or polymer film that either (i) carries reactive sites (e.g., carbon halogen or carbon tosyl groups) configured to be converted by quaternization (e.g., with an amine-containing treatment solution) into an anion-conducting membrane containing covalently bonded cationic groups (e.g., quaternary ammonium), or (ii) is itself an anion-conducting polymer membrane or film containing covalently bonded positively charged groups that conduct anions and repel cations. The positively charged groups of the AEM attract electrostatically mobile, negatively charged ions (counterions) from the surrounding solution, which migrate through the membrane during operation.References to “AEM”, as used herein, include such precursors when the context concerns their treatment or conversion into the quaternized, anion-conducting form.

[0019] “Counterions” refer to the mobile ions present in an ion exchange membrane that balance the fixed ionic charges of the polymer backbone. In an AEM, the counterions are anions such as halides (Cl⁻). - , Br - , I - , F - ) Hydroxide (OH - ), Carbonate (CO3 2- ), Nitrate (NO3), Sulfate (SO4) 2 ) or organic anions such as acetate, formate, or tosylate. In a CEM or PEM, the counterions are cations such as protons (H₂). + , H3O + ), alkali or alkaline earth metals (Li + , N / a + , K + , Mg 2+ , Ca 2+), transition metal ions or organic cations such as ammonium, tetraalkylammonium, imidazolium, pyrrolidinium, or phosphonium species. The counterions migrate through the membrane and enable ion transport and exchange during operation.

[0020] “Anion exchange membrane electrolyzers (AEME)” or “AEM water electrolyzers (AEMWE)” are electrochemical cells that use an AEM to separate the anode and cathode and split water into hydrogen and oxygen.

[0021] “Cation exchange membrane (CEM)” refers to a semipermeable polymer membrane that contains covalently bonded negatively charged groups such as sulfonate groups (-SO3). - ), carboxylate groups (-COO) or phosphonate moieties (-PO3) 2 ) contains. These fixed anionic groups attract mobile cations, including H + , Li + , N / a + , K + , NH4 + , Mg 2+ , Ca 2+or multivalent and organic cations that migrate across the membrane under an applied potential or concentration gradient.

[0022] "Proton exchange membrane (PEM)" refers to a polymer membrane with fixed acidic groups such as sulfonic acid, phosphonic acid or carboxylic acid components that exchange protons (H + or H3O + ) as charge carriers. The PEM functions as a solid electrolyte in electrochemical devices by selectively conducting protons and blocking electron and gas transport.

[0023] "Ion exchange membrane (IEM)" refers to anion, cation, and proton exchange membranes. An IEM comprises fixed ion sites and corresponding counterions capable of selective ion transport and exchange. The specific ion form—e.g., hydroxide, carbonate, halide, proton, metal cation, or organic ion—depends on the membrane chemistry and the conditioning or ion exchange treatment applied.

[0024] The "True Hydroxide Conductivity" test method refers to the procedure described by Dekel et al. (Ziv & Dekel, Electrochemistry Communications, 2018) for measuring the ionic conductivity of a membrane. In this method, the carbonate or bicarbonate ions remaining in the membrane are electrochemically purified by applying an external current under controlled conditions. This current converts these ions back to CO2, leaving the membrane in a fully hydroxide state. The conductivity measured in this state is considered the true OH conductivity, which reflects the intrinsic anion transport capacity.

[0025] "Water absorption" or "weight gain" refers to the weight difference (W%) of a membrane before and after immersion in water for a specific period (e.g., 5 hours, 1 day, 1 week, longer, etc.). The weight gain is calculated as follows: W% = (W2 - W1) / W1 × 100, where W1 is the weight of the membrane before immersion and W2 is the weight after immersion.

[0026] "Ion exchange capacity (IEC)" refers to the total number of ion-exchangeable sites in a membrane, expressed in milliequivalents per gram (mEq / g) of dry polymer. The IEC is determined by acid-base titration.

[0027] "Ion exchange efficiency" or "activation" refers to the degree of replacement of original counterions in a membrane by desired counterions after ion exchange treatment, expressed as a percentage of the theoretical maximum. The efficiency can be determined by elemental analysis, ion chromatography, or X-ray photoelectron spectroscopy (XPS) based on residual halide or other ions before and after treatment.

[0028] "Device" and "system" refer to devices or assemblies configured to circulate or contain one or more liquid treatment solutions in contact with a membrane. The device or system may be used for ion exchange, conditioning, regeneration, or chemical functionalization of the membrane, including reactions such as quaternization or other ionic substitution or exchange processes. Unless otherwise specified, references to an "ion exchange device" or "ion exchange system" refer generally to such devices or systems and are not limited to a particular ion exchange chemistry or ionic species.

[0029] The present disclosure relates to a device, a system, and a method for treating a membrane by contacting the membrane with a liquid treatment solution under controlled conditions. The treatment solution may contain ionic species and / or reactive agents to perform (i) ion exchange, replacement, or conditioning of counterions in anion, cation, or proton exchange membranes; and / or (ii) quaternization of halogenated polymers with amines, optionally followed by rinsing and subsequent ion exchange to bring the membrane into a desired ionic form.

[0030] The device includes at least one spacer that is in contact with the membrane to physically support the membrane and maintain flow paths for the solution to enable efficient ion exchange. In embodiments, the spacer maintains the separation between adjacent membrane layers so that open flow channels for the ion exchange solution can come into uniform contact with the membrane surfaces.

[0031] Depending on the configuration, the membrane can be folded, stacked in layers, or wound spirally around a shaft or tube, with the spacer positioned between the membrane layers. The spacer can be in the form of a mesh film, strap-like strips along the membrane edges, a film with raised bumps, or a compressible material.

[0032] In embodiments, the spacer is a compressible spacer that deforms elastically when the membrane swells upon immersion in solution, thereby maintaining contact between the spacer and the membrane while avoiding excessive mechanical stress. The compressible spacer can be formed from a polymer foam, an elastomeric film, a non-woven felt, or an expanded mesh that compresses by 5 to 70%, 10 to 60%, or 15 to 50% of its original thickness under the swelling forces of the membrane. Compressibility can be provided by the inherent elasticity of the material or by a three-dimensional structure such as corrugations, embossing, or cavities that allow deformation under pressure. This property enables swelling during either ion-exchange conditioning or chemical functionalization, such as…the quaternization, while maintaining uniform contact between the treatment solution and the membrane.

[0033] In one embodiment (not shown), the spacer consists of a frame or plate with a plurality of protrusions or projections distributed across its surface. These protrusions provide point contacts with the membrane, thereby keeping adjacent membrane surfaces separated, while maintaining open channels for solution flow between them. The protrusions can be arranged in a regular grid, a staggered pattern, or a random distribution, and can be circular, oval, or polygonal in shape. Depending on the membrane thickness and desired channel height, the protrusions can have heights ranging from 0.05 mm to 2 mm, 0.1 mm to 1 mm, or 0.2 mm to 0.5 mm. Such a spacer can be manufactured from polymer, elastomer, or composite film material by casting, embossing, or thermoforming and provides mechanical support with minimal obstruction of solution flow.

[0034] In some embodiments, the use of a spacer during ion exchange can produce a visible or detectable surface pattern or indentation on the membrane that corresponds to the surface, design, or geometry of the spacer, such as mesh openings, ribs, or raised protrusions. This surface pattern or indentation can be an indicator that the membrane was processed in contact with a spacer using an ion exchange device described herein.

[0035] Anion exchange membranes (AEMs) for counterion exchange: In some embodiments, the device serves to exchange counterions in AEMs. In their as-cast state, AEMs typically contain halide counterions, such as chloride, bromide, or iodide. To optimize performance, these halides are preferably exchanged for hydroxide ions (OH⁻). - ) or carbonate ions (CO3 2-) or other anions suitable for the intended electrochemical environment using the described device and method.

[0036] In embodiments, AEMs comprise a polymer that has been chemically modified to incorporate fixed cationic groups, such as quaternary ammonium, phosphonium, imidazolium, or pyrrolidinium groups, which are responsible for the attraction and transport of anions. In embodiments, the base polymer for use in the AEM is selected from the group consisting of poly(ethylene) and polypropylene functionalized with quaternary ammonium groups, polysulfone (PSU), polyphenylene oxide (PPO), poly(arylene ether), polyvinyl alcohol (PVA), poly(etheretherketone) (PEEK), and styrene block copolymer (SBC) compositions.

[0037] In one embodiment, the AEMs are self-supporting (freestanding) membranes made from functionalized poly(aryl-piperidinium) resins. In such polymers, quaternary ammonium groups are incorporated into the arylpiperidinium backbone to provide fixed cationic sites for anion conduction. These membranes exhibit high chemical stability and mechanical strength, allowing them to be processed in roll form.

[0038] In embodiments, the AEMs are Orion Polymeras CMX or Durion membranes. These membranes are poly(arylpiperidinium)-based anion exchange membranes containing attached quaternary ammonium groups and are provided as freestanding films.

[0039] In some embodiments, the AEMs are sourced from Inonomr Innovation Inc. under the trade name Aemion+™. These membranes are poly(arylpiperidinium) polymers with quaternary ammonium groups, designed for high hydroxide conductivity and mechanical robustness.

[0040] In embodiments, the AEMs are Sustainion™ membranes from Dioxide Materials. These membranes are based on functionalized poly(arylene ether) backbones bearing quaternary ammonium substituents and are provided in the form of freestanding films suitable for use in the device.

[0041] In embodiments, the AEMs are based on a functionalized poly(arylpiperidinium) scaffold, available from Versogen as PiperION membranes, or on polynorbornene-based anion exchange membranes from Promerus, LLC.

[0042] In embodiments, the AEMs are membranes commercially available under the AEMTuff™ brand from Notark Corporation. These membranes are cross-linked, fluorine-free anion exchange membranes containing quaternary ammonium functional groups to provide ionic conductivity. They are supplied as freestanding films approximately 40 to 60 µm thick with a pentablock copolymer architecture for dimensional stability and durability. AEMTuff membranes exhibit extremely low swelling and long-term alkaline stability, for example, more than 10,000 hours in 1 M KOH at 80 °C, making them suitable for robust handling and ion exchange processing in the described device.

[0043] In embodiments, the AEM membranes comprise a styrene-based multiblock copolymer composition with a selectively quaternized middle block, as disclosed in U.S. Patent Publication No. US20230312849A1, which is incorporated herein by reference. The selectively quaternized hydrogenated styrene block copolymer comprises at least one block A derived from (i) para-substituted vinylaromatic monomers and / or (ii) unsubstituted vinylaromatic monomers; at least one block B comprising polymerized hydrogenated 1,4-isoprene or 1,2- and 1,4-butadiene units; and one block C as a middle or end block derived from a vinylaromatic monomer susceptible to quaternization.The selectively quaternized hydrogenated styrene block copolymer has a general configuration of a pentablock, tetrablock, or triblock containing random B / C or C / B segments, with an ion exchange capacity (IEC) of 0.5 to 4.0 mEq / g; and block C is quaternized to provide quaternary ammonium cations with a degree of quaternization of 30 mol% to 95 mol%.

[0044] In embodiments, the AEM comprises a quaternized styrene block copolymer as disclosed in US patent publication no. US20240209202A1.

[0045] The conductivity of AEMs is determined by their ability to dissolve anions such as hydroxide (OH⁻). - ), Carbonate (CO3 2-) or other anions, depending on the application. In embodiments, the AEM has an ionic conductivity in the range of 1 to 150 millisiemens per centimeter (mS / cm) at 25 °C, depending on the ion exchange capacity (IEC) and the degree of hydration of the polymer. In embodiments, the conductivity is 1 to 150 mS / cm, 2 to 100 mS / cm, or 5 to 100 mS / cm at 25 °C, as measured by the true hydroxide conductivity test. In embodiments, the membrane has an IEC of approximately 0.5 to 3.0 mEq / g of dry polymer before the ion exchange treatment (before the exchange of the halide counterions by hydroxide) and exhibits the aforementioned conductivity ranges after conversion to the hydroxide form.

[0046] In certain embodiments, the membrane has an IEC of 0.5 to 5.0 mEq / g of dry polymer before ion exchange treatment (before the exchange of halide or other counterions by hydroxide) and exhibits the conductivity ranges mentioned above after conversion to the hydroxide form. The conductivity is generally correlated with the IEC, although the relationship is not strictly linear.

[0047] For efficient ion exchange to occur, the AEM must exhibit a sufficient degree of hydration to maintain high ionic conductivity. In embodiments, the membrane has a water absorption value of 1 to 100 wt%, or more than 2%, or less than 40%, measured after 4 weeks at 25°C, based on the total weight of the membrane. Together with the IEC (ionic conductivity), the degree of hydration determines the observed conductivity: a higher IEC supports higher conductivity, but adequate hydration is necessary to realize the membrane's ion transport potential.

[0048] In embodiments, the AEM is characterized prior to ion exchange in that it has a halide content (e.g., Br₂) relative to the total weight of the polymer membrane. -) of 1 to 20 wt% or 5 to 18 wt% or 10 to 15 wt%, as determined by ion chromatography or elemental analysis. This original halide content represents counterions that are replaced during ion exchange by hydroxide, carbonate, or other target ions.

[0049] Cation exchange membranes (CEMs): In embodiments, the device serves to treat cation exchange membranes (CEMs) by contacting the membrane with an electrolyte solution containing the desired exchange ions under controlled conditions. CEMs contain fixed anionic groups, such as sulfonate groups (-SO3). - ), Carboxylate broths (-COO - ) or phosphonate groups (-PO3) 2- ), which are electrically balanced by mobile cations within the polymer matrix. During ion exchange, these mobile cations are replaced by other cations provided by the contacting electrolyte solution.

[0050] In certain embodiments, the CEM originally contains sodium (Na). + ) or potassium (K + ) as charge-balancing ions and is converted into a form of lithium (Li + ), Magnesium (Mg 2+ ) or calcium (Ca 2+ ) by immersing the device in a solution of the corresponding metal salt, such as a nitrate, chloride, or sulfate, or by circulating this solution through the device. Conversely, a membrane in the form of a polyvalent cation can be converted into a monovalent form (e.g., Na). + or H +The membrane is converted by bringing it into contact with a solution containing the desired exchange cation. The process proceeds through ion diffusion and charge equalization between the membrane and the solution until the original cations are replaced by ions from the electrolyte. Completion of the exchange can be verified by weight stabilization, ion chromatography, or elemental analysis of the remaining cations.

[0051] In embodiments, the CEMs comprise polymers carrying sulfonic acid, carboxylic acid, or phosphonic acid groups, such as perfluorosulfonic acid (PFSA) polymers, polysulfonated poly(etheretherketone) (SPEEK), sulfonated polysulfone, sulfonated polyimide, polybenzimidazole, or aromatic copolymers containing fluorinated or hydrocarbon segments. CEMs can be provided as freestanding films or reinforced membranes and are suitable for processing in the apparatus either in roll form or as individual sheets.

[0052] Prior to ion exchange, CEMs typically contain metal cations such as Na. + , K + , Ca 2+ or Mg 2+in a concentration of approximately 1 to 15 wt% or 3 to 10 wt% based on the total weight of the dry membrane, as determined by ion chromatography or elemental analysis. After ion exchange or reconditioning, the residual concentration of the original cations is reduced by at least 80% or to less than 1000 ppm, depending on the treatment conditions.

[0053] In embodiments, the CEM exhibits an ion exchange capacity (IEC) in the range of 0.5 to 5 mEq / g or 0.8 to 4.0 mEq / g of dry polymer and an ionic conductivity of 1 to 150 mS / cm or 5 to 80 mS / cm, measured at 25°C using a standard two-probe conductivity method, after ion exchange or reconditioning. The degree of hydration, after equilibration in deionized water at 25°C, can range from 5 to 40 wt%, depending on the polymer backbone and counterion type.

[0054] Proton exchange membranes (PEMs): In embodiments, the device is configured for the treatment of proton exchange membranes (PEMs) containing solid sulfonic acid or similar acidic groups whose charge is transferred by protons (H₂). + ) is balanced. During the treatment process, these protons can be exchanged for metal cations present in the surrounding electrolyte. For example, a PEM in its proton form can be converted into a lithium form (Li + ), sodium form (Na + ), potassium form (K + ), magnesium form (Mg 2+ ) or calcium form (Ca 2+ The membrane can be converted to a metal ionic form by immersing it in a solution of the corresponding metal salt, such as lithium nitrate, sodium chloride, or potassium sulfate, or by circulating it through the device. Conversely, a PEM that has been converted to a metal ionic form can be reprotonated with an acidic solution such as hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid.

[0055] The conversion can take place in one or more stages, e.g. H + → Na + → Li + or conversely, to mitigate swelling and control ion mobility. The extent of proton or metal ion replacement can be monitored by conductivity measurement, titration of the released ions, or weight stabilization.

[0056] In embodiments, PEMs include polymers carrying sulfonic acid or related acidic groups, including perfluorosulfonic acid polymers such as Nafion™, Aquivion™, or Flemion™, as well as hydrocarbon-based alternatives such as sulfonated poly(etheretherketone) (SPEEK), sulfonated polysulfone, or acid-doped polybenzimidazole (PBI). These membranes can be processed in the same mechanical configuration as the AEM and CEM membranes, enabling uniform solution exposure and ion exchange within the same device housing.

[0057] Before ion exchange, PEMs are usually in the proton form (H₂). + or H3O + ) before or contain residual metal ions such as Na + , K + or Ca 2+ from the manufacturing process or a previous operation. The total cation content can range from 0.5 to 10 wt% based on the dry membrane or from 0.01 to 1 mEq / g in ion exchange equivalents. After treatment in the device, the target ionic form—proton, lithium, sodium, or others—is obtained with a residual foreign ion content of less than 1000 ppm or reduced by at least 90%. In embodiments, the PEM exhibits an IEC of 0.5 to 5 mEq / g of dry polymer and an ionic conductivity of 10 to 150 mS / cm or 20 to 100 mS / cm at 25°C. Water uptake is typically between 5 and 35 wt%, depending on the counterion species and polymer composition.

[0058] Quaternization of halogenated polymers: In embodiments, the device is configured to perform an in-situ quaternization treatment of polymer membranes or films containing covalently bonded halogen atoms, such as bromine or chlorine (AEM precursors as defined above). During this treatment, a liquid solution containing one or more amine compounds is circulated through or held in contact with the membrane under controlled temperature and residence conditions. The amine compounds interact with the covalently bonded halogen sites to form quaternary ammonium groups, thereby converting the precursor polymer into a cationic, anion-conducting membrane. Quaternization can be performed in batch mode, with the membrane being immersed in the amine solution, or in continuous mode, with the amine solution being circulated through the device housing.

[0059] In embodiments, the amine compound is selected from primary, secondary, tertiary, or cyclic amines, including but not limited to trimethylamine (TMA), triethylamine (TEA), N,N-dimethylethylamine (DMEA), N,N-dimethylbutylamine (DMBA), N-methylpiperidine, N-methylmorpholine, 1,4-diazabicyclo[2.2.2]octane (DABCO), imidazole, N-methylimidazole, or mixtures thereof. In other embodiments, diamines or multifunctional amines may be used to introduce crosslinked or quaternized structures with multiple sites. Representative diamines include, among others, ethylenediamine, 1,6-hexamethylenediamine, N,N,N',N'-tetramethyl-1,3-propanediamine, piperazine, homopiperazine, m-phenylenediamine, 4,4'-oxydianiline, diethylenetriamine, and tetraethylenepentamine.The treatment solution may contain the amine in water, alcohol or a mixed aqueous-organic solvent at a concentration of 0.1 to 5 M and may optionally contain a base scavenger or a phase transfer agent.

[0060] During quaternization, halogen-substituted sites in the polymer are gradually converted to quaternary ammonium groups, while soluble halide species are released into the treatment solution. The solution temperature ranges from 10°C to 80°C or from 25°C to 60°C, depending on membrane stability and the desired degree of conversion. After completion of the treatment, the amine solution is withdrawn and the membrane is rinsed with deionized water or alcohol to remove any remaining soluble substances. A subsequent ion-exchange conditioning step can then be performed in the same apparatus to remove the halide counterions (e.g., Br⁻) generated during quaternization. -or Cl - ) by hydroxide (OH - ), Carbonate (CO3 2- ) or to replace other desired anions.

[0061] The degree of quaternization (DQ) of the treated membrane ranges from 20 mol% to 95 mol% or 40 mol% to 90 mol%, as determined by elemental analysis or NMR spectroscopy. After quaternization and subsequent ion exchange, the membrane typically exhibits an ion exchange capacity (IEC) of 0.5 to 5.0 mEq g⁻¹. -1 dry polymer and an ionic conductivity of 1 to 150 mS cm -1, measured at 25 °C. The dimensional change under hydrated conditions can be less than 15%, depending on the polymer backbone and crosslinking density. The quaternized membrane can serve directly as an anion exchange membrane or as an intermediate for further chemical or ionic conditioning. In embodiments, the use of the quaternization device ensures uniform conversion across the membrane surface, corresponding to a degree of quaternization within the aforementioned ranges and consistent with substantially complete utilization of the reactive halogen or tosyl sites.

[0062] In embodiments, the device is configured for treating polymer membranes that have been previously functionalized, for example by bromination or tosylation, to introduce reactive leaving groups. The device performs a quaternization treatment on such membranes by circulating an amine-containing solution through or in contact with the membrane under controlled conditions. This treatment converts the reactive halide or tosylate groups into quaternary ammonium sites and simultaneously removes the residual ionic species generated during the conversion. Subsequent rinsing or conditioning by ion exchange can be performed in the same device to replace any remaining halide or tosylate counterions with hydroxide, carbonate, or other desired anions.

[0063] Post-treatment and conditioning of the membranes. After the conversion of brominated or tosylated precursors to the quaternary ammonium form, the membrane can be further conditioned using the device to remove or replace any residual ionic species generated during treatment. In some embodiments, the liquid treatment solution contains hydroxide, carbonate, or other anions suitable for replacing halide or tosylate counterions, resulting in a membrane in its ionic operating form. The same device can also be used for intermediate rinsing, neutralization, or solution replacement between treatments to ensure uniform properties across the membrane surface. The treated membrane is then ready for further processing, drying, or subsequent assembly.

[0064] Sequential functionalization pathways for AEM and PEM formation. In embodiments, the device and method can be used to perform a stepwise functionalization treatment of membranes to produce anion exchange membranes (AEM) or proton exchange membranes (PEM) from hydrogenated polymer precursors.

[0065] For AEM formation, the process typically involves two stages: (i) a first functionalization step, such as bromination or tosylation of the polymer to introduce reactive or activated sites, followed by (ii) a second functionalization step, such as quaternization with an amine-containing treatment solution to introduce quaternary ammonium groups as cationic sites of the membrane. If a brominated or tosylated intermediate is used, a subsequent ion exchange step can be performed in the same apparatus or in series with a second apparatus to replace halide counterions with hydroxide, carbonate, or other desired anions.

[0066] For PEM formation, a single functionalization treatment, such as sulfonation or the introduction of other acidic groups, is sufficient to create the proton-conducting structure, followed by ion conditioning using the device. The ability to perform these operations sequentially by exchanging different treatment solutions or circulating them through the same hardware enables efficient and reproducible membrane preparation with a common device platform.

[0067] Form and handling characteristics of the membrane. After treatment in the device, the membranes are characterized as freestanding films with sufficient mechanical integrity for use in unwinding, coating, winding, slitting, and other web processing operations. In embodiments, the membranes can be processed in roll form or as stacked films in the device, regardless of the type (anion, cation, or proton exchange) or the treatment (ion exchange, conditioning, or quaternization).

[0068] In one embodiment, the membrane thickness ranges from 1 to 150 µm, or 5 to 100 µm, or 10 to 80 µm, or 20 to 50 µm. In certain cases, the membrane length is 5 to 1000 m, or 20 to 500 m, or 50 to 250 m, with a width of 10 to 100 cm, or 25 to 50 cm, or 30 to 40 cm. Due to these dimensions and mechanical properties, the membranes can be used in all the treatment processes described above, in continuous or batch configurations.

[0069] Treatment Method: The device and method described herein are suitable for treating polymer membranes of various types—including anion, cation, and proton exchange membranes, as well as halogenated or hydroxyl-functional membranes—by bringing the membrane into contact with a liquid treatment solution for a controlled duration. During treatment, a solution containing ionic or functionalizing agents is circulated or held in contact with one or more membrane surfaces until the desired ion exchange, conditioning, or chemical modification is achieved. The extent of the treatment is determined by parameters such as residence time, solution concentration, temperature, and membrane configuration within the housing.

[0070] In some embodiments, the treatment can be carried out in batch operation by immersing the membrane or membrane structure in the solution for a selected contact time, or in continuous operation by circulating the solution through the housing using a pump. The contact or residence time is selected between 10 minutes and 48 hours in batch operation or between 0.1 and 6 hours in continuous operation, depending on the membrane type and treatment chemistry. The treatment solutions used in the device can contain ionic or functionalizing species suitable for the respective operation, e.g., hydroxide, carbonate, or other anions, as previously defined, as well as suitable amine-containing solutions for quaternization treatment. The specific concentration, solvent composition, and contact time are selected according to the membrane chemistry and the desired degree of conversion.

[0071] In various embodiments, the concentration of the treatment solution ranges from 0.01 to 7 M or 0.1 to 5 M, and the temperature ranges from 10°C to 80°C or 20°C to 60°C. The pumping or flow system ensures sufficient circulation to provide uniform exposure of the membrane surfaces without mechanical deformation or compression of the spacer layers.

[0072] Representative methods include, but are not limited to: (a) ion exchange or conditioning, whereby originally present counterions in the membrane (e.g. halides, protons or metal cations) are replaced by other ions such as hydroxide, carbonate, sulfate, nitrate or desired cations (Li + , N / a + , K + , Ca 2+etc.); and (b) quaternization treatment, in which halogen-substituted polymers are contacted with amine-containing solutions to introduce quaternary ammonium sites. Each of these treatments is carried out within the same apparatus architecture, so that sequential or one-step treatment of membranes with interchangeable solutions is possible.

[0073] In continuous or semi-continuous operation, the residence time of the membrane in contact with the treatment solution is determined by the membrane feed rate, the volume of the housing, and the length of the flow path through the spacer or roller arrangement. In roller-based configurations, where the membrane moves through a static bath, the residence time is determined by the immersion length and feed rate, corresponding to the ranges described above. The process can therefore be adjusted to achieve uniform conversion or ion exchange across the entire membrane surface.

[0074] In various embodiments, the contact time between the membrane and the treatment solution is controlled to achieve the desired degree of ion exchange or functionalization. In batch operation, the membrane can be immersed in the treatment solution for 6–48 hours, 12–36 hours, or 18–24 hours at a temperature of 20–60°C. In continuous operation, the solution is circulated through the housing for an effective residence time of 1–6 hours or 1.5–4 hours at comparable temperatures. The circulation rate ranges from 0.01 to 10 liters per minute. -1 or 0.05 to 5 l min -1 , depending on the housing volume and membrane area, and is sufficient to provide uniform contact without mechanically deforming the membrane.

[0075] In embodiments such as a roller-based configuration, where the solution is maintained as a static bath and the membrane is advanced through the bath via a series of rollers, the effective residence time of the membrane in the solution is controlled by the membrane advance rate and the path length through the housing. In this case, the residence time corresponds to the same residence time ranges described for continuous circulation operation (e.g., 1–6 hours, 1.5–4 hours, 2–3 hours).

[0076] After treatment, the membrane can be rinsed with deionized water, alcohol, or another compatible solvent to remove any remaining soluble substances. If desired, a subsequent treatment step—e.g., ion exchange after quaternization or amination after tosylation—can be performed in the same apparatus without removing the membrane. In embodiments, the treated membrane exhibits a reduction in residual unwanted ions (e.g., halides or foreign metals) of at least 80% or to less than 1000 ppm, as determined by ion chromatography, elemental analysis, or X-ray photoelectron spectroscopy (XPS).

[0077] After treatment, the membrane exhibits ionic and mechanical properties corresponding to its conditioned ionic form. The ion exchange capacity (IEC) of the treated membrane ranges from 0.5 to 5.0 mEq g, depending on the membrane type and functionalization chemistry. -1 dry polymer. After ion exchange or quaternization, the membrane typically exhibits an ionic conductivity of 1 to 150 mS cm. -1 At 25°C, the dimensional change upon hydration is less than 15%. The water absorption value is generally zero, ranging from 1 to 100 wt%, depending on the ionic form and polymer composition.

[0078] In embodiments, the use of the disclosed device and system achieves a high degree of ion exchange within the treated membrane. The ion exchange efficiency, expressed as the percentage of original counterions replaced by the desired ions, can reach at least 80%, 90%, or 95%, corresponding to essentially complete membrane activation. This high efficiency reflects the uniform flow distribution and controlled residence time within the device, thereby minimizing areas of incomplete exchange and ensuring reproducible conditioning over large membrane areas.

[0079] The treatment methods described above can be carried out using the device configurations shown in the figures. The device facilitates uniform contact of the solution with both membrane surfaces through the use of spacers and defined flow or diffusion paths, enabling uniform ion exchange or functionalization across the entire membrane area.

[0080] With reference to the Fig. 1-2 includes the method in some embodiments to facilitate the exchange of halide ions of membrane 100 by the ions of the solution (represented by the arrows in Fig. 2) the provision of a membrane structure 102 which is located in the Fig. 1 and Fig.Figure 2 shows the membrane 100 and at least one spacer, e.g., a single spacer 104, which is arranged in contact with a surface 108 of the membrane 100. In the Fig. In the embodiment shown in Figure 1, the membrane structure 102 includes the membrane 100 and the spacer 104, which are arranged in a spiral configuration, such that the membrane 100 is arranged in a plurality of circular membrane layers 110 (e.g. layers formed by the spiral winding), wherein the spacer 104 is arranged in a plurality of spacer layers 112, such that a single spacer fold 112 is arranged between two adjacent membrane layers 110.

[0081] In embodiments, the membrane structure is formed by using a cast membrane, wherein the membrane is arranged or coated on a substrate. Accordingly, the substrate is removed from the membrane, and then the membrane is placed next to the spacer, with one surface of the membrane in contact, before the membrane and the spacer are wound together to form a coil. An example of a method for forming the membrane structure 102 is given in Fig. 3 shown. As in Fig.As shown in Figure 3, a spool 200 of a cast membrane 202 is attached to a suitable first roll 300 to allow the cast membrane 202 to be unwound from the spool 200. As shown, the cast membrane 202 includes the membrane 100, which is arranged, attached, or coated on the surface of a substrate 204. The substrate 204 can be a PET (polyethylene terephthalate) substrate. Additionally, a spool 210 of the spacer 104 is attached to a second roll 302 to unwind the spacer 104 from the spool 210.

[0082] In embodiments, to form an assembly 120, as in the Fig. 1 and Fig.Figure 2 shows that the substrate 204 is separated from the membrane 100 by the membrane structure 102, by peeling and removing the substrate 204 from the cast membrane 202. The peeled substrate 204 engages with a tube or shaft attached to a third roller 306 to wind the substrate 204 onto the tube or shaft.

[0083] Furthermore, the specialist personnel position a free end of the spacer 104 so that it rests against a free end of the membrane 100 peeled from the cast membrane 202. The membrane structure 102, and thus the assembly 120, is then formed by winding the membrane 100 and the spacer 104 together onto a tube 122, as shown in the Fig. 1 and Fig.Figure 2 shows a fourth roller 308 attached to it. In embodiments, for winding the substrate 204 in a spiral configuration and for winding the membrane structure 102 around the tube 122 in a spiral configuration, the third roller 306 and the fourth roller 308 can act as drive rollers, while the first and second rollers 300 and 302 can be the driven rollers. Accordingly, the membrane structure 102 is wound around the tube 122 and the peeled substrate 204 is wound around the shaft, while the membrane 100, the substrate 204, and the spacer 104 are unwound from their respective spools 200 and 210 in response to the rotation of the third and fourth rollers 306 and 308.It should be noted that when the membrane 100 and the spacer 104, which rests against the surface of the membrane 100, are wound around the tube 122, the spacer 104 and the membrane 102 are arranged such that a single circular spacer fold 112 is located between each of the two adjacent or successively arranged membrane layers 110. The membrane 100 can be sprayed with water to facilitate the engagement of the membrane 100 with the spacer 104. In this embodiment, the spacer 104 can be a film made of woven or non-woven fabric, the width of which is essentially the same as that of the membrane 100.

[0084] In some embodiments, the cast membrane 202 can include two substrates arranged such that the membrane 100 is embedded between them. In such a case, both substrates are peeled or removed from the surfaces of the membrane 100 before the membrane 100 is attached to the spacer 104. In this case, two third rolls 306 can be used. In some embodiments, the membrane 100 can be used to form the membrane structure 102 without the substrate 204. In this case, a coil of the membrane 100 is mounted on the first roll 300 to form the membrane structure 102, and the third roll 306 is omitted.

[0085] In Fig.4 The spacer 104 comprises a network structure with a plurality of strands 132 extending in a first direction, for example a longitudinal direction, and a plurality of second strands 134 extending in a second direction, for example a lateral direction, which intersect the plurality of first strands 132 and define at least one opening, for example a plurality of openings 136, between them. Due to the openings 136 of the spacer 104, the solution that flows, is present, or is arranged between the two adjacent membrane layers 110 comes into contact with the facing surfaces of the membrane layers 110, thereby facilitating ion exchange between the two membrane layers 110 and the solution.

[0086] With reference to the Fig. 5, Fig. 6 and Fig.Figure 7 shows an alternative membrane structure 102'. As shown, the membrane structure 102' includes the membrane 100 and two spacers 104a, 104b in the form of belts or webs 140a, 140b, arranged along the two longitudinal edges 142, 144 of the membrane 100, the membrane structure 102' being arranged in a helical configuration around the tube 122 and forming an assembly 120'. With reference to Fig. 6 and Fig. 8 The belt 140a has a substantially cuboid shape with a plurality of through holes 150 arranged along a length of the belt 140a, each hole 150 extending along a width of the belt 140a. When the belt 140a is assembled with the diaphragm 100, the Fig.The solution moves between the adjacent membrane layers 110 through the holes 150 of one of the belts 140a, 140b and touches the facing surfaces of the successively arranged membrane layers 110 and leaves the membrane layers 110 through holes 150 of the other of the belts 140a, 140b.

[0087] In embodiments such as those described in Fig.As shown in Figure 8, an upper surface of the belt 140a includes a groove 158 extending over the entire length of the belt 140a, and a lower surface of the belt 140a includes a projection 160 extending over the entire length of the belt 140a. It should be noted that in the membrane structure 102', the projection 160 associated with a fold of the belts 140a, 140b is located within the groove 158 of the adjacent fold of the belts 140a, 140b, with the membrane 100 being arranged between the projection 160 and the groove 158, and membrane layers 110 being attached between the layers of the belts 140a, 140b. This "lane" configuration leaves an open channel between the membrane layers, allowing the membrane to swell freely without being restricted by a lining, and ensuring access of the electrolyte to both sides of the membrane during treatment.Accordingly, the projection 160 and the groove 158 facilitate the correct alignment of the adjacent layers of the belts 140a, 140b.

[0088] The membrane structure 102' is formed in a similar manner to the membrane structure 102, except that instead of a single spacer coil 210, two coils of belts 140a, 140b are mounted on two separate rollers, and the belts 140a, 140b are arranged along the longitudinal edges 142, 144 of the membrane 100 peeled from the cast membrane 202 and then wound spirally.

[0089] In embodiments, the membrane structure 102' includes a plurality of reinforcing bars extending between the membrane layers 110 and running substantially perpendicular to the belts 140a, 140b and connected to the belts 140a, 140b to give additional strength to the membrane structure 102' and to prevent bulging or warping of the membrane layers 110.

[0090] Although the membrane structure 102, 102' is shown in a spiral configuration, it should be noted that the membrane structure 102, 102' can be arranged in the form of a film, with the layers of the membrane 100 arranged one on top of the other as a long, flat film, and the spacer 104 or the belts 140a, 140b arranged between adjacent layers. In some embodiments, the membrane structure 102, 102' comprises a plurality of separate membranes 100 arranged one on top of the other in a film-like manner, with a plurality of spacers 104 or belts 140, 140b arranged between the plurality of membranes 100. Although the flat or spiral configuration of the membrane structure is considered, the membrane structure can be arranged in any other suitable shape or configuration such that a spacer or belt is arranged between adjacent layers or layers of the membrane 100.

[0091] It is noted that the membrane 100 swells when it comes into contact with the solution, and accordingly the spacers 104, 104a, 104b are compressible spacers adapted to allow the membrane 100 to swell in order to prevent distortion of the shape of the membrane structure 102, 102' while the solution can flow through the space or openings defined between adjacent layers of the membrane structure 102, 102'.

[0092] After the formation of the membrane structure 102, 102', the method involves immersing or contacting the membrane structure 102, 102' in the solution. For this purpose, the membrane structure 102, 102', i.e., the assembly 120, 120', is arranged in a suitable housing, and the solution is passed or pumped through the housing at a predefined rate. In embodiments, the solution is circulated at a relatively low pressure (e.g., < 2 bar). In some embodiments, the solution is not pumped through the housing but is stored in the housing, and the membrane structure 102, 102' is immersed in the solution and held there for a specific duration to allow an exchange of halide ions for hydroxyl or carbonate ions.

[0093] In some embodiments, the membrane structure is rinsed with deionized water after ion exchange to remove residual salts and then dried, e.g., with air or nitrogen, before further processing or assembly. This optional rinsing / drying step reduces the carryover of salts into downstream processes.

[0094] In Fig.Figure 9 shows a system 400 that facilitates the soaking of the membrane structure 102 in the solution. The system 400 includes a device 402 with a housing 404 having a first end face 406 and a second end face 408 arranged opposite the first end face 406. In the illustrated embodiment, the housing 404 is a hollow cylindrical housing 408, and the first end face 406 is a base 410 of the housing 404, while the second end face 408 is a removable cover 412 of the housing 404. However, the housing 404 can also have any other shape, e.g., cubic, cuboid, or any other suitable shape known in the field.

[0095] As in Fig.As shown in Figure 9, the assembly 120 of the device 402 is arranged inside the housing 404. In the assembly, one axial end, e.g., a first axial end 154, of the tube 122 is connected to the cover 412 of the housing 404, while another axial end, i.e., a second axial end 156, of the tube 122 is located near or in contact with the base 410 of the housing. The tube 122 also includes an inlet opening, defined near the first axial end 154, and an outlet opening, located near the second axial end 156 of the tube 122. A line leads from a pump 420 to the inlet opening of the tube 122 to supply the solution to the device 402. In some embodiments, the inlet opening of the tube 122 may extend outside the housing 404.Alternatively, the inlet opening of the tube 122 is arranged inside the housing 404, and the tube can extend inside the housing 404 and be connected to the tube 122. Accordingly, in the illustrated arrangement of the device 402, the solution enters the tube 122 through the inlet opening of the tube 122, flows through the tube 122, exits the tube 122 through the outlet opening located near the base 410 of the housing 404, enters the housing 404, and then moves upwards to the cover 412 and through the membrane structure 102.

[0096] To store the solution, the system 400 includes a tank 422, and the pump 420 pumps or delivers the solution to the device 402, i.e., to the pipe 122. In some embodiments, the system 400 may also include a filter 424, which is arranged downstream of the pump 420 and between the pump 420 and the device 402, to filter foreign particles from the solution before the solution is conveyed into the housing 404 and through the membrane structure 102, in order to prevent damage to the membrane structure 102 or clogging of the space defined between successively arranged layers 110 of the membrane. Although the filter 424 is shown downstream of the pump 420, it can also be arranged upstream of the pump 420 and between the pump 420 and the tank 422.

[0097] The system 400 can also include a salt trap or filter 430, which is arranged downstream of the device 402 and fluidically connected to an outlet 432 of the housing 404 to receive a mixture of solution and salt exiting the housing 404. As shown, the outlet 432 is located on the top of the housing 404; that is, the cover 412 defines the outlet 432 of the device 402. It should be noted that salt is formed due to the chemical reaction that takes place between the polymer of the membrane 100 and the solution, enabling the exchange of the halide ions of the membrane 100 for the hydroxyl or carbonate ions of the solution. The salt trap 430 is arranged to remove the salt from the solution and return the filtered solution to the tank 422. In some embodiments, the salt trap 430 can be omitted.

[0098] A flow path of the solution within the device 402 is now described. The solution enters the device 402 from the pump 420 through the inlet opening of the tube 122, which is located near the cover 412 of the housing 404, flows through the tube 122 and exits the tube 122 through the outlet opening of the tube 122, which is located near the base 410 of the housing 404. Upon exiting the tube 122, the solution begins to fill the housing 404 and moves upwards towards the lid 412, exiting the housing 404, i.e., the device 402, through the outlet 432. As the solution flows upwards, i.e., along the axial direction of the membrane structure 102, i.e., the tube 122, the solution, due to the presence of the openings 136 or the gap defined between the layers 110 of the membrane 100, enters the space between the layers 110 of the membrane 100 and touches the facing surfaces of the layers 110 of the membrane 100.

[0099] In some embodiments where the membrane structure 102' is used, the solution between the layers 110 of the membrane 100 enters through the holes 150 of one of the belts 140a, 140b and leaves the membrane structure 102' through the holes 150 of another of the belts 140a, 140b.

[0100] Although it has been shown that the solution enters the tube 122 from the top of the housing 404 and exits the housing 404 from the top of the housing 404, as shown and conceived, it is also conceivable or possible that the solution enters the tube 122 or the housing 404 from an end face and exits from any other face, e.g. the opposite end face of the housing 404, and the scope of the disclosure is not limited by the locations of entry and exit of the solution from the housing 404.

[0101] When the solution flows through the membrane layers 110 and comes into contact with the membrane surface, a chemical reaction takes place between the polymer of the membrane 100 and the solution, causing the exchange of halide ions from the membrane 100 for hydroxyl or carbonate ions from the solution. It should be noted that while the solution is pumped into the housing 404, the pumping rate is controlled to keep the housing 404 filled with the solution and to maintain a desired contact or residence time between the solution and the membrane surfaces. This facilitates the chemical reaction that leads to the exchange of ions between the membrane polymer and the solution. The reaction of the solution with the polymer forms a salt, which mixes with the solution to form the solution-salt mixture. This mixture exits the housing 404 through the outlet 432.In this way, the pump 420 enables a continuous flow of the fresh solution into the housing 404, while the mixture of solution and salt is removed from the housing 404.

[0102] In the illustrated embodiment, the system 400 comprises a single device 402; however, the system 400 can also comprise a plurality of devices 402 arranged either in a series configuration or a parallel configuration. In the series configuration, the outlet 432 of one device 402 is connected to an inlet opening of another device 402, and so on. In this way, the solution exiting one exchange device 402 is supplied to the adjacent device 402 to exchange halide ions for hydroxyl or carbonate ions.

[0103] In a parallel configuration, each of the devices 402 is connected to the pump 420 to receive the solution from the tank 422. The supply from the pump 422 is divided into a plurality of feeders, each feeder delivering to a separate device 402. The solution exiting the plurality of devices 402 is directed into the tank 422.

[0104] In Fig.Figure 10 shows an embodiment of a membrane structure 120''. The structure 120'' is similar to the assembly 120, except that the membrane 100 and the spacer 104 are wound around a solid shaft 122'' instead of the tube 122. In this case, the solution enters the housing of the device through an inlet opening defined at a first end face of the housing and exits the housing through a second end face, which may be located opposite the first end face. In this case, the solution moves axially between the membrane layers 110.

[0105] In Fig.Figure 11 shows another embodiment of the membrane structure 120'''. The assembly 120''' is similar to the assembly 120, except that a tube 122''' of the assembly 120''' has a plurality of outlet openings 158''' extending radially along the tube 122''' and located below the spiral membrane structure 102. In this case, as the solution exits the tube 122''' through the outlet openings 158''', it moves circumferentially around the tube 122''' and between the membrane layers 110, as shown in Figure 11. Fig. Figure 12 shows the schematic cross-sectional representation of the membrane structure.

[0106] In Fig.Figure 13 shows an alternative system 1200. System 1200 facilitates ion exchange between the membrane 100 and the solution without requiring the spacer 104, 104a, 104b. System 1200 includes a housing 1202, and the solution is stored inside the housing 1202 (as a static bath) or continuously or intermittently supplied by a pump inside the housing 1200 (for continuous or filled operation). A coil of untreated membrane 100 is arranged outside the housing 1202 as a supply reel, and the treated membrane is wound around a suitable shaft rotatably attached to another reel arranged outside the housing 1202. System 1200 includes a plurality of reels 1204 arranged inside the housing 1202 and rotatably attached to the housing 1202.The membrane is moved by the housing 1202, which is immersed in the solution, along the plurality of rollers 1204, contacting each roller 1204. The residence time of the membrane 100 in the solution can be controlled by adjusting the speed of its movement through the housing 1202, enabling a continuous "web process" suitable for treating long membrane rolls without interruption. This maximizes the throughput and uniformity of the ion exchange and eliminates the need for linings. In this embodiment, the plurality of rollers 1204 is arranged in a substantially horizontal direction, i.e., along the length of the housing 1202. However, the plurality of rollers 1204 can also be arranged vertically, i.e., along the height of the housing 1202.

[0107] Examples 1 to 7 (bromide-hydroxide ion exchange from AEM). In these examples, an anion exchange membrane in the form of a pentablock copolymer membrane from Notark Corporation was used in the form of bromide (Br). - ). The membrane was characterized by high mechanical strength, low swelling (< 10% dimensional change in 1 M KOH at 80 °C) and alkali resistance of more than 10,000 hours in 1 M KOH at 80 °C, having a nominal thickness of 50-60 µm and an ion exchange capacity (IEC) of approximately 1.6-1.8 mEq / g, which allowed for roll-to-roll handling and repeated immersion in hydroxide or carbonate solutions.

[0108] Membrane samples were cut into 2 cm x 5 cm strips and immersed in aqueous solutions of potassium hydroxide (KOH) under various test conditions to simulate batch operation of the device, including variations in hydroxide concentration, temperature, residence time, and the use of a swelling-promoting solvent such as ethanol. With the exception of Example 6, which was performed at 60°C, all other examples were performed at 25°C. Weight loss and in-plane ionic conductivity were measured to determine the degree of conversion from the bromide to the hydroxide form. Conductivity was determined using the true hydroxide conductivity method (Dekel et al., Electrochemistry Communications, 2018). Table 1 Sentence Electrolyte (M, solvent) Time (hours) Activation (wt%) Conductivity (mS / cm, 60°C) Notes 1 1 M KOH (aqueous) 8 35 26 Start of the partial exchange 2 1 M KOH (aqueous) 12 50 32 Progressive conversion 3 1 M KOH (aqueous) 24 60 36 Nearing completion 4 1 M KOH (aqueous) 48 100 41 Complete exchange of Br- to OH- 5 2 M KOH (aqueous) 24 98 42 Highly concentrated accelerated exchange 6 1 M KOH + 25% EtOH 1 95 40 Quick Activation 7 2 M KCl → 2 MKOH (sequ.) 24 100 43 Two-stage uniform exchange

[0109] The results show that the bromide-to-hydroxide exchange in aqueous KOH proceeds uniformly and can be accelerated by increasing the hydroxide concentration, raising the temperature, or adding a swelling-promoting solvent such as ethanol. Under optimized conditions (1 M KOH + 25% EtOH at 60 °C), a nearly complete exchange was achieved within approximately 30 minutes with an ionic conductivity of ≈ 40 mS / cm at 60 °C, which corresponds to or even exceeds the manufacturer's specifications for the hydroxide form.

[0110] Under all test conditions, the residual halide content decreased by ≥ 90% compared to the starting bromide, and the membranes retained their mechanical integrity without visible deformation. Fully converted membranes exhibited conductivities of 35–45 mS / cm at 60°C and < 1% residual halide, consistent with the reported properties of the starting membrane.

[0111] Performance and Benefits: The treatment process applied to CEMs and PEMs offers measurable and controllable improvements in membrane performance. The change from a multivalent metal form (e.g., Mg) 2+ or Ca 2+ ) to a monovalent or proton form increases the ionic conductivity by at least 20-200% (e.g., from 5-20 mS / cm in Mg). 2+ -Form at 10-60 mS / cm in the H + - or Na +-form at 25 °C). Converting the membrane to a lithium or sodium form can reduce water absorption by 10–40% and dimensional swelling by at least 5%, at least 10%, or 7–25%, respectively, compared to the proton form, while maintaining conductivity values ​​for alkaline or battery environments. Changing the ionic form can also alter the tensile modulus by up to 20%, 30%, or 40%, improving mechanical robustness without compromising transport efficiency. Because the disclosed system allows the same membrane to be reconditioned or converted in situ simply by changing the contact solution, electrode corrosion and scaling due to electrolyte changes are minimized. Under comparable operating conditions, such in-situ treatment can extend membrane lifetime by at least 25–50% compared to conventional solid ionic operation.

[0112] The disclosed device and system can be applied to anion, cation, or proton exchange membranes by selecting an electrolyte solution containing the appropriate ions. The device functions both as an activation platform for newly fabricated membranes and as a reconditioning unit for membranes used in electrochemical cells, providing consistent control of ion shape, conductivity, and mechanical stability across various membrane chemistries and electrochemical applications. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 20230312849A1

[0043] US 20240209202A1

[0044] Cited non-patent literature

[0000] Dekel et al., Electrochemistry Communications, 2018

[0108]

Claims

[1] Device for treating an ion-conducting polymer membrane, comprising: (a) a housing configured to hold a liquid treatment solution for ion exchange or quaternization of the membrane, wherein the membrane is an ion-conducting membrane selected from anion exchange membranes, cation exchange membranes and proton exchange membranes, each having an ion exchange capacity of 0.5 to 5.0 mEq / g dry polymer; (b) at least one support element positioned in relation to the polymer membrane, the support element being configured such that at least one surface of the membrane is in contact with the liquid treatment solution containing a reactive or ionic species; and (c) at least one inlet and one outlet designed to allow circulation, refilling or exchange of the liquid treatment solution within the housing; wherein: the liquid treatment solution contains an ionic species suitable for ion exchange or a reactive species suitable for quaternization; and The device is configured to perform ion exchange or quaternization by bringing the membrane into contact with the liquid treatment solution. [2] Device according to claim 1, wherein the support element comprises a roller around which the membrane is wound. [3] Device according to claim 1, wherein the support element is a spacer and the spacer comprises a structure selected from the group consisting of: a) a network structure with a plurality of first strands spaced apart in a first direction and a plurality of second strands spaced apart in a perpendicular second direction; b) strap-shaped strips arranged along the longitudinal edges of the membrane and containing holes to allow the flow of solution between the membrane layers; and c) a film or frame with a multitude of protrusions or ridges distributed over its surface to maintain separation between adjacent membrane layers. [4] Device according to any one of claims 1 to 3, wherein: the membrane is an anion exchange membrane with halide counterions selected from chloride, bromide or iodide and The liquid treatment solution contains ionic species selected from the group consisting of hydroxide, carbonate, bicarbonate ions and mixtures thereof in a concentration of 0.1 to 7 molar (M), wherein the ionic species replace the halide counterions of the membrane with hydroxide or carbonate ions during treatment. [5] Device according to any one of claims 1 to 3, wherein: the membrane is a cation exchange membrane (CEM) containing anionic functional groups selected from sulfonate, carboxylate or phosphonate groups with charge-balancing cations selected from hydrogen, sodium, potassium or other metal cations, and The liquid treatment solution contains ionic species selected from the group consisting of lithium, sodium, potassium, magnesium and calcium ions in a concentration of 0.01 to 7 molar (M), wherein the ionic species are exchanged during treatment by the charge-balancing cations of the membrane. [6] Device according to any one of claims 1 to 3, wherein: the ion exchange membrane is a proton exchange membrane (PEM) comprising acid groups selected from sulfonic acid, phosphonic acid, or carboxylic acid groups, each acid group having a charge-balancing proton; and The liquid treatment solution contains ionic species selected from the group consisting of: (i) Protons provided by an acid selected from hydrochloric acid, sulfuric acid, nitric acid or phosphoric acid, in a concentration of 0.01 to 7 molar (M) to return the membrane to its protonate form, or (ii) Metal cations provided by an aqueous solution of a metal salt selected from lithium, sodium, potassium, magnesium or calcium salts in a concentration of 0.01 to 7 molar (M) to replace the charge-balancing protons of the membrane during treatment with metal cations. [7] Device according to any one of claims 1 to 3, wherein the ion-conducting polymer membrane comprises a brominated or tosylated polymer with reactive sites formed by carbon-halogen or carbon-tosyl bonds; and The liquid treatment solution contains reactive species selected from the group consisting of: primary, secondary, tertiary or cyclic amines, including trimethylamine, triethylamine, N,N-dimethylethylamine, N-methylpiperidine, N-methylmorpholine, 1,4-diazabicyclo[2.2.2]octane, imidazole and N-methylimidazole, in a concentration of 0.1 to 5 molar(M) and at a temperature of 10°C to 80°C. wherein the reactive species converts the carbon-halogen or carbon-tosyl bonds of the polymer into quaternary ammonium groups that are covalently bonded to the polymer, resulting in an anion exchange membrane with quaternary ammonium groups and halide or tosylate counterions after treatment. [8] System that includes: (a) a device according to any one of claims 1 to 7; (b) a tank or container configured to hold the liquid treatment solution or to collect any outflow from the device; and (c) a pump or flow control unit connected to the device and the tank or container, the system being configured to circulate or transfer the liquid treatment solution for ion exchange or quaternization of the ion-conducting polymer membrane contained in the device through the device. [9] System according to claim 8, wherein the tank or container comprises a first tank for supplying the liquid treatment solution to the device and a second tank for collecting the effluent from the device. [10] System according to one of claims 8 to 9, further comprising a valve, a flow meter or a temperature control element connected to the pump to control the residence time, solution temperature or flow rate of the liquid treatment solution during operation. [11] System according to one of claims 8 to 9, wherein the support element comprises a spacer that touches a surface of the membrane to define a separation between adjacent membrane layers. [12] Ion-conducting polymer membrane produced using the device according to any one of claims 1 to 7 or the system according to any one of claims 8 to 11, configured for use in an electrolyzer, fuel cell or electrodialysis stack. [13] Ion-conducting polymer membrane produced using the device according to any one of claims 1 to 7 or the system according to any one of claims 8 to 11, wherein the membrane comprises: (a) fixed ionic functional groups selected from quaternary ammonium, sulfonate, carboxylate, phosphonate or phosphoric acid groups; and (b) Counterions selected from hydroxide, carbonate, bicarbonate, proton or metal cations, the membrane has an ion exchange capacity of 0.5 to 5.0 mEq / g dry polymer and an ion conductivity of 1 to 150 millisiemens per centimeter at 25°C. [14] Ion-conducting polymer membrane according to claim 13, wherein the membrane is an anion exchange membrane (AEM) comprising a quaternized brominated or tosylated polymer, wherein the polymer contains quaternary ammonium functional groups covalently bonded to the polymer and halide or hydroxide counterions. [15] Ion-conducting polymer membrane according to one of claim 14 having an activation of at least 80% based on a reduction of counterions. [16] An ion-conducting polymer membrane treated using the device according to any one of claims 1 to 7 or the system according to any one of claims 8 to 11, wherein at least one surface of the membrane has a repeating indentation, a repeating rib or a repeating pattern corresponding to a contact area of ​​a spacer or support element used during treatment, wherein the repeating indentation, the repeating rib or the repeating pattern is visible or measurable by optical, tactile or topographic inspection, indicating that the membrane was treated in contact with the spacer or support element.

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