Method for detecting fluorine ions in ion exchange membrane and application thereof

Abstract

The invention belongs to the technical field of nuclear magnetic resonance detection, and particularly relates to a method for detecting fluorine ions in an ion exchange membrane and application of the method. The method comprises the following steps: (1) soaking an ion exchange membrane to prepare a sample, winding the sample on a bar, and loading the sample into the bottom of a nuclear magnetic tube in a screw-in manner; the shape of the sample is a polygon, the polygon has a symmetrical structure, and the number of edges is not less than 4; (2) putting the nuclear magnetic tube prepared in the step (1) into a nuclear magnetic resonance spectrometer, selecting a pulse sequence, tuning, shimming, adjusting nuclear magnetic resonance test parameters, and collecting signals; the nuclear magnetic resonance test parameters comprise: 90-degree pulse width is 9-15 [mu] s; and the power is 20-55W. The pulse width of a nuclear magnetic sample obtained by adopting a specific sample preparation method at 90 degrees is 9-15 microseconds; under the power of 20-55W, < 19 > F in a bulk phase of the ion exchange membrane can be detected, and a powerful support is provided for detecting and analyzing structural information in the bulk phase of the ion exchange membrane.

Description

Technical Field

[0001] The present invention belongs to the field of nuclear magnetic resonance technology detection, and in particular relates to a method for detecting fluoride ions in an ion exchange membrane and an application thereof. Background Art

[0002] Ion exchange membranes are thin films made from polymer materials, typically plastics, adhesives, rubber, or other organic polymers. They include various functional films, such as optical films, water treatment films, battery separators, and conductive films. They are widely used in optical devices, photovoltaic power generation, wastewater treatment, element enrichment, seawater desalination, fluoride ion batteries, and other fields in medicine, food, agriculture, and the chemical industry, offering broad application prospects. Detecting the internal structure, surface morphology, mechanical properties, and electrochemical performance of ion exchange membranes has long been a major research focus in the field. Currently, the main characterization techniques for ion exchange membranes include thermogravimetric analysis, infrared spectroscopy, Raman spectroscopy, atomic force microscopy, and electron microscopy.

[0003] Liquid-State NMR technology has become a core means of chemical structure characterization and dynamic process research due to its excellent resolution (δ≤0.1ppm), non-destructive detection characteristics and multi-dimensional spectral analysis capabilities. However, ion exchange membranes, as a key component of energy conversion and storage systems (such as fuel cells and flow batteries), are functional materials with special microphase separation structures. Their performance is highly dependent on the ion transport channel network and the distribution of hydrophilic and hydrophobic domains in the solid state. If the traditional dissolving liquid NMR detection method is used, its intrinsic structure will be destroyed, resulting in the loss of key microstructural information (such as ion cluster size, connectivity and dynamic behavior). Therefore, how to use liquid NMR to efficiently characterize the microenvironment and ion transport mechanism of ion exchange membranes while maintaining the structural integrity of the membrane material is still a difficulty in the current technical field.

[0004] Fluoride ion (F-) is an important anion that is widely present in nature. It has important application value in environmental monitoring (such as drinking water safety, industrial wastewater treatment, soil and air pollution assessment), biomedicine (clinical diagnosis, oral medicine, drug analysis), industrial production (semiconductor manufacturing, nuclear industry, fluorine battery electrolyte) and food safety. Liquid nuclear magnetic resonance technology can be used to analyze the fluoride ion (F-) - ) detection is of great significance in areas such as protecting public health, environmental protection and industrial quality control. 19The F nuclear spin I = 1 / 2 has high sensitivity. However, in an asymmetric electric field gradient environment, such as the binding sites in ion exchange membranes or the solid-state electrode interface, the spectral peak is significantly broadened and the resolution is reduced, which greatly limits its practical application range. Therefore, there is an urgent need to develop an NMR detection method that can maintain the intrinsic microstructure of ion exchange membrane materials and detect fluoride ions. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is how to detect the nuclear magnetic resonance signal of fluoride ions in the ion exchange membrane while maintaining the intrinsic microstructure of the ion exchange membrane material, thereby providing a method for detecting fluoride ions in the ion exchange membrane and its application.

[0006] The present invention innovatively provides a method for detecting the nuclear magnetic resonance signals of fluoride ions in ion exchange membranes using liquid nuclear magnetic resonance technology. By optimizing sample processing technology and pulse sequence design, it achieves for the first time the simultaneous and efficient detection of fluoride ion and free fluoride ion signals in ion exchange membranes, providing a new method for the structural performance analysis of ion exchange membranes.

[0007] The present invention provides a method for detecting fluoride ions in an ion exchange membrane, comprising the following steps:

[0008] (1) After soaking, the ion exchange membrane is made into a sample, the sample is wrapped around a rod, and the sample is loaded into the bottom of the nuclear magnetic tube by screwing, and the rod is pulled out or retained in the nuclear magnetic tube; the shape of the sample is polygonal, and the polygon has a symmetrical structure and the number of sides is not less than 4; the soaking in step (1) of the present invention refers to soaking the ion exchange membrane in a solution; or, for an ion exchange membrane used in a liquid environment, both of these methods belong to the soaking described in the present invention; the ion exchange membrane of the present invention is made into a sample, and the sample shape is polygonal, such as a quadrilateral, pentagon, hexagon, etc., and the polygon satisfies the number of sides not less than 4 and has a symmetrical structure; further, the polygon also includes chamfers and / or rounded corners. The present invention is simple in preparing nuclear magnetic samples, and has advantages such as good uniform field effect, high detection sensitivity and spectral resolution when the sample is used for detection. The ion exchange membrane is placed uniformly, orderly, and regularly inside the nuclear magnetic tube, and no effective nuclear magnetic signal can be obtained if it is placed irregularly or disorderly. When detecting fluoride ions, the present invention requires that the ion exchange membrane does not bend or break when it is wrapped around the glass rod.

[0009] (2) placing the nuclear magnetic resonance tube obtained in step (1) into a nuclear magnetic resonance spectrometer, selecting a pulse sequence, tuning and shimming, adjusting nuclear magnetic resonance test parameters, and collecting signals; the nuclear magnetic resonance test parameters include: a 90° pulse width of 9 to 15 μs; and a power of 20 to 55 W.

[0010] The principle of the liquid NMR method of the present invention for collecting fluoride ion signals in ion exchange membranes is as follows: the ion exchange membrane swells after being immersed in a solution. Since the ion exchange membrane can selectively pass ions (such as fluorine), ions and water molecules coexist inside the bulk of the ion exchange membrane. That is, the ions and water molecules form countless microscopic liquid environments in the ion exchange membrane. Therefore, the NMR signal of fluoride ions in the ion exchange membrane can be successfully detected using liquid NMR.

[0011] The anion exchange membrane has the characteristics of anion selective transmission. - The fluoride ion concentration in the ion exchange membrane is low. The existing liquid nuclear magnetic resonance technology is limited by the traditional sample preparation method. The fluoride ion concentration inside the membrane is much lower than that in the liquid. Therefore, it is impossible to detect the fluoride ion concentration inside the membrane phase. - Accurate analysis. The present invention adopts a specific sampling method to prepare the nuclear magnetic detection sample, and tests it under the specific nuclear magnetic resonance test parameters of 90° pulse width of 9 to 15μs and power of 20 to 55W. On the basis of not destroying the structural state of the ion exchange membrane, the nuclear magnetic signal of the fluoride ion inside the ion exchange membrane bulk phase can be collected. The signals collected by the conventional liquid nuclear magnetic sampling method are mainly free atoms, that is, the fluoride ions in the nuclear magnetic tube solution (located outside the membrane body), and the fluoride ion signals on the ion exchange membrane cannot be detected. By adopting the sampling method of the present invention and testing it under the specific nuclear magnetic resonance test parameters of 90° pulse width of 9 to 15μs and power of 20 to 55W, the nuclear magnetic signal of the fluoride ion in the ion exchange membrane bulk phase can be detected.

[0012] As an optional implementation, the 90° pulse width is 12 μs; and the power is 32 W.

[0013] Exemplarily, the 90° pulse width is 9 μs, 10 μs, 11 μs, 12 μs, 13 μs, 14 μs, or 15 μs; and the power is 20 W, 30 W, 35 W, 40 W, 45 W, or 55 W.

[0014] As an optional embodiment, the fluorine is 19F; and / or,

[0015] The ion exchange membrane is an anion exchange membrane; preferably, the ion exchange membrane comes from a battery.

[0016] The ion exchange membrane includes an anion exchange membrane, of which several commercial models are listed, Fumasep FAA-3-PK-130 and Fumasep FAAM-PK-75.

[0017] As an optional embodiment, the nuclear magnetic resonance test parameters also include: pulse sequence is zgig; relaxation time: 1 to 5s; number of sampling points: 32k to 128k, k is 1024; sampling time: 0.3 to 5s; spectral width is 200 to 600ppm; spectrum range is: 100ppm to -500ppm, cumulative number of times: 4 to 256 times;

[0018] Preferably, the spectrum width is 300 ppm, and the spectrum range is 0 ppm to -300 ppm.

[0019] Different nuclides have different resonant frequencies and require independent tuning and matching. The present invention selects the 19F tuning channel after selecting the pulse sequence. The resonant frequency of 19F is close to that of hydrogen, so when detecting fluoride ions, the tuning channel is tuned to 1H. The resonant frequency of each nuclide in the detection instrument is related to the field strength of the detection instrument and the type of nuclide. For example, if the detection instrument is a 600MHz resonance spectrometer, the resonant frequency is 564.7MHz. Those skilled in the art can determine the resonant frequency based on the specific nuclide and the field strength of the detection instrument.

[0020] As an optional embodiment, step (2) further includes adding 10 to 100 μL of a fluoride-containing solution before placing the nuclear magnetic resonance tube into the nuclear magnetic resonance spectrometer. By placing the fluoride-containing solution into the nuclear magnetic resonance tube, the method of the present invention can detect the nuclear magnetic signal of fluoride ions outside the bulk of the ion exchange membrane (in a free state, i.e., fluoride ions in the fluoride-containing solution added to the nuclear magnetic resonance tube). Because the present invention can detect fluoride ion signals inside the ion exchange membrane, the fluoride ion transport performance of the ion exchange membrane can be determined based on the difference in chemical shift of the nuclear magnetic signals of fluorine atoms inside and outside the membrane, providing a basis for structural performance analysis of anion exchange membranes, and further application in different fields based on the performance of the ion exchange membranes.

[0021] As an optional embodiment, the fluoride ion-containing solution includes a soluble fluoride salt;

[0022] Preferably, the soluble fluoride salt includes at least one of LiF, NaF, and KF.

[0023] As an optional embodiment, the concentration of the fluoride ion solution is 0.2 to 2.0 mol / L;

[0024] Preferably, the concentration of the fluoride ion-containing solution is 1.0 mol / L.

[0025] As an optional embodiment, the solvent in the fluoride ion-containing solution includes a deuterated solvent or a non-deuterated solvent;

[0026] Preferably, the solvent comprises at least one of methanol, dimethyl sulfoxide (DMSO), chloroform (CHCl3), dichloromethane (CH2Cl2), ethanol, and water;

[0027] Preferably, when the solvent in the fluorine ion-containing solution includes a deuterated solvent, a field lock step is further performed before field shimming.

[0028] As an optional embodiment, in step (1), the soaking solution can dissociate fluoride ions. It should also be noted that during the sample preparation process, the soaking solution of the ion exchange membrane includes a solution that can dissociate F - Compounds capable of dissociating F - The solution of the compound is selected from any of the aforementioned fluoride-containing solutions. The ion exchange membrane soaking solution may be the same as or different from the fluoride-containing solution, preferably the same. The present invention has no specific requirements for the soaking time, and can be any time sufficient to allow the ion exchange membrane to swell and contain ions and water molecules, such as 1 hour, 4 hours, 8 hours, 12 hours, 16 hours, 24 hours, 28 hours, etc.

[0029] As an optional embodiment, in step (1), the sample is square in shape. When the sample is square, the length is 3 to 5 cm. It should be noted that the size of the sample can be selected according to the rod material, as long as it can wrap around the rod. Square includes square, rectangular, etc.

[0030] As an optional embodiment, the diameter of the rod is 2 to 3 mm; and / or,

[0031] The rod material includes a rubber rod, a glass rod or a metal rod; and / or,

[0032] The rod is a hollow cylinder. The rod is a hollow cylinder, meaning it can be an inner lining tube, with a hollow interior where liquid can be added. In this case, a deuterated reagent, such as deuterated water, deuterated DMSO, deuterated chloroform, or other common deuterated reagents, can be added to the hollow center of the rod. This allows for a lock field to accurately locate the chemical shift of the atomic nucleus to be measured, while also preventing the deuterated reagent from affecting the ion exchange membrane structure. Furthermore, since deuterated reagents are relatively expensive, a lock field can be achieved using an inner lining tube, saving on the use of deuterated reagents.

[0033] The present invention provides the application of the above-mentioned detection method to the detection of diaphragms in electrodialysis devices, electrolysis devices, or fuel cells. This application can detect the fluoride ion signal of used ion exchange membranes, providing strong support for the analysis of the structural performance of ion exchange membranes.

[0034] The technical solution of the present invention has the following advantages:

[0035] 1. The method for detecting fluoride ions in an ion exchange membrane provided by the present invention comprises: (1) preparing a sample of the ion exchange membrane after soaking, wrapping the sample around a rod, loading the sample into the bottom of a nuclear magnetic resonance tube by a precession method, and extracting the rod or retaining the sample in the nuclear magnetic resonance tube; the sample is in the shape of a polygon, the polygon has a symmetrical structure and the number of sides is not less than 4; (2) placing the nuclear magnetic resonance tube prepared in step (1) into a nuclear magnetic resonance spectrometer, selecting a pulse sequence, tuning and shimming, adjusting nuclear magnetic resonance test parameters, and collecting signals; the nuclear magnetic resonance test parameters include: a 90° pulse width of 9 to 15 μs; and a power of 20 to 55 W. The nuclear magnetic resonance sample obtained by the specific sample preparation method of the present invention has a good shimming effect, high detection sensitivity and spectral resolution, and can detect 19F inside the ion exchange membrane bulk phase when the 90° pulse width is 9 to 15 μs and the power is 20 to 55 W, providing strong support for detecting and analyzing structural information inside the ion exchange membrane bulk phase.

[0036] Furthermore, the method of the present invention can detect the nuclear magnetic resonance (NMR) signal of fluoride ions outside the bulk of the ion exchange membrane. Because the method can detect the fluoride ion signal inside the ion exchange membrane, the fluoride ion transport performance of the ion exchange membrane can be determined based on the difference in the chemical shift of the NMR signal of fluorine atoms inside and outside the membrane. This provides a basis for structural and performance analysis of anion exchange membranes, and can then be applied to different fields based on the performance of the ion exchange membranes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 This is the NMR spectrum obtained by testing in Example 1 of the present invention;

[0039] Figure 2 This is the NMR spectrum of the blank group of Example 1 of the present invention;

[0040] Figure 3-4 This is the NMR spectrum obtained from the test of Example 2 of the present invention;

[0041] Figure 5 This is the state of the ion exchange membrane in the nuclear magnetic tube of Example 2 of the present invention, referred to as the sample schematic diagram;

[0042] Figure 6 This is the state of the ion exchange membrane of Comparative Example 1 of the present invention in the nuclear magnetic tube, referred to as the sample schematic diagram;

[0043] Figure 7-8The nuclear magnetic spectrum obtained by testing comparative example 1 of the present invention. DETAILED DESCRIPTION

[0044] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0045] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0046] Example 1

[0047] This embodiment provides a method for detecting fluoride ions in an ion exchange membrane, comprising the following steps:

[0048] (1) Ion exchange membrane (Fumasep FAA-3-PK-130) was soaked in 1 mol / L NaF aqueous solution (the solvent was a non-deuterated reagent) for 4 h. After removal, the membrane was wiped dry. The membrane was cut into rectangular samples of 5 cm × 3 cm in size and then wrapped around a glass rod with a diameter of 3 mm. The sample was evenly placed on the bottom of the NMR tube by screwing it in. The glass rod was then removed.

[0049] (2) Place the NMR tube in the NMR spectrometer, tune and homogenize the field. The NMR test parameters include: 90° pulse width of 12 μs; power of 32 W; pulse sequence of zgig; relaxation time: 1 s; number of sampling points: 128 k, k is 1024; sampling time: 0.39 s; spectral width of 300 ppm; spectrum range of: 0 ppm to -300 ppm; accumulation times: 128 times; the detection instrument is a 600 MHz liquid NMR spectrometer with a resonance frequency of 564.7 MHz.

[0050] Figure 2 This is the NMR spectrum of the blank group of this embodiment. The difference between the blank group and Example 1 is that the NMR signal is directly tested after the ion exchange membrane sample is prepared. Figure 2 From the above, we can see that the broad peak at -180 ppm is the 19F nuclear magnetic signal present in the ion exchange membrane itself. Figure 1 This is the nuclear magnetic spectrum of this embodiment, from Figure 1 It can be seen that -119ppm and -180ppm are the 19F nuclear magnetic signals present in the ion exchange membrane. Figure 2The broad peak at -180 ppm is the nuclear magnetic signal of 19F in the ion exchange membrane itself. Therefore, -119 ppm is the nuclear magnetic signal of F ions inside the ion exchange membrane, indicating that the sample preparation method and the testing method of the present invention can obtain the nuclear magnetic signal of 19F in the ion exchange membrane with high resolution and high signal-to-noise ratio.

[0051] Example 2

[0052] This embodiment provides a method for detecting fluoride ions in an ion exchange membrane, comprising the following steps:

[0053] (1) Ion exchange membrane (same as in Example 1) was immersed in 1 mol / L NaF aqueous solution (the solvent was a non-deuterated reagent) for 4 h. After removal, the membrane was wiped dry. The membrane was cut into regular rectangular samples of 5 cm × 3 cm in size. The membrane was then wrapped around a glass rod with a diameter of 3 mm. The sample was evenly placed at the bottom of the NMR tube by screwing it inward. The glass rod was removed. 50 μL of 1 mol / L NaF aqueous solution was added to the NMR tube. The state of the sample in the NMR tube is shown in FIG. Figure 5 .

[0054] (2) Place the NMR tube in the NMR spectrometer, tune and homogenize the field. The NMR test parameters include: 90° pulse width of 12 μs; power of 32 W; pulse sequence of zgig; relaxation time: 1 s; number of sampling points: 128 k, k is 1024; sampling time: 0.39 s; spectral width of 300 ppm; spectrum range of: 0 ppm to -300 ppm; accumulation times: 128 times; the detection instrument is a 600 MHz liquid NMR spectrometer with a resonance frequency of 564.7 MHz.

[0055] NMR spectrum see Figure 3 , Figure 4 This is a zoomed-in view of the NMR signal. As can be seen, the chemical shift of 19F inside the ion exchange membrane is -119 ppm, while that outside the membrane is -120 ppm. The broad peak at -180 ppm represents the 19F NMR signal present in the ion exchange membrane itself. Because the motion of 19F atoms within the bulk of the ion exchange membrane is restricted, the transverse relaxation time (T2) of 19F is shortened, resulting in a broadening of the spectral peak relative to that outside the membrane. This demonstrates that the present invention can detect 19F NMR signals both inside and outside the ion exchange membrane bulk with high resolution and signal-to-noise ratio.

[0056] Comparative Example 1

[0057] This comparative example provides a method for detecting fluoride ions in an ion exchange membrane, comprising the following steps:

[0058] (1) Ion exchange membrane (same as in Example 1) was soaked in 1 mol / L NaF aqueous solution (the solvent was a non-deuterated reagent) for 4 h, taken out and wiped dry, and the ion exchange membrane was cut into regular rectangular samples of 5 cm × 3 cm in size. After curling, it was cut into uniform segments (about 0.3 cm in length) and directly loaded into the bottom of the NMR tube; 50 μL of 1 mol / L NaF aqueous solution was added to the NMR tube. The state of the sample in the NMR tube is shown in FIG. Figure 6 .

[0059] (2) Place the NMR tube in the NMR spectrometer, tune and homogenize the field. The NMR test parameters include: 90° pulse width of 12 μs; power of 32 W; pulse sequence of zgig; relaxation time: 1 s; number of sampling points: 128 k, k is 1024; sampling time: 0.39 s; spectral width of 300 ppm; spectrum range of: 0 ppm to -300 ppm; accumulation times: 128 times; the detection instrument is a 600 MHz liquid NMR spectrometer with a resonance frequency of 564.7 MHz.

[0060] NMR spectrum see Figure 7 , Figure 8 yes Figure 7 A partial magnification of the NMR signal shows that the 19F signal inside the ion exchange membrane overlaps significantly with that outside the membrane, resulting in multiple peaks and broadening of the spectrum, further demonstrating the superiority of the sample preparation and testing methods of the present invention.

[0061] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for detecting fluoride ions in an ion exchange membrane, characterized in that: The following steps are involved: (1) After soaking the ion exchange membrane, a sample is prepared, the sample is wrapped around a rod, the sample is loaded into the bottom of a nuclear magnetic resonance tube by screwing, and the rod is pulled out or retained in the nuclear magnetic resonance tube; the shape of the sample is a polygon, the polygon has a symmetrical structure and the number of sides is not less than 4; (2) placing the nuclear magnetic resonance tube obtained in step (1) into a nuclear magnetic resonance spectrometer, selecting a pulse sequence, tuning, shimming, adjusting nuclear magnetic resonance test parameters, and collecting signals; the nuclear magnetic resonance test parameters include: a 90° pulse width of 9-15 μs; The power is 20~55W.

2. The method according to claim 1, characterized in that The 90° pulse width is 12μs and the power is 32W.

3. The method according to claim 1, characterized in that The fluorine is 19F; and / or, The ion exchange membrane is an anion exchange membrane; preferably, the ion exchange membrane comes from a battery.

4. The method according to any one of claims 1 to 3, characterized in that The NMR test parameters also include: pulse sequence of zgig; relaxation time: 1 to 5s; number of sampling points: 32k to 128k, k is 1024; sampling time: 0.3 to 5s; spectral width of 200 to 600ppm; spectrum range of 100ppm to -500ppm, cumulative number of times: 4 to 256 times; Preferably, the spectrum width is 300 ppm, and the spectrum range is 0 ppm to -300 ppm.

5. The method according to any one of claims 1 to 3, characterized in that The step (2) further comprises adding 10 to 100 μL of a solution containing fluoride ions before placing the nuclear magnetic resonance tube into the nuclear magnetic resonance spectrometer; The fluoride ion-containing solution includes a soluble fluoride salt; Preferably, the soluble fluoride salt includes at least one of LiF, NaF, and KF.

6. The method according to claim 5, characterized in that The concentration of the fluoride ion solution is 0.2 to 2.0 mol / L; Preferably, the concentration of the fluoride ion-containing solution is 1.0 mol / L.

7. The method according to claim 6, characterized in that The solvent in the fluoride ion-containing solution includes a deuterated solvent or a non-deuterated solvent; Preferably, the solvent comprises at least one of dimethyl sulfoxide, chloroform, methanol, dichloromethane, ethanol, and water; Preferably, when the solvent in the fluorine ion-containing solution includes a deuterated solvent, a field lock step is further performed before field shimming.

8. The method according to claim 1, characterized in that In the step (1), the shape of the sample is square.

9. The method according to claim 1, characterized in that The diameter of the rod is 2 to 3 mm; and / or, The rod material includes a rubber rod, a glass rod or a metal rod; and / or, The rod is a hollow cylinder.

10. Use of the method according to any one of claims 1 to 9 in detecting a diaphragm in an electrodialysis device, an electrolysis device or a fuel cell.

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