KR102332295B1 - Organic/Inorganic Composite Membrane and the same as the Methods - Google Patents

Abstract

The present invention relates to an organic/inorganic polymer electrolyte composite membrane and a method for manufacturing the same, and more specifically, to an organic/inorganic polymer electrolyte composite membrane having low vanadium permeability through a structure in which nano silica particles are uniformly distributed in the membrane, and the same It relates to a manufacturing method.

Description

Organic/Inorganic Polyelectrolyte Composite Membrane and Method for Manufacturing Same

The present invention relates to an organic/inorganic polymer electrolyte composite membrane and a method for manufacturing the same, and more specifically, to an organic/inorganic polymer electrolyte composite membrane having low vanadium permeability through a structure in which nano silica particles are uniformly distributed in the membrane, and the same It relates to a manufacturing method.

Recently, along with the leveling of the power load and the expansion of the proportion of renewable energy generation, the development of an energy storage device for storing and managing power energy is urgently required.

A vanadium redox flow battery, which is a type of energy storage device, is attracting attention as a large-capacity long-cycle energy storage device because it is easy to increase the capacity because the capacity and output can be individually designed. In the vanadium redox flow battery, the polymer electrolyte membrane is a very important core component that determines the output and long-term performance of the battery and the price of the stack. acting as a factor. Accordingly, there is a need to develop a low-permeability and low-cost polymer electrolyte membrane capable of increasing the efficiency of an energy storage device.

As a separator used in a vanadium redox flow battery, DuPont's Nafion is commercially available, but it is expensive and has high permeability, so it was difficult to operate the redox flow battery for a long time.

In order to replace Nafion, which has such a problem, various types of polymer electrolyte membranes such as hydrocarbon-based polymer membranes and reinforced composite membranes have been developed. Specifically, hydrocarbon-based polymer membranes are typically sulfonated polyether ketone, sulfonated polyether-etherketone, sulfonated polyethersulfone, sulfonated polysulfone, sulfonated polyphenylene sulfide, sulfonated polyphenylene oxide, and sulfonated polyether. Mead and the like have been proposed, but there is a problem in that flexibility is low and chemical stability is weak.

Reinforced composite membranes have been proposed as a method of manufacturing a porous support with excellent mechanical strength and durability by introducing an ionomer with excellent ion conductivity, but there is a disadvantage in that desorption occurs between the porous support and the ionomer.

Patent Publication No. 10-2018-0003098

As a result of numerous studies, the present inventors have found a composite membrane having a structure in which nano silica particles generated from an alkoxysilane functional material are uniformly distributed in a polymer membrane by inducing crosslinking between the functional groups of an ionomer based on an alkoxysilane functional material, and a method for manufacturing the same. The present invention was completed by developing.

Therefore, an object of the present invention is to solve the problem of non-uniform distribution of nanoparticles appearing in general organic-inorganic nano-composite polymer membranes, so that nano silica particles are generated in the polymer membrane manufacturing process and included in the polymer membrane, so that the inorganic particles of nano silica particles are To provide an organic/inorganic polymer electrolyte composite membrane having low permeability and high ionic selectivity through a membrane structure that is very uniformly dispersed between organic polymers and a method for manufacturing the same.

Another object of the present invention is an organic/inorganic polymer electrolyte composite membrane that can effectively reduce the manufacturing cost of a polymer membrane by introducing a certain amount of an alkoxysilane functional material instead of a perfluorinated polymer, rather than comprising only expensive perfluorinated polymers, and To provide a manufacturing method thereof.

Another object of the present invention is to provide a redox flow battery or water treatment device advantageous for long-term operation by including an organic/inorganic polymer electrolyte composite membrane having low permeability and high ionic selectivity.

The object of the present invention is not limited to the object mentioned above, and even if not explicitly mentioned, the object of the invention that can be recognized by those of ordinary skill in the art from the description of the detailed description of the invention to be described later may also be included. .

In order to achieve the above object of the present invention, the present invention provides a crosslinking structure of an alkoxysilane functional polymer and a perfluorinated polymer; and nano-silica particles uniformly dispersed in the cross-linked structure.

The alkoxysilane functional polymer is at least one selected from the group consisting of D-ASFP (Diol Alkoxysilane- Functionalized Polymer), BD-ASFP (Bisphenol Dimethylbenzanthracene ASFP), BDP-ASFP (Bisphenol Dimethylbenzanthracene Polydimethylsiloxane ASFP) and combinations thereof,

The perfluorinated polymer is Nafion (DuPont), 3M ionomer (3M), Fumion (Fumion), Aciplex (Aciplex), Aquivion (Aquivion), sulfonated perfluorinated polymer (PFSA, perfluorinated sulfonic acid), Polytetrafluoroethylene, polyvinylidene fluoride (poly(vinylidene fluoride)), polyvinyl fluoride (poly (vinyl fluoride)), poly(vinylidene fluo-co- Any one or more selected from the group consisting of a combination of perfluorinated alkyl vinyl ethers))

It provides an organic/inorganic polymer electrolyte composite membrane having an ion permeability of 2×10 ^-7 cm ^{2 /min or less.}

In addition, the present invention comprises the steps of preparing an alkoxysilane functional polymer solution and a perfluorinated polymer solution; preparing a membrane precursor solution by mixing the alkoxysilane functional polymer solution and the perfluorinated polymer solution; A casting step of forming a casting layer by casting the membrane precursor solution; A film forming step of forming a precursor film by crosslinking the alkoxysilane functional polymer and the perfluorinated polymer included in the casting layer; and a pretreatment step of protonating the precursor film.

The alkoxysilane functional polymer contained in the alkoxysilane functional polymer solution is a group consisting of D-ASFP (Diol Alkoxysilane- Functionalized Polymer), BD-ASFP (Bisphenol Dimethylbenzanthracene ASFP), BDP-ASFP (Bisphenol Dimethylbenzanthracene Polydimethylsiloxane ASFP), and combinations thereof. Any one or more selected from

In the film forming step, the cross-linking structure of the alkoxysilane functional polymer and the perfluorinated polymer and the nano-silica particles uniformly dispersed in the cross-linking structure are generated through a thermal cross-linking reaction,

The alkoxysilane functional polymer solution and the perfluorinated polymer solution each contain 5 to 70 parts by weight of the alkoxysilane functional polymer and the perfluorinated polymer per 100 parts by weight of the solvent,

The membrane precursor solution provides an organic/inorganic polymer electrolyte composite membrane manufacturing method comprising 5 to 95% by weight of the alkoxysilane functional polymer solution and 95 to 5% by weight of the perfluorinated polymer solution.

In a preferred embodiment, the solvent is from the group consisting of distilled water, ethanol, isopropanol, methanol, dimethyl sulfoxide, N,N-dimethylacetamide, N-methyl-2-pyrilidinone, and N,N-dimethylformamide. There is more than one selected.

In a preferred embodiment, the membrane precursor solution is obtained by stirring the alkoxysilane functional polymer solution and the perfluorinated polymer solution at a temperature of 20 to 50 degrees.

In a preferred embodiment, the film forming step comprises the steps of drying the casting layer in a vacuum state of 70 ℃ or less; A first heat treatment step of treating the dried casting layer at 70 to 90 ℃; and a secondary heat treatment step of processing at a temperature of 100° C. or higher.

In a preferred embodiment, the protonation is performed by immersing the precursor film in a basic aqueous solution and then immersing it in distilled water, immersing it in an acidic aqueous solution for treatment, and then immersing it in distilled water.

In addition, the present invention provides a fuel cell including the organic/inorganic polymer electrolyte composite membrane or an organic/inorganic polymer electrolyte composite membrane prepared by any one of the above-described organic/inorganic polymer electrolyte composite membranes.

In addition, the present invention provides an energy storage device including an organic/inorganic polymer electrolyte composite membrane or an organic/inorganic polymer electrolyte composite membrane manufactured by any one of the above-described organic/inorganic polymer electrolyte composite membranes.

In a preferred embodiment, the energy storage device is a redox flow cell or a fuel cell.

In addition, the present invention provides a water treatment apparatus including any one of the organic/inorganic polymer electrolyte composite membrane or the organic/inorganic polymer electrolyte composite membrane prepared by the method for manufacturing the composite membrane described above.

The present invention described above has the following effects.

First, according to the present invention, low permeability and high ionic selectivity are achieved through a membrane structure in which nano silica particles, which are inorganic particles, are very uniformly dispersed among organic polymers by generating nano-silica particles in the polymer membrane manufacturing process and being included in the polymer membrane. Therefore, it is possible to solve the problem of non-uniform distribution of nanoparticles appearing in general organic-inorganic nano-composite polymer membranes.

In addition, according to the present invention, the electrolyte polymer membrane is not composed only of expensive perfluorinated polymers, but a certain amount of an alkoxysilane functional material is introduced instead of a perfluorinated polymer to form a composite membrane having the characteristics of a partially fluorinated polymer membrane. Manufacturing cost can be effectively reduced.

In addition, according to the present invention, it is possible to provide a redox flow battery or water treatment device advantageous for long-term operation by including an organic/inorganic polymer electrolyte composite membrane having low permeability and high ion selectivity.

These technical effects of the present invention are not limited only to the above-mentioned range, and even if not explicitly mentioned, the effect of the invention that can be recognized by a person of ordinary skill in the art from the description of the specific content for the implementation of the invention to be described later is also of course included.

1 is a view showing the chemical structure of D-ASFP, which is an alkoxysilane functional polymer included in an organic/inorganic polyelectrolyte composite membrane according to an embodiment of the present invention.
2 is a view showing the chemical structure of BD-ASFP, which is an alkoxysilane functional polymer included in an organic/inorganic polyelectrolyte composite membrane according to another embodiment of the present invention.
3 is a view showing the chemical structure of BDP-ASFP, which is an alkoxysilane functional polymer included in an organic/inorganic polyelectrolyte composite membrane according to another embodiment of the present invention.
4 is an infrared spectroscopy (Fourier-transform infrared spectroscopy, FT-IR) result graph for confirming whether the alkoxysilane functional polymer shown in FIGS. 1 to 3 is synthesized according to the organic/inorganic polyelectrolyte composite membrane manufacturing method of the present invention; am.
5 is a graph showing the results of chemical structural analysis (FT-IR) of the organic/inorganic polyelectrolyte composite membrane of the present invention, Nafion membrane as a control, and alkoxysilane functional polymer (D-ASFP).
6 is a thermogravimetric analysis (TGA) result graph of the organic/inorganic polyelectrolyte composite membrane of the present invention and the control Nafion membrane.
7 is a graph showing (a) moisture content and (b) dimensional change of the organic/inorganic polyelectrolyte composite membrane of the present invention and the control Nafion membrane.
8 is a graph showing the ion exchange capacity (IEC) of the organic/inorganic polyelectrolyte composite membrane of the present invention and the Nafion membrane as a control.
9 is a graph showing the ionic conductivity of the organic/inorganic polyelectrolyte composite membrane of the present invention and the Nafion membrane as a control.
^{10 shows (a) the concentration of VO 2+} ions measured using a UV-vis spectrometer and (b) the calculated VO ²⁺ ion permeability of the organic/inorganic polyelectrolyte composite membrane of the present invention and the Nafion membrane as a control. is a graph showing
11 is a graph showing the ionic conductivity and ion selectivity of the organic/inorganic polyelectrolyte composite membrane of the present invention and the Nafion membrane as a control.

The terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the description of the invention exists, but is not limited to one or more other It should be understood that it does not preclude the possibility of addition or presence of features or numbers, steps, operations, components, parts, or combinations thereof.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present invention. does not

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description. In particular, when the terms "about", "substantially", etc. of degree are used, they may be construed as being used in a sense at or close to the numerical value when manufacturing and material tolerances inherent in the stated meaning are presented. .

In the case of a description of a temporal relationship, for example, if the temporal relationship is described as 'after', 'following', 'after', 'before', etc., 'immediately' or 'directly' This includes cases that are not continuous unless ' is used.

Hereinafter, the technical configuration of the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments.

However, the present invention is not limited to the embodiments described herein, and like reference numerals indicate like elements in different forms.

The technical feature of the present invention is an organic/inorganic polymer electrolyte composite membrane in which nano silica particles, which are inorganic particles, are very uniformly dispersed between organic polymers by generating nano silica particles during the polymer membrane manufacturing process and being included in the polymer membrane. and its manufacturing method. That is, in the present invention, in the process of mixing the alkoxysilane functional polymer and the perfluorinated polymer, a crosslinked structure of the alkoxysilane functional polymer and the perfluorinated polymer is formed, and at the same time, nanosilica particles are generated from the alkoxysilane functional polymer and uniformly in the crosslinked structure. This is because it is possible to solve the problem of non-uniform distribution of nanoparticles appearing in general organic-inorganic nano-composite polymer membranes. As described above, the organic/inorganic polymer electrolyte composite membrane of the present invention is not composed of pure perfluorinated polymer alone, but is in a partially fluorinated polymer state, so it is possible to reduce the manufacturing cost of the polymer membrane, and at the same time, low permeability due to the nano-silica particles uniformly distributed in the composite membrane and high ionic selectivity, and it is possible to realize low permeability and ion selectivity that is improved by 40% or more compared to the conventional polymer electrolyte membrane.

Therefore, the organic/inorganic polymer electrolyte composite membrane of the present invention has a crosslinking structure of an alkoxysilane functional polymer and a perfluorinated polymer; and nano-silica particles uniformly dispersed in the cross-linked structure.

Here, the alkoxysilane functional polymer is capable of cation conduction by introducing COOH, OH, NH and SH functional groups, and can produce nano silica particles in the mixing process with the perfluorinated polymer material. Alkoxysilane functional polymers are all known A silane-based polymer may be used, but as an embodiment, D-ASFP (Diol Alkoxysilane- Functionalized Polymer), BD-ASFP (Bisphenol Dimethylbenzanthracene ASFP), BDP-ASFP (Bisphenol) having the structural formulas shown in FIGS. Dimethylbenzanthracene Polydimethylsiloxane ASFP) and combinations thereof may be at least one selected from the group consisting of.

As the perfluorinated polymer, all known perfluorinated polymers that can be used in the electrolyte polymer membrane may be used, but as an embodiment, Nafion (DuPont), 3M Ionomer (3M), Fumion, Aciplex, Aquivion, sulfonated perfluorinated sulfonic acid (PFSA), polytetrafluoroethylene, poly(vinylidene fluoride), poly(vinyl fluoride) , and may be any one or more selected from the group consisting of a combination of poly (vinylidene fluo-co-perfluorinated alkyl vinyl ethers).

In the organic/inorganic polymer electrolyte composite membrane having the above-described properties, a number of ionic cross-links formed between the alkoxysilane functional polymer and the perfluorinated polymer and the nano silica particles generated from the alkoxysilane functional polymer are uniformly distributed throughout the composite membrane, resulting in VO ²⁺ The ion permeability is ^{significantly lowered to 2×10 -6} cm ² /min or less, preferably 2×10 ^-7 cm ² /min or less. In particular, the minimum ion permeability is experimentally predicted to be ^{1.26×10 -7} cm ^{2 /min.}

In addition, the organic/inorganic polymer electrolyte composite membrane manufacturing method of the present invention comprises the steps of preparing an alkoxysilane functional polymer solution and a perfluorinated polymer solution; preparing a membrane precursor solution by mixing the alkoxysilane functional polymer solution and the perfluorinated polymer solution; a casting step of casting the membrane precursor solution to form a casting film; A film forming step of forming a precursor film by crosslinking the alkoxysilane functional polymer and the perfluorinated polymer included in the casting film; and a pretreatment step of protonating the precursor film.

Here, the solvent contained in the membrane precursor solution dissolves the two polymers and induces easy mixing, thereby inducing uniform dispersion of nano-silica formed during the condensation reaction in the cross-linked polymer membrane manufacturing process. . Therefore, any known solvent may be used as long as the solvent can dissolve the alkoxysilane functional polymer and the perfluorinated polymer, but in one embodiment, distilled water; alcohol solvents including ethanol, isopropanol, and methanol; dimethyl sulfoxide; Any one or more selected from the group consisting of solvents including N,N-dimethylacetamide, N-methyl-2-pyrilidinone, and N,N-dimethylformamide may be used.

The steps of preparing the alkoxysilane functional polymer solution and the perfluorine-based polymer solution may be performed in any order. The alkoxysilane functional polymer and the perfluorinated polymer are completely dissolved in the same solvent, respectively, so that the alkoxysilane functional polymer solution and the perfluorine-based polymer solution are completely dissolved. prepare individually. Here, the mixing ratio of the solvent and the alkoxysilane functional polymer or perfluorinated polymer may be 5 to 70 parts by weight of each polymer based on 100 parts by weight of the solvent. The blending ratio is determined experimentally. If the weight of the polymer is less than 5 parts by weight or exceeds 70 parts by weight, the viscosity is too low or high, and workability is deteriorated and the thickness control of the polymer film is difficult. The solution concentration was set experimentally.

The step of preparing the membrane precursor solution may be performed by mixing the prepared alkoxysilane functional polymer solution and the perfluorinated polymer solution in a predetermined ratio to prepare a homogeneous solution. As an embodiment, the membrane precursor solution may contain 5 to 95 parts by weight and 95 to 5% by weight of the alkoxysilane functional polymer solution and the perfluorinated polymer solution, respectively. can do. On the other hand, the membrane precursor solution can be carried out by stirring for several minutes to several days in a reactor maintained at a temperature of 20 to 50 degrees to prepare a homogeneous phase.

The casting step may be performed by casting the membrane precursor solution on a flat plate such as a glass plate to form a casting layer.

The film forming step is a step of forming a precursor film by crosslinking the alkoxysilane functional polymer and the perfluorinated polymer while removing the solvent contained in the casting layer. By heating to a certain temperature, the crosslinking structure of the alkoxysilane functional polymer and the perfluorinated polymer is formed. At the same time, it is a process of inducing the generation of nano silica particles so that they are uniformly distributed in the cross-linked structure during the condensation reaction. Therefore, the film forming step can be performed by treating the casting layer at a temperature that can cause a thermal crosslinking reaction between the alkoxysilane functional polymer and the perfluorinated polymer while removing the solvent contained in the casting layer. drying in a vacuum of A first heat treatment step of treating the dried casting layer at 70 to 90 ℃; and a secondary heat treatment step of treating at a temperature of 100° C. or higher. As an embodiment, after the casting layer is maintained in an oven at 60° C. under vacuum for 8 hours, it is further treated at 80° C. for 8 hours and at 100° C. for 8 hours to obtain a precursor film.

The pretreatment step is a step in which protonation is performed to increase proton activity while removing organic matter on the surface of the obtained precursor film. As an embodiment, the precursor film is immersed in a basic aqueous solution and treated, then immersed in distilled water, and then immersed in an acidic aqueous solution for treatment and then immersed in distilled water. Aqueous sulfuric acid solution was used. Here, the immersion treatment may be performed at a temperature range of 20 to 90° C. for 0.1 to 2 hours.

Through the above configuration, the organic/inorganic polyelectrolyte composite membrane of the present invention can exhibit improved transmittance and ion selectivity by 40% or more compared to the existing polyelectrolyte membrane, and excellent thermal stability can be realized due to the introduction of silica particles.

Therefore, the energy storage device and water treatment device such as the redox flow cell or fuel cell of the present invention can secure stable performance by including the organic/inorganic polymer electrolyte composite membrane having low permeability and high ion selectivity.

Example 1

1-1. Preparing an alkoxysilane functional polymer solution

14.8 g of DMBA and 34.8 g of TDI were completely dissolved in 100 mL of DMAC in a reaction flask at 60° C. and reacted for 12 hours. Then, 22.1 g of APTES was added and reacted at 50° C. for 8 hours to obtain a nanohybrid alkoxysilane functional precursor. A sol-gel mixture was obtained by hydrolysis of the nanohybrid alkoxy silane functional precursor in an aqueous solution of HCl at a concentration of 0.1M. 3 g of the sol-gel mixture was dispersed in 7 g DMAC to obtain a homogeneous nano-hybrid alkoxy silane functional polymer (D-ASFP) solution.

1-2. Step of preparing a perfluorinated polymer solution

Nafion Dispersion (20wt%) was poured into a petri dish and dried in an oven at 60°C under vacuum for one day to obtain a solid Nafion polymer. To prepare the obtained Nafion as an organic perfluorinated polymer solution, 2 g Nafion and 8 g DMAC were stirred at 60° C. hot-plate for 12 hours to obtain a 20 wt% perfluorinated polymer solution.

2. Membrane precursor solution preparation step

The prepared alkoxysilane functional polymer (D-ASFP) solution and the perfluorinated polymer solution were mixed at a weight ratio of 50:50, 25:75, 20:80, and 10:90 based on the solid content and stirred at room temperature for 24 hours to form a homogeneous membrane precursor. Solutions 1-1 to 1-4 were prepared.

3. Casting step

Membrane precursor solution 1-2 (combination ratio of alkoxysilane functional polymer solution 5g (solid content 1.5g) and perfluorinated polymer solution 22.5g (solid content 4.5g)) was cast on a glass plate at room temperature to form a casting layer.

4. Unveiling stage

After drying the surface of the formed casting layer by maintaining it in an oven at 60° C. under vacuum for 8 hours, and further drying at 80° C. for 8 hours and at 100° C. for 8 hours to remove the solvent, the alkoxysilane functional polymer included in the casting layer A precursor film 1-2 was obtained by performing a thermal crosslinking reaction of the perfluorinated polymer with the alkoxysilane functional polymer and the crosslinked structure of the perfluorinated polymer and nano silica particles uniformly dispersed in the crosslinked structure.

5. Pretreatment step

The precursor film finally obtained _{was immersed in 3% H 2} O ₂ aqueous solution and immersed in distilled water, then immersed in 0.5MH ₂ SO ₄ aqueous solution and immersed in distilled water again to proceed with protonation pretreatment to obtain organic/inorganic polymer electrolyte composite membrane 1. got it Each of the pretreatment steps was carried out at 50° C. for 30 minutes.

Example 2

An organic/inorganic polymer electrolyte composite membrane 2 was obtained in the same manner as in Example 1, except that the step of preparing the alkoxysilane functional polymer solution was performed as follows.

Bisphenol A 22.8g, DMBA 14.6g, and TDI 34.8g were completely dissolved in 100mL of DMAC in a reaction flask at 60℃ and reacted for 12 hours, then 22.1g of APTES was added and reacted at 50℃ for 8 hours with nano-hybrid alkoxysilane functionality A precursor was obtained. A sol-gel mixture was obtained by acid hydrolysis of the nanohybrid alkoxy silane functional precursor in an aqueous HCl solution having a concentration of 0.1M. 1.5 g of the sol-gel mixture was dispersed in 8.5 g of DMAC to obtain a homogeneous nano-hybrid alkoxy silane functional polymer (BD-ASFP) solution.

Example 3

An organic/inorganic polymer electrolyte composite membrane 3 was obtained in the same manner as in Example 1, except that the step of preparing the alkoxysilane functional polymer solution was performed as follows.

Bisphenol A 22.8g, DMBA 14.6g, TDI 34.8g, PDMS 55g were completely dissolved in 100mL of DMAC in a reaction flask at 60℃ and reacted for 12 hours. An alkoxy silane functional precursor was obtained. A sol-gel mixture was obtained by acid hydrolysis of the nanohybrid alkoxy silane functional precursor in an aqueous HCl solution having a concentration of 0.1M. 1 g of the sol-gel mixture was dispersed in 9 g DMAC to obtain a homogeneous nanohybrid alkoxy silane functional polymer (BDP-ASFP) solution.

Experimental Example 1

In order to confirm whether the D-ASFP, BD-ASFP, and BDP-ASFP prepared in Examples 1 to 3 were synthesized, comparative analysis was performed by Fourier-transform infrared spectroscopy (FT-IR), and the results are shown in FIG. indicated.

^{As shown in FIG. 4, the peaks (1000 - 1100 cm -1} ) of the Si-O-Si and Si-OC groups of PDMS and APTES were all found in D-ASFP, BD-ASFP, and BDP-ASFP, and TDI and ^{The NHC=O functional group (1600 - 1650cm -1} ) peak derived from the Urea group of the crosslinked structure between DMBAs appeared in all of D-ASFP, BD-ASFP, and BDP-ASFP, confirming that the synthesis was done. In addition, since the C = O functional group (1700 -1750 cm ^-1 ) peak derived from the carboxyl group of DMBA appeared in all of D-ASFP, BD-ASFP, and BDP-ASFP, it was confirmed that the alkoxysilane functional polymer was successfully prepared. can

Experimental Example 2

In order to confirm the ionic bond crosslinking structure between the alkoxysilane functional polymer and the perfluorinated polymer of the organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1, an alkoxysilane functional polymer (ASFP) as a control group was used as a control. Spectroscopy (Fourier-transform infrared spectroscopy, FT-IR) was used for comparative analysis, and the results are shown in FIG. 5 .

As shown in FIG. 5, when the peaks of the control group Nafion, alkoxysilane functional polymer (ASFP) and organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) are compared, it can be observed in the Nafion membrane. carboxyl group, C = O functional group derived from a free ASFP (1700 - 1750cm ^-1) peak appears in the composite membrane, one NHC = O functional group derived from the group of Urea ASFP (1600 - 1650cm ^-1) peaks in the composite film It was confirmed that ASFP was introduced into the composite membrane. In addition, the alkoxysilane functionality is a peak of Si-OC, Si-O- Si group in the polymer 1000 - 1100cm ^-1 were observed in, in particular, the characteristic peak observed at 1000 cm ^-1 is a silane-based polymer is combined with a perfluorinated polymer Subtotal It can be confirmed that it is a characteristic peak forming a film. ^{On the other hand, the peaks (1000 - 1100 cm -1} ) of the Si-OC and Si-O-Si groups of the alkoxysilane functional polymer _{overlapped with the peaks of the SO 3} H group of the perfluorinated polymer, but as described above, 1000 cm ^{Through the characteristic peak observed at -1} , it can be confirmed that the composite membrane was successfully prepared.

Experimental Example 3

In order to confirm the thermal stability of the organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1, thermogravimetric analysis (TGA) was performed on Nafion 212 and organic/inorganic polymer electrolyte composite membrane 1 was carried out and the results are shown in FIG. 6 .

In the TGA analysis graph of FIG. 6 _{, it was confirmed that the SO 3} H group of Nafion 212 was dissociated at 350° C., and the main chain was degraded at 450° C. and completely disappeared at 500° C. In the organic/inorganic polyelectrolyte composite membrane 1 _{, dissociation of the SO 3} H group occurred at 350°C, and degradation of the main chain started to occur at 450°C, but it was confirmed that residual substances were present after 500°C. It is determined that the silica particles formed due to the introduction of the inorganic polymer exist as residual substances after 500°C. This not only confirmed that inorganic particles were introduced into the organic/inorganic polymer electrolyte composite membrane 1, but also confirmed that the organic/inorganic polymer electrolyte composite membrane 1 has superior thermal stability than Nafion 212.

Experimental Example 4

To measure the water uptake and dimensional change of the organic/inorganic polyelectrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1, the organic/inorganic polyelectrolyte composite membrane and Nafion212 were subjected to the following The moisture content and dimensional change rate were measured as follows, and the results are shown in FIG. 7 .

Specifically, the organic/inorganic polyelectrolyte composite membrane 1 and Nafion 212 were dried in an oven at 80° C. under vacuum for 24 hours or more, then the mass was measured, and after soaking in distilled water for 24 hours, moisture on the surface was removed to increase the weight and change the dimensions. was measured and the moisture content and dimensional change rate were measured through the following equation.

As shown in FIG. 7, which is the result of measuring the moisture content and dimensional change rate of the organic/inorganic polyelectrolyte composite membrane 1 and Nafion 212, in the case of Nafion 212, the moisture content was 24% and the dimensional change rate was significantly changed to 14%. In the case of organic/inorganic polyelectrolyte composite membrane 1, the moisture content was 13% and the dimensional change rate was 4%, confirming the very low moisture content and dimensional change rate compared to Nafion 212. This is considered to be because the hydrophilic channel of the organic/inorganic polyelectrolyte composite membrane 1 was reduced due to the introduction of the alkoxysilane functional polymer and the generation of nano silica particles.

Experimental Example 5

To analyze the ion exchange capacity (IEC) of the organic/inorganic polyelectrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1, the organic/inorganic polyelectrolyte composite membrane 1 and Nafion212 were as follows. The ion exchange capacity was also measured and the results are shown in FIG. 8 .

Specifically, the organic/inorganic polymer electrolyte composite membrane 1 or Nafion212 was impregnated in 1M NaCl solution for 24 hours and then titrated with 0.1M NaOH solution as a phenolphthalein indicator.

As shown in FIG. 8, which is the result of measuring the ion exchange capacity of the organic/inorganic polyelectrolyte composite membrane 1 and Nafion212, the ion exchange capacity of Nafion212 was measured to be higher than that of the organic/inorganic polyelectrolyte composite membrane 1. This is considered to be because the hydrophilic channel of the organic/inorganic polyelectrolyte composite membrane 1 was reduced due to the introduction of the alkoxysilane functional polymer and the generation of nano silica particles.

Experimental Example 6

The organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1 was immersed in distilled water at room temperature for 24 hours, then the membrane was placed between the electrodes of the ion conductivity cell, and AC impedance was measured in distilled water. The ionic conductivity of the membrane was measured and the results are shown in FIG. 9 .

From Figure 9, which is the result of measuring the ionic conductivity of organic/inorganic polyelectrolyte composite membrane 1 and Nafion212, Nafion 212 had higher ionic conductivity than organic/inorganic polyelectrolyte composite membrane 1, which was obtained by introduction of alkoxysilane functional polymer and nano silica. It is considered that the channel for ion transfer in the organic/inorganic polyelectrolyte composite membrane is reduced due to the generation of particles.

Experimental Example 7

To measure the transmittance of the organic/inorganic polyelectrolyte composite membrane 1 (Nafion-ASFP) obtained in Example 1, the organic/inorganic polyelectrolyte composite membrane and Nafion 212 were subjected to transmittance measurements as follows, and the results are shown in FIG. 10 shown in

Specifically, an organic/inorganic polymer electrolyte composite membrane 1 or Nafion 212 was assembled in a vanadium redox flow battery unit cell, and 1.5M VOSO ₄ / 3M H ₂ SO ₄ solution and 1.5M MgSO ₄ / 3M H were respectively placed in both electrolyte containers. _{50 mL of 2} SO ₄ solution was added, and samples were collected from the electrolyte container containing the _{MgSO 4} solution at regular time intervals while flowing the electrolyte in the direction of the unit cell. The collected samples were measured using a UV-vis spectrometer using a 1.5M MgSO _{4 solution dissolved in 3M H 2} SO ₄ solution as a blank to measure the amount of vanadium ions transmitted.

^{From FIG. 10 showing the permeability of VO 2+} ions of the organic/inorganic polyelectrolyte composite membrane 1 and Nafion 212 ^{and the change in the concentration of VO 2+} ions over time, in the case of Nafion 212, the transmittance was 2.217×10 ^-7 cm ² /min. The permeability of the organic/inorganic polymer electrolyte composite membrane 1 was 1.259×10 ^-7 cm ² /min, which was 40% lower than that of Nafion 212. Through this, it was confirmed that the organic/inorganic polyelectrolyte composite membrane ^{significantly improved the permeation characteristics of VO 2+ ions.}

Experimental Example 8

To analyze the ion selectivity of the organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) obtained in Example 1, using the ion conductivity of Experimental Example 5 and the permeability of Experimental Example 6, the organic/inorganic polymer through the following formula The ion selectivity of the electrolyte composite membrane 1 and Nafion212 was calculated, and the results are shown in FIG. 11 .

The ionic conductivity of Nafion212 was measured to be high, but the permeability was measured to be high, indicating that the ion selectivity was lower than that of the organic/inorganic polyelectrolyte composite membrane. On the other hand, in the case of organic/inorganic polyelectrolyte composite membrane 1, although the ionic conductivity was low, the permeability was low, indicating that the ion selectivity was higher than 39%. Through this, it was confirmed that the organic/inorganic polyelectrolyte composite membrane 1 had excellent ion-selective properties.

The above-described experimental results only exemplified the case where the organic/inorganic polymer electrolyte composite membrane of the present invention was used in a redox flow battery, but it not only improves cell performance when used in energy storage devices such as other types of secondary batteries or fuel cells. It can also be predicted that long-term driving performance can also be improved.

Although the present invention has been illustrated and described with reference to preferred embodiments as described above, it is not limited to the above-described embodiments, and those of ordinary skill in the art to which the present invention pertains within the scope not departing from the spirit of the present invention Various changes and modifications will be possible.

Claims (10)

a cross-linked structure of an alkoxysilane functional polymer and a perfluorinated polymer; and
Including; nano-silica particles uniformly dispersed in the cross-linked structure;
The alkoxysilane functional polymer is at least one selected from the group consisting of D-ASFP (Diol Alkoxysilane- Functionalized Polymer), BD-ASFP (Bisphenol Dimethylbenzanthracene ASFP), BDP-ASFP (Bisphenol Dimethylbenzanthracene Polydimethylsiloxane ASFP) and combinations thereof,
The perfluorinated polymer is Nafion (DuPont), 3M ionomer (3M), Fumion (Fumion), Aciplex (Aciplex), Aquivion (Aquivion), sulfonated perfluorinated polymer (PFSA, perfluorinated sulfonic acid), Polytetrafluoroethylene, polyvinylidene fluoride (poly(vinylidene fluoride)), polyvinyl fluoride (poly (vinyl fluoride)), poly(vinylidene fluo-co- Any one or more selected from the group consisting of a combination of perfluorinated alkyl vinyl ethers))
An organic/inorganic polymer electrolyte composite membrane, characterized in that the ion permeability is 2×10 ^-7 cm ^{2 /min or less.}
Preparing an alkoxysilane functional polymer solution and a perfluorinated polymer solution;
preparing a membrane precursor solution by mixing the alkoxysilane functional polymer solution and the perfluorinated polymer solution;
a casting step of casting the membrane precursor solution to form a casting layer;
A film forming step of forming a precursor film by crosslinking the alkoxysilane functional polymer and the perfluorinated polymer included in the casting layer; and
Including; a pretreatment step of protonating the precursor film;
The alkoxysilane functional polymer contained in the alkoxysilane functional polymer solution is a group consisting of D-ASFP (Diol Alkoxysilane- Functionalized Polymer), BD-ASFP (Bisphenol Dimethylbenzanthracene ASFP), BDP-ASFP (Bisphenol Dimethylbenzanthracene Polydimethylsiloxane ASFP), and combinations thereof. Any one or more selected from
In the film forming step, the cross-linking structure of the alkoxysilane functional polymer and the perfluorinated polymer and the nano-silica particles uniformly dispersed in the cross-linking structure are generated through a thermal cross-linking reaction,
The alkoxysilane functional polymer solution and the perfluorinated polymer solution each contain 5 to 70 parts by weight of the alkoxysilane functional polymer and the perfluorinated polymer per 100 parts by weight of the solvent,
The membrane precursor solution comprises 5 to 95% by weight of the alkoxysilane functional polymer solution and 95 to 5% by weight of the perfluorinated polymer solution. 3. The method of claim 2,
The solvent is at least one selected from the group consisting of distilled water, ethanol, isopropanol, methanol, dimethyl sulfoxide, N,N-dimethylacetamide, N-methyl-2-pyrilidinone, and N,N-dimethylformamide. A method for manufacturing an organic/inorganic polymer electrolyte composite membrane.
3. The method of claim 2,
The membrane precursor solution is a method for producing an organic/inorganic polymer electrolyte composite membrane, characterized in that obtained by stirring the alkoxysilane functional polymer solution and the perfluorinated polymer solution at a temperature of 20 to 50 degrees.
3. The method of claim 2,
The film forming step includes drying the casting layer in a vacuum state of 70° C. or less; A first heat treatment step of treating the dried casting layer at 70 to 90 ℃; and a secondary heat treatment step of treating at a temperature of 100° C. or higher.
3. The method of claim 2,
The protonation is an organic/inorganic polymer electrolyte composite membrane manufacturing method, characterized in that the precursor film is treated by immersing it in a basic aqueous solution, immersing it in distilled water, immersing it in an acidic aqueous solution, and then immersing it in distilled water.
A fuel cell comprising the organic/inorganic polymer electrolyte composite membrane of claim 1 or the organic/inorganic polymer electrolyte composite membrane manufactured by the manufacturing method of any one of claims 2 to 6.
An energy storage device comprising the organic/inorganic polymer electrolyte composite membrane of claim 1 or the organic/inorganic polymer electrolyte composite membrane manufactured by the method of any one of claims 2 to 6.
9. The method of claim 8,
The energy storage device is an energy storage device, characterized in that the redox flow cell or fuel cell.
A water treatment device comprising the organic/inorganic polymer electrolyte composite membrane of claim 1 or the organic/inorganic polymer electrolyte composite membrane manufactured by the method of any one of claims 2 to 6.

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