KR102193759B1 - 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 of manufacturing the same, and more specifically, 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 Polymer Electrolyte Composite Membrane and its Manufacturing Method {Organic/Inorganic Composite Membrane and the same as the Methods}

The present invention relates to an organic/inorganic polymer electrolyte composite membrane and a method of manufacturing the same, and more specifically, 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.

In recent years, there is an urgent need to develop an energy storage device for storing and managing power energy, along with equalizing power load and increasing the proportion of renewable energy generation.

A vanadium redox flow battery, a type of energy storage device, is attracting attention as a large-capacity long-cycle energy storage device because it is easy to increase its 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, but the commercially available polymer membrane has high manufacturing cost and high permeability, which hinders the commercialization of the vanadium redox flow battery. It is acting as a factor. Accordingly, there is a need to develop a polymer electrolyte membrane having low transmittance and low cost that can increase the efficiency of an energy storage device.

The separator used for the vanadium redox flow battery is typically commercially sold by DuPont's Nafion, but this is expensive and has high transmittance characteristics, so it was difficult to drive the redox flow battery for a long time.

In order to replace Nafion having 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-ether ketone, sulfonated polyether sulfone, sulfonated polysulfone, sulfonated polyphenylene sulfide, sulfonated polyphenylene oxide, and sulfonated polyether. Although mid and the like have been proposed, there is a problem in that the flexibility is low and the chemical stability is weak.

The reinforced composite membrane has been proposed as a method of manufacturing a porous support having excellent mechanical strength and durability by introducing an ionomer having excellent ion conductivity, but has a disadvantage in that separation between the porous support and the ionomer occurs.

Patent Publication No. 10-2018-0003098

As a result of a number of studies, the present inventors have developed a composite film having a structure in which the nano-silica particles produced from the alkoxy silane functional material are uniformly distributed in the polymer film by inducing crosslinking of the functional period of the ionomer based on the alkoxy silane functional material and a method for manufacturing the same. By developing, the present invention was completed.

Accordingly, an object of the present invention is to solve the problem of the heterogeneous distribution of nanoparticles in the general organic-inorganic nanocomposite polymer membrane. In the process of manufacturing a polymer membrane, nano silica particles are generated and included in the polymer membrane. It is to provide an organic/inorganic polymer electrolyte composite membrane having low transmittance and high ion selectivity through a very uniformly dispersed membrane structure among organic polymers, and a method for manufacturing the same.

Another object of the present invention is an organic/inorganic polymer electrolyte composite membrane capable of effectively reducing the manufacturing cost of a polymer membrane by introducing a certain amount of an alkoxysilane functional material instead of a perfluorinated polymer instead of comprising the electrolyte polymer membrane only of expensive perfluorine polymers, and It is to provide a manufacturing method.

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

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

In order to achieve the object of the present invention described above, the present invention provides a crosslinked structure of an alkoxysilane functional polymer and a perfluorine-based polymer; It provides an organic/inorganic polymer electrolyte composite film comprising; and nano silica particles uniformly dispersed within the crosslinked structure.

In a preferred embodiment, the alkoxysilane functional polymer is 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. Is any one or more.

In a preferred embodiment, the perfluorine-based polymer is Nafion (Dupon), 3M ionomer (3M), Fumion, Aciplex, Aquivion, sulfonated perfluorine-based polymer (PFSA). , perfluorinated sulfonic acid), polytetrafluoroethylene, poly(vinylidene fluoride), poly(vinyl fluoride), polyvinylidene fluoride, perfluorinated alkyl vinyl ether (poly (vinylidene fluo-co-perfluorinated alkyl vinyl ethers)) is any one or more selected from the group consisting of.

In a preferred embodiment, the ion permeability is 2x10 ^-7 cm ² /min or less.

In addition, the present invention comprises the steps of preparing an alkoxysilane functional polymer solution and a perfluorine-based polymer solution; Preparing a membrane precursor solution by mixing the alkoxysilane functional polymer solution and the perfluorine-based 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 an alkoxysilane functional polymer and a perfluorine-based polymer included in the casting layer; And a pretreatment step of protonating the precursor film.

In a preferred embodiment, the alkoxysilane functional polymer solution and the perfluorine-based polymer solution each contain 5 to 70 parts by weight of an alkoxysilane functional polymer and a perfluorine-based polymer per 100 parts by weight of a solvent.

In a preferred embodiment, the solvent is in the group consisting of distilled water, ethanol, isopropanol, methanol, dimethyl sulfoxide, N,N-dimethylacetamide, N-methyl-2-pyrillydinone, and N,N-dimethylformamide. Is more than one to be selected.

In a preferred embodiment, the membrane precursor solution includes 5 to 95% by weight of the alkoxysilane functional polymer solution and 95 to 5% by weight of the perfluorine-based polymer solution.

In a preferred embodiment, the membrane precursor solution is obtained by stirring the alkoxy silane functional polymer solution and the perfluorine-based polymer solution at a temperature of 20 to 50 degrees.

In a preferred embodiment, the film forming step includes drying the casting layer in a vacuum of 70° C. or less; A first heat treatment step of treating the dried casting layer at 70 to 90°C; And a second heat treatment step of treating at a temperature of 100° C. or higher.

In a preferred embodiment, the crosslinking structure of the alkoxysilane functional polymer and the perfluorine-based polymer and nanosilica particles uniformly dispersed within the crosslinking structure are generated through a thermal crosslinking reaction in the film forming step.

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

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

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

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 an organic/inorganic polymer electrolyte composite membrane manufactured by any one of the organic/inorganic polymer electrolyte composite membranes or the composite membrane manufacturing method described above.

The present invention described above has the following effects.

First, according to the present invention, nano silica particles are generated during the manufacturing process of the polymer film and are included in the polymer film, so that low transmittance and high ion selectivity are achieved through a membrane structure in which nano silica particles, which are inorganic particles, are very uniformly dispersed between organic polymers. As a result, it is possible to solve the problem of heterogeneous distribution of nanoparticles in general organic-inorganic nanocomposite polymer membranes.

In addition, according to the present invention, the polymer membrane is prepared in the form of a composite membrane having the characteristics of a partially fluorine-based polymer membrane by introducing a certain amount of an alkoxysilane functional material replacing the perfluorinated polymer instead of comprising only expensive perfluorine-based polymers. It can effectively reduce the manufacturing cost.

In addition, according to the present invention, it is possible to provide a redox flow battery or a water treatment apparatus 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 ranges mentioned above, and even if not explicitly mentioned, the effects of the invention that can be recognized by those of ordinary skill in the art from the description of specific details for the implementation of the invention described later are also Of course it is included.

1 is a view showing the chemical structure of D-ASFP, which is an alkoxysilane functional polymer included in an organic/inorganic polymer electrolyte composite film 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 polymer electrolyte composite film according to another embodiment of the present invention.
3 is a view showing the chemical structure of BDP-ASFP, an alkoxy silane functional polymer included in an organic/inorganic polymer electrolyte composite film according to another embodiment of the present invention.
FIG. 4 is a result graph of Fourier-transform infrared spectroscopy (FT-IR) for confirming whether the alkoxysilane functional polymer shown in FIGS. 1 to 3 is synthesized according to the method of manufacturing an organic/inorganic polymer electrolyte composite film of the present invention. to be.
5 is a graph of the results of chemical structure analysis (FT-IR) of the organic/inorganic polymer electrolyte composite membrane of the present invention, the Nafion membrane as a control, and the alkoxy silane functional polymer (D-ASFP).
6 is a thermogravimetric analysis (TGA) result graph of the organic/inorganic polymer electrolyte composite membrane of the present invention and the Nafion membrane as a control.
7 is a graph showing (a) moisture content and (b) dimensional change rate of the organic/inorganic polymer electrolyte composite membrane of the present invention and the Nafion membrane as a control.
8 is a graph showing the ion exchange capacity (IEC) of the organic/inorganic polymer electrolyte 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 polymer electrolyte composite membrane of the present invention and the Nafion membrane as a control.
Figure 10 is the organic / inorganic polymer electrolyte composite membrane of the present invention and the control Nafion membrane (a) concentration of VO ²⁺ ions measured using a UV-vis spectrometer and (b) VO ²⁺ ion permeability calculated through this It is a graph showing.
11 is a graph showing the ion conductivity and ion selectivity of the organic/inorganic polymer electrolyte 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. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the existence of features, numbers, steps, actions, elements, parts, or a combination thereof described in the description of the invention, but one or more other It is to be understood that it does not preclude the presence or addition of features, numbers, steps, actions, components, parts, or combinations thereof.

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

Unless otherwise defined, 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 the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present invention. Does not.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description. In particular, when the terms "about", "substantially" and the like of degree are used, it can be interpreted as being used in or close to that value when manufacturing and material tolerances specific to the stated meaning are presented. .

In the case of a description of a temporal relationship, for example,'after','following','after','before', etc. It 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 the same reference numerals denote the same elements in different forms.

Technical features of the present invention are organic/inorganic polymer electrolyte composite membranes in which nano-silica particles, which are inorganic particles, are very uniformly dispersed between organic polymers by generating nano-silica particles during the manufacturing process of the polymer film and being included in the polymer film. And its manufacturing method. That is, in the present invention, in the process of mixing the alkoxysilane functional polymer and the perfluorine-based polymer, a crosslinked structure of the alkoxysilane functional polymer and the perfluorine-based polymer is formed, and at the same time, nanosilica particles are generated from the alkoxysilane functional polymer to uniformly form the crosslinking structure. Because it is distributed, it is possible to solve the problem of heterogeneous distribution of nanoparticles that appear in general organic-inorganic nanocomposite polymer membranes. As described above, the organic/inorganic polymer electrolyte composite membrane of the present invention is not composed of only pure perfluorine polymer but is in a partially fluorine polymer state, so the manufacturing cost of the polymer membrane can be reduced, and at the same time, low permeability due to the nanosilica particles uniformly distributed in the composite membrane. And high ion selectivity, which can achieve a low transmittance and ion selectivity improved by 40% or more compared to a conventional polymer electrolyte membrane.

Accordingly, the organic/inorganic polymer electrolyte composite film of the present invention comprises a crosslinked structure of an alkoxysilane functional polymer and a perfluorine-based polymer; And nano-silica particles uniformly dispersed within the crosslinked structure.

Here, the alkoxy silane functional polymer is capable of cation conduction by introducing COOH, OH, NH and SH functional groups, and can generate nano silica particles in the process of mixing with a perfluorine-based polymer material. Alkoxy silane functional polymers are all known well-known. Although a silane-based polymer may be used, as an embodiment, D-ASFP (Diol Alkoxysilane-functionalized Polymer), BD-ASFP (Bisphenol Dimethylbenzanthracene ASFP), BDP-ASFP (Bisphenol) having the structural formulas shown in FIGS. 1 to 3, respectively. Dimethylbenzanthracene Polydimethylsiloxane ASFP) and combinations thereof may be any one or more selected from the group consisting of.

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

Complex organic / inorganic polymer electrolyte having the above-described film characteristic alkoxysilane functional polymer with a plurality of perfluorinated subtotal binding ion crosslinked product formed between the polymer and the alkoxysilane functionality is a nano-silica particles produced from the polymer are uniformly distributed within the whole composite film 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 method for producing an organic/inorganic polymer electrolyte composite film of the present invention includes the steps of preparing an alkoxysilane functional polymer solution and a perfluorine-based polymer solution; Preparing a membrane precursor solution by mixing the alkoxysilane functional polymer solution and the perfluorine-based polymer solution; A casting step of forming a casting film by casting the membrane precursor solution; A film forming step of forming a precursor film by crosslinking an alkoxysilane functional polymer and a perfluorine-based polymer included in the casting film; And a method of manufacturing an organic/inorganic polymer electrolyte composite film including a pre-treatment step of protonating the precursor film.

Here, the solvent contained in the membrane precursor solution can play a role of inducing uniform dispersion of the nano-silica formed in the condensation reaction process in the process of preparing the crosslinked polymer membrane by dissolving the two polymers and inducing them to be easily mixed. . Accordingly, all known solvents may be used as long as the solvent can dissolve the alkoxy silane functional polymer and the perfluorine-based polymer, but as an embodiment, distilled water; Alcohol solvents including ethanol, isopropanol, and methanol; Dimethyl sulfoxide; Any one or more selected from the group consisting of a solvent including N,N-dimethylacetamide, N-methyl-2-pyrillydinone, and N,N-dimethylformamide may be used.

The steps of preparing the alkoxy silane functional polymer solution and the perfluorine-based polymer solution can be performed in any order.The alkoxy silane functional polymer solution and the perfluorine-based polymer solution are completely dissolved in the same solvent, respectively. Prepare individually. Here, the mixing ratio of the solvent and the alkoxy silane functional polymer or perfluorine-based 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, and 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, resulting in poor workability and difficulty in controlling the thickness of the polymer film. The solution concentration was set experimentally.

The step of preparing the membrane precursor solution may be performed by preparing a homogeneous solution by mixing the prepared alkoxysilane functional polymer solution and the perfluorine-based polymer solution in a predetermined ratio. As an embodiment, the membrane precursor solution may contain 5 to 95% by weight and 95 to 5% by weight of an alkoxysilane functional polymer solution and a perfluorine-based polymer solution, respectively, and is composed by mixing at various mixing ratios required according to the composition of the finished film. can do. Meanwhile, the membrane precursor solution may 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 onto 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 perfluorine-based 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 perfluorine-based 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 crosslinked structure during the condensation reaction. Therefore, the film-forming step can be performed by treating the casting layer at a temperature capable of removing the solvent contained in the casting layer and causing a thermal crosslinking reaction between the alkoxysilane functional polymer and the perfluorine-based polymer. Drying in a vacuum state of; A first heat treatment step of treating the dried casting layer at 70 to 90°C; And a second heat treatment step of treating at a temperature of 100° C. or higher. As an embodiment, the casting layer is maintained in an oven at 60° C. under vacuum for 8 hours, and then further processed 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 may be immersed in a basic aqueous solution, treated, and then immersed in distilled water, further treated by immersing in an acidic aqueous solution, and then immersed in distilled water.In the examples to be described later, the basic aqueous solution is hydrogen peroxide and the acidic aqueous solution is Aqueous sulfuric acid solution was used. Here, the immersion treatment may be performed for 0.1 to 2 hours at a temperature range of 20 to 90°C.

Through the above configuration, the organic/inorganic polymer electrolyte composite membrane of the present invention can exhibit 40% or more improved permeability and ion selectivity compared to the conventional polymer electrolyte membrane, and excellent thermal stability due to the introduction of silica particles.

Therefore, the energy storage device and water treatment device such as a redox flow cell or a fuel cell of the present invention can secure stable performance by including an 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, and then 22.1 g of APTES was added and reacted at 50° C. for 8 hours to obtain a nanohybrid alkoxy silane functional precursor. The nanohybrid alkoxy silane functional precursor was obtained as a sol-gel mixture through a hydrolysis reaction in a 0.1M HCl aqueous solution. 3 g of the sol-gel mixture was dispersed in 7 g DMAC to obtain a homogeneous nanohybrid alkoxy silane functional polymer (D-ASFP) solution.

1-2. 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 perfluorine-based polymer solution, 2g Nafion and 8g DMAC were stirred in a hot-plate at 60℃ for 12 hours to obtain a 20wt% perfluorine-based polymer solution.

2. Membrane precursor solution preparation step

Homogeneous membrane precursor by mixing the prepared alkoxy silane functional polymer (D-ASFP) solution and the perfluorine-based polymer solution in a weight ratio of 50:50, 25:75, 20:80, 10:90 based on solid content and stirring at room temperature for 24 hours Solutions 1-1 to 1-4 were prepared.

3. Casting Step

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

4. Production stage

Alkoxy silane functional polymer contained in the casting layer by maintaining the formed casting layer in an oven at 60°C under vacuum for 8 hours, drying the surface, and further drying at 80°C for 8 hours and at 100°C for 8 hours to remove the solvent By performing a thermal crosslinking reaction between the alkoxysilane functional polymer and the perfluorine-based polymer, a precursor film 1-2 including nano-silica particles uniformly dispersed in the crosslinked structure and the crosslinked structure was obtained.

5. Pre-treatment step

The finally obtained precursor film was immersed in 3% H ₂ O ₂ aqueous solution and then immersed in distilled water, then immersed in 0.5 MH ₂ SO ₄ aqueous solution, and then immersed in distilled water to proceed with protonation pretreatment to prepare an organic/inorganic polymer electrolyte composite film 1 Got it. Each process of the pretreatment step was performed at 50°C for 30 minutes.

Example 2

An organic/inorganic polymer electrolyte composite film 2 was obtained by performing the same procedure 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 to perform nanohybrid alkoxysilane functionality. The precursor was obtained. The nanohybrid alkoxy silane functional precursor was subjected to an acid hydrolysis reaction in a 0.1M HCl aqueous solution to obtain a sol-gel mixture. 1.5 g of the sol-gel mixture was dispersed in 8.5 g DMAC to obtain a homogeneous nanohybrid alkoxy silane functional polymer (BD-ASFP) solution.

Example 3

An organic/inorganic polymer electrolyte composite film 3 was obtained by performing the same procedure 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, then 22.1g of APTES was added and reacted at 50℃ for 8 hours to make nanohybrid An alkoxy silane functional precursor was obtained. The nanohybrid alkoxy silane functional precursor was subjected to an acid hydrolysis reaction in a 0.1M HCl aqueous solution to obtain a sol-gel mixture. 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 (1000-1100cm ^-1 ) of the Si-O-Si and Si-OC groups of PDMS and APTES appeared in all of D-ASFP, BD-ASFP, and BDP-ASFP, and TDI and It was confirmed that the synthesis was made by seeing that the peak of the NHC=O functional group (1600-1650cm ^-1 ) derived from the Urea group of the crosslinked structure between DMBAs appeared in all of D-ASFP, BD-ASFP, and BDP-ASFP. In addition, as 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 alkoxy silane functional polymer was successfully prepared. I can.

Experimental Example 2

In order to confirm the ionic bond crosslinking structure between the alkoxy silane functional polymer and the perfluorine-based polymer of the organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1, the alkoxy silane functional polymer (ASFP) was used as a control. Comparative analysis was performed by spectroscopy (Fourier-transform infrared spectroscopy, FT-IR), and the results are shown in FIG. 5.

As shown in Figure 5, when comparing the peaks of the control Nafion (Nafion), alkoxy silane functional polymer (ASFP) and the organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP), it can be observed in the Nafion membrane. The C=O functional group (1700-1750cm ^-1 ) peak derived from the carboxyl group of ASFP without ASFP appears in the composite membrane, and the NHC=O functional group (1600-1650cm ^-1 ) peak derived from the Urea group of ASFP appears in the composite membrane. As shown, it was confirmed that ASFP was introduced into the composite membrane. In addition, the peaks of Si-OC and Si-O-Si groups of the alkoxysilane functional polymer were observed at 1000-1100cm ^-1 , and in particular, the characteristic peak observed at 1000 cm ^-1 was that the silane-based polymer was complex with the perfluorine-based polymer. It can be seen that this is a characteristic peak that forms a film. On the other hand, the peak of the Si-OC, Si-O-Si group (1000-1100cm ^-1 ) of the alkoxy silane functional polymer overlapped with the peak of the SO ₃ H group of the perfluorine-based polymer, but as described above, 1000 cm ^It can be confirmed that the composite membrane was successfully manufactured through the characteristic peak observed in ^-1 .

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, the thermogravimetric analysis (Thermogravimetric analysis, TGA) of Nafion 212 and the organic/inorganic polymer electrolyte composite membrane 1 And the results are shown in FIG. 6.

In the TGA analysis graph of FIG. 6, it was confirmed that dissociation of the SO ₃ H group of Nafion 212 occurs at 350° C., and degradation of the main chain occurs at 450° C. and completely disappears at 500° C. In the organic/inorganic polymer electrolyte composite membrane 1, dissociation of the SO ₃ H group occurred at 350°C, and degradation of the main chain began to occur at 450°C, but it was confirmed that residual substances existed after 500°C. It is believed that the silica particles formed due to the introduction of the inorganic polymer exist as residual materials after 500°C. Through this, it was confirmed that inorganic particles were introduced into the organic/inorganic polymer electrolyte composite membrane 1, as well as that the organic/inorganic polymer electrolyte composite membrane 1 had better thermal stability than Nafion 212.

Experimental Example 4

In order to measure the water uptake and dimensional change of the organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1, the following targeting the organic/inorganic polymer electrolyte composite membrane and Nafion 212 The moisture content and the dimensional change rate were measured as follows, and the results are shown in FIG. 7.

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

As shown in Fig. 7, which is a result of measuring the moisture content and dimensional change rate of the organic/inorganic polymer electrolyte composite membrane 1 and Nafion 212, the moisture content of Nafion 212 was significantly changed to 24% and the dimensional change rate to 14%. In the case of the organic/inorganic polymer electrolyte composite membrane 1, the moisture content was 13% and the dimensional change rate was 4%, indicating very low moisture content and dimensional change rate compared to Nafion 212. This is believed to be due to the decrease in the hydrophilic channel of the organic/inorganic polymer electrolyte composite film 1 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 polymer electrolyte composite membrane 1 (Nafion-ASFP) prepared in Example 1, the following targeting the organic/inorganic polymer electrolyte composite membrane 1 and Nafion 212 Likewise, the ion exchange capacity was 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 a result of measuring the ion exchange capacity of the organic/inorganic polymer electrolyte composite membrane 1 and Nafion 212, the ion exchange capacity of Nafion 212 was measured higher than that of the organic/inorganic polymer electrolyte composite membrane 1. This is believed to be due to the decrease in the hydrophilic channel of the organic/inorganic polymer electrolyte composite film 1 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, and 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 FIG. 9, which is a result of measuring the ionic conductivity of the organic/inorganic polymer electrolyte composite membrane 1 and Nafion 212, Nafion 212 had higher ionic conductivity than the organic/inorganic polymer electrolyte composite membrane 1, which is the introduction of alkoxysilane functional polymer and nano silica It is believed that this is because the channel for ion transport of the organic/inorganic polymer electrolyte composite membrane has been reduced due to the generation of particles.

Experimental Example 7

In order to measure the transmittance of the organic/inorganic polymer electrolyte composite membrane 1 (Nafion-ASFP) obtained in Example 1, the transmittance of the organic/inorganic polymer electrolyte composite membrane and Nafion 212 was measured as follows, and the results are shown in FIG. Shown in.

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

From Fig. 10 showing the permeability of VO ²⁺ ions of the organic/inorganic polymer electrolyte 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 is 2.217×10 ^-7 cm ² /min. The transmittance 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 permeation characteristics of VO ²⁺ ions were greatly improved in the organic/inorganic polymer electrolyte composite membrane.

Experimental Example 8

In order 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 transmittance of Experimental Example 6, the organic/inorganic polymer The ion selectivity of the electrolyte composite membrane 1 and Nafion 212 was calculated and the results are shown in FIG. 11.

The ion conductivity of Nafion212 was measured to be high, but the transmittance was measured to be high, indicating that the ion selectivity was lower than that of the organic/inorganic polymer electrolyte composite membrane. On the other hand, in the case of the organic/inorganic polymer electrolyte composite membrane 1, the ion conductivity was low, but the transmittance was measured to be low, indicating that the ion selectivity was higher than 39%. Through this, it was confirmed that the organic/inorganic polymer electrolyte composite membrane 1 has excellent ion selection characteristics.

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

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

Claims (16)

A crosslinked structure of an alkoxysilane functional polymer and a perfluorine-based polymer; And
Including; nano-silica particles uniformly dispersed within the cross-linked structure,
The alkoxysilane functional polymer is one or more 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. Organic/inorganic polymer electrolyte composite membrane.
delete The method of claim 1,
The perfluorinated polymer is Nafion (DuPont), 3M ionomer (3M), Fumion, Aciplex, Aquivion, sulfonated perfluorinated polymer (PFSA, perfluorinated sulfonic acid), Polytetrafluoroethylene, poly(vinylidene fluoride), poly(vinyl fluoride), polyvinylidene fluorocoperfluorinated alkyl vinyl ether (poly (vinylidene fluo-co- An organic/inorganic polymer electrolyte composite membrane, characterized in that at least one selected from the group consisting of a combination of perfluorinated alkyl vinyl ethers)).
The method of claim 1,
Organic/inorganic polymer electrolyte composite membrane, characterized in that ion permeability is 2×10 ^-7 cm ² /min or less.
Preparing an alkoxysilane functional polymer solution and a perfluorine-based polymer solution;
Preparing a membrane precursor solution by mixing the alkoxysilane functional polymer solution and the perfluorine-based polymer solution;
A casting step of casting the film precursor solution to form a casting layer;
A film forming step of forming a precursor film by crosslinking an alkoxysilane functional polymer and a perfluorine-based polymer included in the casting layer; And
Includes; 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. Is any one or more selected from,
The organic/inorganic polymer electrolyte composite membrane, characterized in that the crosslinking structure of the alkoxysilane functional polymer and the perfluorine-based polymer and nanosilica particles uniformly dispersed within the crosslinking structure are generated through a thermal crosslinking reaction in the film forming step Manufacturing method.
The method of claim 5,
The alkoxysilane functional polymer solution and the perfluorine-based polymer solution each contain 5 to 70 parts by weight of an alkoxysilane functional polymer and a perfluorine-based polymer per 100 parts by weight of a solvent.A method for producing an organic/inorganic polymer electrolyte composite film.
The method of claim 6,
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-pyrillydinone, and N,N-dimethylformamide. Organic/inorganic polymer electrolyte composite membrane manufacturing method.
The method of claim 5,
The membrane precursor solution comprises 5 to 95% by weight of the alkoxy silane functional polymer solution and 95 to 5% by weight of the perfluorine-based polymer solution.
The method of claim 8,
The membrane precursor solution is an organic/inorganic polymer electrolyte composite membrane manufacturing method, characterized in that it is obtained by stirring the alkoxysilane functional polymer solution and the perfluorine-based polymer solution at a temperature of 20 to 50 degrees.
The method of claim 5,
The film forming step may include drying the casting layer in a vacuum of 70° C. or less; A first heat treatment step of treating the dried casting layer at 70 to 90°C; And a second heat treatment step of treating at a temperature of 100° C. or higher. 2. A method of manufacturing an organic/inorganic polymer electrolyte composite film comprising: a.
delete The method of claim 5,
The protonation is performed by immersing the precursor film in a basic aqueous solution, immersing it in distilled water, immersing it in an acidic aqueous solution, and then immersing in distilled water to prepare an organic/inorganic polymer electrolyte composite membrane.
The organic/inorganic polymer electrolyte composite membrane of any one of claims 1, 3, and 4 or the organic/inorganic polymer electrolyte composite membrane manufactured by the manufacturing method of any of claims 5 to 10, 12 Fuel cell including.
The organic/inorganic polymer electrolyte composite membrane of any one of claims 1, 3, and 4 or the organic/inorganic polymer electrolyte composite membrane manufactured by the manufacturing method of any of claims 5 to 10, 12 Energy storage device comprising.
The method of claim 14,
The energy storage device is an energy storage device, characterized in that the redox flow cell or fuel cell.
The organic/inorganic polymer electrolyte composite membrane of any one of claims 1, 3, and 4 or the organic/inorganic polymer electrolyte composite membrane manufactured by the manufacturing method of any of claims 5 to 10, 12 Water treatment device comprising.

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