Preparation methods and applications of polymer hydrogels with ultra-high ionic conductivity

Abstract

This invention belongs to the field of ion-conducting hydrogel materials, specifically disclosing a method for preparing a polymer hydrogel with ultra-high ion conductivity and its application. This invention obtains chemically modified amylated polyacrylonitrile containing active double bonds by heat treatment of amylated polyacrylonitrile, and then further prepares an ultra-high ion conductivity hydrogel by graft polymerization with a zwitterionic polymer. The prepared hydrogel exhibits excellent recoverability and ultra-high ion conductivity, showing great application potential in fields such as electrolyte membranes for energy storage devices, flexible sensors, and proton exchange membranes.

Description

Technical Field

[0001] This invention belongs to the field of ion-conducting hydrogel materials, and relates to a method for preparing a polymer hydrogel with ultra-high ion conductivity and its application. Background Technology

[0002] Polymer ion-conductive hydrogels have been widely used in electrolyte membranes for implantable bioelectronics, proton exchange membranes, electronic skin, wearable sensors, and energy storage devices due to their excellent biocompatibility, good mechanical properties, mechanical recoverability, and ability to capture electrolyte ions to promote the dissociation of metal salts.

[0003] Generally, polymer-based ion-conducting hydrogels consist of a hydrophilic cross-linked polymer network and an acid / salt / alkali solution. For example, Professor Zhi Chunyi's research group at City University of Hong Kong summarized the research progress of hydrogel electrolytes applied to flexible energy storage devices in recent years, analyzed the potential problems of the current technology, and looked forward to possible future research directions. The results were published in *Advanced Functional Materials* (Adv. Funct. Mater. 2018, 1804560.), which disclosed a trifluoromethanesulfonyl zinc hydrogel. Another example is Professor Liu Zhiqiang's research group at Nankai University, which disclosed a bacterial cellulose / polyacrylamide / sulfate ion-conducting hydrogel, published in *Angewandte Chemie International Edition* (Angewandte Chemie. Int. Ed. 2019, 131, 4357-4361). These hydrogels exhibit excellent flexibility, but due to the limited ion dissociation ability of the polymer chains in the hydrogel, the prepared ion-conducting hydrogels usually have low ion conductivity (<8S m). -1 ).

[0004] To prepare ionically conductive hydrogels with higher ion conductivity, some polymers that can form strong interactions with salt ions have been used. For example, Adv. Energy Mater. 2019, 1803046 disclosed that Professor Zhi Chunyi's research group at City University of Hong Kong, led by Ma Longtao et al., synthesized a sodium polyacrylate / cellulose dual-network structure hydrogel; Small 2022, 2200055 disclosed that Professor Yang Nianjun's research group at Xinjiang University, led by Zhu Xiaoqing et al., synthesized a polyacrylol / negatively charged hydroxymethyl cellulose / sodium chloride hydrogel; both of these hydrogels belong to hydrogels with cationic polymers. Furthermore, ChemSusChem 2018, 11, 3410-3415 disclosed that Professor Wang Qinggang's research group at Tongji University, led by Wei Junjie et al., synthesized a carboxymethyl cellulose / methacrylamidopropyltrimethylammonium chloride / polyacrylamide hydrogel, which belongs to hydrogels with anionic polymers. For example, ACS Appl. Mater. Interfaces 2010, 1, 203-211 disclosed that Professor Yonghong Zhao et al. from Professor Renbi Bai's group at the National University of Singapore synthesized a cellulose-grafted methacrylic acid sulfobetaine / sodium chloride hydrogel, which belongs to the category of hydrogels with zwitterionic polymers. The above three types of polymer ion-conductive hydrogels exhibit high ionic conductivity (8–26 mS). -1 ).

[0005] However, in some applications, such as electrolyte membranes for energy storage devices and flexible electronic devices, ion-conducting hydrogels require ultra-high conductivity to enable these devices to exhibit superior performance. Therefore, the conductivity of ion-conducting hydrogels still needs further improvement. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a polymer hydrogel with ultra-high ionic conductivity. The method involves heat-treating a metallo-oxime-modified polyacrylonitrile to obtain a chemically modified metallo-oxime-modified polyacrylonitrile containing active double bonds, and then further grafting it with a zwitterionic polymer to obtain a hydrogel with ultra-high ionic conductivity. The hydrogel exhibits excellent recoverability and ultra-high ionic conductivity.

[0007] Another objective of this invention is to provide applications of the aforementioned polymer hydrogel with ultra-high ionic conductivity.

[0008] To achieve the above objectives, the technical solution adopted by this invention is as follows:

[0009] A method for preparing a polymer hydrogel with ultra-high ionic conductivity includes the following steps performed sequentially:

[0010] S1. Preparation of amylated polyacrylonitrile

[0011] Polyacrylonitrile was dissolved in mixture A, and after heat treatment, mixture B was obtained. After centrifugation, the supernatant was collected, and the supernatant was washed and dried to obtain chemically modified hydrophilic polyacrylonitrile powder, namely, amylated polyacrylonitrile.

[0012] The mixture A is a mixture of hydroxylamine hydrochloride, sodium carbonate, sodium hydroxide, and N,N-dimethylformamide;

[0013] S2. Preparation of chemically modified amylopyridine-oxime-modified polyacrylonitrile solution

[0014] A metallo-oxime-modified polyacrylonitrile was dissolved in tetrabutylammonium hydroxide solution to obtain solution C. Then, allyl glycidyl ether solution was added to solution C, and after mixing evenly, heat treatment and dialysis were performed to obtain a chemically modified metallo-oxime-modified polyacrylonitrile solution.

[0015] S3. Hydrothermal preparation of hydrogels

[0016] A chemically modified amylated polyacrylonitrile solution was mixed with a zwitterionic polymer, then an initiator was added, and after heat treatment, a polymer hydrogel with ultra-high ionic conductivity was obtained.

[0017] As a limitation, in step S1, the heat treatment temperature is 40–80°C and the reaction time is 8–48 h.

[0018] As a second limitation, in the chemically modified amylopyroxymethylene polyacrylonitrile solution obtained in step S2, the solvent is tetrabutylammonium hydroxide solution, and the chemically modified amylopyroxymethylene polyacrylonitrile solution is obtained by chemically modifying amylopyroxymethylene polyacrylonitrile with allyl glycidyl ether.

[0019] As a third limitation, the concentration of amine-oxime polyacrylonitrile in solution C is 0.582–1.745 mol / L; the molar ratio of amine-oxime polyacrylonitrile to allyl glycidyl ether is 50:1–150:1.

[0020] As a fourth limitation, in step S2, the heat treatment temperature is 45–80°C and the reaction time is 2–6 h.

[0021] As a fifth limitation, in step S2, during the dialysis process, the solution obtained after heat treatment is dialyzed in deionized water until 8 ≤ pH ≤ 10.

[0022] As a sixth limitation, in step S3, the zwitterionic polymer is [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, dimethyl-(4-vinylphenyl)propanesulfonate ammonium, or carboxybetaine, and the initiator is sodium persulfate, potassium persulfate, or azobisisobutyronitrile.

[0023] As a seventh limitation, in step S3, the heat treatment temperature is 45–80°C and the reaction time is 3–18 h.

[0024] This invention also discloses the application of the above-mentioned ultra-high ionic conductivity polymer hydrogel in the preparation of flexible electronic devices.

[0025] As a limitation, the flexible electronic device is an electrolyte diaphragm, a flexible sensor, or a proton exchange membrane.

[0026] The present invention, by adopting the above-described technical solution, achieves the following technical advancements compared to existing technologies:

[0027] (1) The present invention uses a grafting method to prepare a cross-linked polymer network structure hydrogel. The excellent grafting further increases the stability of the hydrogel network. Therefore, when pressure is applied during compression, the compression energy can be dissipated through the grafted cross-linked network, thereby greatly improving its recoverable compression performance and fatigue resistance.

[0028] (2) The large number of hydrophilic amino, hydroxyl, amylopyroxime and zwitterionic groups in the polymer hydrogel with ultra-high ionic conductivity prepared by the present invention can interact strongly with ions in LiCl solution, thereby enabling LiCl to fully dissociate and more conducive to the formation of free active ions, thus exhibiting ultra-high ionic conductivity under the action of electric field.

[0029] (3) The ultra-high ionic conductivity polymer hydrogel prepared by this invention has good elasticity, fast recovery speed and good fatigue resistance. It can be compressed and deformed to 93% without damage and can quickly and completely recover, and exhibits a strength of 26.9 S m. -1 Extremely high ionic conductivity;

[0030] This invention belongs to the field of ion-conducting hydrogel materials technology and can greatly improve the mechanical properties and conductivity of ion-conducting hydrogel materials. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0032] In the attached diagram:

[0033] Figure 1 a is a flowchart of the preparation process in Example 1 of the present invention;

[0034] Figure 1 b is a flowchart of the ion transport mechanism in Embodiment 1 of the present invention;

[0035] Figure 2 Example 1 of the present invention relates to PAO, SBMA, and PAO.60 -AGE 1 / 100 and PAO 60 -g-PSBMA 60 The Fourier transform infrared spectral analysis curves were obtained by performing separate analyses.

[0036] Figure 3 a represents PAO in Embodiment 1 of this invention. 60 -g-PSBMA 60 Atomic force microscopy height diagram of hydrogels;

[0037] Figure 3 b represents PAO in Embodiment 1 of this invention. 60 -g-PSBMA 60 Phase diagram corresponding to hydrogel height diagram;

[0038] Figure 4 In Embodiment 1 of the present invention, PAO was respectively... 60 -g-PSBMA 60 Hydrogel, PAO 60 -g-PSBMA 60 (7M LiCl) hydrogel and PAO 60 / PSBMA 60 The hydrogel was tested for compressibility, and the results are shown in the graph.

[0039] Figure 5 The PAO in Embodiment 1 of the present invention 60 -g-PSBMA 60 PAO 60 / PSBMA 60 and PVA 120 The ionic conductivity of the hydrogel was tested, and the results are shown in the graph. Detailed Implementation

[0040] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0041] Unless otherwise specified, the experimental conditions in the examples are generally as per conventional conditions or as recommended by the reagent company. Unless otherwise specified, the reagents, consumables and other materials used in the following examples are commercially available, and the processes used are conventional processes in the art.

[0042] Raw materials: Polyacrylonitrile, allyl glycidyl ether (AGE), [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), hydroxylamine hydrochloride, polyvinyl alcohol (PVA), N,N-dimethylformamide, dimethyl-(4-vinylphenyl)propanesulfonate ammonium, and carboxybetaine were purchased from Shanghai Maclean Biochemical Co., Ltd. Sodium hydroxide, sodium carbonate, tetrabutylammonium hydroxide (TBAOH), potassium persulfate (KPS), sodium persulfate, azobisisobutyronitrile, and lithium chloride (LiCl) were purchased from China National Pharmaceutical Group Chemical Co., Ltd.

[0043] Example 1: Preparation method of polymer hydrogel with ultra-high ionic conductivity

[0044] This embodiment includes the following steps performed sequentially:

[0045] S1. Preparation of amylated polyacrylonitrile

[0046] Take 78 kg of hydroxylamine hydrochloride, 54 kg of sodium carbonate, 14 kg of sodium hydroxide and 840 L of N,N-dimethylformamide and mix them to prepare a mixture A; then slowly add 60 kg of polyacrylonitrile, and stir the reaction at T1 = 60 °C for t1 = 24 h to obtain solution B. After centrifuging the mixture B, take the supernatant and wash it in 5000 L of deionized water. Then dry the precipitate to obtain chemically modified hydrophilic polyacrylonitrile powder, namely, amylated polyacrylonitrile (PAO) powder.

[0047] S2. Preparation of chemically modified amylopyridine-oxime-modified polyacrylonitrile solution

[0048] 34.9 mol of PAO was dissolved in 30 L of tetrabutylammonium hydroxide solution and mixed well to obtain solution C. Then, 0.349 mol of AGE solution was added to solution C, mixed well, and stirred at T2 = 60 °C for t2 = 2 h. The resulting solution was then dialysis in deionized water until pH = 8 to obtain chemically modified amine oxime-modified polyacrylonitrile (PAO). 60 -AGE 1 / 100 ) solution;

[0049] In this step, the solvent in the chemically modified amylopyroxymethylene polyacrylonitrile solution is tetrabutylammonium hydroxide solution, and the chemically modified amylopyroxymethylene polyacrylonitrile solution is obtained by chemically modifying amylopyroxymethylene polyacrylonitrile with allyl glycidyl ether.

[0050] S3. Hydrothermal preparation of hydrogels

[0051] To obtain PAO 60 -AGE 1 / 10010.8 mol of zwitterionic polymer was added to the solution and mixed thoroughly. Then, 120 g of KPS was added as an initiator. The well-stirred mixture was then allowed to stand at T3 = 60 °C for t3 = 12 h to obtain a polymer hydrogel with ultra-high ionic conductivity, namely PAO. 60 -g-PSBMA 60 Hydrogel.

[0052] In this embodiment, the zwitterionic polymer is [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide.

[0053] The following section presents the performance tests of hydrogel materials prepared by four different methods.

[0054] 1) Preparation of hydrogel materials

[0055] ①PAO 60 -g-PSBMA 60 Hydrogel: prepared by the method of this embodiment;

[0056] ②PAO 60 -g-PSBMA 60 (7M LiCl) hydrogel: The hydrogel prepared in this example is obtained by immersing it in a 7M LiCl solution for 12 hours;

[0057] ③PAO 60 / PSBMA 60 Hydrogel: Prepared without adding AGE in step S1 of embodiment 1, with the remaining steps being the same as in embodiment 1;

[0058] ④PVA 120 Hydrogel: Add 600 mg PVA to 5 mL of deionized water, stir and disperse evenly at 90 °C, and then let stand at 25 °C for 48 h to obtain the hydrogel.

[0059] (ii) Analysis of preparation process and ion transport mechanism

[0060] PAO 60 -g-PSBMA 60 The preparation process and ion transport mechanism of the hydrogel were analyzed in the form of a flowchart;

[0061] The results are as follows Figure 1 ,from Figure 1 In step a, PAO, which contains abundant metamine oxime groups, and AGE, which has active double bonds, are first dissolved in tetrabutylammonium hydroxide. After heat treatment and ring-opening modification, PAO is obtained. 60 -AGE 1 / 100 Solution containing PAO 60 -AGE 1 / 100The active double bonds in PAO can undergo subsequent graft polymerization reactions. Finally, after adding SBMA and KPS and heat treatment, and then cooling, PAO with ultra-high ionic conductivity is obtained. 60 -g-PSBMA 60 Hydrogel.

[0062] from Figure 1 As shown in b, the abundant hydrophilic amine oxime groups in PAO can form lithium bonds with lithium ions. The rich zwitterions in PSBMA can fully dissociate the lithium salt through electrostatic interaction, thus enabling PAO to undergo lithium ion ionization after immersion in LiCl solution under an electric field. 60 -g-PSBMA 60 Hydrogels possess excellent ion transport capabilities and exhibit extremely high ionic conductivity.

[0063] (iii) Fourier transform infrared spectroscopy analysis

[0064] For PAO, SBMA, PAO 60 -AGE 1 / 100 and PAO 60 -g-PSBMA 60 The Fourier transform infrared (FTIR) spectrometer was used for analysis, and the results are as follows: Figure 2 As shown.

[0065] See Figure 2 In the PAO spectral curve, at 1633 cm⁻¹ -1 3355cm -1 and 930cm -1 Characteristic peaks can be observed for stretching vibrations with respect to C=N, -OH, and NO, respectively. PAO 60 -AGE 1 / 100 In the spectral curve of PAO 60 -AGE 1 / 100 At 915cm -1 The characteristic peak appears due to the shift of the NO peak, and is located at 1498 cm⁻¹. -1 The appearance of new characteristic peaks, attributed to the C=C vibration peaks, indicates that PAO was successfully chemically modified into PAO by AGE. 60 -AGE 1 / 100 In the SBMA spectrum, at 1041 cm⁻¹ -1 and 651cm -1 It has a characteristic peak, which is attributed to -SO3 - The vibration peak of PAO. 60 -g-PSBMA 60 In the spectral curve, PAO 60 -g-PSBMA 60 At 1037 and 645cm-1 The appearance of a sharp peak indicates that PAO 60 -AGE 1 / 100 PAO was obtained by grafting with SBMA. 60 -g-PSBMA 60 .

[0066] (iv) Atomic force microscope images

[0067] For PAO 60 -g-PSBMA 60 The microstructure of the hydrogel was analyzed using atomic force microscopy (AFM), specifically the Asylum Research MFP-3D AFM microscope. The results are as follows: Figure 3 As shown.

[0068] Figure 3 a is PAO 60 -g-PSBMA 60 The atomic force microscopy (AFM) image of the hydrogel shows a distinct microstructure consisting of two phases: a bright area attributed to the relatively hard PAO phase with a larger molecular weight, and a darker area attributed to the softer PSBMA phase with a smaller molecular weight. The uniform distribution of these two phases indicates the presence of two distinct PAO phases. 60 -g-PSBMA 60 The internal structure of the hydrogel is very uniform. The maximum height difference between the two phases is only 13 nm, indicating that PAO and PSBMA are very tightly bound together. Figure 3 b is PAO 60 -g-PSBMA 60 The phase diagram corresponding to the hydrogel height map shows that the originally bright PAO region corresponds to the darker region in the phase diagram. This is because PAO, which has lower viscosity in the phase diagram, exhibits a larger angular shift and appears as a darker region. In contrast, the amphoteric functional groups in PSBMA can generate strong electrostatic interactions with the probe, exhibiting greater viscosity and thus appearing as a brighter region in the phase diagram. This further proves the existence of two phases and their close binding.

[0069] (v) Mechanical property testing

[0070] PAO was tested using the MTS mechanical testing system. 60 -g-PSBMA 60 Hydrogel, PAO 60 -g-PSBMA 60 (7M LiCl) hydrogel, and PAO 60 / PSBMA 60The hydrogel was tested for compressibility at a compression rate of 0.5 mm / min. The cylindrical aerogel had a diameter of 17 mm and a height of 6 mm. The results are as follows: Figure 4 .

[0071] from Figure 4 PAO can be seen from 60 -g-PSBMA 60 PAO 60 -g-PSBMA 60 (7M LiCl), and PAO 60 / PSBMA 60 Hydrogels can withstand extremely high mechanical deformation, with a recoverable deformation of up to 93%. When the deformation is 93%, PAO... 60 -g-PSBMA 60 PAO 60 -g-PSBMA 60 (7M LiCl), and PAO 60 / PSBMA 60 The compressive stresses corresponding to the hydrogels were 7.7, 5.4, and 4.8 kPa, respectively, compared to PAO. 60 / PSBMA 60 Hydrogel, PAO 60 -g-PSBMA 60 and PAO 60 -g-PSBMA 60 The high mechanical strength of (7M LiCl) hydrogel is due to the grafting process, which makes the cross-linked network more robust. In contrast, PAO... 60 -g-PSBMA 60 Comparison of the mechanical strength of hydrogels, PAO 60 -g-PSBMA 60 The strength of the (7M LiCl) hydrogel decreases because the introduction of LiCl leads to a salt ingress effect, causing the hydrogen and ionic bonds between the molecular chains of the hydrogel network to break, resulting in low mechanical strength. This effect also indirectly indicates the degradation of PAO. 60 -g-PSBMA 60 (7M LiCl) hydrogel has a significant effect on the dissociation of LiCl.

[0072] The results are summarized in Table 1:

[0073] Table 1 Comparison of mechanical properties of hydrogels prepared by the three methods

[0074]

[0075] (vi) Detection of ionic conductivity

[0076] The ionic conductivity of the prepared polymer hydrogel was tested using a CHI660E electrochemical workstation.

[0077] Take an area of ​​1×1cm respectively 2 PAO with a height of 2mm 60 -g-PSBMA 60 PAO 60 / PSBMA 60 and PVA 120 Hydrogels were soaked in LiCl solutions of different concentrations (1-9M), and gold sheets were attached to both ends of the hydrogels. The hydrogels were then encapsulated with PET film, and the ionic conductivity was tested.

[0078] Ionic conductivity (σ, S m) -1 It is calculated using the following formula:

[0079] σ = L / (R×S);

[0080] In the formula, L, R, and S represent, in order: the thickness of the hydrogel (m); the electrical resistance of the hydrogel (Ω); and the overlap area between the gold sheet and the hydrogel (m²). 2 ;

[0081] The results of the ionic conductivity test are as follows: Figure 5 As can be seen from the figure, PAO 60 -g-PSBMA 60 The ionic conductivity of the hydrogel increases with increasing LiCl concentration. When the LiCl concentration is 7 mol / L... -1 It reaches its maximum value at this time, with a maximum conductivity of 26.9 Sm. -1 At this point, the functional groups in the hydrogel interact with Li + and Cl - The effect of PAO has reached saturation. 60 / PSBMA 60 Its maximum ionic conductivity is only 17.2 S m. -1 This is due to PAO 60 -g-PSBMA 60 Grafting in hydrogels reduces the number of crystalline polymer chains and increases the number of ionically conductive polymer chains, thus facilitating ion transport. In contrast, the ionic conductivity of PVA ion-conducting hydrogels, most widely used in electrolyte membranes for energy storage devices, is only 11.3 S / m. -1 The concentration of LiCl at this time is 4 mol L. -1 .

[0082] The prepared PAO 60 -g-PSBMA 60 Hydrogels compared to PVA 120The reason why hydrogels have high ionic conductivity is that the large number of hydrophilic amino, hydroxyl, amine oxime and zwitterionic groups in hydrogels can interact strongly with ions in LiCl solution, thereby enabling LiCl to fully dissociate and more conducive to the formation of free active ions, thus exhibiting ultra-high ionic conductivity under the action of an electric field.

[0083] In summary, PAO-AGE containing active double bonds was obtained through chemical modification of PAO, and flexible PAO with ultra-high ionic conductivity was prepared by graft polymerization of SBMA. 60 -g-PSBMA 60 The hydrogel exhibits a maximum recoverable deformation of 93%, with a maximum stress of 7.7 kPa at 93% deformation. This is due to PAO... 60 -g-PSBMA 60 Hydrogels contain a large number of hydrophilic amino, hydroxyl, metamine oxime, and zwitterionic groups. When the hydrogel is soaked in LiCl solution, it interacts strongly with the ions in the solution, greatly enhancing the dissociation of LiCl. Therefore, when soaked in 7 mol L... - 1 After being treated with LiCl solution, the hydrogel exhibited a diameter of 26.9 S m. -1 It has ultra-high ionic conductivity.

[0084] Preparation methods of polymer hydrogels with ultra-high ionic conductivity in Examples 2-6

[0085] The preparation processes of Examples 2 to 6 are largely the same as those of Example 1, except for the specific process parameters, which are shown in the table below:

[0086] Table 2 Process parameters for Examples 1-6

[0087]

[0088]

[0089]

[0090] The chemical formulas of ultra-high ionic conductivity polymer hydrogels synthesized from different zwitterionic polymers are different. Specifically, the ultra-high ionic conductivity polymer hydrogel obtained by using 2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide has the chemical formula ①, the ultra-high ionic conductivity polymer hydrogel obtained by using carboxybetaine has the chemical formula ②, and the ultra-high ionic conductivity polymer hydrogel obtained by using dimethyl-(4-vinylphenyl)propanesulfonate has the chemical formula ③.

[0091] Upon testing, the PAO prepared in Examples 2 to 6...60 -g-PSBMA 60 Hydrogel and PAO prepared in Example 1 60 -g-PSBMA 60 Hydrogels have the same properties.

[0092] Examples 7-8: Preparation method of polymer hydrogels with ultra-high ionic conductivity

[0093] The preparation processes of Examples 7 and 8 are largely the same as those of Example 1, except that the pH values ​​after percolation in step S2 are different. In Example 7, the pH was percolated to 9, and in Example 8, the pH was percolated to 10. The properties of the ultra-high ionic conductivity polymer hydrogels prepared in Examples 1, 7, and 8 were tested, and the test results are shown in Table 3.

[0094] Table 3. PAO prepared at different pH values 60 -g-PSBMA 60 Comparison of mechanical strength and ionic conductivity of hydrogels

[0095]

[0096]

[0097] Example 9: Application of ultra-high ionic conductivity polymer hydrogels

[0098] This embodiment provides the application of the ultra-high ionic conductivity polymer hydrogels prepared in Examples 1 to 8. They can be used to prepare flexible electronic devices and have great application prospects. For example, flexible electronic devices are electrolyte membranes for energy storage devices, flexible sensors, or proton exchange membranes.

Claims

1. A method for preparing a superionically conductive polymer hydrogel, characterized by, This includes the following steps performed sequentially: S1. Preparation of amylated polyacrylonitrile Polyacrylonitrile was dissolved in mixture A, and after heat treatment, mixture B was obtained. After centrifugation, the supernatant was collected, and the supernatant was washed and dried to obtain chemically modified hydrophilic polyacrylonitrile powder, namely, amylated polyacrylonitrile. The mixture A is a mixture of hydroxylamine hydrochloride, sodium carbonate, sodium hydroxide, and N,N-dimethylformamide; S2. Preparation of chemically modified amylopyridine-oxime-modified polyacrylonitrile solution A metallo-oxime-modified polyacrylonitrile was dissolved in tetrabutylammonium hydroxide solution to obtain solution C. Then, allyl glycidyl ether solution was added to solution C, and after mixing evenly, heat treatment and dialysis were performed to obtain a chemically modified metallo-oxime-modified polyacrylonitrile solution. S3. Hydrothermal preparation of hydrogels A chemically modified amylated polyacrylonitrile solution was mixed with a zwitterionic polymer, then an initiator was added, and after heat treatment, a polymer hydrogel with ultra-high ionic conductivity was obtained. The zwitterionic polymer is [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, dimethyl-(4-vinylphenyl)propanesulfonate ammonium or carboxybetaine, and the initiator is sodium persulfate, potassium persulfate or azobisisobutyronitrile.

2. The method for preparing the super-ionic conductivity polymer hydrogel according to claim 1, characterized in that, In step S1, the heat treatment temperature is 40–80 °C, and the reaction time is 8–48 h.

3. The method for preparing the super-ionic conductive polymer hydrogel according to claim 1 or 2, characterized in that, In the chemically modified amylopyroxymethylene polyacrylonitrile solution obtained in step S2, the solvent is tetrabutylammonium hydroxide solution, and the chemically modified amylopyroxymethylene polyacrylonitrile solution is obtained by chemically modifying amylopyroxymethylene polyacrylonitrile with allyl glycidyl ether.

4. The method for preparing the super-ionic conductive polymer hydrogel according to claim 1 or 2, characterized in that, The concentration of amine-oxime polyacrylonitrile in solution C is 0.582–1.745 mol / L; the molar ratio of amine-oxime polyacrylonitrile to allyl glycidyl ether is 50:1–150:

1.

5. The method for preparing the super-ionic conductive polymer hydrogel according to claim 1 or 2, characterized in that, In step S2, the heat treatment temperature is 45–80 °C, and the reaction time is 2–6 h.

6. The method for preparing the super-ionic conductive polymer hydrogel according to claim 1 or 2, characterized in that, In step S2, during the dialysis process, the solution obtained after heat treatment is dialyzed in deionized water until 8 ≤ pH ≤ 10.

7. The method for preparing the superionically conductive polymer hydrogel according to claim 1 or 2, characterized by, In step S3, the heat treatment temperature is 45–80 °C, and the reaction time is 3–18 h.

8. The application of the ultra-high ionic conductivity polymer hydrogel according to any one of claims 1-7 in the preparation of flexible electronic devices.

9. Use of the superionically conductive polymer hydrogel according to claim 8, characterized in that, The flexible electronic device is an electrolyte diaphragm, a flexible sensor, or a proton exchange membrane.

Images