Preparation method of conductive polymer ionic gel

Abstract

The invention discloses a conductive polymer ionic gel preparation method, which comprises: mixing a flexible monomer and a conductive monomer in an ionic liquid, carrying out light curing to form a pre-gel, and soaking the pre-gel in a FeCl3 solution to carry out in-situ pyrrole oxidation so as to prepare the conductive polymer ionic gel. The preparation method is simple, the process is easy to control, and the prepared conductive polymer ionic gel is composed of a chemical cross-linked flexible polymer network and a polypyrrole interpenetrating network and has excellent performance: the conductive polymer ionic gel shows good flexibility at normal temperature, the tensile strength can reach 0.026-0.034 MPa, the fracture strain can reach 356-483%, and the conductive polymer ionic gel can be used for preparing a conductive polymer. The conductivity at room temperature is up to 0.6 S / m; in addition, the conductive polymer ionic gel can still keep excellent tensile property at-20 DEG C, and meanwhile, the conductivity reaches 0.28 S / m.

Description

Technical Field

[0001] The invention belongs to the technical field of functional materials and relates to a method for preparing a conductive polymer ion gel. Background Art

[0002] With the rapid development of flexible electronic technology, flexible conductive materials with good stretchability and conductivity have shown great application potential. Conductive polymers (CPs), including polyaniline (PANI), polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS), are widely used to develop high-performance conductive materials due to their unique conjugated structures, tunable physical / chemical properties and optoelectronic properties. However, the inherent rigidity and brittleness of conductive polymer chains are contrary to the flexibility and ductility required for tissue-like electronics, which severely limits their application in flexible electronics. To overcome the mechanical brittleness of CPs, a mature and effective strategy is to prepare conductive polymer-based hydrogels by introducing conductive polymers into mechanically flexible substrate networks through a simple method of direct mixing or in situ polymerization, achieving a good integration of mechanical properties and conductive properties. However, the development of conductive polymer hydrogels based on aqueous media faces some severe challenges, including the unsatisfactory solubility and dispersibility of CPs in water, crystallization of water at sub-zero temperatures, and inevitable water loss in the open state. Therefore, the synthetic method, working range and long-term usability of conductive polymer hydrogels need to be further improved. Therefore, it is of great application value to study and develop a highly stretchable, highly conductive, adhesive and low-temperature resistant CPs-based flexible conductive material.

[0003] In recent years, ion gels rich in ionic liquids (ILs) in three-dimensional polymer networks have attracted much attention. Due to their excellent chemical stability, intrinsic ionic conductivity and wide electrochemical window, ILs have been vigorously developed for wearable sensors, soft robots and human-machine interaction. However, the main application limitations of ion gels are their weak mechanical properties and low ionic conductivity. Although it has been proven that the mechanical strength and toughness of ion gels can be significantly improved by changing or adjusting the structure of gel materials at the molecular level and at the micro- and nanoscales, the optimization of the conductive properties of ion gels is still insufficient. In addition, based on the doping of ILs to CP and the interaction between them, ILs have been successfully used as ideal media for the polymerization of CP monomers, especially imidazolyl ionic liquids. However, it is a blank to combine CPs and ILs with polymer materials to explore a wider range of functions and applications. Therefore, the development of a conductive polymer ion gel with excellent comprehensive properties is an urgent problem to be solved. Summary of the invention

[0004] In view of the above technical problems, the present invention aims to provide a method for preparing a conductive polymer ion gel, wherein a flexible monomer and a conductive monomer are mixed in an ionic liquid, and a pre-gel is formed by photocuring and then immersed in FeCl 3 The conductive polymer ion gel is prepared by in-situ oxidation of pyrrole in a solution. The preparation method of the present invention is simple, the process is easy to control, and the prepared conductive polymer ion gel is composed of a chemically cross-linked flexible polymer network and a polypyrrole interpenetrating network, and has excellent properties: the conductive polymer ion gel exhibits good flexibility at room temperature, the tensile strength can reach 0.026-0.034MPa, the fracture strain can reach 356%-483%, and the conductivity at room temperature is as high as 0.6S / m; in addition, the conductive polymer ion gel can still maintain excellent tensile properties at -20°C, and the conductivity reaches 0.28S / m.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for preparing a conductive polymer ion gel is carried out in the following steps in sequence:

[0007] (1) adding acrylic acid (AA) and N-(2-hydroxyethyl) acrylamide (HEAA) to 1-ethyl-3-methylimidazole ethyl sulfate and stirring evenly, then adding pyrrole, stirring at 60° C. for 10 min, adding 39 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate and 5.8 g of polyethylene glycol diacrylate and stirring at room temperature for 1 h, to obtain solution A;

[0008] (2) Solution A was transferred into the mold and irradiated under UV light for 4 h to form P(AA-co-HEAA)@Py pregel;

[0009] (3) FeCl 3 1-ethyl-3-methylimidazole ethyl sulfate is added to form a mixed solution, and then the P(AA-co-HEAA)@Py pregel prepared in step (2) is immersed in the mixed solution to obtain a conductive polymer ion gel.

[0010] As a limitation of the preparation method of the present invention, in step (1), the molar ratio of acrylic acid to N-(2-hydroxyethyl)acrylamide and 1-ethyl-3-methylimidazole ethyl sulfate is 11:11:35.

[0011] In the present invention, the molar ratio between acrylic acid and N-(2-hydroxyethyl)acrylamide and 1-ethyl-3-methylimidazolium ethyl sulfate is extremely important. When the molar ratio is 11:11:35, the crosslinking density of the ion gel is optimal, which can provide sufficient elasticity and toughness to achieve various degrees of deformation and neutralize the rigidity of the conductive polymer chain; if it is less than this molar ratio, the crosslinking density of the ion gel network will become lower, the interaction will be weakened, and it will be difficult to effectively resist external forces, resulting in poor mechanical properties; if it is greater than this molar ratio, the covalent crosslinking points and non-covalent interactions between the polymer molecular chains will greatly increase, the crosslinking degree will increase, and the structure will become dense, thereby causing the stretchability of the ion gel to deteriorate. In addition, an overly dense polymer network will restrict the free movement of ions and increase the resistance to electron transmission, thereby reducing the conductivity of the conductive polymer ion gel.

[0012] As another limitation of the preparation method of the present invention, it is characterized in that, in step (1), the molar ratio of acrylic acid to pyrrole is 33:23.

[0013] In the present invention, the polypyrrole chain plays an important role in improving the conductivity as a conductive path in the ion gel network. When the molar ratio of acrylic acid to pyrrole is 33:23, the polymer network is dense enough and not too crowded, and can provide an effective charge carrier flow channel, so the conductivity reaches a peak; if the molar ratio of acrylic acid to pyrrole is greater than 33:23, the conductive polymer network formed is sparse, and the distance between individual polypyrrole chains increases, which increases the difficulty of charge carriers (electrons or holes) moving in the polymer network. Therefore, the channels with fewer charge migrations cause the ion gel to exhibit lower conductivity; if the molar ratio of acrylic acid to pyrrole is less than 33:23, the polypyrrole chains are over-accumulated and isolated from each other, and the charge carriers will face greater resistance when migrating between polymer chains, thereby reducing the overall conductivity.

[0014] As a third limitation of the preparation method of the present invention, it is characterized in that in step (3), the FeCl 3 The molar ratio of 1-ethyl-3-methylimidazolium ethyl sulfate is 1:26.

[0015] As a fourth limitation of the preparation method of the present invention, it is characterized in that in step (3), the soaking time is 24-72 hours.

[0016] In the present invention, controlling the immersion time (i.e., oxidation time) of the P(AA-co-HEAA)@Py pregel in the mixed solution is crucial for adjusting the performance of the conductive polymer ion gel. Too short an oxidation time will result in incomplete polymerization, insufficient doping, poor conductivity, and weak mechanical properties. Too long an oxidation time will result in overoxidation, excessive rigidity, and reduced ionic conductivity. Oxidation for 24-72 hours can ensure good formation, sufficient doping, and stability of the polypyrrole network, thereby providing optimal conductivity and mechanical properties.

[0017] The present invention also has a limitation that the conductive polymer ion gel is composed of a chemically cross-linked flexible polymer network and a polypyrrole interpenetrating network.

[0018] In this system, in addition to the covalent cross-linking points formed by free radical polymerization of acrylic acid and N-(2-hydroxyethyl) acrylamide, there are abundant non-covalent interactions between the monomers and between the monomers and the solvent. Specifically:

[0019] 1. The carboxyl group (–COOH) in acrylic acid and the amino group (–NH 2 There are a large number of hydrogen bonding interactions between pyrrole and hydroxyl groups (–OH), which improves the compatibility between the two and increases the efficiency of the copolymerization reaction. In addition, the nitrogen atoms in pyrrole can also form hydrogen bonds with the carboxyl, amino and hydroxyl groups in acrylic acid and N-(2-hydroxyethyl)acrylamide. On the one hand, hydrogen bonds increase the network crosslinking density and enhance the cohesion between molecular chains, thereby improving the mechanical strength and toughness of the conductive polymer ion gel; on the other hand, the formation of hydrogen bonds makes the polymer chains present a more regular arrangement, thereby ensuring the transmission path of connected electrons and improving the conductive properties.

[0020] 2. Imidazole ring and sulfate group (SO 4 2- ) can form hydrogen bonds and electrostatic interactions with the carboxyl group (–COOH) in acrylic acid molecules and with the amino group (–NH 2 ) and hydroxyl (–OH) to form hydrogen bonds and stable charge-dipole interactions. These physical interactions increase the compatibility between the components and help form a uniform polymer structure, which helps to improve the uniformity and stability of the final ion gel. Non-covalent interactions and covalent crosslinking together give conductive polymer ion gels excellent mechanical properties.

[0021] 3. Pyrrole molecules have an aromatic ring structure, which can interact with ions (especially imidazolium cations) in 1-ethyl-3-methylimidazolium ethyl sulfate to form π-π interactions and electrostatic interactions. As a conductive monomer, the aromatic ring of pyrrole can form π-π stacking with other pyrrole molecules or surrounding molecules (such as acrylic acid and N-(2-hydroxyethyl) acrylamide). Through these interactions, pyrrole molecules and other molecules can form a stable cross-linked structure and a tighter electron conduction channel, synergistically achieving a more solid, flexible and highly conductive conductive polymer ion gel.

[0022] The present invention also provides an application of the conductive polymer ion gel, and the prepared conductive polymer ion gel is applied in the field of wearable sensors for human body.

[0023] The above technical solution of the present invention is taken as a whole, and each step is closely related and influences each other, which jointly determine the morphological characteristics and performance of the product.

[0024] The above technical solution has the following advantages or beneficial effects:

[0025] 1. The conductivity of the conductive polymer ion gel prepared by the present invention is as high as 0.6S / m at room temperature and can still reach 0.28S / m at -20°C;

[0026] 2. The conductive polymer ion gel prepared by the present invention exhibits good flexibility at room temperature, with a tensile strength of 0.026-0.034MPa and a breaking strain of 356%-483%. In addition, the conductive polymer ion gel can still maintain excellent stretchability at -20°C;

[0027] 3. The conductive polymer ion gel prepared by the present invention has good adhesion performance and a wide range of applications. It can be tightly adhered to the surface of various substrates, such as paper, polydimethylsiloxane, copper sheet, polyethylene, plastic and rubber, and the adhesion strength can reach up to 17.7 kPa;

[0028] 4. The present invention combines free radical photopolymerization and in-situ polymerization to prepare conductive polymer ion gel, the preparation method is simple and the process is easy to control;

[0029] 5. The present invention uses acrylic acid, N-(2-hydroxyethyl)acrylamide and pyrrole as raw materials, which are abundant in source, easy to obtain and low in cost.

[0030] The invention is suitable for preparing conductive polymer ion gel.

[0031] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a differential scanning calorimetry analysis diagram of the conductive polymer ion gel prepared in Example 1 of the present invention;

[0033] Figure 2 The tensile mechanical properties of the ion gels prepared in Examples 1-5 and Comparative Examples 1-6 of the present invention at room temperature are shown in Figures 1-5 and 1-6, wherein (a) is a tensile mechanical properties diagram of Examples 1-5, and (b) is a tensile mechanical properties diagram of Example 1 and Comparative Examples 1-6;

[0034] Figure 3 This is a graph showing the conductivity of the conductive polymer ion gel prepared in Example 1 of the present invention at -20°C to 25°C;

[0035] Figure 4 Figure 1 is a graph showing the adhesion performance of the conductive polymer ion gel prepared in Example 1 of the present invention, wherein (a) is a schematic diagram of an optical photograph of the ion gel attached between a glass sheet and various substrates, and (b) is the adhesion strength of the ion gel on different substrates measured by a lap-shear test;

[0036] Figure 5 The figures show the tensile mechanical properties and conductivity properties of the conductive polymer ion gel prepared in Example 1 of the present invention under low temperature conditions, wherein (a) is a schematic diagram of the stretchability of the ion gel at -7.6°C monitored by an infrared thermal imager, and (b) is a diagram of the conductivity properties of the ion gel at -10°C. DETAILED DESCRIPTION

[0037] The following embodiments are only some embodiments of the present invention, rather than all embodiments. Therefore, the detailed description in the embodiments of the present invention provided below is not intended to limit the scope of the present invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the protection scope of the present invention.

[0038] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. The methods in the following embodiments are all conventional methods in the art unless otherwise specified.

[0039] Example 1

[0040] This embodiment prepares a conductive polymer ion gel, and its preparation process and steps are as follows:

[0041] (1) 6.6 mol of acrylic acid and 6.6 mol of N-(2-hydroxyethyl)acrylamide were added to 21 mol of 1-ethyl-3-methylimidazole ethyl sulfate and stirred evenly, and then 4.6 mol of pyrrole was added. After stirring at 60° C. for 10 min, 39 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate and 5.8 g of polyethylene glycol diacrylate were added and stirred at room temperature for 1 h to obtain solution A;

[0042] (2) Solution A was transferred into a mold assembled by a polytetrafluoroethylene plate and an acrylic plate and irradiated under a UV lamp for 4 h to form a P(AA-co-HEAA)@Py pregel;

[0043] (3) 1 mol FeCl 3 26 mol of 1-ethyl-3-methylimidazole ethyl sulfate was added to form a mixed solution, and then the P(AA-co-HEAA)@Py pregel prepared in step (2) was immersed in the mixed solution for 48 hours to obtain a conductive polymer ion gel.

[0044] Example 2

[0045] This embodiment prepares a conductive polymer ion gel, and its preparation process and steps are as follows:

[0046] (1) 6.6 mol of acrylic acid and 6.6 mol of N-(2-hydroxyethyl)acrylamide were added to 21 mol of 1-ethyl-3-methylimidazole ethyl sulfate and stirred evenly, and then 4.6 mol of pyrrole was added. After stirring at 60° C. for 10 min, 39 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate and 5.8 g of polyethylene glycol diacrylate were added and stirred at room temperature for 1 h to obtain solution A;

[0047] (2) Solution A was transferred into a mold assembled by a polytetrafluoroethylene plate and an acrylic plate and irradiated under a UV lamp for 4 h to form a P(AA-co-HEAA)@Py pregel;

[0048] (3) 1 mol FeCl 3 26 mol of 1-ethyl-3-methylimidazole ethyl sulfate was added to form a mixed solution, and then the P(AA-co-HEAA)@Py pregel prepared in step (2) was immersed in the mixed solution for 24 hours to obtain a conductive polymer ion gel.

[0049] Example 3

[0050] This embodiment prepares a conductive polymer ion gel, and its preparation process and steps are as follows:

[0051] (1) 6.6 mol of acrylic acid and 6.6 mol of N-(2-hydroxyethyl)acrylamide were added to 21 mol of 1-ethyl-3-methylimidazole ethyl sulfate and stirred evenly, and then 4.6 mol of pyrrole was added. After stirring at 60° C. for 10 min, 39 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate and 5.8 g of polyethylene glycol diacrylate were added and stirred at room temperature for 1 h to obtain solution A;

[0052] (2) Solution A was transferred into a mold assembled by a polytetrafluoroethylene plate and an acrylic plate and irradiated under a UV lamp for 4 h to form a P(AA-co-HEAA)@Py pregel;

[0053] (3) 1 mol FeCl 3 26 mol of 1-ethyl-3-methylimidazole ethyl sulfate was added to form a mixed solution, and then the P(AA-co-HEAA)@Py pregel prepared in step (2) was immersed in the mixed solution for 36 hours to obtain a conductive polymer ion gel.

[0054] Example 4

[0055] This embodiment prepares a conductive polymer ion gel, and its preparation process and steps are as follows:

[0056] (1) 6.6 mol of acrylic acid and 6.6 mol of N-(2-hydroxyethyl)acrylamide were added to 21 mol of 1-ethyl-3-methylimidazole ethyl sulfate and stirred evenly, and then 4.6 mol of pyrrole was added. After stirring at 60° C. for 10 min, 39 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate and 5.8 g of polyethylene glycol diacrylate were added and stirred at room temperature for 1 h to obtain solution A;

[0057] (2) Solution A was transferred into a mold assembled by a polytetrafluoroethylene plate and an acrylic plate and irradiated under a UV lamp for 4 h to form a P(AA-co-HEAA)@Py pregel;

[0058] (3) 1 mol FeCl 3 26 mol of 1-ethyl-3-methylimidazole ethyl sulfate was added to form a mixed solution, and then the P(AA-co-HEAA)@Py pregel prepared in step (2) was immersed in the mixed solution for 60 hours to obtain a conductive polymer ion gel.

[0059] Example 5

[0060] This embodiment prepares a conductive polymer ion gel, and its preparation process and steps are as follows:

[0061] (1) 6.6 mol of acrylic acid and 6.6 mol of N-(2-hydroxyethyl)acrylamide were added to 21 mol of 1-ethyl-3-methylimidazole ethyl sulfate and stirred evenly, and then 4.6 mol of pyrrole was added. After stirring at 60° C. for 10 min, 39 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate and 5.8 g of polyethylene glycol diacrylate were added and stirred at room temperature for 1 h to obtain solution A;

[0062] (2) Solution A was transferred into a mold assembled by a polytetrafluoroethylene plate and an acrylic plate and irradiated under a UV lamp for 4 h to form a P(AA-co-HEAA)@Py pregel;

[0063] (3) 1 mol FeCl 3 26 mol of 1-ethyl-3-methylimidazole ethyl sulfate was added to form a mixed solution, and then the P(AA-co-HEAA)@Py pregel prepared in step (2) was immersed in the mixed solution for 72 hours to obtain a conductive polymer ion gel.

[0064] Comparative Example

[0065] In order to explore the effects of different parameters and different substances in the preparation process of the present invention on the performance of the product of the present invention, the following comparative experiments were conducted. Different ion gels or conductive polymer ion gels were prepared in the following comparative examples, as follows:

[0066] Comparative Example 1

[0067] In this comparative example, an ion gel is prepared. The preparation process is similar to that of Example 1, except that in step (1), pyrrole is not added and the soaking step in step (3) is not performed.

[0068] Comparative Example 2

[0069] In this comparative example, an ion gel is prepared. The preparation process is similar to that of Example 1, except that pyrrole is not added in step (1).

[0070] Comparative Example 3

[0071] In this comparative example, a conductive polymer ion gel is prepared. The preparation process is similar to that of Example 1, except that the soaking step (3) is not performed.

[0072] Comparative Example 4

[0073] In this comparative example, a conductive polymer ion gel is prepared. The preparation process is similar to that of Example 1, except that in step (3), the immersion time is 12 h.

[0074] Comparative Example 5

[0075] In this comparative example, a conductive polymer ion gel is prepared. The preparation process is similar to that of Example 1, except that in step (3), the immersion time is 84 hours.

[0076] Comparative Example 6

[0077] In this comparative example, a conductive polymer ion gel is prepared. The preparation process is similar to that of Example 1, except that in step (1), the molar ratio of acrylic acid, 1-ethyl-3-methylimidazole ethyl sulfate and pyrrole is 7:23:1.

[0078] Comparative Example 7

[0079] In this comparative example, a conductive polymer ion gel is prepared. The preparation process is similar to that of Example 1, except that in step (1), N-(2-hydroxyethyl)acrylamide is not added.

[0080] Comparative Example 8

[0081] In this comparative example, a conductive polymer ion gel is prepared. The preparation process is similar to that of Example 1, except that in step (1), acrylic acid is not added.

[0082] Performance Testing

[0083] The ion gels prepared in Examples 1-5 and Comparative Examples 1-8 were subjected to relevant performance tests, and the specific test results are as follows:

[0084] like Figure 1 , the conductive polymer ion gel prepared in Example 1 of the present invention was subjected to differential scanning calorimetry analysis to explore the glass transition temperature of the ion gel at low temperatures of 20°C to -80°C. It can be seen from the figure that due to the inherent low temperature resistance and high stability of the 1-ethyl-3-methylimidazolium ethyl sulfate ionic liquid, no obvious endothermic or exothermic peaks were observed in the conductive polymer ion gel, indicating that the ion gel has no significant phase change or glass transition in the temperature range of 20°C to -80°C. This means that the ion gel has a wide stable temperature range and is suitable for applications in extreme temperature environments.

[0085] like Figure 2, which is a tensile mechanical property diagram of the ion gels prepared in Examples 1-5 and Comparative Examples 1-6 of the present invention at room temperature. It can be seen from the figure that the tensile strength of the conductive polymer ion gel prepared in Example 1 can reach 0.031MPa, and the fracture strain can reach 435%. This is due to the rich physical interactions between the polypyrrole chains and the flexible polymer chains, which increases the network crosslinking density, thereby giving the ion gel good mechanical properties. Moderate tensile strength can give the ion gel mechanical robustness and durability, ensuring that the flexible sensor can effectively absorb and disperse energy when subjected to external forces, reducing damage to the internal structure of the sensor, and achieving stability and long-term use of the sensor. At the same time, good elasticity and flexibility enable the ion gel sensor to better fit the human skin and adapt to different degrees of human activities without falling off or breaking, thereby obtaining accurate and stable real-time monitoring signals. The single network copolymer ion gel prepared in Comparative Example 1, although the fracture strain can reach 612%, exhibits a lower tensile strength due to the inability to provide sufficient crosslinking points to disperse stress; the ion gel prepared in Comparative Example 2, due to Fe 3+ After the ions are introduced, they form a strong metal coordination interaction with the carboxyl groups in acrylic acid, resulting in a wide improvement in the tensile strength of the gel, but at the expense of the elongation at break of the gel; although the fracture strain of the conductive polymer ion gel prepared in Comparative Example 3 is high, the tensile strength still shows a low level. Therefore, the conductive polymer ion gel based on the flexible support network and the polypyrrole interpenetrating network shows the best mechanical properties. In addition, it can be seen from the figure that the tensile strength and fracture strain of the conductive polymer ion gels prepared in Comparative Examples 4-6 cannot be maintained at a high level as in Example 1. Due to the low crosslinking density of the homopolymer network at the same content, the ion gels prepared in Comparative Examples 7 and 8 are too thin and soft, so it is impossible to obtain an ideal tensile curve.

[0086] like Figure 3 , is a graph showing the conductivity of the conductive polymer ion gel prepared in Example 1 at -20°C to 25°C. It can be seen from the graph that when the temperature is as low as -20°C, the conductive polymer ion gel can still work normally. As the temperature increases, the conductivity of the ion gel increases to 0.60S / m, showing excellent conductivity.

[0087] like Figure 4 , is a graph showing the adhesion performance of the conductive polymer ion gel prepared in Example 1 of the present invention, such as Figure 4 As shown in (a), the ion gel can be seen to be tightly attached to the surfaces of paper, polydimethylsiloxane, copper sheet, polyethylene, plastic and rubber. The lap-shear test was then used to further quantitatively evaluate the adhesion strength of the ion gel to different substrates. The results are shown in Figure 4 As shown in b, the adhesion strength can reach up to 17.7 kPa.

[0088] like Figure 5 , which is a graph of the tensile mechanical properties and conductive properties of the conductive polymer ion gel prepared in Example 1 of the present invention at low temperatures. It can be seen from the figure that the ion gel can still withstand large tensile deformation even at -7.6°C, showing good mechanical properties. In addition, the ion gel can be successfully connected to the circuit at -10°C to light up the LED lamp, showing good conductive properties under low temperature conditions.

[0089] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a conductive polymer ion gel, characterized in that: Follow the steps below in order: (1) acrylic acid and N-(2-hydroxyethyl)acrylamide were added to 1-ethyl-3-methylimidazole ethyl sulfate and stirred evenly, and then pyrrole was added. After stirring at 60° C. for 10 min, 39 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate and 5.8 g of polyethylene glycol diacrylate were added and stirred at room temperature for 1 h to obtain solution A; (2) Transferring solution A into a mold and irradiating it under UV light for 4 h to form a pre-gel; (3) Adding FeCl3 to 1-ethyl-3-methylimidazole ethyl sulfate to form a mixed solution, and then immersing the pregel prepared in step (2) in the mixed solution to obtain a conductive polymer ion gel.

2. The method for preparing a conductive polymer ion gel according to claim 1, characterized in that: In step (1), the molar ratio of acrylic acid to N-(2-hydroxyethyl)acrylamide and 1-ethyl-3-methylimidazole ethyl sulfate is 11:11:

35.

3. The method for preparing a conductive polymer ion gel according to claim 1, characterized in that: In step (1), the molar ratio of acrylic acid to pyrrole is 33:

23.

4. The method for preparing a conductive polymer ion gel according to claim 1, characterized in that: In step (3), the molar ratio of FeCl3 to 1-ethyl-3-methylimidazole ethyl sulfate is 1:

26.

5. The method for preparing a conductive polymer ion gel according to claim 1, characterized in that: In step (3), the soaking time is 24-72 hours.

6. A method for preparing a conductive polymer ion gel according to any one of claims 1 to 5, characterized in that: The conductive polymer ion gel consists of a chemically cross-linked flexible polymer network and a polypyrrole interpenetrating network.

7. A method for preparing a conductive polymer ion gel according to any one of claims 1 to 5, characterized in that: The prepared conductive polymer ion gel is used in the field of wearable human body sensors.

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