Ion gel and its preparation method and application

Abstract

The present invention discloses an ion gel and its preparation method and application, belonging to the field of ion gel technology. The preparation method of the ion gel comprises the following steps: S1, adding a photoinitiator and a certain concentration of zirconium oxychloride solution to a mixed solution of polymer monomers and ionic liquids, heating and stirring until completely dissolved; S2, dispersing and defoaming the solution obtained in S1 to obtain a precursor solution; S3, subjecting the precursor solution obtained in S2 to polymerization reaction under ultraviolet light irradiation to obtain a metal complex ion gel. The metal complex ion gel provided by the present invention has excellent mechanical properties, electrical conductivity, environmental stability and low temperature resistance, and maintains high adhesion properties on the surfaces of materials such as polyvinyl chloride, copper, glass and stainless steel, and can be used in devices such as wearable devices, gel electrode sheets, soft robots and strain sensors.

Description

Technical Field

[0001] The present invention belongs to the technical field of ion gels, and in particular relates to an ion gel and a preparation method and application thereof. Background Art

[0002] Ion gel is a gel-like flexible material composed of a high-molecular-weight organic polymer and a salt electrolyte (ionic liquid) that can be electrolyzed into ions. Ion gel has high ionic conductivity, electrochemical stability, and good deformability. However, in reality, although ion gel can theoretically meet the requirements of good electrical conductivity and mechanical properties, most current ion gels suffer from low conductivity, low fracture strength, and poor fracture toughness. These disadvantages make ion gels unsuitable for use under high strain, cyclic stress, and high-intensity conditions, greatly limiting their application scenarios. Summary of the Invention

[0003] The problem to be solved by the present invention is to provide an ion gel and its preparation method and application, and to improve the strength and conductivity of the ion gel through metal complexation, thereby solving the problem that the ion gel in the prior art cannot obtain high mechanical properties and conductive properties.

[0004] The present invention includes a method for preparing an ion gel, comprising the following steps:

[0005] S1. Adding a photoinitiator and a certain concentration of zirconium oxychloride solution to a mixed solution of polymer monomers and ionic liquid, heating and stirring until completely dissolved;

[0006] S2, dispersing and defoaming the solution obtained in S1 to obtain a precursor solution;

[0007] S3. The precursor solution obtained in S2 is irradiated with ultraviolet light to undergo polymerization reaction to obtain a metal complex ion gel.

[0008] Furthermore, in S1, the molar concentration of the zirconium oxychloride solution is 0.5 mol / L-0.875 mol / L.

[0009] Furthermore, in S1, the polymer monomers include acrylic acid and 2-acrylamido-2-methyl-1-propanesulfonic acid, and the ratio of acrylic acid to 2-acrylamido-2-methyl-1-propanesulfonic acid is 9:1.

[0010] Furthermore, in S1, the ionic liquid includes 1-ethyl-3-methylimidazolium acetate.

[0011] Furthermore, in S1, the photoinitiator includes 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, and the molar percentage of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to the polymer monomer is 1%.

[0012] Furthermore, in S1, the heating temperature during heating and stirring is 80°C-90°C, the stirring rate is 300rpm-600rpm, and the time is 0.3h-1h.

[0013] Furthermore, in S2, the solution obtained in S1 is placed in an ultrasonic cleaning machine for dispersion and foaming; the cleaning power of the ultrasonic cleaning machine is 300W, and the cleaning time is 15min-30min.

[0014] Furthermore, in S3, the precursor solution obtained in S2 is placed in a UV light machine for polymerization reaction; the UV light machine has an operating wavelength of 365 nm and an operating power of 100 W; and the polymerization reaction time is 10 min-20 min.

[0015] As a general inventive concept, the present invention also provides an ion gel, which is prepared by the above-mentioned method for preparing the ion gel.

[0016] As a general inventive concept, the present invention also provides an application of an ion gel, wherein the ion gel is applied to a wearable device, a gel electrode sheet, a soft robot or a strain sensor.

[0017] Beneficial effects of the present invention:

[0018] The preparation method of the ion gel provided by the present invention forms a stable complex by introducing zirconium oxychloride into the polymer. Compared with other low-valent metal ions such as aluminum ions and iron ions, on the one hand, zirconium ions carry four positive charges and a smaller radius, and have a good ability to accept non-bonding electron pairs. On the other hand, the sulfonic acid group is a hard base and can be used as a multi-dentate ligand to coordinate with the zirconium ion. Its coordination ability is stronger than that of the monodentate ligand. Therefore, the complex ligand formed by zirconium oxychloride is usually more stable than the individual ligands or central ions it constitutes, thereby playing a role of physical cross-linking between polymer molecular chains. The complex ligand formed based on zirconium oxychloride can transfer electrons through the charge from the metal to the ligand. These characteristics effectively improve the conductive properties and mechanical properties of the ionic liquid; in addition, the ionic liquid can provide a conductive path as a dispersed phase in the gel, and the ionic liquid has different solubility with the two-phase polymer. The structure of the combination of the soft phase and the hard phase can effectively improve the strength and toughness of the ion gel, thereby achieving a simultaneous improvement in mechanical properties and conductive properties.

[0019] The metal complexation-based ion gel preparation method provided by this invention can adjust the mechanical and electrical properties of the ion gel by regulating the metal ion content in the system. Experiments have shown that by adjusting the composition, the ion gel can achieve a maximum fracture strength of 2.98 MPa while maintaining a fracture strain of 575%.

[0020] The metal complex ion gel provided by the present invention has excellent environmental stability and low-temperature resistance, and maintains high adhesion performance on the surfaces of materials such as polyvinyl chloride, copper, glass and stainless steel.

[0021] The metal complex ion gel provided by the present invention can be applied to devices such as wearable devices, gel electrode sheets, soft robots and strain sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Attachment Figure 1 is a process flow chart of the method for preparing the ion gel of the present invention;

[0023] Attachment Figure 2 The infrared spectra of ion gels with different zirconium oxychloride contents are shown in Figure 1, where (a) is 4000-400 cm -1 Infrared spectrum in the wavenumber range, (b) 1200~700cm -1 Infrared spectra in a range of wavenumbers;

[0024] Attachment Figure 3 is the electrical conductivity of the ion gel at different zirconium oxychloride contents;

[0025] Attachment Figure 4 1 is a stress-strain curve diagram of the ion gel in Examples 1-3 and Comparative Example 2;

[0026] Attachment Figure 5 The variable strain cyclic stretching diagram of the ion gel of Example 3 and the energy dissipation of the ion gel under different tensile strain conditions, wherein (a) is the variable strain cyclic stretching diagram of the ion gel, and (b) is the energy dissipation of the ion gel under different tensile strain conditions;

[0027] Attachment Figure 6 is a differential scanning calorimetry analysis diagram of the ion gel of Example 3;

[0028] Attachment Figure 7 This is the thermogravimetric analysis diagram of the ion gel of Example 3;

[0029] Attachment Figure 8 Schematic diagrams of the adhesion properties of the ion gel of Example 3 on four surfaces, wherein (a) is a schematic diagram of the adhesion performance test of the ion gel, and (b) is a diagram showing the adhesion test results of the ion gel on different surfaces;

[0030] Attachment Figure 9 Graph showing the dissolution of the solution at different heating and stirring temperatures in Comparative Example 2 and Example 1;

[0031] Attachment Figure 10 This is the stress-strain curve when the zirconium oxychloride concentration in Comparative Example 3 is 0.25 mol / L. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] Unless otherwise specified, all drugs / reagents used were commercially available.

[0035] As attached Figure 1 As shown, an embodiment of the present invention provides a method for preparing an ion gel, comprising the following steps:

[0036] S1. Adding a photoinitiator and a certain concentration of zirconium oxychloride solution to a mixed solution of polymer monomers and ionic liquid, heating and stirring until completely dissolved;

[0037] S2, dispersing and defoaming the solution obtained in S1 to obtain a precursor solution;

[0038] S3. The precursor solution obtained in S2 is irradiated with ultraviolet light to undergo polymerization reaction to obtain a metal complex ion gel.

[0039] The preparation method of the ion gel provided by the embodiment of the present invention forms a stable complex by introducing zirconium oxychloride into the polymer. Compared with other low-valent metal ions such as aluminum ions and iron ions, on the one hand, zirconium ions carry four positive charges and a smaller radius, and have a good ability to accept non-bonding electron pairs. On the other hand, the sulfonic acid group is a hard base and can be used as a multi-dentate ligand to coordinate with the zirconium ion. Its coordination ability is stronger than that of the monodentate ligand. Therefore, the complex ligand formed by zirconium oxychloride is usually more stable than the individual ligands or central ions it constitutes, thereby playing a role of physical cross-linking between polymer molecular chains. The complex ligand formed based on zirconium oxychloride can transfer electrons through the charge from the metal to the ligand. These characteristics effectively improve the conductive properties and mechanical properties of the ionic liquid; in addition, the ionic liquid can provide a conductive path as a dispersed phase in the gel, and the ionic liquid has different solubility with the two-phase polymer. The structure of the combination of the soft phase and the hard phase can effectively improve the strength and toughness of the ion gel, thereby achieving a simultaneous improvement in mechanical properties and conductive properties.

[0040] The metal complexation-based ion gel preparation method provided in this embodiment can adjust the mechanical and electrical properties of the ion gel by regulating the ratio of the two polymer phases and the metal ion content in the system. Experimental results show that by adjusting the composition, the ion gel can achieve a maximum fracture strength of 2.98 MPa while maintaining a fracture strain of 575%.

[0041] In a preferred embodiment, in S1, the molar concentration of the zirconium oxychloride solution is 0.5 mol / L-0.875 mol / L; the concentration of zirconium oxychloride is different, and the content of the introduced metal ions is different. The ion gel preparation method provided by the present invention can adjust the mechanical properties and electrical conductivity of the ion gel by regulating the content of metal ions. The higher the molar concentration of the introduced zirconium oxychloride, the better the conductivity of the obtained ion gel. Within the preferred range of this embodiment, the ion gel can simultaneously obtain high mechanical properties. Within this range, the ion gel has both excellent mechanical properties and electrical conductivity. More preferably, the molar concentration of the zirconium oxychloride solution is 0.5 mol / L-0.75 mol / L. Most preferably, the molar concentration of the zirconium oxychloride solution is 0.75 mol / L, at which time the obtained ion gel has excellent conductivity and optimal mechanical properties.

[0042] In a preferred embodiment, in S1, the polymer monomers include acrylic acid (PAA) and 2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS), and the ratio of acrylic acid to 2-acrylamido-2-methyl-1-propanesulfonic acid is 9:1.

[0043] In a preferred embodiment, in S1, the ionic liquid includes 1-ethyl-3-methylimidazolium acetate, and the amount added is calculated by converting the ratio of different polymer systems into volume.

[0044] In a preferred embodiment, in S1, the molar ratio of photoinitiator to monomer is 1%. This high content of photoinitiator reduces the inhibitory effect of oxygen in the air on the polymerization reaction during the photoinitiation process, ensuring sufficient polymerization of the monomer. Optionally, the photoinitiator includes 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone.

[0045] In a preferred embodiment, in S1, the heating temperature during heating and stirring is 80°C-90°C, the stirring rate is 300rpm-600rpm, and the time is 0.3h-1h; more preferably, the stirring rate is 500rpm, and the time is 0.3h; when the temperature is lower than 80°C, zirconium oxychloride and the initiator cannot be fully dissolved in the ionic liquid, and excessively high temperature will cause thermal initiation of the initiator, thereby causing the polymerization reaction to occur prematurely.

[0046] In a preferred embodiment, in S2, the solution obtained in S1 is placed in an ultrasonic cleaning machine for dispersion and foaming; the cleaning power of the ultrasonic cleaning machine is 300W, and the cleaning time is 15min-30min; ultrasound makes the solution disperse more evenly and effectively removes the air mixed in the solution due to stirring. If the ultrasonic time is too short, the air cannot be fully removed, and if the ultrasonic time is too long, the solution temperature will rise and cause the polymer to cross-link.

[0047] In a preferred embodiment, in S3, the precursor solution obtained in S2 is placed in an ultraviolet light machine for polymerization reaction; the operating wavelength of the ultraviolet light machine is 365nm, and the operating power is 100W; the polymerization reaction time is 10min-20min; as the zirconium oxychloride content increases, the time required for initiation gradually increases. If the reaction time is too short, crosslinking is incomplete and no gel can be formed.

[0048] An embodiment of the present invention also provides an ion gel, which is prepared by any of the above-mentioned ion gel preparation methods; the ion gel includes a dispersed phase composed of an ionic liquid and a polymer phase composed of a two-phase polymer. The ionic liquid has a high bulk conductivity and can also provide a conductive path as a dispersed phase, thereby improving the electrical properties of the gel. The two-phase polymer has different compatibilities in the ionic liquid, thereby exhibiting mechanical properties with both strength and toughness. By introducing metal ions into the polymer, the conductive properties and mechanical properties of the ionic liquid are further improved through metal complexation. The metal complex ion gel provided by the embodiment of the present invention has excellent environmental stability and low-temperature resistance, and maintains high adhesion properties on the surfaces of materials such as polyvinyl chloride, copper, glass and stainless steel.

[0049] An embodiment of the present invention further provides an application of an ion gel, wherein the metal complex ion gel provided by the present invention is applied to a wearable device, a gel electrode sheet, a soft robot or a strain sensor.

[0050] Example 1

[0051] This embodiment provides a method for preparing an ion gel, comprising the following steps:

[0052] S1. To a mixed solution of 2-acrylamido-2-methyl-1-propanesulfonic acid and polyacrylic acid monomers in a molar ratio of 1:9, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (photoinitiator) was added at a molar percentage of 1% of the photoinitiator to the polymer monomer, followed by the addition of zirconium oxychloride having a molar concentration of 0.50 mol / L, and finally, 2.35 ml of 1-ethyl-3-methylimidazolium acetate (ionic liquid) to form a 10 ml solution, which was then placed on a heated magnetic stirrer and heated with stirring until completely dissolved, the heating temperature being 90° C., the heating time being 30 min, and the stirring rate being 500 rpm;

[0053] S2. Place the solution after dissolving S1 in an ultrasonic cleaning machine for dispersion and defoaming, set the power to 100W, and the time to 20 minutes to prepare a precursor solution;

[0054] S3. Transfer the precursor solution obtained in S2 into a mold and place it into a UV light machine. Set the power to 100 W and perform a polymerization reaction under UV light for 15 minutes to obtain a metal complex ion gel.

[0055] The metal complex ion gel obtained in this embodiment was tested, and the breaking strength reached 0.873 MPa, the breaking elongation was 957%, and the breaking energy was 3.37 MJ / m 3 , the conductivity is 2.53S / m.

[0056] Example 2

[0057] This embodiment provides a method for preparing an ion gel, comprising the following steps:

[0058] S1. To a mixed solution of 2-acrylamido-2-methyl-1-propanesulfonic acid and polyacrylic acid monomers in a molar ratio of 1:9, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (photoinitiator) was added in an amount of 1% by molar percentage of photoinitiator to polymer monomer, followed by adding zirconium oxychloride with a molar concentration of 0.625 mol / L, and finally adding 2.04 ml of 1-ethyl-3-methylimidazolium acetate (ionic liquid) to make a 10 ml solution, which was then placed on a heated magnetic stirrer and heated with stirring until completely dissolved, the heating temperature being 90° C., the heating time being 30 min, and the stirring rate being 500 rpm;

[0059] S2. Place the solution after dissolving S1 in an ultrasonic cleaning machine for dispersion and defoaming, set the power to 100W, and the time to 20 minutes to prepare a precursor solution;

[0060] S3. Transfer the precursor solution obtained in S2 into a mold and place it into a UV light machine. Set the power to 100 W and perform a polymerization reaction under UV light for 15 minutes to obtain a metal complex ion gel.

[0061] The metal complex ion gel obtained in this embodiment was tested and the breaking strength reached 2.00 MPa, the breaking elongation was 886%, and the breaking energy was 7.76 MJ / m 3 , the conductivity is 4.23S / m.

[0062] Example 3

[0063] This embodiment provides a method for preparing an ion gel, comprising the following steps:

[0064] S1. To a mixed solution of 2-acrylamido-2-methyl-1-propanesulfonic acid and polyacrylic acid monomers in a molar ratio of 1:9, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (photoinitiator) was added at a molar percentage of 1% of the photoinitiator to the polymer monomer, followed by the addition of zirconium oxychloride having a molar concentration of 0.75 mol / L, and finally, 2.30 ml of 1-ethyl-3-methylimidazolium acetate (ionic liquid) to form a 10 ml solution, which was then placed on a heated magnetic stirrer and heated with stirring until completely dissolved, the heating temperature being 90° C., the heating time being 30 min, and the stirring rate being 500 rpm;

[0065] S2. Place the solution after dissolving S1 in an ultrasonic cleaning machine for dispersion and defoaming, set the power to 100W, and the time to 20 minutes to prepare a precursor solution;

[0066] S3. Transfer the precursor solution obtained in S2 into a mold and place it into a UV light machine. Set the power to 100 W and perform a polymerization reaction under UV light for 15 minutes to obtain a metal complex ion gel.

[0067] The metal complex ion gel obtained in this embodiment was tested and the breaking strength reached 2.98 MPa, the breaking elongation was 575%, and the breaking energy was 7.76 MJ / m 3 , the conductivity is 6.69S / m.

[0068] The performance of ion gel samples prepared by introducing different concentrations of zirconium oxychloride was tested. The samples were recorded as PAMPS-co-PAA-1 to PAMPS-co-PAA-8 according to the concentration of zirconium oxychloride from low to high. The zirconium oxychloride concentration corresponding to each sample is shown in Table 1.

[0069] Table 1 Zirconium oxychloride concentration corresponding to each sample

[0070] Sample Zirconium oxychloride concentration (mol / L) PAMPS-co-PAA-1 0 PAMPS-co-PAA-2 0.125 PAMPS-co-PAA-3 (Comparative Example 3) 0.25 PAMPS-co-PAA-4 0.375 PAMPS-co-PAA-5 (Example 1) 0.5 PAMPS-co-PAA-6 (Example 2) 0.625 PAMPS-co-PAA-7 (Example 3) 0.75 PAMPS-co-PAA-8 0.875

[0071] As shown in Table 1, PAMPS-co-PAA-1 to PAMPS-co-PAA-4 are all lower than the preferred zirconium oxychloride concentration range of 0.5 mol / L-0.875 mol / L of the present invention, PAMPS-co-PAA-3 corresponds to the ion gel prepared in Example 3, PAMPS-co-PAA-5 corresponds to the ion gel prepared in Example 1, PAMPS-co-PAA-6 corresponds to the ion gel prepared in Example 2, and PAMPS-co-PAA-7 corresponds to the ion gel prepared in Example 3.

[0072] As attached Figure 2 As shown in the figure, the functional group changes of zirconium oxychloride with different molar concentrations were analyzed by infrared spectrometer. It can be seen from the spectrum that with the continuous increase of zirconium oxychloride content, the signal peak representing the sulfur-oxygen bond (1150cm -1 and 998cm -1 ) underwent a blue shift, indicating that a complex coordination bond was formed between the zirconium ion and the sulfonate.

[0073] As attached Figure 3 As shown in the figure, the zirconium oxychloride content in PAMPS-co-PAA-5 to PAMPS-co-PAA-8 increases continuously, and with the continuous increase of zirconium oxychloride content, the conductivity of the ion gel increases continuously. This is mainly because the metal ions improve the ability of electron transfer in the ion gel system, thereby increasing the conductivity of the system and showing a higher conductivity. In Example 3 (PAMPS-co-PAA-67), when the zirconium oxychloride concentration is 0.75 mol / L, the conductivity can reach 6.69 S / m.

[0074] As attached Figure 4 As shown in Figure 1, the stress-strain curves of the ion gels obtained by introducing a cross-linking agent and different concentrations of zirconium oxychloride are shown. The stress-strain curves of the ion gel obtained by introducing 0.75 mol / L zirconium oxychloride in Example 3 (PAMPS-co-PAA-7) show that the introduced high-valent metal salt zirconium oxychloride forms a metal complex and exhibits excellent mechanical properties. On the basis of a fracture strength of 2.98 MPa, it can also maintain a fracture strain of 575%, and its fracture energy is 7.76 MJ / m 3 In addition, the conductivity test shows that its conductivity is also at a relatively high level, reaching 6.69S / m.

[0075] As attached Figure 5 As shown in the graph, the energy dissipation of the ion gel of Example 3 (PAMPS-co-PAA-7) under different tensile strain conditions, with the increase of strain, the hysteresis loop area gradually increases, indicating that under higher strain conditions, the metal complex ion gel also has excellent energy dissipation performance, so that the ion gel has excellent fracture strength.

[0076] The ion gel of Example 3 (PAMPS-co-PAA-7) was subjected to differential scanning calorimetry and thermogravimetric analysis. Figure 6 As shown in the figure, the results show that in the temperature range of -50℃ to 25℃, the heat flow curve of the metal complex ion gel in Example 3 (PAMPS-co-PAA-7) does not show a glass transition, which indicates that in the temperature range of -50℃ to 25℃, the ion gel can still maintain good elasticity; as shown in the attached figure Figure 7 As shown in the figure, thermogravimetric analysis shows that the ion gel undergoes significant thermal weight loss above 300°C, indicating that the ion gel has good stability under room temperature to medium and low temperature conditions.

[0077] The ion gel used in the device also requires good bonding performance with the substrate to ensure stable signal transmission. Figure 8 As shown, shear tests were conducted to test the adhesion strength of the metal complex ion gel prepared in Example 3 (PAMPS-co-PAA-7) on four common surfaces: plastic, stainless steel, copper, and glass. Due to the ion gel's abundant hydrogen bonding, the ion gel of this embodiment exhibited good adhesion to all four surfaces.

[0078] Comparative Example 1

[0079] In this comparative example, crosslinking was performed by adding a crosslinking agent to the polymer system, and other settings were the same as those in Example 1.

[0080] The specific steps include:

[0081] S1. To a solution of 2-acrylamido-2-methyl-1-propanesulfonic acid and polyacrylic acid monomers in a molar ratio of 1:9, 0.05% of the polymer monomer was added 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (photoinitiator), followed by 0.1% of the polymer monomer was added N,N-methylenebisacrylamide (cross-linker), and finally 2.35 ml of 1-ethyl-3-methylimidazolium acetate (ionic liquid) was added to make a 10 ml solution, which was then placed on a heated magnetic stirrer and heated with stirring until completely dissolved, the heating temperature was 90°C, the heating time was 30 min, and the stirring rate was 500 rpm;

[0082] S2, same as Example 1;

[0083] S3. Same as Example 1.

[0084] The ion gel of this comparative example was tested, and the breaking strength was 1.06 MPa, the breaking elongation was 216%, and the breaking energy was 1.12 MJ / m 3 , combined with the attached Figure 4 Compared with Example 1 (PAMPS-co-PAA-5), the ion gel with the addition of a crosslinker in Comparative Example 1 has a significant decrease in elongation at break. This is because the addition of the crosslinker forms irreversible chemical bonds in the system, which easily leads to local stress concentration during the stretching process and overall failure of the gel.

[0085] Comparative Example 2

[0086] In this comparative example, the heating and stirring temperature in S1 is 60° C., and other settings are the same as those in Example 1.

[0087] As attached Figure 9 As shown, the left side is the effect after stirring at 60°C for 20 minutes in Comparative Example 2, and the solution is an opaque turbid liquid, indicating that the solute cannot be completely dissolved at this temperature, while the right side is the state after stirring at 90°C for 20 minutes in Example 1, and the liquid as a whole is transparent, indicating that the solute has been completely dissolved.

[0088] Comparative Example 3

[0089] In this comparative example, the amount of zirconium oxychloride added to S1 was 0.25 mol / L, and other settings were the same as those in Example 1.

[0090] The specific steps include:

[0091] S1. To a mixed solution of 2-acrylamido-2-methyl-1-propanesulfonic acid and polyacrylic acid monomers in a molar ratio of 1:9, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (photoinitiator) was added at a rate of 0.05% of the polymer monomer, followed by the addition of zirconium oxychloride at a molar concentration of 0.25 mol / L, and finally, 3.04 ml of 1-ethyl-3-methylimidazolium acetate (ionic liquid) was added to form a 10 ml solution, which was then placed on a heated magnetic stirrer and heated with stirring until completely dissolved, the heating temperature being 90° C., the heating time being 30 min, and the stirring rate being 500 rpm;

[0092] S2, same as Example 1;

[0093] S3. Same as Example 1.

[0094] The ion gel of this comparative example was tested, as shown in the attached Figure 10 As shown, the breaking strength is 0.217MPa, the breaking elongation is 1410%, and the breaking energy is 1.21MJ / m 3 , it can be seen that at lower zirconium oxychloride addition, the ion gel exhibits soft and weak mechanical properties, i.e., high elongation at break and low fracture strength.

[0095] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

[0097] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A method for preparing an ion gel, characterized in that: The following steps are involved: S1. Adding a photoinitiator and a certain concentration of zirconium oxychloride solution to a mixed solution of polymer monomers and ionic liquid, heating and stirring until completely dissolved; The polymer monomers include acrylic acid and 2-acrylamido-2-methyl-1-propanesulfonic acid, and the ratio of acrylic acid to 2-acrylamido-2-methyl-1-propanesulfonic acid is 9:1; The molar concentration of the zirconium oxychloride solution is 0.5 mol / L-0.875 mol / L; The heating temperature during the heating and stirring is 80°C-90°C, the stirring rate is 300 rpm-600 rpm, and the time is 0.3 h-1 h; S2, dispersing and defoaming the solution obtained in S1 to obtain a precursor solution; S3. The precursor solution obtained in S2 is irradiated with ultraviolet light to undergo polymerization reaction to obtain a metal complex ion gel.

2. The method for preparing the ion gel according to claim 1, wherein: In S1, the ionic liquid includes 1-ethyl-3-methylimidazolium acetate.

3. The method for preparing the ion gel according to claim 1, wherein: In S1, the photoinitiator includes 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, and the molar percentage of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone to the polymer monomer is 1%.

4. The method for preparing the ion gel according to claim 1, wherein: In S2, the solution obtained in S1 is placed in an ultrasonic cleaning machine for dispersion and foaming; the cleaning power of the ultrasonic cleaning machine is 300 W, and the cleaning time is 15 min-30 min.

5. The method for preparing the ion gel according to claim 1, wherein: In S3, the precursor solution obtained in S2 is placed in an ultraviolet light machine to carry out the polymerization reaction; the operating wavelength of the ultraviolet light machine is 365 nm, and the operating power is 100 W; the polymerization reaction time is 10 min-20 min.

6. An ion gel, characterized in that The ion gel is prepared by the preparation method according to any one of claims 1 to 5.

7. An application of an ion gel, characterized in that: The ion gel as claimed in claim 6 is applied to wearable devices, gel electrode sheets, soft robots or strain sensors.

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