High-strength high-elasticity ionic gel and preparation method thereof
By covalently grafting crystalline polyethylene glycol segments onto the surface of inorganic nanoparticles, a heterostructured high-strength and high-elasticity ionic gel was constructed, resolving the inherent contradiction between elasticity and strength in existing technologies, achieving a balance between high strength and high elasticity, and improving mechanical properties and signal stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU UNIV
- Filing Date
- 2026-03-06
- Publication Date
- 2026-05-29
AI Technical Summary
There is an inherent contradiction between improving elasticity and strength in existing ion gels. It is difficult to achieve high strength without sacrificing elasticity, and existing optimization strategies are prone to problems such as residual strain and high mechanical hysteresis.
By using heterogeneous phase transformation technology, crystalline polyethylene glycol segments with reversible phase transformation characteristics from crystalline to amorphous are covalently grafted onto the surface of an inorganic nanoparticle framework to construct heterogeneous modified organic nanoparticles. This enhances the strong interfacial bonding between the enhanced phase and the flexible polymer matrix, transferring external stress, forming a highly elastic buffer layer, improving mechanical strength, and preserving the freedom of chain segment movement.
A synergistic balance between high strength and high elasticity of ionogels has been achieved, resulting in excellent mechanical strength, high elasticity, and ultra-fast elastic recovery capability. This solves the sensor signal drift problem and ensures the functional stability and long-term durability of the device under dynamic service environments.
Smart Images
Figure CN122103410A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer materials technology, and particularly relates to a high-strength, high-elasticity ionogel and its preparation method. Background Technology
[0002] Ionogels, with their unique ionic conductivity and flexibility, have shown broad application prospects in flexible electronics, soft robotics, and flexible sensing. In dynamic service environments, ionogels must simultaneously possess excellent elasticity to adapt to complex deformations and sufficient mechanical strength to withstand external damage in order to ensure the functional stability and long-term durability of devices.
[0003] However, there is an inherent trade-off between the elasticity and strength of polymer materials, which stems from the intrinsic contradiction between entropy elasticity and enthalpy enhancement mechanisms. Entropy elasticity depends on the conformational transformation of polymer chains from directional extension to random coiling. Improving entropy elasticity requires reducing crosslinking density and intermolecular interactions, which directly leads to a decrease in the mechanical strength of the material. On the other hand, increasing strength through conventional toughening methods such as increasing crosslinking density and adding rigid fillers restricts the degree of freedom of movement of polymer chain segments, thus significantly reducing entropy elasticity.
[0004] Among the existing strategies for optimizing the mechanical properties of ionogels, methods such as pearl necklace supramolecular structures and slip ring topological networks can improve gel elasticity and reduce energy dissipation during deformation, but they are difficult to meet the high strength requirements. While methods such as microphase separation, nanocomposite, and directional freezing can significantly enhance the strength of materials, they can inhibit chain segment migration and conformational freedom, easily leading to problems such as residual strain and high mechanical hysteresis. Furthermore, the rigid components in the system can easily cause stress concentration and irreversible plastic deformation.
[0005] Therefore, achieving high strength in ionogels without sacrificing elasticity remains a key technical challenge that urgently needs to be addressed in the field of ionogel materials. Summary of the Invention
[0006] To address the aforementioned technical problems, this invention provides a high-strength, high-elasticity ionic gel and its preparation method. The high-strength ionic elastomer is prepared through a heterogeneous phase transformation. Crystalline polyethylene glycol segments with reversible crystalline-amorphous phase transformation characteristics are covalently grafted onto the surface of an inorganic nanoparticle framework to obtain modified organic nanoparticles. After phase transformation, the polyethylene glycol segments form a highly elastic buffer layer and constitute the polymer nanoparticles. These modified organic nanoparticles, acting as a reinforcing phase, can efficiently transfer external stress through strong interfacial bonding, significantly improving the overall mechanical strength of the ionic gel. Simultaneously, the highly elastic buffer layer formed by the polyethylene glycol phase transformation effectively solves the modulus mismatch problem between the rigid reinforcing phase and the flexible polymer matrix, alleviating interfacial slippage and energy dissipation, while preserving the degrees of freedom of movement of the polymer network segments. This significantly improves the elasticity and toughness of the ionic gel, ultimately achieving a balance between high strength and high elasticity. Its high-entropy elasticity can also solve the problem of sensor signal drift, showing promising application prospects in the field of flexible electronics.
[0007] The first objective of this invention is to provide a method for preparing a high-strength, high-elasticity ionic gel, comprising the following steps: S1. Inorganic nanoparticles and polyethylene glycol are dissolved in a solvent, stirred evenly, and then reacted and precipitated. After washing and drying, modified organic nanoparticles are obtained. S2. Acryloyl monomers, modified organic nanoparticles described in S1, and initiator are added to water, stirred evenly, and then subjected to photo-initiated polymerization and solvent exchange to obtain the high-strength, high-elasticity ionic gel.
[0008] In one embodiment of the present invention, in S1, the inorganic nanoparticles are selected from one or more of titanium oxide nanoclusters, titanium dioxide, aluminum oxide and zirconium oxide; And / or, the weight-average molecular weight of the polyethylene glycol is 400-4000; modified organic nanoparticles are prepared by covalently grafting crystalline polyethylene glycol segments with crystalline-amorphous reversible phase transition characteristics onto the surface of inorganic nanoparticles, thereby constructing heterostructure polymer nanoparticles that have both rigidity reinforcement and flexible buffering effects. And / or, the mass ratio of the inorganic nanoparticles to polyethylene glycol is 1:(1-20). And / or, the solvent is dichloromethane.
[0009] In one embodiment of the present invention, in S1, the stirring speed is 300 r / min-400 r / min, and the time is 5 h-7 h.
[0010] In one embodiment of the present invention, in S1, the drying vacuum degree is 0.08MPa-0.1MPa, the temperature is 20℃-50℃, and the time is 8h-12h.
[0011] In one embodiment of the present invention, in S2, the acryloyl monomer is selected from one or more of acrylamide, N,N-dimethylacrylamide, acrylic acid, hydroxyethyl methacrylate, acrylmorpholine, 2-acrylamido-2-methylpropanesulfonic acid, methyl acrylate, ethyl acrylate and butyl acrylate. And / or, the initiator is selected from one or more of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylpropanone.
[0012] And / or, the mass ratio of the acryloyl monomer, the modified organic nanoparticles, and the initiator is (1800-2200):4:(9-11). And / or, the mass ratio of the acryloyl monomer to water is 1:(1.5-2.5). In one embodiment of the present invention, in S2, the stirring time is 1h-10h.
[0013] In one embodiment of the present invention, in S2, the photo-initiated polymerization reaction is carried out under a UV curing lamp with a wavelength of 365nm and a power of 16W-20W for 10min-30min.
[0014] In one embodiment of the present invention, in S2, the solvent exchange is a solvent exchange in an ionic liquid for 1-10 hours.
[0015] In one embodiment of the present invention, the ionic liquid is tris(2-hydroxyethyl)methylammonium sulfate.
[0016] A second objective of this invention is to provide a high-strength, high-elasticity ionogel prepared by the method described above.
[0017] The technical solution of the present invention has the following advantages compared with the prior art: (1) The preparation method described in this invention uses heterogeneous phase transformation technology to prepare high-strength ionic elastomers. Crystalline polyethylene glycol segments with reversible phase transformation characteristics from crystalline to amorphous are covalently grafted onto the surface of inorganic nanoparticle skeletons to obtain modified organic nanoparticles. These modified organic nanoparticles are used as reinforcements in the gel system and can efficiently transfer external stress through strong interfacial bonding effects, which can significantly improve the overall mechanical strength of the ionic gel and effectively resist external damage. The highly elastic buffer layer formed by the polyethylene glycol segments after phase transformation can accurately solve the modulus mismatch problem between the rigid reinforcing phase and the flexible polymer matrix, effectively alleviating the interfacial slip phenomenon. At the same time, it can also retain the degree of freedom of movement of polymer network segments to the maximum extent, greatly improving the elasticity and toughness of the ionic gel, allowing the ionic gel to adapt to complex deformation requirements.
[0018] (2) The preparation method described in this invention successfully achieves a synergistic balance between high strength and high elasticity of ion gel in the same system. The ion gel obtained has excellent mechanical strength, high elasticity and ultra-fast elastic recovery capability, and has outstanding application value. This method fundamentally breaks through the technical bottleneck of conventional ion gels, which are difficult to balance rigidity and flexibility due to the inherent contradiction between entropy elasticity and enthalpy enhancement mechanism. It solves the problem that existing optimization strategies cannot meet the high strength requirements or are prone to residual strain and high mechanical hysteresis. It also avoids stress concentration and irreversible plastic deformation caused by rigid components, giving ion gels better mechanical stability and structural adaptability. At the same time, its high entropy elasticity can also effectively solve the sensor signal drift problem, and effectively ensure the functional stability and long-term durability of flexible devices in dynamic service environment.
[0019] (3) The preparation method described in this invention is simple to operate, the process parameters are controllable, the raw materials have a wide range of selection and scientific ratio, and the ion gel obtained has good application prospects in the fields of flexible electronics, soft robots, and flexible sensing. It also provides a new technical idea and implementation path for optimizing the mechanical properties of ion gel materials. Attached Figure Description
[0020] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 The figures show the compressive stress-strain curves of the ionogel in Test Example 1 of this invention; the left figure is Comparative Example 1, and the right figure is Example 1. Figure 2 The images show the cyclic compressive stress-strain curves of the ionogel in Test Example 2 of this invention; the left image is Comparative Example 1, and the right image is Example 1. Figure 3 The stress-strain curves of the ion gel prepared in Example 1 of this invention are obtained after 20 consecutive cycles of compression. Figure 4 This is a schematic diagram of the microstructure / mechanism of action of the ion gel prepared in Example 1 of the present invention. Detailed Implementation
[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.
[0022] In this invention, unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0023] In this invention, unless otherwise stated, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0024] In this invention, unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified. Example 1
[0025] The high-strength, high-elasticity ionic gel and its preparation method in this embodiment specifically include the following steps: S1. Preparation of modified titanium oxide nanoclusters: 0.5 g of titanium oxide nanoclusters and 7.9 g of polyethylene glycol with a weight average molecular weight of 4000 were dissolved in 2 mL of dichloromethane. The mixture was stirred continuously at 350 r / min for 6 h at room temperature. After reaction and sedimentation, a precipitate was obtained. The precipitate was then washed three times with anhydrous tetrahydrofuran and dried in a vacuum drying oven at 0.09 MPa and 40 °C for 10 h to obtain modified titanium oxide nanoclusters. S2. Preparation of high-strength and high-elasticity ionic gel: First, 2g of acrylamide, 0.004g of modified titanium oxide nanoclusters, and 0.01g of 1-hydroxycyclohexylphenyl ketone were added to 4g of deionized water and stirred thoroughly for 1h to obtain a uniformly dispersed mixed solution. Then, the mixed solution was placed at room temperature and photo-initiated polymerization was carried out using a UV curing lamp with a wavelength of 365nm and a power of 16W for 20min to obtain a hydrogel precursor. Finally, the hydrogel precursor was placed in tris(2-hydroxyethyl)methylammonium sulfate for solvent exchange for 3h to obtain a high-strength and high-elasticity ionic gel. Comparative Example 1
[0026] The ion gel and its preparation method in this comparative example specifically include the following steps: First, 2g of acrylamide, 0.004g of titanium oxide nanoclusters, and 0.01g of 1-hydroxycyclohexylphenyl ketone were added to 4g of deionized water and stirred thoroughly for 1 hour to obtain a uniformly dispersed mixed solution. Then, the mixed solution was placed at room temperature and photo-initiated polymerization was carried out using a UV curing lamp with a wavelength of 365nm and a power of 16W for 20 minutes to obtain a hydrogel precursor. Finally, the hydrogel precursor was placed in tris(2-hydroxyethyl)methylammonium sulfate for solvent exchange for 3 hours to obtain an ionomer. Test Example 1
[0027] First, sample pretreatment was performed. The ionogels prepared in Example 1 and Comparative Example 1 were cut into cylindrical samples of uniform size. The samples were then placed in a dry environment at room temperature for 24 hours. Subsequently, the testing instrument was calibrated, and the test was conducted using an electronic universal testing machine. The instrument was preheated for 30 minutes beforehand, and horizontal calibration and force zeroing were completed. The compression mode was set to rate control, and the compression rate was adjusted to a fixed value commonly used in polymer gel material testing. The test termination condition was set when the sample compression strain reached 99% or obvious breakage occurred. Next, the samples were clamped, and the pretreated samples from Example 1 and Comparative Example 1 were placed stably on the upper and lower compression heads of the testing machine. To ensure alignment between the sample center and the indenter center, the electronic universal testing machine was started for formal testing. The sample was unidirectionally compressed according to the set parameters. The instrument automatically recorded the compressive stress and strain data in real time during the test until the preset termination condition was met, at which point the test was stopped and the sample was removed. To ensure the reliability and repeatability of the experimental data, three parallel tests were conducted on each of the samples from Example 1 and Comparative Example 1, with a new sample used for each test. Finally, data processing was performed, collecting the raw stress-strain data from each test group. After removing outliers, data processing software was used to fit the valid data, and the compressive stress-strain curves of the ionomer gels from Example 1 and Comparative Example 1 were plotted. The results are shown below. Figure 1 As shown. From Figure 1 It can be seen that the ion gel of Example 1, prepared by the heterogeneous phase transformation method, withstands a much higher compressive stress under the same strain conditions than the ion gel of Comparative Example 1, which did not use this method. Moreover, the stress-strain curve of the ion gel of Example 1 is more favorable, showing superior compressive mechanical properties. Test Example 2
[0028] Based on Test Example 1, cyclic compression performance tests were conducted. The instrument automatically recorded the stress and strain data during each compression-rebound process in real time. After 20 consecutive cycles of compression, the test was stopped and the sample was removed. After the test, the data was systematically processed. The raw stress-strain data of each set of cyclic compression was collected. After removing outliers, data processing software was used to fit and analyze the effective data, and the stress-strain curves of the ionogel of Example 1 after 20 consecutive cycles of compression were plotted. The results are as follows: Figures 2-3 As shown. By Figures 2-3 It can be seen that the high-strength, high-elasticity ionogel prepared by the heterogeneous phase transformation method in Example 1 exhibits significant low hysteresis characteristics in its cyclic compression stress-strain curve, with a very high degree of overlap between the compression and rebound curves. In contrast, the ionogel prepared by directly adding unmodified organic nanoparticles in Comparative Example 1 shows a clear hysteresis loop in its cyclic compression stress-strain curve, with a large deviation between the compression and rebound curves, and the stress decay phenomenon becomes more significant with increasing cycle number. In comparison, the stress retention of the sample in Example 1 is superior. During 20 consecutive cycles of 100% strain compression, the stress-strain curves of each cycle show almost no shift and a very high degree of overlap. There is no significant stress decay or residual strain generated during the cycle, which fully demonstrates that the ionogel has excellent fatigue resistance and rapid elastic recovery capability.
[0029] This is because the ionogel prepared in the examples has a three-layer core structure ( Figure 4The ion gel consists of an inorganic nanoparticle core with rigid strength support, a polyethylene glycol (PEG) elastic buffer layer covalently grafted onto the surface of the inorganic nanoparticle core and possessing reversible crystalline-amorphous phase transition properties, and a flexible polymer matrix formed by photo-initiated polymerization of acryloyl monomers. Simultaneously, modified organic nanoparticles are non-agglomerated and uniformly dispersed within the flexible polymer matrix, which also contains tris(2-hydroxyethyl)methylammonium sulfate ionic liquid conduction channels. External stress can be rapidly and uniformly transferred from the flexible polymer matrix to the rigid inorganic nanoparticle core via the PEG elastic buffer layer, and the inorganic nanoparticles effectively disperse the stress, thus significantly improving the overall mechanical strength of the ion gel. The PEG elastic buffer layer, through the reversible crystalline-amorphous phase transition, stretches its chain segments to absorb stress under load, precisely resolving the tension between the rigid reinforcing phase and the flexible polymer matrix. This invention addresses the issue of quantity mismatch, effectively mitigating interface slippage and energy dissipation. Furthermore, the flexible buffer layer's connection method does not restrict the chain segment movement of the polymer matrix's three-dimensional network, maximizing the preservation of the system's entropy elasticity. This allows the ionogel to possess both high elasticity and ultra-fast elastic recovery capability without significant residual strain. The embodiment, by constructing this heterogeneous structure of "rigid core-flexible buffer layer-flexible matrix," fundamentally overcomes the inherent contradiction between the entropy elasticity and enthalpy enhancement mechanism of ionogels. It solves the technical problem in existing technologies where ionogel mechanical property optimization strategies struggle to simultaneously meet high strength requirements or easily induce residual strain and stress concentration. It also directly demonstrates that this heterogeneous structure endows the ionogel with excellent mechanical strength, high elasticity, and ultra-fast elastic recovery capability. Moreover, its high entropy elasticity can effectively solve the sensor signal drift problem, highlighting the technical advantages of this ionogel in applications such as flexible electronics.
[0030] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A method for preparing a high-strength, high-elasticity ionic gel, characterized in that, Includes the following steps: S1. Inorganic nanoparticles and polyethylene glycol are dissolved in a solvent, stirred evenly, and then reacted and precipitated. After washing and drying, modified organic nanoparticles are obtained. S2. Acryloyl monomers, modified organic nanoparticles described in S1, and initiator are added to water, stirred evenly, and then subjected to photo-initiated polymerization and solvent exchange to obtain the high-strength, high-elasticity ionic gel.
2. The method for preparing the high-strength, high-elasticity ionogel according to claim 1, characterized in that, In S1, the inorganic nanoparticles are selected from one or more of titanium oxide nanoclusters, titanium dioxide, aluminum oxide, and zirconium oxide; And / or, the weight-average molecular weight of the polyethylene glycol is 400-4000; And / or, the mass ratio of the inorganic nanoparticles to polyethylene glycol is 1:(1-20). And / or, the solvent is dichloromethane.
3. The method for preparing the high-strength, high-elasticity ionogel according to claim 1, characterized in that, In S1, the stirring speed is 300 r / min-400 r / min, and the stirring time is 5 h-7 h.
4. The method for preparing the high-strength, high-elasticity ionogel according to claim 1, characterized in that, In S1, the drying process involves a vacuum of 0.08 MPa to 0.1 MPa, a temperature of 20°C to 50°C, and a time of 8 to 12 hours.
5. The method for preparing the high-strength, high-elasticity ionogel according to claim 1, characterized in that, In S2, the acryloyl monomer is selected from one or more of acrylamide, N,N-dimethylacrylamide, acrylic acid, hydroxyethyl methacrylate, acrylmorpholine, 2-acrylamido-2-methylpropanesulfonic acid, methyl acrylate, ethyl acrylate, and butyl acrylate. And / or, the initiator is selected from one or more of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylpropanone.
6. And / or, the mass ratio of the acryloyl monomer, the modified organic nanoparticles, and the initiator is (1800-2200):4:(9-11); And / or, the mass ratio of the acryloyl monomer to water is 1:(1.5-2.5). The method for preparing a high-strength, high-elasticity ionic gel according to claim 1 is characterized in that, In S2, the stirring time is 1h-10h.
7. The method for preparing the high-strength, high-elasticity ionogel according to claim 1, characterized in that, In S2, the photo-initiated polymerization reaction is carried out under a UV curing lamp with a wavelength of 365nm and a power of 16W-20W for 10min-30min.
8. The method for preparing the high-strength, high-elasticity ionogel according to claim 1, characterized in that, In S2, the solvent exchange is a solvent exchange in an ionic liquid for 1-10 hours.
9. The method for preparing the high-strength, high-elasticity ionogel according to claim 8, characterized in that, The ionic liquid is tris(2-hydroxyethyl)methylammonium sulfate.
10. A high-strength, high-elasticity ionogel prepared by the method according to any one of claims 1-9.