A room-temperature self-healing electromagnetic shielding hydrogel composite material and its preparation method
By constructing a multi-dynamic cross-linked network of polyvinyl alcohol containing aryl indole groups and conductive materials, the contradiction between maintaining electromagnetic shielding effectiveness and mechanical flexibility in hydrogel materials is resolved, achieving efficient self-healing and electromagnetic shielding performance at room temperature, making it suitable for flexible electronic devices.
Patent Information
- Application Number
- CN202610340569.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-26
AI Technical Summary
Existing hydrogel materials struggle to maintain high electromagnetic shielding effectiveness while also possessing excellent mechanical flexibility and self-healing capabilities, resulting in poor performance recovery after repeated deformation or damage.
By using polyvinyl alcohol containing aryl indole groups and conductive materials, combined with ferric chloride and borax as crosslinking agents, a multi-layer dynamic reversible crosslinking network is constructed. The material achieves efficient self-healing and electromagnetic shielding performance by utilizing steric hindrance effect and dynamic bonds.
The material possesses efficient self-healing capabilities and excellent electromagnetic shielding performance at room temperature. After damage, it can quickly restore structural integrity and shielding effectiveness, making it suitable for flexible electronic devices.
Smart Images
Figure CN122080557A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite materials technology, specifically to a room-temperature self-healing electromagnetic shielding hydrogel composite material and its preparation method. Background Technology
[0002] With the rapid development of communication technology and medical electronics, the number of electronic devices has surged and their integration has continuously increased, leading to an increasingly complex electromagnetic environment in space and prominent issues of electromagnetic interference and radiation pollution. Excessive electromagnetic radiation can not only cause signal distortion, malfunction, and even hardware damage in precision electronic devices, but also pose a potential threat to human health. Meanwhile, the rise of emerging applications such as wearable devices and flexible displays has placed comprehensive performance requirements on electromagnetic shielding materials, demanding ultra-thinness, flexibility, lightweight, and stretchability. Furthermore, the ability of materials to maintain performance stability after repeated deformation or accidental damage has become a key indicator for evaluating their practical application value. Therefore, developing new materials that combine high-efficiency electromagnetic shielding performance, excellent mechanical flexibility, and intrinsic self-healing capabilities has become an important and urgent task.
[0003] Hydrogels, composed of a three-dimensional hydrophilic polymer network, are considered ideal matrices for constructing flexible electromagnetic shielding materials due to their excellent flexibility, stretchability, and structural designability. By introducing dynamic reversible chemical bonds (such as hydrogen bonds and coordination bonds), hydrogels can achieve intrinsic self-healing capabilities, autonomously restoring their structure and properties after physical damage, thereby significantly improving their reliability and lifespan. Combining self-healing properties with electromagnetic shielding functions is of great significance for developing a new generation of adaptive, long-life flexible electronic protection materials.
[0004] Currently, the main approach to improving the electromagnetic shielding effectiveness of hydrogels is to incorporate conductive fillers to construct a conductive network. However, adding large amounts of fillers to enhance shielding performance often disrupts the uniformity of the gel network, leading to a significant decrease in the material's flexibility and stretchability. Simultaneously, the introduction of high filler content and its inherent rigidity can severely inhibit or interfere with the formation and function of the dynamic reversible network within the hydrogel, causing the material to lose its self-healing ability. Therefore, there is a difficult-to-coordinate contradiction between high electromagnetic shielding effectiveness, excellent mechanical properties, and efficient self-healing capability. How to effectively retain or construct sufficient dynamic reversible cross-linking points while building stable and efficient conductive pathways to achieve reliable self-healing performance is a key technological bottleneck in this field. Therefore, the industry urgently needs an innovative material design strategy and preparation method that can effectively coordinate the balance between conductivity, mechanical properties, and dynamic repair, thereby developing hydrogel composite materials that integrate efficient electromagnetic shielding, superior mechanical properties, and rapid self-healing capabilities to meet the urgent needs of cutting-edge fields such as flexible electronics and wearable devices for high-performance, high-reliability protective materials. Summary of the Invention
[0005] The purpose of this invention is to provide a room-temperature self-healing electromagnetic shielding hydrogel composite material and its preparation method. Based on the steric hindrance effect introduced by the large-volume groups and the multiple dynamic bonds constructed in the system, the composite material exhibits high self-healing ability, high mechanical strength and excellent electromagnetic interference shielding performance at room temperature. Through repeated wetting and drying treatments, the electromagnetic shielding efficiency of the hydrogel can be reversibly switched between on and off states, making it suitable for applications in flexible electronics and smart shielding, thereby solving the problem that traditional hydrogel materials cannot simultaneously achieve self-healing performance, mechanical strength and electromagnetic shielding effectiveness.
[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:
[0007] In a first aspect, the present invention provides a room temperature self-healing electromagnetic shielding hydrogel composite material, wherein the composite material is prepared using polyvinyl alcohol containing aryl indole groups and conductive materials as raw materials, and ferric chloride and borax as crosslinking agents;
[0008] The composite material uses polyvinyl alcohol containing aryl indole groups to enhance the mobility of polymer chain segments. At the same time, it constructs a multi-layered dynamic reversible cross-linked network including coordination bonds, hydrogen bonds, borate ester bonds and cation-π interactions. This network can be reconstructed using dynamic bonds after being damaged, giving the composite material a highly efficient self-healing ability at room temperature.
[0009] Furthermore, polyvinyl alcohol containing aryl indole groups is... , , or .
[0010] Furthermore, the conductive material is at least one of MXene, silver nanowires, reduced graphene oxide, poly(3,4-ethylenedioxythiophene) and 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid.
[0011] The room-temperature self-healing electromagnetic shielding hydrogel composite material of the present invention exhibits excellent reversible swelling properties. Even after complete drying, it can rapidly absorb water and return to its original state before drying, and this process can be repeated multiple times.
[0012] Polyvinyl alcohol containing aryl indole groups can enhance chain flowability through steric hindrance, thereby significantly improving the self-healing speed of the composite material. Simultaneously, using ferric chloride and borax as crosslinking agents not only promotes the uniform dispersion of MXene in the hydrogel system but also introduces multiple dynamic crosslinking bonds, giving the composite material both excellent mechanical properties and self-healing capabilities. Furthermore, the uniformly dispersed MXene constructs a continuous conductive network in the system, thus endowing the composite material with superior electromagnetic shielding performance.
[0013] Secondly, the present invention provides a method for preparing the above-mentioned room temperature self-healing electromagnetic shielding hydrogel composite material, comprising the following steps:
[0014] S1. Dissolve polyvinyl alcohol containing aryl indole groups in water, and then add ferric chloride and an aqueous solution of conductive material in sequence to obtain a mixed solution;
[0015] S2. Add the borax aqueous solution to the mixed solution and stir at room temperature to obtain a room temperature self-healing electromagnetic shielding hydrogel composite material.
[0016] This invention modifies polyvinyl alcohol (PVA) by introducing bulky functional groups, enabling it to remain readily soluble in aqueous solutions even under heating conditions, thus facilitating the preparation of hydrogels. The modified PVA chain segments exhibit enhanced fluidity, creating favorable conditions for subsequent self-healing processes. Furthermore, the introduced bulky functional groups are all electron-rich, capable of forming dynamic cation-π interactions with iron ions. Based on this, the sequential addition of ferric chloride and conductive materials allows for initial cross-linking of the modified PVA chains through coordination and hydrogen bonds; the subsequent addition of borax further promotes cross-linking to form a hydrogel and constructs dynamic borate ester bonds. This sequence optimizes the hydrogel's network structure, synergistically enhancing its mechanical properties, self-healing capabilities, and electromagnetic shielding effectiveness.
[0017] Furthermore, in step S1, the polyvinyl alcohol containing aryl indole groups is obtained by modifying polyvinyl alcohol with a modifier.
[0018] Furthermore, the modifier is 2-phenyl-1H-indole-3-carboxaldehyde, 2-(4-ethylphenyl)-1H-indole-3-carboxaldehyde, 2-[4-(1-methylethyl)phenyl]-1H-indole-3-carboxaldehyde, or (2-(2-naphthyl)-1H-indole-3-carboxaldehyde; its structural formula is as follows: , , or .
[0019] Furthermore, in step S1, the mass ratio of polyvinyl alcohol containing aryl indole groups to ferric chloride is 50-500:1.
[0020] Furthermore, the mass ratio of polyvinyl alcohol containing aryl indole groups to conductive materials is 20-150:1.
[0021] Furthermore, in step S2, the mass ratio of polyvinyl alcohol containing aryl indole groups to borax is 10-150:1.
[0022] Furthermore, in step S2, the mixture is stirred at room temperature for 1-12 hours.
[0023] Thirdly, the present invention also provides the application of the above-mentioned room temperature self-healing electromagnetic shielding hydrogel composite material as an electromagnetic shielding material in electronic devices.
[0024] Traditional hydrogel composites often face the dilemma of balancing self-healing performance, electromagnetic shielding effectiveness, and mechanical properties; that is, improving electromagnetic shielding performance often comes at the cost of sacrificing self-healing ability and mechanical strength. This invention achieves highly efficient self-healing and excellent mechanical properties at room temperature by constructing rich dynamic interactions and combining them with steric hindrance effects. After damage, the material not only restores its structural integrity but also maintains a high level of electromagnetic interference shielding effectiveness, thus providing a new feasible path for developing long-life, multifunctional integrated materials. This invention successfully and synergistically improves the overall performance of the material through ingenious material design and dynamic bonding strategies, achieving the best of both worlds.
[0025] The present invention has the following beneficial effects:
[0026] 1. This invention, through molecular structure design and multi-scale network regulation, enables the material to simultaneously possess excellent flexibility, high mechanical strength, efficient self-healing ability, and stable and superior electromagnetic shielding performance. By introducing polyvinyl alcohol modified with large-volume groups, the mobility of polymer chain segments is significantly enhanced, and a multi-layered dynamic reversible cross-linked network, including coordination bonds, hydrogen bonds, borate ester bonds, and cation-π interactions, is constructed, endowing the material with excellent mechanical properties. This network can rapidly reconstruct itself after damage using abundant dynamic bonds, enabling the material to possess efficient self-healing ability at room temperature. Simultaneously, the uniformly dispersed MXene conductive network recovers its structure synchronously during the repair process, ensuring almost no loss of electromagnetic shielding performance. This characteristic significantly improves the reliability and service life of the material in long-term use, solving the key problem of delayed or difficult functional recovery in traditional self-healing materials. Based on its excellent comprehensive performance, this material demonstrates significant application value and broad market prospects in fields such as flexible electronic devices, providing new ideas for the design and development of next-generation durable functional materials.
[0027] 2. The modified polyvinyl alcohol containing aryl indole groups retains excellent water solubility under heating conditions, greatly simplifying the preparation process of the hydrogel precursor solution, avoiding the use of organic solvents, making it more environmentally friendly and easier to operate. By introducing ferric chloride and borax as crosslinking agents in steps and controlling the order of addition of conductive materials, precise control of the crosslinking process and network structure is achieved. This process is simple, mild, and highly reproducible, providing a feasible technical path for the large-scale and continuous production of high-performance multifunctional composite materials. Thanks to this controllable synthesis strategy, the resulting composite material exhibits highly reversible swelling behavior. Even in a completely dry state, it can be rapidly rehydrated upon contact with water, restoring its shape and volume to its pre-dry state. This swelling-dehydration cycle can be repeated multiple times, maintaining the stability of the material structure, providing a reliable material solution for the field of smart devices requiring long-term stable operation. Attached Figure Description
[0028] Figure 1 The Fourier transform infrared spectrum of 2-phenyl-1H-indole-3-carboxaldehyde in Example 1;
[0029] Figure 2 This is a scanning electron microscope image of the room temperature self-healing electromagnetic shielding hydrogel composite material obtained in Example 1;
[0030] Figure 3 These are photographs of the room-temperature self-healing electromagnetic shielding hydrogel composite material obtained in Example 1 before and after self-healing.
[0031] Figure 4 The stress-strain curves of the room temperature self-healing electromagnetic shielding hydrogel composite material obtained in Example 1 before and after self-healing are shown.
[0032] Figure 5 The figures show the electromagnetic shielding performance of the room-temperature self-healing electromagnetic shielding hydrogel composite material obtained in Example 1 before and after self-healing. Detailed Implementation
[0033] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.
[0034] Example 1:
[0035] A room-temperature self-healing electromagnetic shielding hydrogel composite material, the preparation method of which includes the following steps:
[0036] S1. Weigh 720 mg of 2-phenyl-1H-indole-3-carboxaldehyde modified polyvinyl alcohol and place it together with 5 mL of distilled water in a two-necked flask. Heat and stir in a 90 ℃ oil bath until the polyvinyl alcohol is completely dissolved to obtain a homogeneous and transparent solution (polyvinyl alcohol containing aryl indole groups). Stop heating and allow the solution to cool naturally to room temperature. Then transfer it to a beaker and add 10 mg of MXene dispersion and 1 mL of 2 mg / mL ferric chloride solution in sequence under magnetic stirring. Continue stirring for 2 hours to obtain a mixed solution.
[0037] S2. Add 2 mL of sodium borate solution with a concentration of 80 mg / mL to the mixed solution and stir at room temperature for 2 h to obtain a room temperature self-healing electromagnetic shielding hydrogel composite material.
[0038] Example 2:
[0039] The difference between Example 2 and Example 1 is that Example 2 uses 1 mL of ferric chloride solution with a concentration of 1 mg / mL.
[0040] Example 3:
[0041] The difference between Example 3 and Example 1 is that Example 3 uses 2 mL of sodium borate solution with a concentration of 40 mg / mL.
[0042] Example 4:
[0043] The difference between Example 4 and Example 1 is that in Example 4, 2-(4-ethylphenyl)-1H-indole-3-carboxaldehyde modified polyvinyl alcohol is used instead of 2-phenyl-1H-indole-3-carboxaldehyde modified polyvinyl alcohol in Example 1.
[0044] Example 5:
[0045] The difference between Example 5 and Example 1 is that in Example 5, 2-[4-(1-methylethyl)phenyl]-1H-indole-3-carboxaldehyde modified polyvinyl alcohol is used instead of 2-phenyl-1H-indole-3-carboxaldehyde modified polyvinyl alcohol in Example 1.
[0046] Example 6:
[0047] The difference between Example 6 and Example 1 is that in Example 6, polyvinyl alcohol modified with (2-(2-naphthyl)-1H-indole-3-carboxaldehyde) is used instead of polyvinyl alcohol modified with 2-phenyl-1H-indole-3-carboxaldehyde in Example 1.
[0048] Example 7:
[0049] The difference between Example 7 and Example 1 is that silver nanowires are used in Example 7 instead of the MXene solution in Example 1.
[0050] Example 8:
[0051] The difference between Example 8 and Example 1 is that in Example 8, reduced graphene oxide is used instead of the MXene solution in Example 1.
[0052] Example 9:
[0053] The difference between Example 9 and Example 1 is that in Example 9, poly(3,4-ethylenedioxythiophene) is used instead of the MXene solution in Example 1.
[0054] Example 10:
[0055] The difference between Example 10 and Example 1 is that in Example 10, 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid is used instead of MXene solution in Example 1.
[0056] Comparative Example 1:
[0057] The difference between Comparative Example 1 and Example 1 is that unmodified polyvinyl alcohol was used in Comparative Example 1 instead of the modified polyvinyl alcohol in Example 1.
[0058] Experimental example:
[0059] Obtain the Fourier transform infrared spectrum of 2-phenyl-1H-indole-3-carboxaldehyde in Example 1, as follows: Figure 1 As shown.
[0060] Depend on Figure 1 The presence of characteristic peaks for aldehyde groups in the Fourier transform infrared spectrum indicates that 2-phenyl-1H-indole-3-carboxaldehyde was successfully prepared.
[0061] Obtain scanning electron microscope images of the room-temperature self-healing electromagnetic shielding hydrogel composite material obtained in Example 1, such as... Figure 2 As shown in the figure. Also included are photographs of the composite material before and after self-healing, stress-strain curves before and after self-healing, and electromagnetic shielding performance diagrams before and after self-healing, as shown in the figure. Figures 3-5 As shown.
[0062] Depend on Figure 2 It can be seen that the hydrogel composite material exhibits a uniform network structure and is very dense.
[0063] Depend on Figure 3 It is known that if the composite material is cut in half, it can completely heal itself within a few minutes.
[0064] Depend on Figure 4 It can be seen that the composite material exhibits excellent mechanical properties. After self-healing for only a few minutes at room temperature, its mechanical properties show significant recovery and remain essentially consistent with the initial state.
[0065] Depend on Figure 5 It is evident that this composite material exhibits excellent electromagnetic shielding performance. After self-repairing for only a few minutes at room temperature, its electromagnetic shielding effectiveness is significantly restored, remaining essentially consistent with its initial state. This performance recovery is attributed to the dynamic migration of the modified polymer chains and the synergistic effect of multiple dynamic bonds, which facilitates the efficient reconstruction of the damaged conductive network.
[0066] In summary, this invention modifies polyvinyl alcohol with electron-rich indole derivatives, uses ferric ions and borax as crosslinking agents, and combines it with conductive materials to prepare a room-temperature self-healing electromagnetic shielding hydrogel composite material. Its steric hindrance effect and multiple dynamic bonds give the prepared composite material excellent mechanical properties, high electromagnetic shielding performance, and significant room-temperature self-healing efficiency. This invention provides a convenient and rapid new method for developing next-generation multifunctional materials for flexible electronics, and has great application prospects.
[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A room-temperature self-healing electromagnetic shielding hydrogel composite material, characterized in that, The composite material is prepared using polyvinyl alcohol containing aryl indole groups and conductive materials as raw materials, and ferric chloride and borax as crosslinking agents. The composite material uses polyvinyl alcohol containing aryl indole groups to enhance the mobility of polymer chain segments. At the same time, it constructs a multi-layered dynamic reversible cross-linked network including coordination bonds, hydrogen bonds, borate ester bonds and cation-π interactions. This network can be reconstructed using dynamic bonds after being damaged, giving the composite material a highly efficient self-healing ability at room temperature.
2. The room-temperature self-healing electromagnetic shielding hydrogel composite material according to claim 1, characterized in that, The polyvinyl alcohol containing aryl indole groups is , , or .
3. The room-temperature self-healing electromagnetic shielding hydrogel composite material according to claim 1, characterized in that, The conductive material is at least one of MXene, silver nanowires, reduced graphene oxide, poly(3,4-ethylenedioxythiophene) and 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid.
4. The method for preparing the room-temperature self-healing electromagnetic shielding hydrogel composite material according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Dissolve polyvinyl alcohol containing aryl indole groups in water, and then add ferric chloride and an aqueous solution of conductive material in sequence to obtain a mixed solution; S2. Add the borax aqueous solution to the mixed solution and stir at room temperature to obtain a room temperature self-healing electromagnetic shielding hydrogel composite material.
5. The preparation method of the room temperature self-healing electromagnetic shielding hydrogel composite material according to claim 4, characterized in that, In step S1, the polyvinyl alcohol containing aryl indole groups is obtained by modifying polyvinyl alcohol with a modifier. The modifier is 2-phenyl-1H-indole-3-carboxaldehyde, 2-(4-ethylphenyl)-1H-indole-3-carboxaldehyde, 2-[4-(1-methylethyl)phenyl]-1H-indole-3-carboxaldehyde, or (2-(2-naphthyl)-1H-indole-3-carboxaldehyde).
6. The preparation method of the room temperature self-healing electromagnetic shielding hydrogel composite material according to claim 4, characterized in that, In step S1, the mass ratio of the polyvinyl alcohol containing the aryl indole group to ferric chloride is 50-500:
1. The mass ratio of the polyvinyl alcohol containing aryl indole groups to the conductive material is 20-150:
1.
7. The preparation method of the room temperature self-healing electromagnetic shielding hydrogel composite material according to claim 4, characterized in that, In step S2, the mass ratio of polyvinyl alcohol containing aryl indole groups to borax is 10-150:
1.
8. The preparation method of the room temperature self-healing electromagnetic shielding hydrogel composite material according to claim 4, characterized in that, In step S2, stir at room temperature for 1-12 hours.
9. The application of the room temperature self-healing electromagnetic shielding hydrogel composite material according to any one of claims 1-3 as an electromagnetic shielding material in electronic devices.