A method for preparing self-growing hydrogels based on spatial confinement effect and the hydrogels themselves.

Abstract

This invention relates to a method for preparing self-growing hydrogels based on spatial confinement effects, and the hydrogel itself. The method includes: constructing a mixed reaction system for hydrogel self-growth, the mixed reaction system comprising, from bottom to top, a first spatial confinement network, a free radical initiator layer, and a second spatial confinement network, both of which are polyvinyl alcohol chemically cross-linked networks containing hydrogel self-growth monomers; the free radical initiator layer comprising a free radical initiator compatible with the hydrogel self-growth monomers; and culturing the mixed reaction system under isothermal conditions. Based on the spatial confinement effect of the first and second spatial confinement networks in the mixed reaction system, the hydrogel self-growth monomers form a hydrogel through self-growth under the action of the free radical initiator. Based on the above method, both the controllability of the hydrogel self-growth direction and the improvement of the hydrogel's mechanical properties and structural stability are achieved.

Description

Technical Field

[0001] This invention relates to the field of hydrogel materials technology, and in particular to a method for preparing self-growing hydrogels based on spatial confinement effect and the hydrogel itself. Background Technology

[0002] Hydrogels are three-dimensional network structures with high water content. Due to their unique physical and chemical properties, they are widely used in fields such as biomedicine, environmental engineering, agriculture, and food processing. With the continuous improvement of the mechanical properties of hydrogels, researchers have begun to explore their intelligent design to achieve more functional applications.

[0003] Currently, self-growing hydrogels are a class of hydrogel materials that can automatically grow and form under specific environmental conditions through intermolecular self-assembly and self-crosslinking mechanisms. However, related technologies cannot achieve precise control over the self-growth process of hydrogels, resulting in poor controllability of the self-growth direction. Summary of the Invention

[0004] The present invention provides a method for preparing a self-growing hydrogel based on the spatial confinement effect and a hydrogel, which at least solves the problem in related technologies that it is impossible to achieve precise control over the self-growth process of hydrogels, resulting in poor controllability of the self-growth direction of hydrogels.

[0005] According to a first aspect of the present invention, a method for preparing a self-growing hydrogel based on the spatial confinement effect is provided, comprising:

[0006] A hybrid reaction system for hydrogel self-growth is constructed, the hybrid reaction system comprising a first spatial confinement network, a free radical initiator layer and a second spatial confinement network arranged sequentially from bottom to top, wherein the first spatial confinement network and the second spatial confinement network are both polyvinyl alcohol chemical crosslinking networks containing hydrogel self-growth monomers, and the free radical initiator layer comprises a free radical initiator adapted to the hydrogel self-growth monomer;

[0007] The mixed reaction system is cultured under constant temperature conditions. Based on the spatial confinement effect of the first and second spatial confinement networks in the mixed reaction system, the hydrogel self-growing monomers form hydrogels through self-growth under the action of the free radical initiator.

[0008] According to a second aspect of the present invention, a hydrogel is provided, which is prepared according to the self-growing hydrogel preparation method based on the spatial confinement effect described in the first aspect.

[0009] The self-growing hydrogel preparation method based on the spatial confinement effect provided by the present invention can control the self-growth direction of the hydrogel by constructing a hybrid reaction system. Specifically, the reaction system includes a first spatial confinement network, a free radical initiator layer, and a second spatial confinement network stacked sequentially from bottom to top. On the one hand, based on the spatial confinement effect, the self-growing monomers of the hydrogel embedded in the first and second spatial confinement networks can undergo a directionally controllable self-growth reaction under the action of the free radical initiator. On the other hand, the polyvinyl alcohol chemically crosslinked spatial confinement network and the self-growing hydrogel network form a dual-network structure, improving the mechanical properties and structural stability of the hydrogel. Based on the above method, the effective self-growing hybrid reaction system constructed by utilizing the spatial confinement effect not only achieves controllability of the self-growth direction of the hydrogel, solving the problem of uncontrollable self-growth direction of hydrogels in the prior art, but also improves the mechanical properties and structural stability of the hydrogel, providing a new solution for the preparation of intelligent hydrogels.

[0010] Details of one or more embodiments of the present invention are set forth in the following drawings and description, so that other features, objects and advantages of the invention will be more readily understood. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a flowchart illustrating a method for preparing a self-growing hydrogel based on the spatial confinement effect, as provided in an embodiment of the present invention.

[0013] Figure 2 A flowchart of a method for constructing a mixed reaction system provided in an embodiment of the present invention.

[0014] Figure 3 This is a schematic diagram of different stages in the self-growth process of the hydrogel in the control group provided in an embodiment of the present invention.

[0015] Figure 4 This is a schematic diagram of different stages in the self-growth process of the hydrogel in test group 1 provided in the embodiments of the present invention.

[0016] Figure 5 This is a schematic diagram of different stages in the self-growth process of the hydrogel in test group 2 provided in the embodiments of the present invention.

[0017] Figure 6This is a schematic diagram of different stages in the self-growth process of the hydrogel in test group 3 provided in the embodiments of the present invention. Detailed Implementation

[0018] Embodiments of this embodiment will now be described in more detail with reference to the accompanying drawings. While some embodiments of this embodiment are shown in the drawings, it should be understood that this embodiment can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this embodiment. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this embodiment.

[0019] Hydrogels are polymeric materials with a three-dimensional network structure that can absorb large amounts of water while maintaining structural stability. These materials have wide applications in many fields, such as biomedicine, cosmetics, and agriculture. Hydrogels can absorb hundreds or even thousands of times their own weight in water. They are composed of cross-linked polymer chains, a structure that allows them to maintain a certain level of mechanical strength after absorbing water. By changing the synthesis methods and raw materials, the physicochemical properties of hydrogels, such as water absorption, mechanical strength, and degradation rate, can be controlled. However, the related technologies cannot achieve precise control over the self-growth process of hydrogels, resulting in poor controllability of the self-growth direction.

[0020] In order to control the self-growth direction of hydrogels, this invention provides a method for preparing self-growing hydrogels based on the spatial confinement effect.

[0021] Figure 1 This is a flowchart illustrating a method for preparing a self-growing hydrogel based on the spatial confinement effect, provided as an embodiment of the present invention. Figure 1 As shown, the method includes the following steps.

[0022] Step S101: Construct a hybrid reaction system for hydrogel self-growth. The hybrid reaction system includes a first spatial confinement network, a free radical initiator layer, and a second spatial confinement network arranged sequentially from bottom to top. Both the first spatial confinement network and the second spatial confinement network are polyvinyl alcohol chemical crosslinking networks containing hydrogel self-growth monomers. The free radical initiator layer includes a free radical initiator adapted to the hydrogel self-growth monomer.

[0023] Step S102: The mixed reaction system is cultured under constant temperature conditions. Based on the spatial confinement effect of the first and second spatial confinement networks in the mixed reaction system, the hydrogel self-growing monomers form hydrogels through self-growth under the action of free radical initiators.

[0024] First, a hybrid reaction system for hydrogel self-growth is constructed. In this embodiment, the hybrid reaction system is the core of the entire preparation method. It consists of three main parts from bottom to top: a first spatial confinement network, a free radical initiator layer, and a second spatial confinement network.

[0025] The first and second spatially confined networks are both polyvinyl alcohol (PVA) chemical cross-linked networks containing hydrogel self-growing monomers. The PVA network serves both as a spatially confined environment for hydrogel self-growth, enabling controllable growth direction, and as a dual-network hydrogel structure, enhancing the hydrogel's mechanical properties and structural stability. The free radical initiator layer is a free radical initiator compatible with the hydrogel self-growing monomers, capable of initiating self-growth reactions in the monomers embedded in both the first and second spatially confined networks.

[0026] In an optional embodiment, a first spatially confined network, a free radical initiator layer, and a second spatially confined network can be sequentially prepared from bottom to top in a pre-set container to ultimately form a mixed reaction system. The pre-set container may include a glass bottle with a cap, etc. Optionally, the glass bottle may have a diameter of 20 mm and a height of 50 mm.

[0027] After constructing the mixed reaction system, it can be cultured under constant temperature conditions. Based on the spatial confinement effect of the first and second spatial confinement networks in the mixed reaction system, the monomers form hydrogels through self-growth under the action of free radical initiators.

[0028] In this embodiment, culturing the mixed reaction system under isothermal conditions ensures the stability of the reaction conditions and facilitates the smooth self-growth of the hydrogel. Simultaneously, based on the spatial confinement effect of the first and second spatial confinement networks—that is, through the microscopic spatial restriction of the first and second spatial confinement network structures—the self-growth direction of the hydrogel can be effectively controlled, solving the problem of uncontrollable growth direction during the traditional self-growth process of hydrogels.

[0029] In one optional embodiment, the constant temperature condition is a constant temperature environment with a temperature range of 20°C to 70°C. Under a constant temperature environment, the chemical reaction can be ensured to proceed stably, improving the self-growth effect of the hydrogel.

[0030] Figure 2 A flowchart illustrating a method for constructing a mixed reaction system, as provided in an embodiment of the present invention. Figure 2 As shown, the method includes the following steps.

[0031] Step S201: Construct a first spatially confined network based on polyvinyl alcohol and hydrogel self-growing monomers through a chemical cross-linking mechanism.

[0032] Step S202: The free radical initiator is uniformly placed on the first spatial confinement network to construct a free radical initiator layer.

[0033] Step S203: On the free radical initiator layer, the second spatially confined network is constructed based on polyvinyl alcohol and the hydrogel self-growing monomer through a chemical cross-linking mechanism.

[0034] First, polyvinyl alcohol, water, crosslinking agent, catalyst and self-growing monomer can be uniformly mixed to form a polyvinyl alcohol network based on the chemical crosslinking mechanism, thus obtaining a polyvinyl alcohol chemical crosslinking network containing self-growing monomer, namely the first spatial confinement network.

[0035] Specifically, the first spatially confined network can be prepared based on the following method.

[0036] Polyvinyl alcohol (PVA) is added to water and heated until completely dissolved to obtain a first PVA aqueous solution. In this embodiment, PVA can be first added to water to obtain an initial PVA-water mixed solution. Then, the initial PVA-water mixed solution is placed in an environment of 95°C and heated until the PVA is completely dissolved to obtain a homogeneous and transparent first PVA aqueous solution.

[0037] In an optional embodiment, the molecular weight of polyvinyl alcohol can be 89,000–98,000, 85,000–124,000, or 146,000–186,000, with a mass fraction of 5 wt.%–20 wt.%; the water can be tap water, deionized water, ultrapure water, or distilled water; the self-growing monomer can be a vinyl monomer or an acrylate monomer. The vinyl monomer can be acrylamide, acrylic acid, methacrylamide, N-isopropylacrylamide, N-phenylacrylamide, N-tert-butylacrylamide, or diacetone acrylamide, with a mass fraction of 17 wt.%–42 wt.%; the acrylate monomer can be 2-hydroxyethyl methacrylate or polyethylene glycol monomaleate, with a mass fraction of 29 wt.%–50 wt.%.

[0038] The self-grown monomer is added to the first aqueous solution of polyvinyl alcohol and stirred until homogeneous to obtain a first mixed solution of polyvinyl alcohol and self-grown monomer. In this embodiment, the self-grown monomer is added to the above-mentioned first aqueous solution of polyvinyl alcohol and stirred until homogeneous to obtain a uniform and transparent first mixed solution.

[0039] After adding a crosslinking agent and a catalyst sequentially to the first mixed solution and stirring until homogeneous, a polyvinyl alcohol crosslinking network is formed based on the chemical crosslinking mechanism, resulting in a polyvinyl alcohol chemically crosslinked network containing self-growing monomers, i.e., the first spatially confined network. In this embodiment, after adding a crosslinking agent and a catalyst sequentially to the first mixed solution and stirring until homogeneous, the first spatially confined network can be constructed through chemical crosslinking at room temperature.

[0040] In an optional embodiment, the crosslinking agent may be glutaraldehyde with a volume fraction of 50%, and the amount added is 1‰ to 1% of the volume of the first mixed solution or the second mixed solution; the catalyst may be hydrochloric acid with a mass fraction of 36.5wt.% to 38wt.%, and the amount added is 1‰ to 1% of the volume of the first mixed solution or the second mixed solution.

[0041] Then, the free radical initiator is uniformly placed on the first spatial confinement network to obtain a free radical initiator layer.

[0042] In an optional embodiment, the free radical initiator can be metallic gallium or liquid gallium-indium alloy, and the mass fraction can be 2 wt.% to 50 wt.%.

[0043] Finally, polyvinyl alcohol, water, crosslinking agent, catalyst and self-growing monomer can be uniformly mixed on the free radical initiator layer to form a polyvinyl alcohol network based on the chemical crosslinking mechanism, thus obtaining a polyvinyl alcohol chemical crosslinking network containing self-growing monomer, namely the second spatial confinement network.

[0044] Specifically, the second spatial confined network can be prepared based on the following method.

[0045] Polyvinyl alcohol (PVA) is added to water and heated until completely dissolved to obtain a second PVA aqueous solution. In this embodiment, the initial PVA aqueous solution can be prepared first using the same method as the method used to prepare the first spatial confined network in the above embodiment. That is, PVA is first added to water to obtain an initial PVA-water mixed solution, and then the initial PVA-water mixed solution is placed in an environment of 95°C and heated until the PVA is completely dissolved to obtain a homogeneous and transparent second PVA aqueous solution.

[0046] In an optional embodiment, the molecular weight of polyvinyl alcohol can be 89,000–98,000, 85,000–124,000, or 146,000–186,000, with a mass fraction of 5 wt.%–20 wt.%; the water can be tap water, deionized water, ultrapure water, or distilled water; the self-growing monomer can be a vinyl monomer or an acrylate monomer. The vinyl monomer can be acrylamide, acrylic acid, methacrylamide, N-isopropylacrylamide, N-phenylacrylamide, N-tert-butylacrylamide, or diacetone acrylamide, with a mass fraction of 17 wt.%–42 wt.%; the acrylate monomer can be 2-hydroxyethyl methacrylate or polyethylene glycol monomaleate, with a mass fraction of 29 wt.%–50 wt.%.

[0047] The self-grown monomer was added to the second aqueous solution of polyvinyl alcohol and stirred until homogeneous to obtain a second mixed solution of polyvinyl alcohol and self-grown monomer. In this embodiment, the self-grown monomer was added to the above-mentioned second aqueous solution of polyvinyl alcohol and stirred until homogeneous to obtain a uniform and transparent second mixed solution.

[0048] After adding a crosslinking agent and a catalyst sequentially to the second mixed solution and stirring until homogeneous, the solution was added onto the free radical initiator layer. Based on the chemical crosslinking mechanism, a polyvinyl alcohol crosslinking network was formed, resulting in a polyvinyl alcohol chemically crosslinked network containing self-growing monomers, i.e., the second spatially confined network. In this embodiment, after adding a crosslinking agent and a catalyst sequentially to the second mixed solution and stirring until homogeneous, the solution was poured onto the free radical initiator layer, and then the second spatially confined network was constructed through chemical crosslinking at room temperature.

[0049] In an optional embodiment, the crosslinking agent may be glutaraldehyde with a volume fraction of 50%, and the amount added is 1‰ to 1% of the volume of the first mixed solution or the second mixed solution; the catalyst may be hydrochloric acid with a mass fraction of 36.5wt.% to 38wt.%, and the amount added is 1‰ to 1% of the volume of the first mixed solution or the second mixed solution.

[0050] To further illustrate the method for preparing self-growing hydrogels based on spatial confinement effect provided in the embodiments of the present invention, the following describes the method for preparing self-growing hydrogels based on spatial confinement effect in conjunction with several embodiments.

[0051] To illustrate the difference between the preparation method provided in this embodiment and related technologies, a control group, experimental group 1, experimental group 2, and experimental group 3 are set up for description below. The control group represents a self-growing hydrogel preparation method without spatially confined networks in related technologies, while experimental groups 1, 2, and 3 represent a self-growing hydrogel preparation method based on the spatial confinement effect provided in this embodiment. The control group, experimental group 1, 2, and 3 are described in detail below.

[0052] Control group:

[0053] In this embodiment, 29 wt.% 2-hydroxyethyl methacrylate was used as the self-growing monomer for the hydrogel, and 3 wt.% gallium particles were used as the free radical initiator. A transparent, capped glass bottle with a diameter of 20 mm and a height of 50 mm was used as the container for the experiment. The specific experimental steps are as follows:

[0054] Step 1: Dissolve 2g of 2-hydroxyethyl methacrylate monomer in 5g of ultrapure water and stir magnetically for 20min until completely dissolved to obtain an aqueous solution of 2-hydroxyethyl methacrylate with a mass fraction of 29wt.%.

[0055] Step 2: Add 7g of the aqueous solution of 2-hydroxyethyl methacrylate obtained in the above steps to a transparent, capped glass bottle with a diameter of 20mm and a height of 50mm, and then add 0.2g of metallic gallium particles with a melting point of 29.8℃ as a free radical initiator.

[0056] Step 3: Conduct a self-growth experiment at 65℃ and record the self-growth phenomenon of the hydrogel using a camera.

[0057] The schematic diagram of different stages of the self-growth process of the hydrogel in the control group provided in the embodiments of the present invention is shown below. Figure 3 As shown. Based on Figure 3 The experimental results of the control group shown show the self-growth process of hydrogels at different time points (from 0 hours to 225.5 hours). It can be seen that the growth rate of the hydrogels in the control group is relatively slow and the growth direction is not unique. The main growth direction is longitudinal growth from bottom to top along the height of the glass bottle, and there is also transverse growth along the diameter of the glass bottle.

[0058] Experimental group 1:

[0059] In this embodiment, 29 wt.% 2-hydroxyethyl methacrylate was used as the self-growing monomer for the hydrogel, and 3 wt.% gallium particles were used as the free radical initiator. A transparent, capped glass bottle with a diameter of 20 mm and a height of 50 mm was used as the container for the experiment. The specific experimental steps are as follows:

[0060] Step 1: Build the first spatial restricted network.

[0061] Under stirring conditions, 10g of polyvinyl alcohol with a molecular weight of 146,000 to 186,000 was added to 90g of ultrapure water;

[0062] Continue stirring at 95℃ until completely dissolved to obtain a homogeneous, transparent polyvinyl alcohol aqueous solution with a mass fraction of 10 wt.%, for later use;

[0063] Add 2g of 2-hydroxyethyl methacrylate monomer to 5g of 10wt.% polyvinyl alcohol aqueous solution and stir until homogeneous to obtain a uniform and transparent polyvinyl alcohol-self-growing monomer mixed solution.

[0064] Take 3.5 mL of the above polyvinyl alcohol-self-grown monomer mixed solution and add it to a transparent, capped glass bottle with a diameter of 20 mm and a height of 50 mm. Then, add 3.5 μL of a crosslinking agent with a volume fraction of 50% (glutaraldehyde in this example) and 3.5 μL of a catalyst with a mass fraction of 36.5 wt.% to 38 wt.% (hydrochloric acid in this example), and stir until homogeneous. Chemical crosslinking is carried out at room temperature for 4 hours to complete the construction of the first spatially confined network.

[0065] Step 2: Prepare the free radical initiator layer.

[0066] 0.2g of gallium metal particles were uniformly placed above the first spatial confinement network to obtain a free radical initiator layer.

[0067] Step 3: Build a second spatial restricted network.

[0068] A second spatial confinement network was constructed on the free radical initiator layer using the same construction method as the first spatial confinement network.

[0069] Step 4: Hydrogel self-growth.

[0070] A self-growth experiment was conducted at 65℃, and the self-growth phenomenon of the hydrogel based on spatial confinement was recorded by a camera.

[0071] The schematic diagrams of different stages in the self-growth process of the hydrogel in experimental group 1 provided in the embodiments of the present invention are as follows: Figure 4 As shown. Based on Figure 4 The experimental results of test group 1 shown illustrate the self-growth process of the hydrogel from 0 hours to 10 hours. It can be seen that, compared with the control group, the hydrogel in the experimental group has a faster self-growth rate and a controllable growth direction, which is a ring-shaped growth from the inside out with the liquid metal particles as the center.

[0072] Experimental group 2:

[0073] In this embodiment, 29 wt.% 2-hydroxyethyl methacrylate was used as the self-growing monomer for the hydrogel, and 3 wt.% gallium particles were used as the free radical initiator. A transparent, capped glass bottle with a diameter of 20 mm and a height of 50 mm was used as the container for the experiment. The specific experimental steps are as follows:

[0074] Step 1: Build the first spatial restricted network.

[0075] Under stirring conditions, 10g of polyvinyl alcohol with a molecular weight of 146,000 to 186,000 was added to 90g of ultrapure water;

[0076] Continue stirring at 95℃ until completely dissolved to obtain a homogeneous, transparent polyvinyl alcohol aqueous solution with a mass fraction of 10 wt.%, for later use;

[0077] Add 2g of 2-hydroxyethyl methacrylate monomer to 5g of 10wt.% polyvinyl alcohol aqueous solution and stir until homogeneous to obtain a uniform and transparent polyvinyl alcohol-self-growing monomer mixed solution.

[0078] Take 3.5 mL of the above polyvinyl alcohol-self-grown monomer mixed solution and add it to a transparent, capped glass bottle with a diameter of 20 mm and a height of 50 mm. Then, add 17.5 μL of a 50% (v / v) crosslinking agent (glutaraldehyde in this example) and 17.5 μL of a 36.5 wt.%–38 wt.% (w / w) catalyst (hydrochloric acid in this example) and stir until homogeneous. Chemical crosslinking is carried out at room temperature for 4 hours to complete the construction of the first spatially confined network.

[0079] Step 2: Prepare the free radical initiator layer.

[0080] 0.2g of gallium metal particles were uniformly placed above the first spatial confinement network to obtain a free radical initiator layer.

[0081] Step 3: Build a second spatial restricted network.

[0082] A second spatial confinement network was constructed on the free radical initiator layer using the same construction method as the first spatial confinement network.

[0083] Step 4: Hydrogel self-growth.

[0084] A self-growth experiment was conducted at 65℃, and the self-growth phenomenon of the hydrogel based on spatial confinement was recorded by a camera.

[0085] The schematic diagrams of different stages in the self-growth process of the hydrogel in experimental group 2 provided in the embodiments of the present invention are as follows: Figure 5 As shown. Based on Figure 5 The experimental results for group 2 shown illustrate the self-growth process of the hydrogel from 0 hours to 8 hours. It can be seen that, compared to group 1, the self-growth rate of the hydrogel is further accelerated, and the growth direction is exactly the same as that of group 1.

[0086] Experimental group 3:

[0087] In this embodiment, 29 wt.% 2-hydroxyethyl methacrylate was used as the self-growing monomer for the hydrogel, and 3 wt.% gallium particles were used as the free radical initiator. A transparent, capped glass bottle with a diameter of 20 mm and a height of 50 mm was used as the container for the experiment. The specific experimental steps are as follows:

[0088] Step 1: Build the first spatial restricted network.

[0089] Under stirring conditions, 10g of polyvinyl alcohol with a molecular weight of 146,000 to 186,000 was added to 90g of ultrapure water;

[0090] Continue stirring at 95℃ until completely dissolved to obtain a homogeneous, transparent polyvinyl alcohol aqueous solution with a mass fraction of 10 wt.%, for later use;

[0091] Add 2g of 2-hydroxyethyl methacrylate monomer to 5g of 10wt.% polyvinyl alcohol aqueous solution and stir until homogeneous to obtain a uniform and transparent polyvinyl alcohol-self-growing monomer mixed solution.

[0092] Take 3.5 mL of the above polyvinyl alcohol-self-grown monomer mixed solution and add it to a transparent, capped glass bottle with a diameter of 20 mm and a height of 50 mm. Then, add 35 μL of a crosslinking agent with a volume fraction of 50% (glutaraldehyde in this example) and 35 μL of a catalyst with a mass fraction of 36.5 wt.% to 38 wt.% (hydrochloric acid in this example), and stir until homogeneous. Chemical crosslinking is carried out at room temperature for 4 hours to complete the construction of the first spatially confined network.

[0093] Step 2: Prepare the free radical initiator layer.

[0094] 0.2g of gallium metal particles were uniformly placed above the first spatial confinement network to obtain a free radical initiator layer.

[0095] Step 3: Build a second spatial restricted network.

[0096] A second spatial confinement network was constructed on the free radical initiator layer using the same construction method as the first spatial confinement network.

[0097] Step 4: Hydrogel self-growth.

[0098] A self-growth experiment was conducted at 65℃, and the self-growth phenomenon of the hydrogel based on spatial confinement was recorded by a camera.

[0099] The schematic diagrams of different stages in the self-growth process of the hydrogel in experimental group 3 provided in the embodiments of the present invention are as follows: Figure 6 As shown. Based on Figure 6 The experimental results for test group 3 show the hydrogel self-growth process from 0 hours to 4.2 hours. It can be seen that, compared with other test groups, the hydrogel self-growth rate is the fastest, and the self-growth direction is still controllable.

[0100] In summary, the comparative analysis of experimental results between the control and experimental groups shows that the growth direction of the self-growing hydrogel preparation method based on the spatial confinement effect is controllable. With increasing amounts of crosslinking agent and catalyst, the self-growth rate of the hydrogel further accelerates, indicating the crucial role of the spatial confinement network in hydrogel growth.

[0101] It should be noted that the term "comprising" and its variations used in the embodiments of the present invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that, unless explicitly indicated otherwise in the context, they should be understood as "one or more".

[0102] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of the present invention are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation entry points are provided for users to choose to authorize or refuse.

[0103] The steps described in the method embodiments provided by this invention can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of protection of this invention is not limited in this respect.

[0104] The term "embodiment" in this specification refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply independence or alternativeity from other embodiments. The various embodiments in this specification are described in a related manner, with reference to each other for similar or identical parts. In particular, for apparatus, device, and system embodiments, since they are substantially similar to method embodiments, the description is relatively simple, and relevant details are referred to in the description of the method embodiments.

[0105] The embodiments described above are merely illustrative of 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 patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method for preparing self-growing hydrogels based on spatial confinement effect, characterized in that, include: A hybrid reaction system for hydrogel self-growth is constructed, comprising a first spatial confinement network, a free radical initiator layer, and a second spatial confinement network arranged sequentially from bottom to top. Both the first and second spatial confinement networks are polyvinyl alcohol chemical crosslinking networks containing hydrogel self-growth monomers. The free radical initiator layer includes a free radical initiator adapted to the hydrogel self-growth monomers. The self-growth monomers are vinyl monomers or acrylate monomers, and the free radical initiator is gallium particles or liquid gallium-indium alloy. The mixed reaction system is cultured under constant temperature conditions. Based on the spatial confinement effect of the first and second spatial confinement networks in the mixed reaction system, the hydrogel self-growing monomers form hydrogels through self-growth under the action of the free radical initiator.

2. The method according to claim 1, characterized in that, The construction of the hybrid reaction system for hydrogel self-growth includes: The first spatial confinement network is constructed based on polyvinyl alcohol and the self-growing monomer of the hydrogel through a chemical cross-linking mechanism. The free radical initiator is uniformly placed on the first spatial confinement network to construct the free radical initiator layer; On the free radical initiator layer, the second spatially confined network is constructed based on polyvinyl alcohol and the hydrogel self-growing monomer through a chemical cross-linking mechanism.

3. The method according to claim 2, characterized in that, The construction of the first spatially confined network based on polyvinyl alcohol and the self-growing monomer of the hydrogel through a chemical cross-linking mechanism includes: The polyvinyl alcohol is added to water and heated until it is completely dissolved to obtain a first polyvinyl alcohol aqueous solution. The hydrogel self-growing monomer is added to the first polyvinyl alcohol aqueous solution and stirred evenly to obtain a first mixed solution of polyvinyl alcohol and self-growing monomer. After adding a crosslinking agent and a catalyst to the first mixed solution and stirring until homogeneous, a polyvinyl alcohol crosslinking network is formed based on the chemical crosslinking mechanism, thus obtaining the first spatially confined network.

4. The method according to claim 2, characterized in that, The second spatially confined network is constructed on the free radical initiator layer through a chemical cross-linking mechanism based on polyvinyl alcohol and the hydrogel self-growing monomer, including: The polyvinyl alcohol is added to water and heated until it is completely dissolved to obtain a second polyvinyl alcohol aqueous solution. The self-growing monomer is added to the second polyvinyl alcohol aqueous solution and stirred evenly to obtain a second mixed solution of polyvinyl alcohol and self-growing monomer; After adding a crosslinking agent and a catalyst to the second mixed solution in sequence and stirring until homogeneous, the solution is placed on the free radical initiator layer to form a polyvinyl alcohol crosslinking network based on the chemical crosslinking mechanism, thus obtaining the second spatially confined network.

5. The method according to any one of claims 3 or 4, characterized in that, The crosslinking agent is glutaraldehyde with a volume fraction of 50%, and the amount added is 1‰ to 1% of the volume of the first mixed solution or the second mixed solution; The catalyst has a mass fraction of 36.5%. wt. % ~ 38 wt. % hydrochloric acid, added at a rate of 1‰ to 1% of the volume of the first or second mixed solution.

6. The method according to any one of claims 3 or 4, characterized in that, The polyvinyl alcohol has a molecular weight of 89,000~98,000, 85,000~124,000, or 146,000~186,000, and a mass fraction of 5%. wt. %~20 wt. %.

7. The method according to any one of claims 3 or 4, characterized in that, The vinyl monomer is acrylamide, acrylic acid, methacrylamide, N-isopropylacrylamide, N-phenylacrylamide, N-tert-butylacrylamide, or diacetone acrylamide, with a mass fraction of 17%. wt. %~42 wt. % The acrylate monomer is 2-hydroxyethyl methacrylate or polyethylene glycol monomaleate, with a mass fraction of 29%. wt. %~50 wt. %.

8. The method according to claim 1, characterized in that, The free radical initiator has a mass fraction of 2%. wt. %~50 wt. %.

9. The method according to claim 1, characterized in that, The constant temperature condition is a constant temperature environment with a temperature range of 20 ℃ to 70 ℃.

10. A hydrogel, said hydrogel being prepared by the self-growing hydrogel preparation method based on spatial confinement effect according to any one of claims 1 to 9.

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