Anti-swelling gel, application thereof and alarm device

Abstract

The invention provides an anti-swelling gel and application thereof and an alarm device, the anti-swelling gel has a three-dimensional cross-linked network structure and a layered structure body, the layered structure body is located in the three-dimensional cross-linked network structure, the layered structure body comprises catechol substances and an intercalation compound, the intercalation compound has a layered structure, and the intercalation compound is located in the three-dimensional cross-linked network structure. The catechol substance is located in the layered structure. The anti-swelling gel disclosed by the invention has excellent anti-swelling performance.

Description

[0001] This application is based on the invention with the application number 202410320225.9, the application date is March 20, 2024, the applicant is Ludong University, and the invention name is "Anti-swelling gel and its preparation method and application". The divisional application is proposed. TECHNICAL FIELD

[0002] The present application relates to the field of high polymer materials, in particular to an anti-swelling gel and its application and alarm device. BACKGROUND

[0003] As a kind of soft material, compared with traditional sensors (rigid substrate sensors, metal semiconductor material sensors), gels have the characteristics of flexibility, good skin compatibility, etc., so they are gradually developed as flexible sensor devices to realize underwater application scenarios.

[0004] Although gels have broad development potential, they still face many problems in practical application, such as swelling, structural damage, etc. in water environment, which will cause signal transmission interruption or distortion when used as underwater sensors, making it difficult to realize stable sensing application in water. SUMMARY

[0005] To solve the above technical problems, the purpose of the present application is to provide an anti-swelling gel and its preparation method and application.

[0006] In a first aspect, the present application provides a preparation method of an anti-swelling gel, which comprises: mixing a catechol substance, an intercalation compound and an organic solvent into a precursor solution; mixing at least an acrylamide monomer and an acrylic ester monomer with the precursor solution into a pre-polymerization solution; and using a photoinitiator to initiate crosslinking copolymerization of the pre-polymerization solution to form an anti-swelling gel.

[0007] In any of the embodiments of the first aspect of the present application, the catechol substance includes at least one of gallic acid, o-methoxyphenol and 2-methoxy-4-methylphenol.

[0008] In any of the embodiments of the first aspect of the present application, the mass fraction of the catechol substance is 0.1% to 0.5% based on the total mass of the precursor solution.

[0009] In any of the embodiments of the first aspect of the present application, the intercalation compound includes at least one of lithium mica, clay and montmorillonite.

[0010] In any of the embodiments of the first aspect of the present application, the mass fraction of the intercalation compound is 0.5% to 2.5% based on the total mass of the precursor solution.

[0011] In any of the embodiments of the first aspect of the present application, the organic solvent comprises at least one of dimethyl sulfoxide, methanol, methyl ether, and acetone.

[0012] In any of the embodiments of the first aspect of the present application, the photoinitiator is at least one of a dialkoxyacetophenone derivative (2,2-diethoxyacetophenone) and a chlorinated acetophenone derivative (dichloro- or trichloro-acetophenone).

[0013] In any of the embodiments of the first aspect of the present application, the mass fraction of the photoinitiator is 0.6% to 1.5% based on the total mass of the prepolymerization solution.

[0014] In any of the embodiments of the first aspect of the present application, the acrylamide monomer comprises at least one of acrylamide, dimethyl acrylamide, diethyl acrylamide, and N-isopropyl acrylamide solution.

[0015] In any of the embodiments of the first aspect of the present application, the mass fraction of the acrylamide monomer is 1% to 15% based on the total mass of the prepolymerization solution.

[0016] In any of the embodiments of the first aspect of the present application, the acrylate monomer comprises at least one of ethyl acrylate, propyl acrylate, butyl acrylate, and tert-butyl acrylate solution.

[0017] In any of the embodiments of the first aspect of the present application, the mass fraction of the acrylate monomer is 1% to 15% based on the total mass of the prepolymerization solution.

[0018] In any of the embodiments of the first aspect of the present application, the sum of the mass fraction of the acrylamide monomer and the mass fraction of the acrylate monomer is 12% to 18% based on the total mass of the prepolymerization solution.

[0019] In any of the embodiments of the first aspect of the present application, the hydrophilic monomer acrylamide monomer and the hydrophobic monomer acrylate monomer are mixed with the precursor solution, and the step of cross-linking and copolymerization of the photoinitiated prepolymerization solution to form the anti-swelling gel is ultrasonicating the prepolymerization solution for 5 to 10 minutes and photoinitiating for 3 to 5 hours at room temperature.

[0020] In the second aspect, the present application provides an anti-swelling gel prepared by the preparation method of the first aspect of the present application.

[0021] In any of the embodiments of the second aspect of the present application, the anti-swelling gel has a swelling rate of -145% to 350%, optionally -50% to 110%, and further optionally -10% to 20%. When the anti-swelling gel is immersed in a water environment and reaches a swelling equilibrium, it exhibits a low swelling rate and excellent anti-swelling performance.

[0022] The anti-swelling gel network is constructed by hydrophilic monomers and hydrophobic monomers, and the anti-swelling gel is formed by photopolymerization of the monomers. The introduction of the hydrophobic monomers enables the hydrophobic interaction between the anti-swelling gel, and the introduction of the hydrophilic monomers enables the anti-swelling gel to have certain hydrophilic effect. The organic solvent is used as a solvent, which is a good solvent for the polymer chain. In the presence of the good solvent, the polymer chain is in an extended conformation and is uniformly distributed in the network. After the anti-swelling gel is soaked in water, solvent replacement occurs between the organic solvent and water. After the replacement with water, the water is a poor solvent for the anti-swelling gel, and therefore, the polymer chains are curled and the non-covalent interaction (such as hydrophobic interaction, hydrogen bond interaction, etc.) between the molecular chains is activated, so as to drive the high cross-linking density network to be formed between the polymer chains in the anti-swelling gel.

[0023] In addition, for the anti-swelling gel that is not soaked in water, the distribution of the hydrophobic groups at the anti-swelling gel-air interface is sparse. After the anti-swelling gel is soaked in water, the hydrophobic groups cannot effectively prevent the entry of water molecules in time, and therefore, swelling occurs. Subsequently, due to the repulsion between the hydrophobic segments and the water molecules in the anti-swelling gel, the hydrophobic groups are hydrophobically aggregated at the interface through hydrophobic interaction, so that the anti-swelling performance of the anti-swelling gel is enhanced.

[0024] In a third aspect, the application provides an application of the anti-swelling gel in the field of alarm. The anti-swelling gel includes the anti-swelling gel prepared by the preparation method of the first aspect of the application, or includes the anti-swelling gel provided in the second aspect of the application.

[0025] In a fourth aspect, the application provides an alarm device, which includes a flexible anti-swelling gel sensor and an alarm. The flexible anti-swelling gel sensor includes the anti-swelling gel prepared by the preparation method of the first aspect of the application, or includes the anti-swelling gel provided in the second aspect of the application. The flexible anti-swelling gel sensor is electrically connected to the alarm. For example, the alarm can be an alarm indicator.

[0026] According to the anti-swelling gel obtained in the embodiments of the application, the anti-swelling gel is fixed on the wrist of a human body, and an alarm indicator is connected to realize the danger alarm and rescue when the human body works in water.

[0027] In the embodiments of the application, after the anti-swelling gel is soaked in water to reach swelling equilibrium, the excellent anti-swelling performance of the anti-swelling gel provides a premise and basis for the stable application of the anti-swelling gel as a flexible sensor in a water environment.

[0028] Furthermore, due to the negative charge inherent in the intercalation compound used in this application, it can adsorb between polymer chains to form electrostatic interactions and provide migration channels for ion transport within the anti-swelling gel, thereby improving the electrochemical performance of the anti-swelling gel. As a flexible sensor, it can achieve high sensitivity, fast response, and excellent fatigue resistance. Based on this, the flexible anti-swelling gel sensor is used as a touch sensor. Underwater workers need to respond within a set time (i.e., press the anti-swelling gel sensor once). If no response is received after the set time, the alarm light circuit is automatically activated, the alarm indicator light sounds, and a distress message is sent to people on shore to achieve distress.

[0029] The preparation method described in this application is simple, easy to implement, and highly applicable. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0031] Figure 1 The infrared spectrum of an anti-swelling gel provided according to an embodiment of this application is shown.

[0032] Figure 2 This is a graph showing the change in swelling rate over time of an anti-swelling gel provided according to an embodiment of this application at different monomer ratios.

[0033] Figure 3 Macroscopic images of anti-swelling gels with different monomer ratios during immersion in water.

[0034] Figure 4 This is a graph showing the change in swelling rate over time of an anti-swelling gel provided according to an embodiment of this application under different solution environments.

[0035] Figure 5 This is a schematic diagram illustrating the application of an anti-swelling gel alarm device according to an embodiment of this application. Detailed Implementation

[0036] To make the purpose, technical solution, and beneficial technical effects of this application clearer, the following detailed description is provided in conjunction with specific embodiments. It should be understood that the embodiments described in this specification are merely for explaining this application and are not intended to limit it.

[0037] For simplicity, this paper only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an undefined range; and any lower limit can be combined with other lower limits to form an undefined range, just as any upper limit can be combined with any other upper limit to form an undefined range. Furthermore, although not explicitly stated, every point or individual value between the endpoints of a range is included within that range. Therefore, each point or individual value can serve as its own lower or upper limit and be combined with any other point or individual value, or with other lower or upper limits, to form an undefined range.

[0038] In this description, it should be noted that, unless otherwise stated, "above" and "below" include the stated number, and "multiple" in "one or more" means two or more.

[0039] The foregoing description of this application is not intended to describe every disclosed implementation or method. Instead, the following description provides more specific examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments that can be used in various combinations. The examples listed are representative only and should not be construed as exhaustive.

[0040] The applicant has conducted extensive research on the anti-swelling properties of anti-swelling gels. The research found that by constructing an anti-swelling gel network using hydrophilic and hydrophobic monomers, and by immersing the gel in water, the aggregation of hydrophobic monomers on the surface of the anti-swelling gel can drive the hydrophobic interactions of the anti-swelling gel to prevent water molecules from entering the interior of the anti-swelling gel, thereby achieving anti-swelling.

[0041] Based on the problems identified by the applicant, the applicant further discovered that excellent anti-swelling properties can be effectively achieved through hydrophilic monomers such as acrylamides and hydrophobic monomers such as acrylates.

[0042] Therefore, the first aspect of this application provides a method for preparing an anti-swelling gel, the method comprising: step S100 of preparing a precursor solution, step S200 of mixing the precursor solution with a hydrophilic acrylamide monomer and a hydrophobic acrylate monomer to form a prepolymer solution, and step S300 of photoinitiating crosslinking copolymerization of the prepolymer solution to form an anti-swelling gel.

[0043] In step S100, the catechins, intercalation compounds, and organic solvents are stirred at the ambient temperature of the reaction system.

[0044] In some embodiments, the catechins include at least one of gallic acid, o-methoxyphenol, and 2-methoxy-4-methylphenol. The phenyl, methoxy, and other groups contained in the above-mentioned catechins can form non-covalent interactions with the substrate, thereby enhancing the adhesion properties of the anti-swelling gel.

[0045] In some embodiments, the mass fraction of catechols is 0.1% to 0.5% based on the total mass of the precursor solution. Exemplarily, the mass fraction of catechols is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, or any combination of two of these values. A mass fraction of catechols within the above range is advantageous for the anti-swelling gel to possess excellent adhesive properties while still maintaining excellent anti-swelling properties.

[0046] In some embodiments, the intercalation compound has a layered structure to allow catechins to be embedded within the layered structure, thereby protecting the groups of the catechins from oxidation by air or the like.

[0047] In some embodiments, the intercalation compound has a negative charge, which, when introduced into the anti-swelling gel, enables the anti-swelling gel to have excellent electrochemical properties.

[0048] In some embodiments, the intercalation compound includes at least one of lithium saponite, clay, and montmorillonite. Lithium saponite is lithium magnesium silicate. Montmorillonite is a type of inorganic ultra-high molecular weight silicate polymer. Clay is an aluminosilicate mineral. On one hand, the intercalation compound can protect the functional groups in catechols from oxidation by oxygen, for example, preventing the phenolic hydroxyl groups from being oxidized by air, thus improving the adhesion properties of catechols. On the other hand, the intercalation compound contains a negative charge, which can form electrostatic interactions with the polymer chains, endowing the anti-swelling gel with certain electrochemical properties.

[0049] In some embodiments, the mass fraction of the intercalating compound is 0.5% to 2.5% based on the total mass of the precursor solution. Exemplarily, the mass fraction of the intercalating compound is 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, or any combination of two of the above values. When the mass fraction of the intercalating compound is within the above range, it, when combined with 0.1% to 0.5% of catechols, provides excellent protection against catechols; moreover, the introduction of the above-mentioned mass fractions of intercalating compound does not substantially affect the anti-swelling properties of the anti-swelling gel.

[0050] In some embodiments, the organic solvent may include at least one of dimethyl sulfoxide, methanol, dimethyl ether, and acetone.

[0051] In step S200, at least acrylamide monomers, acrylate monomers, and precursor solutions are mixed to form a prepolymerization solution.

[0052] In some embodiments, the mass fraction of acrylamide monomers is 1% to 15% based on the total mass of the prepolymer solution. Exemplarily, the mass fraction of hydrophilic monomers is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any combination of two of the above values.

[0053] In some embodiments, the mass fraction of acrylate monomers is 1% to 15% based on the total mass of the prepolymer solution. Exemplarily, the mass fraction of hydrophobic monomers is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any combination of two of the above values.

[0054] In some embodiments, the sum of the mass fractions of acrylamide monomers and acrylate monomers, based on the total mass of the prepolymer solution, is 12% to 18%. Exemplarily, the sum of the mass fractions of acrylamide monomers and acrylate monomers is 12%, 13%, 14%, 15%, 16%, 17%, 18%, or any combination of the two values ​​mentioned above.

[0055] For example, the mass fraction of acrylamide monomers is greater than that of acrylate monomers. This results in superior hydrophilic-hydrophobic interactions within the anti-swelling gel. For example, the mass fraction of acrylamide monomers is 8%–15%, optionally 10%–15%, optionally 10.5%–11.5%. For example, the mass fraction of acrylate monomers is 1%–8%, optionally 1%–5%, optionally 3.5%–4.5%.

[0056] Alternatively, for example, the mass fraction of acrylate monomers is greater than the mass fraction of acrylamide monomers.

[0057] When the combined mass fractions of acrylamide monomers and acrylate monomers are within the above range, the hydrophobic and hydrophilic monomers work together to give the anti-swelling gel both hydrophobic and hydrophilic properties. This results in hydrophilic-hydrophobic interactions within the anti-swelling gel, which increases the crosslinking density of the anti-swelling gel network, thereby achieving anti-swelling performance. Furthermore, in an aqueous environment, the hydrophobic monomers aggregate on the surface of the anti-swelling gel to prevent the entry of water molecules, thus preventing the expansion and destruction of the anti-swelling gel network and achieving excellent anti-swelling performance.

[0058] In some embodiments, the acrylamide monomer includes at least one of acrylamide, dimethylacrylamide, diethylacrylamide, and N-isopropylacrylamide solution.

[0059] In some embodiments, the acrylate monomers include at least one of ethyl acrylate, propyl acrylate, butyl acrylate, and tert-butyl acrylate solutions.

[0060] For example, the hydrophilic monomer solution may include an acrylamide solution, and the hydrophobic monomer solution may include a butyl acrylate solution. Another example is that the hydrophobic monomer may include a mixed solution of butyl acrylate and tert-butyl acrylate. Yet another example is that the hydrophilic monomer may include a mixed solution of acrylamide and dimethacrylamide, which copolymerizes with the hydrophobic monomer to form the framework of an anti-swelling gel network, enabling it to achieve excellent anti-swelling properties in an aqueous environment.

[0061] In step S300, a photoinitiator is used to photoinitiate the cross-linking copolymerization of the prepolymer solution to form an anti-swelling gel.

[0062] In some embodiments, the mass fraction of the photoinitiator is 0.6% to 1.5% based on the total mass of the prepolymer solution. Exemplarily, the mass fraction of the photoinitiator is 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, or a range of any two of the above values.

[0063] The system prior to copolymerization can be understood as a prepolymerization solution. For example, the total mass of each raw material (catechins, intercalation compounds, organic solvents, monomers, photoinitiators, and crosslinking agents, etc.) in the system is taken as the total mass of the prepolymerization solution.

[0064] In some embodiments, the prepolymer solution is sonicated for 5 to 10 minutes at the ambient temperature of the reaction system, followed by photo-initiated crosslinking polymerization for 3 to 5 hours.

[0065] In some embodiments, the photoinitiator includes at least one of a diekoxyacetophenone derivative (2,2-diethoxyacetophenone) and a chlorinated acetophenone derivative (dichloro or trichloroacetophenone) to photoinitiate the generation of free radicals, thereby initiating free radical polymerization between hydrophilic and hydrophobic monomers.

[0066] According to embodiments of this application, an anti-swelling gel is obtained by photo-initiated free radical copolymerization of hydrophilic monomers acrylamides and hydrophobic monomers acrylates. The introduction of hydrophilic and hydrophobic monomers introduces hydrophilic-hydrophobic interactions into the anti-swelling gel, which increases the crosslinking density of the anti-swelling gel network, thereby achieving anti-swelling properties. Furthermore, in an aqueous environment, the hydrophobic monomers aggregate on the surface of the anti-swelling gel to prevent the entry of water molecules, thus preventing the expansion and destruction of the anti-swelling gel network and achieving excellent anti-swelling properties.

[0067] According to the embodiments of this application, catechols are added because their phenyl, methoxy, and other groups can form non-covalent interactions with the substrate, enhancing the adhesion of the anti-swelling gel. The purpose of adding intercalation compounds is twofold: firstly, since the phenolic hydroxyl groups of catechols are easily oxidized by air, intercalation compounds are introduced to protect the phenolic hydroxyl groups, allowing them to be embedded in the layered structure of the intercalation compounds; secondly, because they themselves carry a negative charge, they can form electrostatic interactions with the polymer chains, and the resulting anti-swelling gel can have electrochemical properties, enabling it to be used as a flexible anti-swelling gel sensor for underwater alarm and rescue applications.

[0068] The second aspect of this application provides an anti-swelling gel, which can be prepared based on the method for preparing the anti-swelling gel provided in the first aspect of this application.

[0069] In some embodiments, the anti-swelling gel has a three-dimensional cross-linked network structure and a layered structure, the layered structure being located within the three-dimensional network structure, the layered structure comprising catechols and intercalation compounds, the intercalation compounds having a layered structure, and the catechols being located within the layered structure;

[0070] The hydrophobic and hydrophilic monomers form a three-dimensional cross-linked network structure, giving the anti-swelling gel excellent anti-swelling properties. The layered structure is located in the three-dimensional cross-linked network structure, that is, between the polymer molecular chains. The layered structure is composed of catechols and intercalation compounds. Introducing them into the interior of the anti-swelling gel gives the anti-swelling gel excellent adhesion and electrochemical properties.

[0071] The anti-swelling gel provided according to the embodiments of this application has excellent anti-swelling properties, and the swelling rate in an aqueous environment can reach -145% to 350%, optionally -50% to 110%, and further optionally -10% to 20%.

[0072] The anti-swelling gel exhibits excellent anti-swelling properties in solutions with different pH values ​​(pH 3–7.5) and can also remain stable in water (pH approximately 7). It can be used as a flexible anti-swelling gel sensor in water to enable alarm and distress signals.

[0073] The anti-swelling gel provided according to the embodiments of this application has good electrochemical properties.

[0074] In some embodiments, the compression sensitivity GF of the anti-swelling gel can reach 0.55 to 1.50, and the compression response time and recovery time can both reach 130 ms to 240 ms. It has excellent fatigue resistance and can achieve about 1000 compression cycle sensing tests. The above results show that the anti-swelling gel can realize information transmission underwater, laying the foundation for the underwater application of flexible anti-swelling gel.

[0075] The above test parameters can be tested using test equipment and methods known in the field, or tested in accordance with national standards.

[0076] The added intercalation compound forms an electrostatic interaction with the polymer chain, giving the anti-swelling gel excellent electrochemical properties, enabling rapid response and fatigue resistance for long-term stable application in water.

[0077] The third aspect of this application provides an application of an anti-swelling gel in an alarm device, in which the anti-swelling gel with swelling balance is fixed as a flexible sensor on the wrist of the human body, and information is transmitted by pressing and connected to an alarm indicator light to realize the danger alarm and rescue when people are working in water.

[0078] According to the embodiments of this application, the anti-swelling gel is simple to prepare and the raw materials are readily available. The introduction of hydrophobic monomers enables the anti-swelling gel to achieve a low swelling rate when immersed in an aqueous environment, giving it excellent anti-swelling properties. The addition of intercalation compounds is due to their own charge, which can form electrostatic interactions with polymer chains, giving the anti-swelling gel good electrochemical properties. As a flexible anti-swelling gel sensor, it can achieve long-term stable application in water. At the same time, its rapid response capability can realize alarm and distress applications.

[0079] Examples

[0080] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all fractions, percentages, and ratios reported in the following embodiments are based on weight, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0081] Example 1

[0082] In this embodiment, gallic acid, lithium saponite, and dimethyl sulfoxide are used as raw materials to prepare a precursor. Acrylamide and butyl acrylate are used as monomers, and N,N'-methylenebisacrylamide is used as a crosslinking agent. After mixing and ultrasonication with the precursor, an anti-swelling gel is prepared by polymerization initiated by a photoinitiator. The specific steps include the following:

[0083] (1) Preparation of precursor: Accurately weigh 0.0075 g of gallic acid and 0.05 g of lithium saponite, mix them, and add 4.1475 g of dimethyl sulfoxide. Stir for 5 h at the ambient temperature of the reaction system and a stirring speed of 500 rpm. Utilize the layered structure of lithium saponite to allow gallic acid to intercalate, protecting its phenolic hydroxyl groups from oxidation by air and preventing gallic acid from losing its ability to provide viscosity for the anti-swelling gel. Based on the total mass of the precursor solution, the mass fraction of catechols is 0.18%, and the mass fraction of the intercalating compound is 1.19%.

[0084] (2) Preparation of anti-swelling gel: Accurately weigh 0.55g acrylamide and 0.2g butyl acrylate, add 0.005g N,N-methylenebisacrylamide, add the precursor solution from (1) to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04g 2,2-diethoxyacetophenone as a prepolymer solution. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. Among them, based on the total mass of the prepolymer solution, the mass fraction of acrylamide (AAM) is 11%, and the mass fraction of butyl acrylate (BA) is 4%.

[0085] Figure 1 The infrared spectra of the anti-swelling gel prepared in the examples, along with those of various monomers and solvents, are shown. A comparison of the infrared spectra of acrylamide and butyl acrylate monomers with the spectrum of the anti-swelling gel reveals that the polymerization mechanism of the anti-swelling gel is a photoinitiated free radical polymerization mechanism. Figure 1 It can be seen from this that 1608cm -1 The peak of the C=C double bond in acrylamide and the peak at 1637 cm⁻¹ -1 The peak of the C=C double bond in butyl acrylate was not observed in the infrared spectrum of the anti-swelling gel, indicating that the polymerization mechanism of acrylamide and butyl acrylate monomers is that photoinitiates the formation of free radicals from the C=C double bonds in the monomers, and then further cross-linking polymerization forms a gel network structure.

[0086] Example 2

[0087] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the mass of acrylamide and butyl acrylate was adjusted in Example 2, specifically including the following steps:

[0088] (1) Preparation of precursor: Accurately weigh 0.0075 g gallic acid and 0.05 g lithium saponite, mix them and add 4.1475 g dimethyl sulfoxide, stir for 5 h at the ambient temperature of the reaction system and the stirring speed is 500 rpm.

[0089] (2) Preparation of anti-swelling gel: Accurately weigh 0.5g acrylamide and 0.25g butyl acrylate, add 0.005g N,N'-methylenebisacrylamide, add the precursor solution from (1) above to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04g 2,2-diethoxyacetophenone. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 10% and butyl acrylate (BA) is 5% based on the total mass of the prepolymer solution.

[0090] Example 3

[0091] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the mass of acrylamide and butyl acrylate was adjusted in Example 3, specifically including the following steps:

[0092] (1) Preparation of precursor: Accurately weigh 0.0075 g gallic acid and 0.05 g saponite, mix them and add 4.1475 g dimethyl sulfoxide, stir for 5 h at the ambient temperature of the reaction system and the stirring speed is 500 rpm.

[0093] (2) Preparation of anti-swelling gel: Accurately weigh 0.6 g acrylamide and 0.15 g butyl acrylate, add 0.005 g N,N'-methylenebisacrylamide, add the precursor solution from (1) above to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 12% and that of butyl acrylate (BA) is 3% based on the total mass of the prepolymer solution.

[0094] Figure 2 This image shows the swelling ratio over time for different monomer ratios. The swelling ratio of the anti-swelling gel was tested by immersing the polymerized gel in 50 mL of ultrapure water at room temperature. The method involved weighing the anti-swelling gel before immersion, then setting a series of immersion times. After each set time, the gel was removed, dried, and weighed again. The swelling ratio was calculated using the formula: Swelling ratio = (Mass after swelling - Mass before swelling) / Mass before swelling * 100%.

[0095] The images show that the swelling rate is lowest when the acrylamide mass fraction is 11% and the butyl acrylate mass fraction is 4%, indicating the best anti-swelling performance. Example 1 showed a swelling rate of approximately 4.79% at swelling equilibrium, Example 2 showed a swelling rate of approximately -46.83% at swelling equilibrium, and Example 3 showed a swelling rate of approximately 101.7% at swelling equilibrium.

[0096] Figure 3 The images show macroscopic views after soaking in different monomer ratios until swelling equilibrium is reached. It is clear that the swelling rate of the anti-swelling gel is relatively large when the mass fraction of acrylamide to butyl acrylate is 12:3 during soaking; the degree of swelling may be too large underwater.

[0097] The swelling rate of the anti-swelling gel with a mass fraction of acrylamide to butyl acrylate of 10:5 is relatively small, and the degree of swelling underwater is too small.

[0098] Overall, the anti-swelling gel with a monomer ratio of 11:4 (acrylamide to butyl acrylate) showed little morphological change after equilibrium, and could persist in water for a long time, exhibiting excellent performance.

[0099] Figure 4 The swelling ratio curves of the sample prepared in Example 1, after immersion in different solutions until swelling equilibrium is reached, are shown over time. The polymerized anti-swelling gel was immersed in 50 mL of solvent to test its swelling ratio. The experimental temperature was the ambient temperature of the system. The swelling ratio of the anti-swelling gel was then calculated in the same manner. Figure 2 The calculation method in [the text].

[0100] Figure 4 The main component of the salted water is NaCl, with a mass content of 5.85%.

[0101] Example 4

[0102] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the mass of lithium saponite was adjusted in Example 4, specifically including the following steps:

[0103] (1) Preparation of precursor: Accurately weigh 0.0075 g of gallic acid and 0.04 g of lithium saponite, mix them, and add 4.1575 g of dimethyl sulfoxide. Stir the mixture for 5 h at the ambient temperature of the reaction system and a stirring speed of 500 rpm. Based on the total mass of the precursor solution, the mass fraction of catechols is 0.18%, and the mass fraction of the intercalation compound is 0.95%.

[0104] (2) Preparation of the anti-swelling gel: Accurately weigh 0.55 g of acrylamide and 0.2 g of butyl acrylate, add 0.005 g of N,N'-methylenebisacrylamide, add the precursor solution from (1) above to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. The swelling rate of the anti-swelling gel at swelling equilibrium is approximately 8.5%.

[0105] Example 5

[0106] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the mass of lithium saponite was adjusted in Example 5, specifically including the following steps:

[0107] (1) Preparation of precursor: Accurately weigh 0.0075 g of gallic acid (a catechol) and 0.06 g of lithium saponite, mix them, and add 4.1375 g of dimethyl sulfoxide. Stir the mixture for 5 h at the ambient temperature of the reaction system and a stirring speed of 500 rpm. Based on the total mass of the precursor solution, the mass fraction of catechol is 0.18%, and the mass fraction of the intercalating compound is 1.19%.

[0108] (2) Preparation of the anti-swelling gel: Accurately weigh 0.55 g of acrylamide and 0.2 g of butyl acrylate, add 0.005 g of N,N'-methylenebisacrylamide, add the precursor solution from (1) above to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. The swelling rate of the anti-swelling gel at swelling equilibrium is approximately 4%.

[0109] Example 6

[0110] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the mass of the catechols was adjusted in Example 6, specifically including the following steps:

[0111] (1) Preparation of precursor: Accurately weigh 0.005 g of gallic acid and 0.05 g of lithium saponite, mix them, and add 4.1475 g of dimethyl sulfoxide. Stir for 5 h at the ambient temperature of the reaction system and a stirring speed of 500 rpm. Utilize the layered structure of lithium saponite to allow gallic acid to intercalate, protecting its phenolic hydroxyl groups from oxidation by air and preventing catechols from losing their ability to provide viscosity for the anti-swelling gel. Based on the total mass of the precursor solution, the mass fraction of catechols is 0.12%, and the mass fraction of the intercalating compound is 1.19%.

[0112] (2) Preparation of the anti-swelling gel: Accurately weigh 0.55 g of acrylamide and 0.2 g of butyl acrylate, add 0.005 g of N,N-methylenebisacrylamide, add the precursor solution from (1) to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 11%, and that of butyl acrylate (BA) is 4%. The swelling rate of the anti-swelling gel at swelling equilibrium is approximately 4.5%.

[0113] Example 7

[0114] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the acrylamide monomers were adjusted in Example 7, specifically including the following steps:

[0115] (1) Preparation of precursor: Accurately weigh 0.0075 g gallic acid and 0.05 g lithium saponite, mix them and add 4.1475 g dimethyl sulfoxide. Stir for 5 h at the ambient temperature of the reaction system and at a stirring speed of 500 rpm. Utilize the layered structure of lithium saponite to allow gallic acid to be embedded to protect its phenolic hydroxyl groups from oxidation by air and prevent catechols from losing their ability to provide viscosity for anti-swelling gel.

[0116] (2) Preparation of the anti-swelling gel: Accurately weigh 0.55 g of dimethacrylamide and 0.2 g of butyl acrylate, add 0.005 g of N,N-methylenebisacrylamide, add the precursor solution from (1) above to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone, and initiate with ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of dimethacrylamide (DMAA) is 11%, and the mass fraction of butyl acrylate (BA) is 4%. The swelling rate of the anti-swelling gel at swelling equilibrium is approximately 15%.

[0117] Example 8

[0118] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the acrylate monomers were adjusted in Example 8, specifically including the following steps:

[0119] (1) Preparation of precursor: Accurately weigh 0.0075 g gallic acid and 0.05 g lithium saponite, mix them and add 4.1475 g dimethyl sulfoxide. Stir for 5 h at the ambient temperature of the reaction system and at a stirring speed of 500 rpm. Utilize the layered structure of lithium saponite to allow gallic acid to be embedded to protect its phenolic hydroxyl groups from oxidation by air and prevent catechols from losing their ability to provide viscosity for anti-swelling gel.

[0120] (2) Preparation of the anti-swelling gel: Accurately weigh 0.55 g of acrylamide and 0.2 g of ethyl acrylate, add 0.005 g of N,N-methylenebisacrylamide, add the precursor solution from (1) above to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone, and initiate with ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 11%, and the mass fraction of ethyl acrylate (EA) is 4%. The swelling rate of the anti-swelling gel at swelling equilibrium is approximately 38%.

[0121] Example 9

[0122] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the intercalation compound was adjusted in Example 9, specifically including the following steps:

[0123] (1) Preparation of precursor: Accurately weigh 0.0075 g of gallic acid and 0.05 g of montmorillonite, mix them and add 4.1475 g of dimethyl sulfoxide. Stir for 5 h at the ambient temperature of the reaction system and at a stirring speed of 500 rpm. Utilize the layered structure of montmorillonite to allow gallic acid to be embedded to protect its phenolic hydroxyl groups from oxidation by air and prevent catechols from losing their ability to provide viscosity for anti-swelling gel.

[0124] (2) Preparation of the anti-swelling gel: Accurately weigh 0.55 g of acrylamide and 0.2 g of butyl acrylate, add 0.005 g of N,N-methylenebisacrylamide, add the precursor solution from (1) to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 11%, and that of butyl acrylate (BA) is 4%. The swelling rate of the anti-swelling gel at swelling equilibrium is approximately 5%.

[0125] Example 10

[0126] The anti-swelling gel was prepared using a method similar to that of Example 1. The difference from Example 1 is that the catechols were adjusted in Example 10, specifically including the following steps:

[0127] (1) Preparation of precursor: Accurately weigh 0.0075 g of o-methoxyphenol and 0.05 g of lithium saponite, mix them and add 4.1475 g of dimethyl sulfoxide. Stir for 5 h at the ambient temperature of the reaction system and at a stirring speed of 500 rpm. Utilize the layered structure of lithium saponite to allow o-methoxyphenol to be intercalated to protect its phenolic hydroxyl groups from oxidation by air and prevent catechols from losing their ability to provide viscosity for anti-swelling gel.

[0128] (2) Preparation of the anti-swelling gel: Accurately weigh 0.55 g of acrylamide and 0.2 g of butyl acrylate, add 0.005 g of N,N-methylenebisacrylamide, add the precursor solution from (1) to the weighed monomer and crosslinking agent, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 11%, and that of butyl acrylate (BA) is 4%. The swelling rate of the anti-swelling gel at swelling equilibrium is approximately 6%.

[0129] Example: Anti-swelling gel alarm device

[0130] The anti-swelling gel can be obtained by the preparation method in Example 1. The anti-swelling gel, as a flexible anti-swelling gel sensor, is connected to an alarm (indicator light). After the anti-swelling gel is soaked until it reaches swelling equilibrium, it is assembled and fixed on the wrist as a flexible anti-swelling gel sensor, and simultaneously connected to a current sensor. Under a constant voltage, changes in current are detected in real time. The current sensor transmits the captured current value to a microcontroller unit to achieve information transmission. Based on its excellent anti-swelling properties, electrochemical properties, and fatigue resistance, it is expected to be used in underwater alarm and rescue applications.

[0131] Figure 5 A schematic diagram of the connection of a flexible, anti-swelling gel sensor alarm device is shown to enable information transmission and emergency calls for help from personnel working in water. Figure 5 As shown, pressing the flexible anti-swelling gel sensor once will display "Safety" on the computer interface, indicating that the underwater worker is in a safe state. The initial alarm timeout is set to 5 minutes. Within 5 minutes, the underwater worker must press the flexible anti-swelling gel sensor once to indicate that they are in a safe working state. If the underwater worker fails to press the sensor after 5 minutes, the alarm will be activated, alerting personnel on shore that the underwater worker is in danger and needs immediate rescue.

[0132] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An anti-swelling gel, characterized in that, The anti-swelling gel has a three-dimensional cross-linked network structure and a layered structure. The layered structure is located in the three-dimensional cross-linked network structure. The layered structure includes catechols and intercalation compounds. The intercalation compounds have a layered structure, and the catechols are located in the layered structure.

2. The anti-swelling gel according to claim 1, characterized in that, The three-dimensional cross-linked network structure is formed by polymerization of acrylamide monomers and acrylate monomers.

3. The anti-swelling gel according to claim 1, characterized in that, The catechins include at least one of gallic acid, o-methoxyphenol, and 2-methoxy-4-methylphenol.

4. The anti-swelling gel according to claim 1, characterized in that, The intercalation compound includes at least one of lithium saponite, clay, and montmorillonite.

5. The anti-swelling gel according to claim 1, characterized in that, The swelling rate of the anti-swelling gel is -50% to 110%.

6. The anti-swelling gel according to claim 5, characterized in that, The swelling rate of the anti-swelling gel is -10% to 20%.

7. The anti-swelling gel according to claim 1, characterized in that, The compression sensitivity (GF) of the anti-swelling gel reaches 0.55–1.50; and / or The compression response time and recovery time of the anti-swelling gel both reach 130ms to 240ms.

8. The application of an anti-swelling gel in the field of alarm systems, characterized in that, The anti-swelling gel comprises the anti-swelling gel as described in any one of claims 1 to 7.

9. An alarm device, characterized in that, The invention includes a flexible anti-swelling gel sensor and an alarm, wherein the flexible anti-swelling gel sensor comprises an anti-swelling gel as described in any one of claims 1 to 7, and the flexible anti-swelling gel sensor is electrically connected to the alarm.

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