Anti-swelling gel and its preparation method and application

Abstract

This application provides an anti-swelling gel, its preparation method, and application. The preparation method comprises: mixing at least a catechol-based substance, an intercalation compound, and an organic solvent to form a precursor solution; mixing an acrylamide monomer and an acrylate monomer with the precursor solution to form a prepolymer solution; and using a photoinitiator to initiate crosslinking and copolymerization of the prepolymer solution to form the anti-swelling gel. The preparation method of the anti-swelling gel is simple and the raw materials are readily available.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and in particular to an anti-swelling gel and a preparation method and application thereof. Background Art

[0002] As a soft material, gel has the characteristics of flexibility and good skin compatibility compared with traditional sensors (rigid substrate sensors, metal semiconductor material sensors). Therefore, it has gradually been developed into flexible sensor devices to realize underwater application scenarios.

[0003] Although gels have broad development potential, they still face many problems in practical applications, such as swelling and structural damage in water environments. As underwater sensors, they can cause signal transmission interruption or distortion, making it difficult to achieve stable sensing applications in water. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide an anti-swelling gel and its preparation method and application.

[0005] In a first aspect, the present application provides a method for preparing an anti-swelling gel, which comprises: mixing a catechol substance, an intercalation compound and an organic solvent to form a precursor solution; mixing at least an acrylamide monomer and an acrylate monomer with the precursor solution to form a pre-polymerization solution; and using a photoinitiator to initiate cross-linking copolymerization of the pre-polymerization solution to form an anti-swelling gel.

[0006] In any embodiment of the first aspect of the present application, the catechols include at least one of gallic acid, o-methoxyphenol, and 2-methoxy-4-methylphenol.

[0007] In any embodiment of the first aspect of the present application, the mass fraction of catechols is 0.1% to 0.5% based on the total mass of the precursor solution.

[0008] In any embodiment of the first aspect of the present application, the intercalation compound includes at least one of hectorite, clay, and montmorillonite.

[0009] In any embodiment 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.

[0010] In any embodiment of the first aspect of the present application, the organic solvent includes at least one of dimethyl sulfoxide, methanol, methyl ether, and acetone.

[0011] In any embodiment 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 trichloroacetophenone).

[0012] In any embodiment 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 pre-polymerization solution.

[0013] In any embodiment of the first aspect of the present application, the acrylamide monomer includes at least one of acrylamide, dimethylacrylamide, diethylacrylamide, and N-isopropylacrylamide solution.

[0014] In any embodiment 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 pre-polymerization solution.

[0015] In any embodiment of the first aspect of the present application, the acrylate monomer includes at least one of ethyl acrylate, propyl acrylate, butyl acrylate, and tert-butyl acrylate solution.

[0016] In any embodiment of the first aspect of the present application, the mass fraction of the acrylic acid ester monomer is 1% to 15% based on the total mass of the pre-polymerization solution.

[0017] In any embodiment of the first aspect of the present application, based on the total mass of the pre-polymerization solution, the sum of the mass fraction of the acrylamide monomer and the mass fraction of the acrylate monomer is 12% to 18%.

[0018] In any embodiment of the first aspect of the present application, a hydrophilic monomer acrylamide monomer and a hydrophobic monomer acrylate monomer are mixed with a precursor solution; and finally, the step of photoinitiating cross-linking and copolymerizing the prepolymer solution to form an anti-swelling gel is to ultrasonicate the prepolymer solution for 5 to 10 minutes at room temperature and photoinitiate for 3 to 5 hours.

[0019] In a second aspect, the present application provides an anti-swelling gel, which is prepared by the preparation method of the first aspect of the present application.

[0020] In any embodiment of the second aspect of the present application, the swelling rate of the anti-swelling gel is -145% to 350%, optionally -50% to 110%, and further optionally -10% to 20%. When the anti-swelling gel is immersed in water and reaches swelling equilibrium, it exhibits a low swelling rate and excellent anti-swelling properties.

[0021] The present application embodiment is to construct an anti-swelling gel network by hydrophilic monomers and hydrophobic monomers, and light-triggered monomer polymerization forms an anti-swelling gel. The introduction of hydrophobic monomers can form hydrophobic interactions inside the anti-swelling gel, and the introduction of hydrophilic monomers makes the anti-swelling gel have a certain hydrophilic effect. Using an organic solvent as a solvent, it is a good solvent relative to the polymer chain. In the presence of a good solvent, the polymer chain is in a stretched conformation and presents a uniform distribution inside the network. After the anti-swelling gel is immersed in water, due to solvent replacement between the organic solvent and water, after being replaced by water, for the anti-swelling gel, water is a poor solvent, so curling occurs between the polymer chains and the non-covalent interaction between the molecular chains (such as hydrophilic and hydrophobic interactions, hydrogen bond interactions, etc.) is activated, thereby driving the anti-swelling gel to form a high cross-linking density network between the polymer chains.

[0022] Furthermore, for the anti-swelling gel before immersion in water, the hydrophobic groups at the gel-air interface are sparsely distributed. After immersion in water, the hydrophobic groups are unable to effectively block the entry of water molecules, resulting in swelling. Subsequently, due to the mutual repulsion between the hydrophobic segments and the water molecules in the anti-swelling gel, the hydrophobic groups aggregate at the interface through hydrophobic interactions, enhancing the anti-swelling properties of the anti-swelling gel.

[0023] In a third aspect, the present application provides an application of an anti-swelling gel in the alarm field, wherein the anti-swelling gel includes the anti-swelling gel prepared by the preparation method of the first aspect of the present application, or includes the anti-swelling gel provided by the second aspect of the present application.

[0024] In a fourth aspect, the present application provides an alarm device comprising a flexible anti-swelling gel sensor and an alarm. The flexible anti-swelling gel sensor comprises the anti-swelling gel produced by the preparation method of the first aspect of the present application, or the anti-swelling gel provided by the second aspect of the present application. The flexible anti-swelling gel sensor is electrically connected to the alarm. For example, the alarm may be an alarm indicator light.

[0025] According to the anti-swelling gel obtained in the embodiment of the present application, the anti-swelling gel is fixed on the human wrist and connected to an alarm indicator light to realize danger alarm and help when people are working in water.

[0026] In the embodiments of the present application, after the anti-swelling gel is immersed in water and reaches swelling equilibrium, its excellent anti-swelling performance provides the premise and basis for the stable application of the anti-swelling gel as a flexible sensor in an aqueous environment.

[0027] In addition, since the intercalation compound used in this application carries a negative charge, it can be adsorbed between polymer chains to form electrostatic interactions, and can provide a migration channel for ion transport inside the anti-swelling gel, thereby improving the electrochemical properties of the anti-swelling gel. As a flexible sensor, it can achieve high sensitivity, fast response, and excellent anti-fatigue performance. Based on this, the flexible anti-swelling gel sensor is used as a touch sensor. The operator in the water needs to respond within the set time (i.e., press the anti-swelling gel sensor once). If no response is received within the set time, the alarm light circuit is automatically connected, the alarm indicator light is started to sound, and a distress message is sent to the people on the shore to seek help.

[0028] The preparation method of the present application is simple, easy to implement and has high universality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0030] Figure 1 This is an infrared spectrum test chart of the anti-swelling gel provided according to one embodiment of the present application.

[0031] Figure 2 This is a graph showing the change in swelling rate over time of an anti-swelling gel provided at different monomer ratios according to one embodiment of the present application.

[0032] Figure 3 Macroscopic images of anti-swelling gels with different monomer ratios during immersion in water.

[0033] Figure 4 The figure shows the change of swelling rate of the anti-swelling gel in different solution environments over time according to one embodiment of the present application.

[0034] Figure 5 This is a schematic diagram of the application of the anti-swelling gel alarm device provided according to one embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the application purpose, technical solution and beneficial technical effects of this application clearer, the following describes this application in detail with reference to specific embodiments. It should be understood that the embodiments described in this specification are only for the purpose of explaining this application and are not intended to limit this application.

[0036] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and similarly, any upper limit can be combined with any other upper limit to form an unspecified range. In addition, although not explicitly stated, each point or individual value between the endpoints of a range is included in the range. Thus, each point or individual value can serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.

[0037] In the description of this article, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number themselves, and “a variety” in “one or more” means more than two.

[0038] The above disclosure of the present application is not intended to describe every disclosed embodiment or every implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided through a series of examples, which can be used in various combinations. In each example, the enumeration is intended only as a representative group and should not be construed as exhaustive.

[0039] 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 through hydrophilic monomers and hydrophobic monomers, and by immersing it in water, the aggregation characteristics of hydrophobic monomers on the surface of the anti-swelling gel can drive the hydrophobic interaction of the anti-swelling gel to prevent water molecules from entering the interior of the anti-swelling gel, thereby achieving anti-swelling.

[0040] Based on the above problems discovered by the applicant, the applicant conducted further research and found that excellent anti-swelling performance can be effectively achieved by using hydrophilic monomers acrylamide and hydrophobic monomers acrylate.

[0041] Therefore, in a first aspect, the present application provides a method for preparing an anti-swelling gel, which includes: a step S100 of preparing a precursor solution, a step S200 of mixing a hydrophilic monomer acrylamide monomer and a hydrophobic monomer acrylate monomer with the precursor solution to form a pre-polymer solution, and a step S300 of photoinitiating cross-linking and copolymerizing the pre-polymer solution to form an anti-swelling gel.

[0042] In step S100, the catechols, the intercalation compound and the organic solvent are stirred at the ambient temperature of the reaction system.

[0043] In some embodiments, the catechols include at least one of gallic acid, o-methoxyphenol, and 2-methoxy-4-methylphenol. The phenyl and methoxy groups contained in the catechols can form non-covalent interactions with the substrate, thereby enhancing the adhesion of the anti-swelling gel.

[0044] In some embodiments, the mass fraction of catechols, based on the total mass of the precursor solution, is 0.1% to 0.5%. Exemplarily, the mass fraction of catechols is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, or a range consisting of any two of these values. A mass fraction of catechols within the above ranges facilitates the anti-swelling gel to have excellent adhesion properties while still maintaining excellent anti-swelling properties.

[0045] In some embodiments, the intercalation compound has a layered structure, so that the catechols are embedded in the layered structure, thereby protecting the groups of the catechols from oxidation by air and the like.

[0046] In some embodiments, the intercalation compound has a negative charge, and when introduced into the anti-swelling gel, the anti-swelling gel can have excellent electrochemical properties.

[0047] In some embodiments, the intercalation compound comprises at least one of laponite, clay, and montmorillonite. Laponite 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 oxygen oxidation, for example, preventing phenolic hydroxyl groups from being oxidized by air, thereby improving the adhesion of catechols. On the other hand, the intercalation compound contains negative charges, which can form electrostatic interactions with polymer chains, imparting certain electrochemical properties to the anti-swelling gel.

[0048] In some embodiments, the mass fraction of the intercalation compound is 0.5% to 2.5% based on the total mass of the precursor solution. For example, the mass fraction of the intercalation 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 a range consisting of any two of the above values. When the mass fraction of the intercalation compound is within the above range, combined with 0.1% to 0.5% of catechols, it can provide excellent protection against catechols. Moreover, the introduction of the intercalation compound at the above mass fraction does not substantially affect the anti-swelling properties of the anti-swelling gel.

[0049] In some embodiments, the organic solvent may include at least one of dimethyl sulfoxide, methanol, dimethyl ether, and acetone.

[0050] In step S200 , at least acrylamide monomers, acrylate monomers and a precursor solution are mixed to form a pre-polymerization solution.

[0051] In some embodiments, based on the total mass of the pre-polymerization solution, the mass fraction of the acrylamide monomer is 1% to 15%. For example, the mass fraction of the hydrophilic monomer is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or a range consisting of any two of the above values.

[0052] In some embodiments, based on the total mass of the pre-polymerization solution, the mass fraction of the acrylate monomer is 1% to 15%. Exemplarily, the mass fraction of the hydrophobic monomer is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or a range consisting of any two of the above values.

[0053] In some embodiments, based on the total mass of the pre-polymerization solution, the sum of the mass fraction of the acrylamide monomer and the mass fraction of the acrylate monomer is 12% to 18%. Illustratively, the sum of the mass fraction of the acrylamide monomer and the mass fraction of the acrylate monomer is 12%, 13%, 14%, 15%, 16%, 17%, 18%, or a range consisting of any two of the above values.

[0054] For example, the mass fraction of acrylamide monomers is greater than that of acrylate monomers. This results in a more favorable hydrophilic-hydrophobic interaction within the anti-swelling gel. For example, the mass fraction of acrylamide monomers is 8% to 15%, optionally 10% to 15%, or even 10.5% to 11.5%. For example, the mass fraction of acrylate monomers is 1% to 8%, optionally 1% to 5%, or even 3.5% to 4.5%.

[0055] Alternatively, for example, the mass fraction of the acrylate monomer is greater than the mass fraction of the acrylamide monomer.

[0056] When the sum of the mass fractions of the acrylamide monomers and the acrylate monomers is within the above range, the hydrophobic monomers and the hydrophilic monomers are combined to provide the anti-swelling gel with both hydrophobic and hydrophilic properties, resulting in hydrophilic-hydrophobic interactions within the anti-swelling gel, which can increase the crosslinking density of the anti-swelling gel network, thereby achieving anti-swelling performance. In addition, in an aqueous environment, the hydrophobic monomers aggregate on the surface of the anti-swelling gel to prevent the entry of water molecules, thereby preventing the expansion and destruction of the anti-swelling gel network and achieving excellent anti-swelling performance.

[0057] In some embodiments, the acrylamide monomer includes at least one of acrylamide, dimethylacrylamide, diethylacrylamide, and N-isopropylacrylamide solution.

[0058] In some embodiments, the acrylate monomer includes at least one of ethyl acrylate, propyl acrylate, butyl acrylate, and tert-butyl acrylate solution.

[0059] 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 solution may include a mixed solution of butyl acrylate and tert-butyl acrylate. Another example is that the hydrophilic monomer solution may include a mixed solution of acrylamide and dimethylacrylamide, which copolymerizes with the hydrophobic monomer to form the backbone of the anti-swelling gel network, thereby achieving excellent anti-swelling properties in an aqueous environment.

[0060] In step S300, a photoinitiator is used to photoinitiate cross-linking and copolymerization of the pre-polymerized solution to form an anti-swelling gel.

[0061] In some embodiments, the mass fraction of the photoinitiator is 0.6% to 1.5% based on the total mass of the pre-polymerization solution. For example, 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 consisting of any two of the foregoing values.

[0062] The system before copolymerization can be understood as a prepolymerization solution. For example, the total mass of the raw materials (catechols, intercalation compounds, organic solvents, monomers, photoinitiators and crosslinking agents, etc.) in the system is taken as the total mass of the prepolymerization solution.

[0063] In some embodiments, the prepolymerization solution is sonicated for 5 to 10 minutes at the ambient temperature of the reaction system, and then photo-initiated cross-linking polymerization is carried out for 3 to 5 hours.

[0064] In some embodiments, the photoinitiator includes at least one of a dialkoxyacetophenone derivative (2,2-diethoxyacetophenone) and a chlorinated acetophenone derivative (dichloro or trichloroacetophenone), which is used to generate free radicals through photoinitiation, thereby initiating free radical polymerization between the hydrophilic monomer and the hydrophobic monomer.

[0065] According to the embodiments of the present application, an anti-swelling gel is obtained by photoinitiated free radical copolymerization of hydrophilic monomers such as acrylamide and hydrophobic monomers such as acrylate. The introduction of hydrophilic and hydrophobic monomers creates a hydrophilic-hydrophobic interaction within the anti-swelling gel, increasing the crosslink density of the anti-swelling gel network and thus achieving anti-swelling properties. Furthermore, in an aqueous environment, the hydrophobic monomers aggregate on the surface of the anti-swelling gel to prevent the ingress of water molecules, preventing the expansion and destruction of the anti-swelling gel network, thereby achieving excellent anti-swelling properties.

[0066] According to the embodiments of the present application, catechols are added because the phenyl, methoxy and other groups they contain can form non-covalent interactions with the substrate, thereby enhancing the adhesion properties of the anti-swelling gel; and the purpose of adding intercalation compounds is, on the one hand, because the phenolic hydroxyl groups of catechols are easily oxidized by air, in order to protect the phenolic hydroxyl groups, intercalation compounds are introduced so that the phenolic hydroxyl groups are embedded in the layered structure of the intercalation compounds; on the other hand, since they themselves carry negative charges, they can form electrostatic interactions with polymer chains, and the prepared anti-swelling gel can have electrochemical properties, so that it can be used as a flexible anti-swelling gel sensor to realize underwater alarm and rescue applications.

[0067] The second aspect of the present application provides an anti-swelling gel, which can be prepared based on the preparation method of the anti-swelling gel provided in the first aspect of the present application.

[0068] In some embodiments, the anti-swelling gel has a three-dimensional cross-linked network structure and a lamellar structure, the lamellar structure is located in the three-dimensional network structure, the lamellar structure includes catechols and intercalation compounds, the intercalation compounds have a lamellar structure, and the catechols are located in the lamellar structure.

[0069] The hydrophobic monomers and the hydrophilic monomers form a three-dimensional cross-linked network structure, which gives 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 catechol substances and intercalated compounds, which are introduced into the interior of the anti-swelling gel, giving the anti-swelling gel excellent adhesion and electrochemical properties.

[0070] The anti-swelling gel provided according to the embodiments of the present 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%.

[0071] The anti-swelling gel exhibits excellent anti-swelling properties in solutions with different pH values ​​(pH 3 to 7.5), and can also exist stably in water (pH approximately equal to 7). It can be used as a flexible anti-swelling gel sensor in water to provide alarms and help.

[0072] The anti-swelling gel provided according to the embodiments of the present application has good electrochemical properties.

[0073] In some embodiments, the compression sensitivity GF of the anti-swelling gel can reach 0.55 to 1.50, the compression response time and recovery time can both reach 130ms to 240ms, it has excellent anti-fatigue performance, and can achieve about 1,000 compression cycle sensing tests. The above results indicate that the anti-swelling gel can realize information transmission underwater, laying the foundation for the underwater application of flexible anti-swelling gel.

[0074] The above test parameters can be tested using test equipment and test methods known in the art, or tested with reference to national standards.

[0075] Due to the electrostatic interaction between the added intercalation compound and the polymer chain, the anti-swelling gel is endowed with good electrochemical properties, which can achieve rapid response and have anti-fatigue properties for long-term stable application in water.

[0076] The third aspect of the present application provides an application of an anti-swelling gel in an alarm device, in which the swelling-balanced anti-swelling gel is fixed on the human wrist as a flexible sensor, and information is transmitted by pressing and connected to an alarm indicator light to realize danger alarm and rescue when people are working in water.

[0077] According to the embodiments of the present application, the anti-swelling gel is simple to prepare and the raw materials are easily available. The introduction of hydrophobic monomers enables the anti-swelling gel to achieve a low swelling rate when immersed in a water environment, giving it excellent anti-swelling properties. The addition of intercalated compounds is due to the fact that they themselves carry charges and can form electrostatic interactions with polymer chains, giving the anti-swelling gel good electrochemical properties. As a flexible anti-swelling gel sensor, it can be used in water for a long time and stably. At the same time, its rapid response capability can realize the application of alarm and rescue.

[0078] Example

[0079] The following examples describe the present disclosure in more detail and are intended to be illustrative only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and used directly without further processing, and all instruments used in the examples are commercially available.

[0080] Example 1

[0081] In this embodiment, gallic acid, laponite, and dimethyl sulfoxide are used as raw materials to prepare a precursor, acrylamide and butyl acrylate are used as monomers, N,N'-methylenebisacrylamide is used as a crosslinker, and after ultrasonication, the anti-swelling gel is prepared by polymerization initiated by a photoinitiator. The specific steps include:

[0082] (1) Preparation of Precursor: Accurately weigh 0.0075 g of gallic acid and 0.05 g of laponite, mix them, add 4.1475 g of dimethyl sulfoxide, and stir at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm. The laponite's layered structure allows the gallic acid to be embedded, protecting its phenolic hydroxyl groups from oxidation by air and preventing the 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 intercalated compounds is 1.19%.

[0083] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g acrylamide and 0.2 g butyl acrylate, add 0.005 g N,N-methylenebisacrylamide, add the precursor solution of (1) above to the weighed monomer and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone as a prepolymer solution. Initiate with ultraviolet light for 4 h to form an anti-swelling gel. Wherein, based on the total mass of the prepolymer solution, the mass fraction of acrylamide (AAM) is 11% and that of butyl acrylate (BA) is 4%.

[0084] Figure 1 The infrared spectra of the anti-swelling gel prepared in the examples and the various monomers and solvents are shown. From the comparison of the infrared spectra of acrylamide and butyl acrylate monomers with the spectrum of the anti-swelling gel, it can be found that the polymerization mechanism of the anti-swelling gel is a free radical polymerization mechanism initiated by light. Figure 1 As can be seen, 1608cm -1 The peak of the C=C double bond in acrylamide at 1637 cm -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 the C=C double bond in the photoinitiator monomer forms free radicals, which are then further cross-linked and polymerized to form a gel network structure.

[0085] Example 2

[0086] An anti-swelling gel was prepared by a method similar to that of Example 1. Unlike Example 1, the masses of acrylamide and butyl acrylate were adjusted in Example 2. The method specifically includes the following steps:

[0087] (1) Preparation of precursor: 0.0075 g of gallic acid and 0.05 g of laponite were accurately weighed, mixed, and 4.1475 g of dimethyl sulfoxide was added. The mixture was stirred at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm.

[0088] (2) Preparation of anti-swelling gel: Accurately weigh 0.5 g acrylamide and 0.25 g butyl acrylate, add 0.005 g N,N'-methylenebisacrylamide, add the precursor solution of (1) above to the weighed monomer and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate under ultraviolet light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 10% and that of butyl acrylate (BA) is 5% based on the total mass of the prepolymer solution.

[0089] Example 3

[0090] An anti-swelling gel was prepared by a method similar to that of Example 1. Unlike Example 1, the masses of acrylamide and butyl acrylate were adjusted in Example 3. The method specifically includes the following steps:

[0091] (1) Preparation of precursor: 0.0075 g of gallic acid and 0.05 g of saponite were accurately weighed, mixed, and 4.1475 g of dimethyl sulfoxide was added. The mixture was stirred at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm.

[0092] (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 of (1) above to the weighed monomer and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate under 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.

[0093] Figure 2 The graph shows the time-dependent swelling rate for different monomer ratios. The swelling rate of the anti-swelling gel was measured by immersing the polymerized gel in 50 mL of ultrapure water at room temperature. The test method involves weighing the anti-swelling gel before immersion. A series of immersion times are then set. After the set immersion times are reached, the gel is removed, the surface moisture is wiped off, and the gel is weighed again. The swelling rate is calculated using the formula: Swelling rate = (mass after swelling - mass before swelling) / mass before swelling * 100%.

[0094] The images show that the swelling rates for samples with an acrylamide mass fraction of 11% and a butyl acrylate mass fraction of 4% are the lowest, indicating the best anti-swelling properties. The swelling rates for Example 1 at swelling equilibrium are approximately 4.79%, for Example 2 at swelling equilibrium, approximately -46.83%, and for Example 3 at swelling equilibrium, approximately 101.7%.

[0095] Figure 3 This is a macroscopic picture after reaching swelling equilibrium after immersion in different monomer ratios. It can be clearly seen that when the mass fraction of acrylamide to the mass fraction of butyl acrylate is 12:3, the swelling rate of the anti-swelling gel during the immersion process is relatively large; the degree of swelling underwater may be too large.

[0096] The anti-swelling gel with a mass fraction of acrylamide to butyl acrylate of 10:5 has a relatively small swelling rate and the degree of swelling under water is too small.

[0097] In general, the anti-swelling gel with a monomer ratio of acrylamide to butyl acrylate of 11:4 has little change in morphology after equilibrium, can exist in water for a long time, and has relatively excellent performance.

[0098] Figure 4 The swelling rate of the sample prepared in Example 1 was soaked in different solutions until the swelling equilibrium was reached. The anti-swelling gel after polymerization was soaked in 50 mL of solvent to test its swelling rate. The experimental temperature was the ambient temperature of the system. The swelling rate of the anti-swelling gel was then calculated in the same way as Figure 2 The calculation method in .

[0099] Figure 4 The main component of salted water is NaCl, with a mass content of 5.85%.

[0100] Example 4

[0101] The anti-swelling gel was prepared by a method similar to that of Example 1. Unlike Example 1, the mass of the hectorite was adjusted in Example 4. The method specifically includes the following steps:

[0102] (1) Preparation of Precursor: Accurately weigh 0.0075 g of gallic acid and 0.04 g of laponite, mix them, add 4.1575 g of dimethyl sulfoxide, and stir at 500 rpm for 5 h at ambient temperature. 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%.

[0103] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g acrylamide and 0.2 g butyl acrylate, add 0.005 g N,N'-methylenebisacrylamide, add the precursor solution described in (1) to the weighed monomers and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate under UV light for 4 h to form an anti-swelling gel. The swelling ratio of the anti-swelling gel at swelling equilibrium is approximately 8.5%.

[0104] Example 5

[0105] The anti-swelling gel was prepared by a method similar to that in Example 1. Unlike Example 1, the mass of the hectorite was adjusted in Example 5. The method specifically includes the following steps:

[0106] (1) Preparation of Precursor: Accurately weigh 0.0075 g of gallic acid (a catechol-like substance) and 0.06 g of laponite, mix them, add 4.1375 g of dimethyl sulfoxide, and stir at 500 rpm for 5 h at ambient temperature. Based on the total mass of the precursor solution, the mass fraction of the catechol-like substance is 0.18%, and the mass fraction of the intercalation compound is 1.19%.

[0107] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g acrylamide and 0.2 g butyl acrylate, add 0.005 g N,N'-methylenebisacrylamide, add the precursor solution described in (1) to the weighed monomers and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate under UV light for 4 h to form an anti-swelling gel. The swelling ratio of the anti-swelling gel at equilibrium was approximately 4%.

[0108] Example 6

[0109] The anti-swelling gel was prepared by a method similar to that of Example 1. Unlike Example 1, the mass of the catechols was adjusted in Example 6. The method specifically includes the following steps:

[0110] (1) Preparation of Precursor: Accurately weigh 0.005 g of gallic acid and 0.05 g of laponite, mix them, and add 4.1475 g of dimethyl sulfoxide. Stir at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm. The laponite's layered structure allows the gallic acid to be embedded, protecting its phenolic hydroxyl groups from oxidation by air and preventing the 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 the catechols is 0.12%, and the mass fraction of the intercalated compound is 1.19%.

[0111] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g acrylamide and 0.2 g butyl acrylate, add 0.005 g N,N-methylenebisacrylamide, add the precursor solution of (1) above to the weighed monomer and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate with UV 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 ratio of the anti-swelling gel at swelling equilibrium is approximately 4.5%.

[0112] Example 7

[0113] The anti-swelling gel was prepared by a method similar to that of Example 1. The difference from Example 1 was that the acrylamide monomer was adjusted in Example 7. Specifically, the steps included:

[0114] (1) Preparation of the precursor: Accurately weigh 0.0075 g of gallic acid and 0.05 g of laponite, mix them, add 4.1475 g of dimethyl sulfoxide, and stir at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm. The layered structure of laponite is used to embed gallic acid to protect its phenolic hydroxyl groups from oxidation by air and prevent catechols from losing their ability to provide viscosity for the anti-swelling gel.

[0115] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g of dimethylacrylamide and 0.2 g of butyl acrylate, add 0.005 g of N,N-methylenebisacrylamide, add the precursor solution of (1) above to the weighed monomers and crosslinker, sonicate for 5-10 min, and finally add 0.04 g of 2,2-diethoxyacetophenone. Initiate with UV light for 4 h to form an anti-swelling gel. The mass fraction of dimethylacrylamide (DMAA) is 11% and that of butyl acrylate (BA) is 4%. The swelling ratio of the anti-swelling gel at swelling equilibrium is approximately 15%.

[0116] Example 8

[0117] The anti-swelling gel was prepared by a method similar to that of Example 1. The difference from Example 1 was that the acrylic acid ester monomer was adjusted in Example 8. Specifically, the steps included:

[0118] (1) Preparation of the precursor: Accurately weigh 0.0075 g of gallic acid and 0.05 g of laponite, mix them, add 4.1475 g of dimethyl sulfoxide, and stir at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm. The layered structure of laponite is used to embed gallic acid to protect its phenolic hydroxyl groups from oxidation by air and prevent catechols from losing their ability to provide viscosity for the anti-swelling gel.

[0119] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g acrylamide and 0.2 g ethyl acrylate, add 0.005 g N,N-methylenebisacrylamide, add the precursor solution of (1) above to the weighed monomer and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate with UV light for 4 h to form an anti-swelling gel. The mass fraction of acrylamide (AAM) is 11% and that of ethyl acrylate (EA) is 4%. The swelling ratio of the anti-swelling gel at swelling equilibrium is approximately 38%.

[0120] Example 9

[0121] The anti-swelling gel was prepared by a method similar to that of Example 1. The difference from Example 1 was that the intercalation compound was adjusted in Example 9. Specifically, the steps included:

[0122] (1) Preparation of the precursor: Accurately weigh 0.0075 g of gallic acid and 0.05 g of montmorillonite, mix them, add 4.1475 g of dimethyl sulfoxide, and stir at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm. The layered structure of montmorillonite is used to embed gallic acid to protect its phenolic hydroxyl groups from oxidation by air and prevent catechols from losing their ability to provide viscosity for the anti-swelling gel.

[0123] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g acrylamide and 0.2 g butyl acrylate, add 0.005 g N,N-methylenebisacrylamide, add the precursor solution of (1) above to the weighed monomer and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate with UV 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 ratio of the anti-swelling gel at swelling equilibrium is approximately 5%.

[0124] Example 10

[0125] The anti-swelling gel was prepared by a method similar to that of Example 1. The difference from Example 1 was that the catechols were adjusted in Example 10. Specifically, the steps included:

[0126] (1) Preparation of the precursor: Accurately weigh 0.0075 g of o-methoxyphenol and 0.05 g of laponite, mix them, add 4.1475 g of dimethyl sulfoxide, and stir at the ambient temperature of the reaction system for 5 h at a stirring speed of 500 rpm. The layered structure of laponite is used to embed o-methoxyphenol to protect its phenolic hydroxyl group from oxidation by air and prevent catechols from losing their ability to provide viscosity for the anti-swelling gel.

[0127] (2) Preparation of anti-swelling gel: Accurately weigh 0.55 g acrylamide and 0.2 g butyl acrylate, add 0.005 g N,N-methylenebisacrylamide, add the precursor solution of (1) above to the weighed monomer and crosslinker, sonicate for 5-10 min, and finally add 0.04 g 2,2-diethoxyacetophenone. Initiate with UV 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 ratio of the anti-swelling gel at swelling equilibrium is approximately 6%.

[0128] Example Anti-swelling gel alarm device

[0129] The anti-swelling gel can be prepared using the preparation method described in Example 1. The anti-swelling gel acts as a flexible anti-swelling gel sensor, connected to an alarm (indicator light). After soaking until swelling equilibrium is reached, the gel is assembled and fixed to a human wrist. Simultaneously, it is connected to a current sensor, which detects current changes in real time under a constant voltage. The current sensor transmits the captured current value to a microcontroller unit for information transmission. Due to its excellent anti-swelling, electrochemical, and fatigue resistance properties, it is expected to be used in underwater alarms and distress calls.

[0130] Figure 5 The figure shows the connection diagram of the flexible anti-swelling gel sensor alarm device, which can realize the information transmission and alarm for help of workers in water. Figure 5 As shown in the figure, when the flexible anti-swelling gel sensor is pressed once, the computer interface displays "Safety," indicating that the underwater worker is safe. The initial alarm timer is set to 5 minutes, meaning that the underwater worker must press the flexible anti-swelling gel sensor once within 5 minutes to indicate that they are safe. If the underwater worker fails to press the flexible anti-swelling gel sensor after 5 minutes, the alarm device will be activated, notifying shore personnel that the underwater worker is in danger and needs to seek help immediately.

[0131] The above are only specific embodiments of the present application, but the scope of protection of the present 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 such modifications or substitutions should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for preparing an anti-swelling gel, characterized in that: include: mixing catechols, intercalation compounds and organic solvents to form a precursor solution; At least acrylamide monomers and acrylate monomers are mixed with the precursor solution to form a prepolymerization solution; Using a photoinitiator to initiate cross-linking and copolymerization of the prepolymer solution to form an anti-swelling gel; The catechols include at least one of gallic acid, o-methoxyphenol, and 2-methoxy-4-methylphenol; the mass fraction of the catechols is 0.1% to 0.5% based on the total mass of the precursor solution; The intercalation compound includes at least one of hectorite, clay, and montmorillonite; the mass fraction of the intercalation compound is 0.5% to 2.5% based on the total mass of the precursor solution; The mass fraction of the acrylamide monomer is 1% to 15% based on the total mass of the prepolymerization solution; Based on the total mass of the prepolymerization solution, the mass fraction of the acrylic acid ester monomer is 1% to 15%.

2. The method for preparing the anti-swelling gel according to claim 1, wherein The organic solvent includes at least one of dimethyl sulfoxide, methanol, methyl ether and acetone.

3. The method for preparing the anti-swelling gel according to claim 1, wherein: The photoinitiator includes at least one of 2,2-diethoxyacetophenone, dichloroacetophenone or trichloroacetophenone; and / or the mass fraction of the photoinitiator is 0.6% to 1.5% based on the total mass of the prepolymerization solution.

4. The method for preparing the anti-swelling gel according to claim 1, wherein: The acrylamide monomer includes at least one of acrylamide, dimethylacrylamide, diethylacrylamide, and N-isopropylacrylamide solution.

5. The method for preparing the anti-swelling gel according to claim 1, wherein: The acrylic acid ester monomer includes at least one of ethyl acrylate, propyl acrylate, butyl acrylate, and tert-butyl acrylate solution.

6. An anti-swelling gel, characterized in that: The anti-swelling gel is prepared by the preparation method of any one of claims 1 to 5.

7. The anti-swelling gel according to claim 6, characterized in that The swelling rate of the anti-swelling gel is -50% to 110%.

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

9. An application of an anti-swelling gel in the field of alarm, characterized in that: The anti-swelling gel comprises the anti-swelling gel according to any one of claims 6 to 8.

10. An alarm device, characterized in that: The flexible anti-swelling gel sensor comprises an anti-swelling gel according to any one of claims 6 to 8, and the flexible anti-swelling gel sensor is electrically connected to the alarm.

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