Low-salt-response adhesive composition, injectable adhesive and preparation method and application of low-salt-response adhesive composition and injectable adhesive

Abstract

The invention discloses a low-salt-response adhesive composition, an injectable adhesive as well as a preparation method and application of the low-salt-response adhesive composition and the injectable adhesive, and belongs to the technical field of adhesive hydrogel. The low-salt-response adhesive composition is mainly a composite sol obtained by dispersing the following precursor components in deionized water, wherein the precursor components comprise () a polyphenol compound; and () a quaternary ammonium salt polymer capable of forming multipoint ion-hydrogen bond functional groups with the polyphenol compound, the molecular weight of the quaternary ammonium salt polymer is 50 kDa to 500 kDa, and the composite sol can be stimulated by Hofmester ion salt to trigger sol-gel phase change. The adhesive composition provided by the invention has excellent injection performance, and also can trigger a polymorphic synergistic process of ion selective water abstracting-salt bridge hydrogen bond formation through 0.01 M low salt induction, so that not only is rapid sol-gel phase-change glue curing triggered by a low salt threshold effectively achieved, but also a strong adhesion effect of underwater universality is achieved, and the adhesive composition has a wide application prospect. The method is suitable for being applied to physiological environments and underwater scenes.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of adhesive hydrogel, and particularly relates to a low-salt-responsive adhesive composition, an injectable adhesive and a preparation method and application thereof. BACKGROUND

[0002] Adhesives have broad prospects in the fields of marine engineering, biomedical engineering and flexible electronics. However, the problems of hydration layer barrier and multivalent ion competition commonly exist in underwater environments, so that conventional adhesive systems are difficult to maintain stable adhesion performance in salt-dissolved water environments, which limits their practical application. Therefore, it is of great significance to develop high-performance adhesives suitable for salt-dissolved water environments.

[0003] At present, the gel-type adhesive with Hofmeister response has been designed and developed in the related field. The adhesive can dynamically regulate the crosslinking density and interfacial interaction strength of the molecular chain through the ion-specific response mechanism, and is expected to realize the precise adaptation of the adhesion performance in the salt-dissolved water environment.

[0004] However, the existing gel-type adhesive with Hofmeister response generally has the problems of high salt response concentration, easy swelling, insufficient adhesion, complex preparation and poor universality, which restricts the development and application of the related adhesive. SUMMARY

[0005] The application discloses a low-salt-responsive adhesive composition, an injectable adhesive and a preparation method and application thereof, which effectively solve the technical problems of high salt response concentration, easy swelling, insufficient adhesion, complex preparation and poor universality of the existing gel-type adhesive with Hofmeister response.

[0006] In order to achieve the above purpose, the technical scheme provided by the application is as follows:

[0007] The first aspect of the application provides a low-salt-responsive adhesive composition, which is mainly a composite sol obtained by dispersing the following precursor components in deionized water, the precursor components comprising:

[0008] a polyphenol compound; and a quaternary ammonium salt polymer capable of forming a multi-point ion-hydrogen bond functional group with the polyphenol compound, the quaternary ammonium salt polymer having a molecular weight of 50 kDa to 500 kDa.

[0009]

[0010] The composite sol can be stimulated by Hofmeister ion salt to trigger sol-gel phase transition.

[0011] ​​According to the disclosure of the first aspect, the polyphenol compound is selected from at least one of tannic acid, caffeic acid or chlorogenic acid.

[0012] According to the disclosure of the first aspect, the quaternary ammonium salt polymer is selected from at least one of quaternized chitosan, polydimethyldiallylammonium chloride, polyquaternium-2, polyquaternium-4, polyquaternium-6 or polyquaternium-10.

[0013] According to the disclosure of the first aspect, the quaternization degree of the quaternized chitosan is 40-98%.

[0014] According to the disclosure of the first aspect, the mass ratio of the quaternary ammonium salt polymer to the polyphenol compound is 1-6:6.

[0015] The second aspect of the present application further discloses an injectable adhesive, which comprises:

[0016] (a) an aqueous solution of Hofmeister ionic salt; and

[0017] (b) the low-salt-responsive adhesive composition according to the first aspect of the present application;

[0018] wherein the aqueous solution of Hofmeister ionic salt and the low-salt-responsive adhesive composition are packaged separately from each other.

[0019] According to the disclosure of the second aspect, the Hofmeister ionic salt is selected from at least one of Na2SO4, Na2HPO4, NaOAc, NaCl, NaBr or NaI.

[0020] According to the disclosure of the second aspect, the concentration of the aqueous solution of Hofmeister ionic salt is 0.01M to a saturated concentration.

[0021] The third aspect of the present application further discloses a preparation method of the injectable adhesive according to the present application, which comprises the following steps:

[0022] providing an aqueous solution of Hofmeister ionic salt; and

[0023] dissolving a quaternary ammonium salt polymer in deionized water to form a solution, then adding a polyphenol compound and dispersing to form a low-salt-responsive adhesive composition;

[0024] wherein the aqueous solution of Hofmeister ionic salt and the low-salt-responsive adhesive composition are packaged separately from each other.

[0025] The fourth aspect of the present application further discloses the use of the low-salt-responsive adhesive composition or the injectable adhesive according to the present application for the adhesive treatment of contact surfaces to be bonded.

[0026] According to the disclosure of the fourth aspect, when performing the bonding treatment on the contact surfaces to be bonded, after uniformly applying the low-salt-responsive adhesive composition to the contact surfaces to be bonded, applying the Hofmeister ionized aqueous salt solution to trigger the bonding, and then allowing it to stand.

[0027] Compared with the prior art, the advantages or beneficial effects of this application include at least:

[0028] The adhesive composition provided in this application utilizes a composite sol of polyphenolic compounds and quaternary ammonium salt polymers. This allows the components to interact and form a loose, multi-point ion-hydrogen bond network, endowing the adhesive composition with excellent injection performance. Furthermore, it can be induced by 0.01M low salt to trigger a polymorphic synergistic process of "ion-selective water-absorption-salt bridge hydrogen bond formation." This process not only rapidly transforms into a dense synergistic network of strongly oriented "ammonium salt-phenoloxy salt bridge hydrogen bonds" with high molecular cohesion, structural stability, and anti-swelling properties, but also effectively achieves a rapid phase transition from sol to gel triggered by a low salt threshold. Moreover, it can strip away the hydration layer around the polymer chains, ensuring the molded gel maintains excellent interfacial water drainage and wetting capabilities at low ion concentrations, ultimately achieving a universally applicable strong adhesion effect suitable for use in physiological environments and underwater scenarios. In addition, the gelation process of the adhesive composition in this application does not involve any chemical reaction, requires no external crosslinking agents or organic solvents, and is environmentally friendly, easy to prepare, injection moldable, with controllable response and excellent underwater stability. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The shear viscosity curve of the composite sol TQ98 provided in this application;

[0031] Figure 2 The injection force-displacement relationship curve of the composite sol TQ98 provided in this application;

[0032] Figure 3 The composite sol TQ98 and adhesive gel TQ98-S provided for this application 0.1 Scanning electron microscope images and cryo-scanning electron microscope images of the transition region during salting out;

[0033] Figure 4 The gelation effect of the composite sol TQ98 provided in this application in Na2SO4 aqueous solution and NaI aqueous solution;

[0034] Figure 5 Adhesive gels TQ98-S obtained by gelation of TQ98 and TQ40 with different degrees of quaternization provided in the present application at different concentrations of Na2SO4 n and TQ40-S n The plots of storage modulus (G') and loss modulus (G'') versus time during gelation of adhesive gels TPDA-S0

[0035] Figure 6 Adhesive gels TQ98, TQ98-S 0.1 , TQ98-P 0.1 , TQ98-A 0.1 and TQ98-C 0.1 provided in the present application

[0036] Figure 7 The results of lap shear strength tests of adhesive gels TPDA-S0 .1 and TPQ-S 0.1 provided in the present application after salting out at different concentrations of Na2SO4 and different types of sodium salts

[0037] Figure 8 The results of lap shear strength tests of adhesive gels TQ98-S 0.1 adhering to glass under acidic and alkaline environments provided in the present application

[0038] Figure 9 The plots of volume change rate versus time and the plots of adhesive strength retention rate versus time of adhesive gels TQ98-S 0.1 provided in the present application under immersion in water and simulated seawater

[0039] Figure 10 Scanning electron microscope images of composite sol TPDA and adhesive gel TPDA-S 0.1 provided in the present application after gelation induced by 0.1 M Na2SO4 solution

[0040] Figure 11 The plots of storage modulus (G') and loss modulus (G'') versus time during gelation of adhesive gels TPDA-S n and TPQ-S n provided in the present application

[0041] Figure 12 The results of lap shear strength tests of adhesive gel samples TPDA-S0 .1 and TPQ-S 0.1 provided in the present application DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments described in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0043] In the following description of the present application, the term "and / or" is used to describe the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent the following three cases: A exists alone, B exists alone, and A and B exist simultaneously. Wherein, A and B can be singular or plural; the symbol " / " represents the meaning of "or".

[0044] In the following description of the present application, the term "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or similar expressions means any combination of the items, including any combination of single or multiple items. For example, "at least one of A, B or C" or "at least one of A, B and C" can mean any one of A, B, C, A+B, A+C, B+C, or A+B+C, wherein A, B, and C can be single or multiple.

[0045] In the following description of the present application, the order of the serial numbers does not mean the order of execution, and some or all steps can be executed in parallel or in sequence. The execution order of each process should be determined according to its function and inherent logic, and does not constitute any limitation on the execution process of the embodiments.

[0046] In the following description of the present application, the numerical range should be understood as also specifically disclosing each intermediate value between the upper limit and the lower limit of the range. Any intermediate value in the stated range and any other stated value or each smaller range between the intermediate values in the stated range are also included in the embodiments, and the upper limit and the lower limit of the smaller range can be independently included or excluded from the range.

[0047] Unless otherwise specified, the technical / scientific terms used in the present application have meanings commonly understood by a person of ordinary skill in the art. Although preferred materials and methods are described in the present application, any method and material similar or equivalent to those described in the specific embodiments or test examples can also be used. All documents mentioned in the present application are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of conflict with any incorporated document, the content of the present application shall prevail.

[0048] To address the problems of high salt response concentration, easy swelling, insufficient adhesion, complex preparation, and poor universality of existing Hofmeister-responsive gel adhesives, the first aspect of this application provides a low-salt-responsive adhesive composition, which mainly comprises a composite sol obtained by dispersing the following precursor components in deionized water, wherein the precursor components include ( Polyphenolic compounds; and, ( The quaternary ammonium salt polymer is capable of forming multi-site ionic-hydrogen bond functional groups with polyphenolic compounds, and the molecular weight of the quaternary ammonium salt polymer is preferably 50 kDa to 500 kDa. The composite sol can be stimulated by Hofmeister ionic salts to trigger a sol-gel phase transition.

[0049] This application's embodiments utilize the design of a composite sol of polyphenolic compounds and quaternary ammonium salt polymers. This allows the components to interact and construct a loose, multi-point ion-hydrogen bond network structure, endowing the adhesive composition with excellent injection performance. Simultaneously, it can trigger a polymorphic synergistic process of "ion-selective water-absorption-salt bridge hydrogen bond formation" through low-salt induction, rapidly transforming into a dense synergistic network of strongly oriented "ammonium salt-phenol-oxygen salt bridge hydrogen bonds" with high molecular cohesion, good structural stability, and long-term anti-swelling properties. This effectively achieves a rapid phase transition from sol to gel triggered by a low-salt concentration threshold, resulting in gelation and curing. Specifically, when a trace amount of Hofmeister anionic salt is added to the composite sol, the Hofmeister anionic salt preferentially interacts with water molecules, initiating directional dehydration within the composite sol and stripping the hydration layer surrounding the polymer chains. This effectively promotes the formation of quaternary ammonium centers (-N) on the quaternary ammonium salt polymer molecules. + (CH3)3) and the phenolic oxygen (-O) on the polyphenol compound molecule - The hydrogels interact and form a strongly oriented salt-bridged hydrogen bond network structure, effectively enhancing the aggregation and salting-out effect between polymer chains. This rapidly increases molecular cohesion and network density, ultimately achieving highly efficient gelation and curing adhesion under ultra-low salt concentration threshold triggering (0.01M). Simultaneously, the salting-out mechanism of the hydrogel possesses excellent interfacial dehydration capabilities and adaptive reconstruction characteristics. It can eliminate interfacial water films in saline underwater environments and universally form interactions and ion bridges with various substrate surfaces (metals, glass, biological tissues, etc.), thereby achieving high-strength, long-lasting underwater adhesion, suitable for applications in physiological environments and underwater scenarios. Furthermore, the gelation process of the adhesive composition in this application does not involve any chemical reactions, requires no external crosslinking agents or organic solvents, and is environmentally friendly, easy to prepare, injection moldable, with controllable response and excellent underwater stability.

[0050] In possible disclosed examples, the polyphenolic compound is selected from at least one of tannic acid, caffeic acid, or chlorogenic acid; the quaternary ammonium salt polymer is preferably at least one of quaternized chitosan, polydiallyldimethylammonium chloride, polyquaternary ammonium salt-2, polyquaternary ammonium salt-4, polyquaternary ammonium salt-6, or polyquaternary ammonium salt-10. The composition of these quaternary ammonium salt polymers and polyphenols possesses characteristics such as rapid gelation at low ion concentrations, strong intramolecular cohesion, and excellent interfacial water drainage and wetting capabilities, making it suitable for applications in physiological environments and underwater scenarios (such as hemostasis, biological tissue adhesion, in-situ sprayed gelled flexible electronic skin patches, underwater structural repair, etc.). It should be noted that this application does not limit the specific source of the quaternary ammonium salt polymer; it can be obtained commercially or prepared using known synthetic methods.

[0051] It should be noted that tannic acid is used as a representative polyphenol compound in the embodiments of this application for illustrative purposes because it has a high content of phenolic hydroxyl groups, is readily available, and has stable effects. However, this does not constitute a limitation on the scope of protection of this application. Those skilled in the art will understand that other polyphenol compounds that meet the characteristic of "containing multiple easily oxidized phenolic hydroxyl groups in the molecule" (such as chlorogenic acid, caffeic acid, gallic acid, etc.) can replace tannic acid in the technical solutions of this application and can achieve the same or similar technical effects. These alternative solutions all fall within the scope of protection of this application.

[0052] In possible disclosed examples, the quaternary ammonium salt polymer is more preferably quaternized chitosan, and the degree of quaternization substitution of the quaternized chitosan is preferably 40-98%, which can be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, etc. In this application, by optimizing the degree of quaternization substitution of the quaternized chitosan, the density of potential salt bridge binding sites can be effectively increased, thereby adjusting the phase transition threshold, response speed, molecular cohesion of the formed gel, and underwater adhesion strength of the sol-gel.

[0053] In possible disclosed examples, the mass ratio of the quaternary ammonium salt polymer to the polyphenol compound is preferably 1 to 6:6, and can be 1:6, 2:6, 3:6, 4:6, 5:6, 6:6, etc. Specifically, by limiting the mass ratio of the quaternary ammonium salt polymer to the polyphenol compound to 1 to 6:6, this application can effectively regulate the molecular cohesion of the gel, the sol-gel phase transition threshold, the response speed, and the underwater adhesion strength.

[0054] In a second aspect, embodiments of this application also provide an injectable adhesive comprising:

[0055] (a) Aqueous solution of Hofmeister ion salt; and

[0056] (b) The low-salt responsive adhesive composition described in aspect 1;

[0057] The Hofmeister ionic salt aqueous solution and the low-salt-responsive adhesive composition are packaged separately from each other.

[0058] This application embodiment, by setting the combination of the above components (a) and (b), makes the quaternary ammonium cation centers (-N) on the quaternary ammonium salt polymer molecules... + (CH3)3) and the phenolic oxygen anion (-O) on polyphenolic compounds - While forming a multi-point salt bridge network structure through the synergistic effect of ions and hydrogen bonds, the composite sol can undergo directional salting-out dehydration induced by anions in the Hofmeister sequence, further promoting the close packing of polymer chains and network densification, and finally undergoing a sol-gel phase transition to form a gel with a stable ion bridge-hydrogen bond composite network at the molecular level, giving it excellent underwater gelation ability and long-term adhesion performance.

[0059] It should be noted that the Hofmeister ion salt refers to a sodium salt capable of inducing a "salting-out effect" or "salting-dissolution effect," preferably at least one of Na₂SO₄, Na₂HPO₄, NaOAc, NaCl, NaBr, or NaI. The concentration of the Hofmeister ion salt solution can be any from 0.01M to the saturation concentration. Here, it should be noted that the unit "M" refers to molar concentration, i.e., "mol / L."

[0060] In a third aspect, embodiments of this application also provide a method for preparing the injectable adhesive described above, which includes the following steps:

[0061] Provide Hofmeister ionized aqueous solution for later use;

[0062] After dissolving quaternary ammonium salt polymers in deionized water to form a solution, polyphenol compounds are added and dispersed to form a low-salt-responsive adhesive composition.

[0063] The Hofmeister ionic salt aqueous solution and the low-salt-responsive adhesive composition are packaged separately from each other.

[0064] It should be noted that the entire preparation process of this application does not require any chemical crosslinking agents or organic solvents, and relies entirely on physical processes to achieve structural curing, which has the advantages of simple operation, low energy consumption, and environmental friendliness. At the same time, the prepared adhesive is light brown and transparent, has good injectable flowability, and can be rapidly cured in situ at extremely low salt concentrations, making it suitable for large-scale preparation and field application.

[0065] Fourthly, embodiments of this application also provide the application of the low-salt-responsive adhesive composition and / or injectable adhesive described in this application, specifically the application of the low-salt-responsive adhesive composition and / or injectable adhesive in the bonding treatment of surfaces to be bonded. The surfaces to be bonded may be located within an aqueous system, which includes, but is not limited to, freshwater systems, complex marine environments, etc.

[0066] In a fifth aspect, embodiments of this application also provide methods of using the low-salt-responsive adhesive composition and / or injectable adhesive described in this application, preferably comprising the following steps:

[0067] After uniformly applying the low-salt-responsive adhesive composition to the surfaces to be bonded, apply a Hofmeister ionized aqueous salt solution to trigger bonding, and then allow it to stand.

[0068] The technical solution of this application will be further described below with reference to specific embodiments.

[0069] Example 1

[0070] This example provides a low-salt-responsive adhesive composition, the raw materials of which include:

[0071] Quaternized chitosan powder (QCS, degree of quaternization substitution of 98%, molecular weight of approximately 150 kDa) 1.0 g;

[0072] Tannic acid powder (TA) 3.0 g;

[0073] 12.0 g of deionized water.

[0074] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a uniform and transparent solution system. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ98 was formed, thus obtaining a low-salt responsive adhesive composition.

[0075] Example 2

[0076] This example provides a low-salt-responsive adhesive composition, the raw materials of which include:

[0077] Quaternized chitosan powder (QCS, degree of quaternization substitution of 40%, molecular weight of approximately 150 kDa) 1.0 g;

[0078] Tannic acid powder (TA) 3.0 g;

[0079] 12.0 g of deionized water.

[0080] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a uniform and transparent solution system. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ40 was formed, thus obtaining a low-salt responsive adhesive composition.

[0081] Example 3

[0082] This example provides an injectable adhesive comprising a composite sol and an aqueous solution of Na₂SO₄ packaged separately. The precursor material of the composite sol includes:

[0083] Quaternized chitosan powder (QCS, degree of quaternization substitution of 98%, molecular weight of approximately 150 kDa) 1.0 g;

[0084] Tannic acid powder (TA) 3.0 g;

[0085] 12.0 g of deionized water;

[0086] One of the Na2SO4 aqueous solutions with concentrations of 0.01 M, 0.1 M, and 1 M.

[0087] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ98 was formed. The composite sol TQ98 was then induced to gel in 0.01 M, 0.1 M, and 1 M Na₂SO₄ aqueous solutions to obtain the adhesive gel TQ98-S. 0.01 TQ98-S 0.1 And TQ98-S1.

[0088] Example 4

[0089] This example provides an injectable adhesive TQ40-S n (n=0.1, 1), comprising separately packaged composite sol and Na2SO4 aqueous solution. The precursor materials for the composite sol include:

[0090] Quaternized chitosan powder (QCS, degree of quaternization substitution of 40%, molecular weight of approximately 150 kDa) 1.0 g;

[0091] Tannic acid powder (TA) 3.0 g;

[0092] 12.0 g of deionized water;

[0093] One of the Na₂SO₄ aqueous solutions with concentrations of 0.1 M and 1 M.

[0094] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ40 was formed. The composite sol TQ40 was then induced to gel in 0.1 M and 1 M Na₂SO₄ aqueous solutions to obtain the adhesive gel TQ40-S. 0.1 And TQ40-S1.

[0095] Example 5

[0096] This example provides an injectable adhesive comprising a composite sol and an aqueous solution of Na2HPO4 packaged separately. The precursor material of the composite sol includes:

[0097] Quaternized chitosan powder (QCS, degree of quaternization substitution of 98%, molecular weight of approximately 150 kDa) 1.0 g;

[0098] Tannic acid powder (TA) 3.0 g;

[0099] 12.0 g of deionized water;

[0100] 0.1 M Na2HPO4 aqueous solution.

[0101] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ98 was formed. The composite sol TQ98 was then induced to gel in a 0.1 M Na₂SO₄ aqueous solution to obtain the adhesive gel TQ98-P. 0.1 .

[0102] Example 6

[0103] This example provides an injectable adhesive comprising a composite sol and an aqueous solution of NaOAc, packaged separately from each other. The precursor material of the composite sol includes:

[0104] Quaternized chitosan powder (QCS, degree of quaternization substitution of 98%, molecular weight of 150 kDa) 1.0 g;

[0105] Tannic acid powder (TA) 3.0 g;

[0106] 12.0 g of deionized water;

[0107] 0.1 M NaOAc aqueous solution.

[0108] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ98 was formed. The composite sol TQ98 was then placed in a 0.1 M NaOAc aqueous solution to induce gelation, yielding the adhesive gel TQ98-A. 0.1 .

[0109] Example 7

[0110] This example provides an injectable adhesive comprising a composite sol and an aqueous NaCl solution packaged separately. The precursor material of the composite sol includes:

[0111] Quaternized chitosan powder (QCS, degree of quaternization substitution of 98%, molecular weight of 150 kDa) 1.0 g;

[0112] Tannic acid powder (TA) 3.0 g;

[0113] 12.0 g of deionized water;

[0114] 0.1 M NaCl aqueous solution.

[0115] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ98 was formed. The composite sol TQ98 was then placed in a 0.1 M NaCl aqueous solution to induce gelation, yielding the adhesive gel TQ98-C. 0.1 .

[0116] Example 8

[0117] This example provides an injectable adhesive comprising a composite sol and an aqueous NaBr solution packaged separately. The precursor material of the composite sol includes:

[0118] Quaternized chitosan powder (QCS, degree of quaternization substitution of 98%, molecular weight of approximately 150 kDa) 1.0 g;

[0119] Tannic acid powder (TA) 3.0 g;

[0120] 12.0 g of deionized water;

[0121] 0.1 M NaBr aqueous solution.

[0122] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ98 was formed. The composite sol TQ98 was then induced to gel in a 0.1 M NaBr aqueous solution to obtain the adhesive gel TQ98-B. 0.1 .

[0123] Example 9

[0124] This example provides an injectable adhesive comprising a composite sol and an aqueous solution of NaI, packaged separately. The precursor material of the composite sol includes:

[0125] Quaternized chitosan powder (QCS, degree of quaternization substitution of 98%, molecular weight of approximately 150 kDa) 1.0 g;

[0126] Tannic acid powder (TA) 3.0 g;

[0127] 12.0 g of deionized water;

[0128] 0.1 M NaI aqueous solution.

[0129] Quaternized chitosan powder was dissolved in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol TQ98 was formed. The composite sol TQ98 was then placed in a 0.1 M NaI aqueous solution to induce gelation, yielding the adhesive gel TQ98-I. 0.1 .

[0130] To verify the actual effectiveness of the adhesive compositions and adhesive gels prepared in Examples 1-9 above, this application conducted structural and performance tests on the adhesive compositions and adhesive gels provided in Examples 1-9 above, as detailed below:

[0131] 1.1 Injectability Performance Testing Experiment

[0132] The composite sol TQ98 was loaded into a syringe, and its shear viscosity and the relationship curves between injection force and displacement were tested. The results were as follows: Figures 1-2 As shown. Among them, Figure 1 The shear viscosity curve of composite sol TQ98; Figure 2 The injection force-displacement relationship curve for composite sol TQ98.

[0133] according to Figures 1-2It is known that composite sol TQ98 exhibits non-Newtonian shear-thinning behavior at low shear rates; at the same time, the shear viscosity of composite sol TQ98 at 37°C is consistently below 80 Pa·s, meeting the requirement for smooth injection through a fine needle, and the injection force is below 6N. These results indicate that the adhesive composition prepared in this application has excellent injectability.

[0134] 1.2 Microscopic morphology characterization

[0135] The adhesive gel TQ98-S was formed by inducing the formation of composite sol TQ98 and adhesive gel TQ98-S through a 0.1 M Na2SO4 aqueous solution. 0.1 After being frozen and sublimated at -90°C in a freeze-drying system, the sample was torn apart to obtain a cross-section. A layer of gold atoms was sputtered to improve conductivity. The microstructure of the material was observed using scanning electron microscopy and cryo-scanning electron microscopy (accelerating voltage 10 kV). The results are as follows: Figure 3 As shown. Among them, Figure 3 In section A, there is composite sol TQ98 and binder gel TQ98-S. 0.1 Scanning electron microscope image; B is the adhesive gel TQ98-S 0.1 Cryo-scanning electron microscopy image of the transition region during salting out.

[0136] according to Figure 3 It is evident that the initial composite sol TQ98 exhibits a distinct three-dimensional porous network structure, while the resulting binder gel TQ98-S, after Na2SO4 "salting out,"... 0.1 It exhibits a denser three-dimensional network with significantly reduced pore size. Meanwhile, cryo-scanning electron microscopy reveals the gradual transition of the porous structure of the three-dimensional network during salting out, indicating that the adhesive composition provided in this application can achieve significant shrinkage and enhanced cohesion of the internal network structure of the gel at low salt concentrations.

[0137] 1.3 Gelation Effect Test

[0138] The composite sol TQ98 was immersed in Na2SO4 aqueous solution and NaI aqueous solution, respectively, and the gelation effect was observed after standing for 24 h. The results were as follows: Figure 4 As shown. Among them, Figure 4 The gelation effect of composite sol TQ98 in Na2SO4 aqueous solution and NaI aqueous solution is shown.

[0139] according to Figure 4 It can be seen that the composite sol TQ98 can achieve gelation after being soaked in sodium salts by both "salting out" and "salting dissolving".

[0140] 1.4 Rheological Characterization

[0141] Composite sols TQ98 and TQ40 were induced to gel in Na₂SO₄ aqueous solutions (0.1 M and 1 M), respectively. Curves showing the salt-responsive modulus versus time were obtained. The changes in storage modulus (G') and loss modulus (G'') over time during gel formation were measured using a rotational rheometer. The results are as follows: Figure 5 As shown.

[0142] according to Figure 5 It can be seen that when induced by 0.01 M Na2SO4 aqueous solution, composite sol TQ40 failed to achieve the transformation of G' exceeding G'; while when induced by 1 M Na2SO4 aqueous solution, composite sols TQ98 and TQ40 both completed gelation, indicating that composite sols TQ98 and TQ40 can both achieve salting-out gel transformation under Na2SO4-induced conditions. At the same time, QCS with a high degree of quaternization is more sensitive to Na2SO4 aqueous solution and can accelerate gel formation under low salt conditions. This indicates that the adhesive composition provided in this application has the salting-out enhanced gelation effect produced by the Hofmeister effect, and the response sensitivity can be adjusted according to the change of the degree of substitution of quaternized chitosan.

[0143] 1.5 Hydrophilicity / Hydrophobicity Test

[0144] After preparing a 1 mm thick coating from composite sol TQ98, the water contact angle of each coating under salting-out treatment with different 0.1 M sodium salt aqueous solutions was measured using an optical contact angle meter via the pendant drop method. The results are as follows: Figure 6 As shown. Among them, Figure 6 For adhesive gels TQ98 and TQ98-S 0.1 TQ98-P 0.1 TQ98-A 0.1 and TQ98-C 0.1 A statistical chart of water contact angles.

[0145] according to Figure 6 It can be seen that the water contact angle of the composite sol TQ98 is much less than 90°, and it has good wettability to the interface. The adhesive gel TQ98-S after salting out... 0.1 TQ98-P 0.1 TQ98-A 0.1 and TQ98-C 0.1 The water contact angles are all equal to or greater than 90°, and increase with the increase of the contribution of anions to salting out, indicating that the adhesive composition provided in this application is hydrophobic after salting out, and that salting out significantly enhances the hydrophobicity of the injectable adhesive.

[0146] 1.6 Overlap Shear Strength Test

[0147] Immerse the glass slide in water at room temperature to prepare it as a substrate;

[0148] Composite sol TQ98 was injected onto each glass substrate to form adhesion zones. These zones were then covered with another glass slide and immersed in a sodium salt solution for 24 hours to obtain adhered glass samples. The adhered glass samples were subjected to tensile tests using a texture analyzer, and the adhesion performance was evaluated through lap shear strength tests. The results were as follows: Figure 7 As shown. Among them, Figure 7 In the figure, A represents the adhesive gel TQ98-S obtained after the composite sol TQ98 adheres to the glass sample and undergoes salting-out in Na2SO4 aqueous solutions of different concentrations for 24 hours. n The results of the lap shear strength test are shown in Figure B, where B represents the adhesive gel TQ98-S obtained after the composite sol TQ98 adhered glass sample underwent salting-out in different sodium salt solutions at 0.1 M concentrations for 24 hours. 0.1 TQ98-P 0.1 TQ98-A 0.1 and TQ98-C 0.1 The results of the lap shear strength test.

[0149] according to Figure 7 As shown in section A, under the same salt conditions, the higher the concentration of the salt solution used for salting out, the better the adhesion enhancement effect; according to Figure 7 As shown in section B, under the same cation conditions, the stronger the Hofmeister sequence order in the anion, the better the adhesion strength enhancement effect; compared with the unsalted composite sol TQ98, the adhesive gel TQ98-S n Due to the initial wetting of the interface and the enhancement of interfacial hydrophobicity and cohesion during the salting-out process by the composite sol TQ98, the introduction of the Hofmeister effect effectively enhances the underwater adhesion strength of this material.

[0150] 1.7 Overlap Shear Strength Test of Bonds in Acid and Alkaline Environments

[0151] The glass slides were immersed in acidic and alkaline environments at room temperature to prepare a substrate.

[0152] The composite sol TQ98 was loaded into a syringe and injected onto a glass substrate in both acidic and alkaline environments to form adhesion zones. The adhesion zones were then covered with another glass slide and immersed in a 0.1 M Na₂SO₄ solution for 24 hours to obtain the adhesive gel TQ98-S. 0.1 Adhere the glass sample. Then, apply adhesive gel TQ98-S. 0.1 The adhesive samples were placed in acidic and ambient environments for 7 days, respectively. The adhesive gel TQ98-S was then applied. 0.1 The adhered glass sample was placed on a mechanical testing instrument for a tensile test, and the result was... Figure 8 As shown.

[0153] according to Figure 8 It can be seen that the adhesive gel TQ98-S 0.1 There was no significant difference in glass adhesion strength between acidic and neutral water environments with different pH levels, indicating that acidic environments have a significant impact on the adhesion strength of the adhesive gel TQ98-S. 0.1 The adhesion properties are not significantly affected; meanwhile, the adhesive gel TQ98-S 0.1 There was no significant difference in glass adhesion strength in alkaline water environments with different pH levels, indicating that the alkaline environment affects the adhesive gel TQ98-S. 0.1 The adhesion properties were not significantly affected.

[0154] 1.8 Underwater Adhesion Stability Test

[0155] The prepared adhesive gel TQ98-S 0.1 Adhesive glass samples were immersed in simulated seawater and physiological saline for 28 days, respectively. The volume change rate and adhesion strength retention rate of the gel were measured periodically. The results were as follows: Figure 9 As shown. Among them, Figure 9 A is TQ98-S 0.1 The change in volumetric rate of the adhered glass sample immersed underwater and in simulated seawater over time; B represents TQ98-S. 0.1 The graph shows the change in adhesion strength of the glass sample immersed in water over time.

[0156] according to Figure 9 It can be seen that the adhesive gel TQ98-S 0.1 The volume change rate after 28 days was less than 10%, and the adhesion strength retention rate was more than 95%, proving that the injectable adhesive provided in this application has excellent anti-swelling properties and long-term structural stability.

[0157] Example 10

[0158] This example provides an adhesive composition whose component raw materials include:

[0159] 5.0 g of polydimethylammonium chloride solution (PDADMAC, 20% aqueous solution, approximately 150 kDa).

[0160] Tannic acid powder (TA) 3.0 g;

[0161] 8.0 g of deionized water.

[0162] Dilute polydimethylammonium chloride solution in deionized water, stir magnetically to form a uniform and transparent solution, then gradually add tannic acid powder and continue stirring until a light brown composite sol TPDA is formed, which is the adhesive composition TPDA.

[0163] Example 11

[0164] This example provides an adhesive composition whose component raw materials include:

[0165] 1.6 g of polyquaternium-2 solution (PQ-2, aqueous solution mass fraction 62%, molecular weight approximately 150 kDa);

[0166] Tannic acid powder (TA) 3.0 g;

[0167] 11.4 g of deionized water.

[0168] After diluting the polyquaternium-2 solution in deionized water and magnetically stirring it into a uniform and transparent solution, tannic acid powder is gradually added and stirred thoroughly until a light brown composite sol TPQ is formed, which is the adhesive composition TPQ.

[0169] Example 12

[0170] This example provides an injectable adhesive comprising a composite sol and an aqueous solution of Na₂SO₄ packaged separately. The precursor material of the composite sol includes:

[0171] 5.0 g of polydimethylammonium chloride solution (PDADMAC, 20% aqueous solution, approximately 150 kDa).

[0172] Tannic acid powder (TA) 3.0 g;

[0173] 8.0 g of deionized water;

[0174] One of the Na2SO4 aqueous solutions with concentrations of 0.01 M, 0.1 M, and 1 M.

[0175] Polydimethylammonium chloride solution was diluted in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol (TPDA) was formed. The composite sol (TPDA) was then induced to gel in 0.01 M, 0.1 M, and 1 M Na₂SO₄ aqueous solutions to obtain the adhesive gel TPDA-S. 0.01 TPDA-S 0.1 And TPDA-S1.

[0176] Example 13

[0177] This example provides an injectable adhesive comprising a composite sol and an aqueous solution of Na₂SO₄ packaged separately. The precursor material of the composite sol includes:

[0178] 1.6 g of polyquaternium-2 solution (PQ-2, aqueous solution mass fraction 62%, molecular weight approximately 150 kDa);

[0179] Tannic acid powder (TA) 3.0 g;

[0180] 11.4 g of deionized water;

[0181] One of the Na2SO4 aqueous solutions with concentrations of 0.01 M, 0.1 M, and 1 M.

[0182] Polyquaternium-2 solution was diluted in deionized water and magnetically stirred to form a homogeneous and transparent solution. Tannic acid powder was then gradually added and stirred thoroughly until a light brown composite sol (TPQ) was formed. The composite sol (TPQ) was then induced to gel in 0.01 M, 0.1 M, and 1 M Na₂SO₄ aqueous solutions to obtain the adhesive gel (TPQ-S) sequentially. 0.01 TPQ-S 0.1 And TPQ-S1.

[0183] To verify the actual effectiveness of the adhesive compositions and adhesive gels prepared in Examples 10-13 above, this application conducted structural and performance tests on the adhesive compositions and adhesive gels provided in Examples 10-13 above, as follows:

[0184] 2.1 Microscopic morphology characterization

[0185] The adhesive gel TPDA-S was formed by inducing the formation of composite sol TPDA and adhesive gel TPDA-S in a 0.1 M Na2SO4 aqueous solution. 0.1 After being frozen and sublimated at -90°C in a freeze-drying system, the sample was torn apart to obtain a cross-section. A layer of gold atoms was sputtered to improve conductivity. The microstructure of the material was observed using scanning electron microscopy and cryo-scanning electron microscopy (accelerating voltage 10 kV). The results are as follows: Figure 10 As shown.

[0186] according to Figure 10 It is evident that the initial composite sol TPDA possesses a porous three-dimensional network structure. After gelation induced by 0.1 M Na₂SO₄ solution, the binder gel TPDA-S... 0.1 At the same scale, the porous three-dimensional network structure is more compact and has smaller pore size, indicating that the injectable adhesive provided in this application has salt-responsive gel structure changes, realizing significant shrinkage of the internal network structure of the gel under Hofmeister effect salt response.

[0187] 2.2 Rheological Characterization

[0188] This application relates to the adhesive gel TPDA-S n and TPQ-S nThe rheological properties of the samples (n=0.01, 0.1, 1) were characterized. Specifically, the changes in storage modulus (G') and loss modulus (G'') during gel formation were measured using a rotational rheometer. The results are as follows: Figure 11 As shown.

[0189] according to Figure 11 It can be seen that in Na2SO4 solutions of different concentrations, even at 0.01 M, both the composite sol TPDA and TPQ systems exhibit salt responsiveness, and the binder gel TPDA-S n and TPQ-S n All showed a positive correlation between the improvement in salt-responsive performance and the increase in salt solution concentration, indicating the universality of the composite system of polyquaternary ammonium salt polymers and tannic acid in the injectable adhesive provided in this application for the Hoffmann effect.

[0190] 2.3 Overlap Shear Strength Test

[0191] Immerse the glass slide in water at room temperature to prepare it as a substrate;

[0192] The composite sols TPDA and TPQ were injected onto various glass substrates to form adhesion zones. These adhesion zones were then covered with another glass slide and immersed in a 0.1 M Na₂SO₄ solution for 24 hours to obtain the adhesive gel TPDA-S. 0.1 and TPQ-S 0.1 Adhesive glass samples were tested using a texture analyzer for tensile strength. The adhesion performance was evaluated by lap shear strength testing. The results were as follows: Figure 12 As shown.

[0193] according to Figure 12 It can be seen that the composite sols TPDA and TPQ are similar to the composite sol TQ98, both exhibiting good underwater adhesion enhancement effects. This indicates that the composite system of quaternary ammonium salt polymers and tannic acid has universal applicability in effectively enhancing underwater adhesion strength through the salt response of the Hofmeister effect.

[0194] The various embodiments in this application are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0195] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A low-salt-responsive adhesive composition, characterized in that, The composite sol is mainly obtained by dispersing the following precursor components in deionized water, wherein the precursor components include: ( Polyphenolic compounds; and ( Quaternary ammonium salt polymers capable of forming multi-point ionic-hydrogen bond functional groups with polyphenol compounds, wherein the molecular weight of the quaternary ammonium salt polymers is 50kDa to 500kDa; The composite sol can be stimulated by Hofmeister ion salts to trigger a sol-gel phase transition.

2. The adhesive composition according to claim 1, characterized in that, The polyphenolic compound is selected from at least one of tannic acid, caffeic acid, or chlorogenic acid; The quaternary ammonium salt polymer is selected from at least one of quaternized chitosan, polydiallyldimethylammonium chloride, polyquaternium salt-2, polyquaternium salt-4, polyquaternium salt-6, or polyquaternium salt-10.

3. The adhesive composition according to claim 2, characterized in that, The degree of quaternization substitution of the quaternized chitosan is 40-98%.

4. The adhesive composition according to claim 1, characterized in that, The mass ratio of the quaternary ammonium salt polymer to the polyphenol compound is 1~6:

6.

5. An injectable adhesive, characterized in that, Include: (a) Aqueous solution of Hofmeister ion salt; and (b) The low-salt responsive adhesive composition according to any one of claims 1 to 4; The Hofmeister ionic salt aqueous solution and the low-salt-responsive adhesive composition are packaged separately from each other.

6. The injectable adhesive according to claim 5, characterized in that, The Hofmeister ionic salt is selected from at least one of Na2SO4, Na2HPO4, NaOAc, NaCl, NaBr, and NaI.

7. The injectable adhesive according to claim 6, characterized in that, The concentration of the Hofmeister ion salt aqueous solution is from 0.01M to saturation concentration.

8. A method for preparing the injectable adhesive according to any one of claims 5 to 7, characterized in that, Includes the following steps: Provide Hofmeister ionized aqueous salt solution; and After dissolving quaternary ammonium salt polymers in deionized water to form a solution, polyphenol compounds are added and dispersed to form a low-salt-responsive adhesive composition. The Hofmeister ionic salt aqueous solution and the low-salt-responsive adhesive composition are packaged separately from each other.

9. The application of the low-salt responsive adhesive composition of any one of claims 1 to 4 or the injectable adhesive of any one of claims 5 to 7 in the bonding treatment of surfaces to be bonded.

10. The application according to claim 9, characterized in that, When performing the bonding treatment on the contact surfaces to be bonded, the low-salt-responsive adhesive composition is uniformly applied to the contact surfaces to be bonded, then Hofmeister ionized aqueous salt solution is applied to trigger the bonding, and the mixture is allowed to stand.

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