A supramolecular eutectic gel and its preparation method and application

Abstract

The present invention provides a supramolecular eutectic gel and a preparation method and application thereof, which relate to the fields of material science and biomedical technology. The supramolecular eutectic gel is formed by polymerization of N,N-dimethylacrylamide and citric acid-betaine deep eutectic solvent. The preparation method of the supramolecular eutectic gel comprises the following steps: mixing citric acid-betaine deep eutectic solvent and N,N-dimethylacrylamide to obtain a supramolecular eutectic gel precursor solution, irradiating with ultraviolet light, and performing a polymerization reaction to obtain the supramolecular eutectic gel. The supramolecular eutectic gel of the present invention has good electrical conductivity, excellent mechanical stability, super strong underwater adhesion performance and adhesion performance under extreme conditions, and has the potential to adapt to tissue adhesion and biosensing for a long time.

Description

Technical Field

[0001] The present invention relates to the fields of material science and biomedicine, and in particular to a supramolecular eutectic gel and a preparation method and application thereof. Background Art

[0002] In recent years, with the continuous development of green chemistry, the development of synthetic systems for environmentally friendly materials has become increasingly important. For example, cellulose-based materials are modified using green solvents, enzymes are used as green catalysts for material synthesis, or reusable photocatalysts are used to synthesize inorganic materials. Among these technologies, the research progress of natural deep eutectic solvents (DES) in the field of green chemistry is quite significant. Natural deep eutectic solvents (DES) are derived from natural biological molecules such as amino acids, sugars, and organic acids. Compared with traditional organic solvents, it has the advantages of biodegradability and low toxicity, and is regarded as a green solvent. At present, the research on DES in the field of green chemistry mainly includes: the synthesis and preparation methods are diverse and continuously optimized; in terms of chemical reactions, it can be applied to catalytic reactions, electrochemical processes, etc.; there are also innovations in the fields of separation and purification, such as liquid-liquid extraction and gas absorption. Therefore, the application of deep eutectic solvent systems in material synthesis and chemical processes has broad prospects.

[0003] Supramolecular eutectic gel is a gel system prepared with DES as solvent, which retains the main characteristics of DES (except fluidity) and can also show the excellent mechanical properties of solid. According to the current research progress, supramolecular eutectic gel can be roughly divided into three types: (1) supramolecular eutectic gel with DES as solvent only; (2) polymer supramolecular eutectic gel with DES and polymer monomers; (3) supramolecular eutectic gel with DES as solvent. Characteristics of supramolecular eutectic gel with DES as solvent only: This type of supramolecular eutectic gel has DES as the only solvent component.

[0004] Betaine, citric acid and DMAA show many advantages in their respective derivative applications and play an important role in different independent fields:

[0005] Betaine is an alkaloid widely found in plants and animals. At present, betaine-derived DES has been successfully used in the field of extraction of natural compounds, and its applicability in other fields is also being explored, which highlights the potential of betaine-derived DES as a new type of alternative solvent. For example, Pedro et al. prepared a switchable adhesive film by incorporating curcumin-loaded betaine-based deep eutectic solvent (DES) into pullulan film for photodynamic therapy of drug-resistant skin infections.

[0006] Citric acid is a natural organic acid that is widely found in plant fruits (such as lemons, citrus fruits, etc.). At present, materials or formulations derived from citric acid have been successfully used in many fields, including food preservation (made into preservatives to inhibit microbial growth and extend shelf life), medicine (preparation of drug excipients for stability and sustained release), development of supramolecular solvents (DES or ionic liquids), etc., and its applicability in other fields is constantly being explored. For example, Lai et al. used cotton stalks as raw materials and choline chloride-citrate DES as solvent to successfully prepare solvent thermal carbon (STC) with high uranium (VI) adsorption performance through thermal carbonization.

[0007] N,N-dimethylacrylamide (DMAA) is an important organic compound. It can be obtained by chemical synthesis and occupies an important position in the field of chemical raw materials. At present, polymers derived from DMAA have been successfully used in many fields, including in the field of polymer materials for the synthesis of polymers with special properties (such as enhancing coating adhesion and water resistance), in the field of biomedicine for tissue engineering (providing a microenvironment for cell growth) and drug delivery (targeted transport of drugs), and continue to explore other fields of application, highlighting its multifunctional potential.

[0008] In view of this, the present invention is proposed. Summary of the invention

[0009] The object of the present invention is to provide a supramolecular eutectic gel and its preparation method and application. The supramolecular eutectic gel of the present invention has good electrical conductivity, excellent mechanical stability and super strong underwater adhesion performance and adhesion performance under extreme conditions, and has the potential to adapt to tissue adhesion and biosensing for a long time.

[0010] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0011] In a first aspect, the present invention provides a supramolecular eutectic gel, wherein the supramolecular eutectic gel is formed by polymerization of N,N-dimethylacrylamide and a citric acid-betaine deep eutectic solvent.

[0012] Preferably, the mass ratio of the N,N-dimethylacrylamide to the citric acid-betaine deep eutectic solvent is (1-9):(9-1), preferably (1-3):(9-7), and more preferably 3:7.

[0013] Preferably, the structural formula of the citric acid-betaine deep eutectic solvent is as shown in Formula I below:

[0014]

[0015] Among them, -O and -OH are connected by hydrogen bonds.

[0016] In a second aspect, the present invention provides a method for preparing the supramolecular eutectic gel as described in the first aspect, the preparation method comprising the following steps:

[0017] The citric acid-betaine deep eutectic solvent and N,N-dimethylacrylamide are mixed to obtain a supramolecular eutectic gel precursor solution, which is irradiated with ultraviolet light to perform a polymerization reaction to obtain the supramolecular eutectic gel.

[0018] Preferably, the supramolecular eutectic gel precursor solution also includes a photoinitiator.

[0019] Preferably, the photoinitiator is selected from 1-hydroxycyclohexyl phenone.

[0020] Preferably, the added amount of the photoinitiator accounts for 0.5-5% of the total mass of the supramolecular eutectic gel precursor solution.

[0021] Preferably, the mixing temperature is 70-80°C.

[0022] Preferably, the power of the ultraviolet light is 35-45 W, and the wavelength of the ultraviolet light is 360-370 nm.

[0023] Preferably, the ultraviolet light irradiation time is 5 to 60 seconds.

[0024] Preferably, the citric acid-betaine deep eutectic solvent is prepared by the following steps:

[0025] Betaine, citric acid and water are mixed to obtain a mixed solution; the mixed solution is concentrated under reduced pressure and then dried to obtain the citric acid-betaine deep eutectic solvent.

[0026] Preferably, the molar ratio of betaine to citric acid is 1:(0.6-2.3).

[0027] Preferably, the amount of water added accounts for 60-90% of the total mass of the mixed solution.

[0028] Preferably, the temperature of the reduced pressure concentration is 50-70°C.

[0029] Preferably, the drying is vacuum drying, the vacuum drying temperature is 45 to 55° C., and the vacuum drying time is 36 to 60 hours.

[0030] In a third aspect, the present invention provides a use of the supramolecular eutectic gel as described in the first aspect in preparing a sealable biological tissue adhesive.

[0031] With respect to the prior art, the present invention has the following beneficial effects:

[0032] (1) The supramolecular eutectic gel of the present invention is synthesized by using citric acid-betaine deep eutectic solvent and N,N-dimethylacrylamide (DMAA), which not only has good conductivity, excellent mechanical stability and super strong underwater adhesion performance and adhesion performance under extreme conditions, but also has the potential to adapt to tissue adhesion and biosensing for a long time.

[0033] (2) The supramolecular eutectic gel of the present invention can be used as a sealing adhesive for biological tissues, and it is found that its adhesion performance is regulated by the interaction energy between the supramolecular eutectic gel and the interface and the thermodynamic properties of the supramolecular eutectic gel itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 This is a diagram of the preparation process of the citric acid-betaine deep eutectic solvent provided in Example 1 and a diagram of the appearance of DES.

[0036] Figure 2 This is a rheological curve of shear rate / shear viscosity of the citric acid-betaine deep eutectic solvent provided in Example 1.

[0037] Figure 3 This is a rheological curve of shear rate / shear stress of the citric acid-betaine deep eutectic solvent provided in Example 1.

[0038] Figure 4 Infrared spectra of citric acid (CA), betaine (BE) and the citric acid-betaine deep eutectic solvent provided in Example 1.

[0039] Figure 5 This is the DSC spectrum of the citric acid-betaine deep eutectic solvent provided in Example 1.

[0040] Figure 6 The diagram shows the preparation process of the supramolecular eutectic gel provided in Examples 2 to 10 and the appearance morphology of DMAA-DES.

[0041] Figure 7 This is a graph showing the variation of G' and G" of the supramolecular eutectic gels provided in Examples 2 to 10 in the frequency range of 0.1 to 10 Hz.

[0042] Figure 8This is a graph showing the variation of G' and G" of the supramolecular eutectic gels provided in Examples 2 to 10 within the strain (γ) range of 0.01 to 10%.

[0043] Fig. 9 This is a graph showing the change in G' and G" of the supramolecular eutectic gel provided in Examples 2 to 10 in the temperature range of 5 to 50°C.

[0044] Fig.10 Actual picture of the compression test process of the supramolecular eutectic gel provided in Examples 2 to 4.

[0045] Fig.11 Compression cycle detection diagram of the supramolecular eutectic gel provided in Examples 2 to 4.

[0046] Fig.12 This is a stress-strain curve diagram of the supramolecular eutectic gel provided in Examples 2 to 4.

[0047] Fig.13 Young's modulus diagram of the supramolecular eutectic gel provided for Examples 2 to 4 in the strain range of 10 to 20%.

[0048] Fig.14 This is the SEM image of the supramolecular eutectic gel provided in Example 2.

[0049] Fig.15 This is the SEM image of the supramolecular eutectic gel provided in Example 3.

[0050] Fig.16 This is the SEM image of the supramolecular eutectic gel provided in Example 4.

[0051] Fig.17 This is the ultra-depth-of-field map of the supramolecular eutectic gel provided in Example 2.

[0052] Fig.18 This is the ultra-depth-of-field map of the supramolecular eutectic gel provided in Example 3.

[0053] Fig.19 This is the ultra-depth-of-field map of the supramolecular eutectic gel provided in Example 4.

[0054] Fig. 20 This is the wide-angle XRD pattern of the supramolecular eutectic gel provided in Examples 2 to 4.

[0055] Fig.21 This is the small-angle XRD pattern of the supramolecular eutectic gel provided in Examples 2 to 4.

[0056] Fig. 22 This is the DSC analysis spectrum of the supramolecular eutectic gel provided in Examples 2 to 4.

[0057] Fig.23This is the infrared spectra of the supramolecular eutectic gel provided in Examples 2 to 4 before and after formation.

[0058] Fig.24 This is a graph showing the self-healing performance and injectability of the supramolecular eutectic gel provided in Examples 2 to 4.

[0059] Fig.25 These are the electrical conductivity and conductivity test diagrams of the supramolecular eutectic gels provided in Examples 2 to 4.

[0060] Fig.26 This is a sensor sensitivity test diagram of the supramolecular eutectic gel provided in Examples 2 to 4.

[0061] Fig. 27 This is a graph showing the adhesion test of the supramolecular eutectic gel provided in Examples 2 to 10 on the glass surface.

[0062] Fig.28 These are graphs showing the adhesion test of the supramolecular eutectic gels provided in Examples 2 to 10 on various tissue surfaces.

[0063] Fig.29 This is a graph showing the lap strength test of the supramolecular eutectic gel provided in Examples 2 to 4.

[0064] Fig.30 Schematic diagram of underwater adhesion of the supramolecular eutectic gel provided in Example 4.

[0065] Fig.31 This is a graph showing the adhesion test of the supramolecular eutectic gel under extreme conditions provided in Example 4. DETAILED DESCRIPTION

[0066] Unless otherwise defined herein, scientific and technological terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0067] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0068] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] In a first aspect, the present invention provides a supramolecular eutectic gel, wherein the supramolecular eutectic gel is formed by polymerization of N,N-dimethylacrylamide and a citric acid-betaine deep eutectic solvent.

[0070] The present invention uses citric acid-betaine deep eutectic solvent and N,N-dimethylacrylamide (DMAA) to synthesize supramolecular eutectic gel, and characterizes its relevant physical and chemical properties. At the same time, experiments such as adhesion, conductivity, fatigue resistance and self-healing are used to explore the influence mechanism of the proportion of DES on the relevant properties of supramolecular eutectic gel. The prepared supramolecular eutectic gel has good conductivity, mechanical stability, super strong underwater adhesion and adhesion under extreme conditions, and has the potential to adapt to tissue adhesion and biosensing for a long time.

[0071] As an optional embodiment, the mass ratio of N,N-dimethylacrylamide and citric acid-betaine deep eutectic solvent is (1-9):(9-1), for example, it can be 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, 9:1, etc., preferably (1-3):(9-7), and more preferably 3:7.

[0072] As an optional embodiment, the structural formula of the citric acid-betaine deep eutectic solvent is shown in Formula I below:

[0073]

[0074] Among them, -O and -OH are connected by hydrogen bonds.

[0075] In a second aspect, the present invention provides a method for preparing the supramolecular eutectic gel as described in the first aspect, the preparation method comprising the following steps:

[0076] The citric acid-betaine deep eutectic solvent and N,N-dimethylacrylamide are mixed to obtain a supramolecular eutectic gel precursor solution, which is irradiated with ultraviolet light to perform a polymerization reaction to obtain the supramolecular eutectic gel.

[0077] As an optional implementation, the supramolecular eutectic gel precursor solution also includes a photoinitiator.

[0078] As an optional embodiment, the photoinitiator is selected from 1-hydroxycyclohexyl phenyl ketone (HCPK).

[0079] As an optional embodiment, the added amount of the photoinitiator accounts for 0.5-5% of the total mass of the supramolecular eutectic gel precursor solution, for example, it can be 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0080] As an optional embodiment, the mixing temperature is 70-80°C, for example, it can be 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, etc.

[0081] As an optional implementation, the power of the ultraviolet light is 35-45 W, for example, it can be 35 W, 36 W, 37 W, 38 W, 39 W, 40 W, 41 W, 42 W, 43 W, 44 W, 45 W, etc.

[0082] As an optional embodiment, the wavelength of the ultraviolet light is 360-370 nm, for example, it can be 360 ​​nm, 361 nm, 362 nm, 363 nm, 364 nm, 365 nm, 366 nm, 367 nm, 368 nm, 369 nm, 370 nm, etc.

[0083] As an optional embodiment, the ultraviolet light irradiation time is 5 to 60 s, for example, it can be 5 s, 10 s, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s, 55 s, 60 s, etc.

[0084] As an optional embodiment, the citric acid-betaine deep eutectic solvent is prepared by the following steps:

[0085] Betaine, citric acid and water are mixed to obtain a mixed solution; the mixed solution is concentrated under reduced pressure and then dried to obtain the citric acid-betaine deep eutectic solvent.

[0086] The reaction formula for preparing the citric acid-betaine deep eutectic solvent is as follows:

[0087]

[0088] As an optional embodiment, the molar ratio of betaine to citric acid is 1:(0.6-2.3), for example, it can be 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.0, 1:2.1, 1:2.2, 1:2.3, etc.

[0089] As an optional embodiment, the amount of water added accounts for 60-90% of the total mass of the mixed liquid, for example, it can be 60%, 65%, 70%, 75%, 80%, 85%, 90%, etc.

[0090] As an optional embodiment, the temperature of the reduced pressure concentration is 50-70°C, for example, it can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, etc.

[0091] As an optional embodiment, the drying is vacuum drying.

[0092] As an optional embodiment, the vacuum drying temperature is 45-55°C, for example, it can be 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, etc.

[0093] As an optional embodiment, the vacuum drying time is 36 to 60 hours, for example, it can be 36 hours, 38 hours, 40 hours, 42 hours, 44 hours, 46 hours, 48 ​​hours, 50 hours, 52 hours, 54 hours, 56 hours, 58 hours, 60 hours, etc.

[0094] In a third aspect, the present invention provides a use of the supramolecular eutectic gel as described in the first aspect in preparing a sealable biological tissue adhesive.

[0095] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market. The raw materials used in the following examples of the present invention are all commercially available products, all purchased from Aladdin Reagents.

[0096] Betaine (BE), citric acid (CA), N,N-dimethylacrylamide (DMAA) and photoinitiator 1-hydroxycyclohexylphenyl ketone (HCPK) were purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0097] Example 1

[0098] This embodiment provides a citric acid-betaine deep eutectic solvent, and the citric acid-betaine deep eutectic solvent is prepared by the following steps:

[0099] Weigh appropriate amounts of betaine (BE) and citric acid (CA), mix them in a molar ratio of 1:1, add appropriate amount of purified water (the amount of purified water added accounts for 80% of the total mass of the mixed solution), and fully dissolve them into a clear and transparent solution. The solution is vacuum-rotated at 55°C and vacuum-dried at 50°C for 48h to obtain a citric acid-betaine deep eutectic solvent (BE-CA DES), which is collected in a desiccator for later use.

[0100] Figure 1 The preparation process diagram of the citric acid-betaine deep eutectic solvent provided in Example 1 of the present invention and the appearance morphology diagram of DES. Figure 1 As shown, the citric acid-betaine deep eutectic solvent prepared by the present invention appears as a colorless, uniform, transparent liquid.

[0101] Test Example 1

[0102] Characterization of Betaine-Citrate DES - Rheological Testing

[0103] Test sample: the citric acid-betaine deep eutectic solvent (BE-CA DES) provided in Example 1.

[0104] Test method: Kinexus pro+ rotational rheometer (Malvern Instruments Ltd.UK) was used to perform rheological analysis on BE-CADES. The viscosity of DES was first tested using the continuous shear sweep method at a temperature of 25°C and a shear rate of 0.1 to 100 s. -1 , lasting 200s.

[0105] Result analysis:

[0106] Figure 2 This is a rheological curve of shear rate / shear viscosity of the citric acid-betaine deep eutectic solvent provided in Example 1 of the present invention. Figure 3 The rheological curve of shear rate / shear stress of the citric acid-betaine deep eutectic solvent provided in Example 1 of the present invention is shown in FIG. Figure 2 and Figure 3 As shown, through rheological research, it is found that the citric acid-betaine deep eutectic solvent provided by the present invention is a non-Newtonian fluid.

[0107] Test Example 2

[0108] Characterization of Betaine-Citrate DES - Fourier Transform Infrared Spectroscopy Test

[0109] Test sample: the citric acid-betaine deep eutectic solvent (BE-CADES) provided in Example 1.

[0110] Test method: FT-IR was used to study the possible molecular interactions of DES. BE, CA and DES were pressed into thin sheets with KBr respectively and measured by Fourier transform infrared spectrometer at 4000-400 cm -1 Scan within the range, scan 64 times, resolution is 4cm -1 , infrared spectra were recorded using OPUS software and data were analyzed using origin software.

[0111] Result analysis:

[0112] Figure 4 The infrared spectra of citric acid (CA), betaine (BE) and the citric acid-betaine deep eutectic solvent of the present invention are shown in FIG. Figure 4 As shown, the FT-IR spectrum of CA shows 3497 cm -1 , 3291cm -1 and 1703cm -1 , 1754cm -1 The stretching vibration peaks at 2223 cm -1 , 1623cm -1 and 1128cm -1 The stretching vibration peaks at 3497 cm-1 and 3577 cm-2 are attributed to CN, C=O and CO, respectively. Compared with CA and BE, the absorption peaks of BE-CADES have shifted significantly. Specifically, the OH peak on CA in BE-CADES shifted from 3497 cm-1 to 3497 cm-2. -1 , 3291cm -1 Transfer to 3411cm -1 The C=O and CO- peaks on BE in BE-CADES are from 1623 cm -1 and 1128cm -1 Transfer to 1605cm -1 and 1185cm -1 .

[0113] Test Example 3

[0114] Characterization of Betaine-Citrate DES-Differential Scanning Calorimetry Test

[0115] Test sample: the citric acid-betaine deep eutectic solvent (BE-CA DES) provided in Example 1.

[0116] Test method: Weigh about 5 mg of DES and place it in an aluminum crucible, and use TA-DSC2500 differential scanning calorimeter for measurement. Use nitrogen as protective gas, first heat the mixture to 100°C at a rate of 10°C / min to remove the trace amount of water remaining in the mixture, then cool it to -80°C at a rate of 10°C / min and keep it constant for 10 minutes, and then continue to heat it to 100°C at a rate of 10°C / min to measure the thermodynamic properties. The temperature at the half height of the DSC curve is defined as the glass transition temperature (Tg).

[0117] Result analysis:

[0118] Figure 5 The DSC curve of BE-CA DES is shown. Figure 5 As shown in the figure, in the first heating process, BE-CA DES did not show a definite melting peak in the range of -80℃~100℃, nor did it show a fixed melting point. Only a single Tg peak (-24.35℃) appeared, and the enthalpy before and after Tg was 0.941J / g·℃. However, in the cooling process, the Tg value (-25.67℃) of BE-CA DES in the range of -80℃~100℃ showed obvious thermal hysteresis, and the enthalpy before and after Tg was 0.698J / g·℃. In the second heating process, the Tg of BE-CA DES in the range of -80℃~100℃ was -23.08℃, which was slightly higher than the first time. This phenomenon may be caused by the evaporation of a small amount of residual water in DES. This phenomenon shows that DES has a high purity and can be used as a green solvent in the pharmaceutical industry and materials science.

[0119] Embodiments 2 to 10

[0120] Examples 2 to 10 provide 9 supramolecular eutectic gels formed by polymerization of N,N-dimethylacrylamide and citric acid-betaine deep eutectic solvents in different mass ratios, and the corresponding proportions are shown in Table 1 below:

[0121] Table 1

[0122]

[0123] The supramolecular eutectic gel is prepared by the following steps:

[0124] As shown in Table 1, different proportions of monomer N,N-dimethylacrylamide (DMAA), photoinitiator 1-hydroxycyclohexylphenyl ketone (HCPK, 1wt%) and supramolecular solvent BE-CADES were dissolved in a water bath at 75°C to form a supramolecular eutectic gel precursor solution, placed in a mold, and irradiated with (40W, 365nm) ultraviolet light (10s).

[0125] Figure 6The figure is a diagram showing the preparation process of the supramolecular eutectic gel of the present invention and the appearance of DMAA-DES. Figure 6 As shown, the supramolecular eutectic gel of the present invention presents a state in which the gel changes from transparent to milky white as the DMAA content increases.

[0126] Test Example 4

[0127] Characterization-Rheological Test of Supramolecular Eutectic Gel DMAA-DES

[0128] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 10.

[0129] Test method: Kinexus pro+ rotational rheometer (Malvern Instruments Ltd.UK) was used to perform oscillation frequency, strain and temperature scanning analysis on DES. The oscillation frequency scanning mode was adopted, with a constant shear strain of 0.1%, a test temperature of 25°C, and a frequency of 0.1-10Hz, to measure the storage modulus (G') and loss modulus (G") at different frequencies. When testing the curves of G' and G" of the supramolecular eutectic gel with strain (γ) at 25°C, the test condition was a frequency of 1Hz. Finally, the relationship between G' and G" and temperature was tested under the conditions of a strain of 0.1%, an operating frequency of 1Hz, and a temperature increase from 0°C to 50°C at a rate of 5°C / min.

[0130] Result analysis:

[0131] Figure 7 The rheological test results of DMAA-DES (1:9~9:1) supramolecular eutectic gel in the range of 0.1~10Hz are shown. The frequency when G” and G’ are equal is the phase transition frequency of supramolecular eutectic gel. Figure 7 As shown, it can be found that the G' of DMAA-DES (8:2 and 9:1) supramolecular eutectic gel in this frequency range is higher than its G". The phase transition frequencies of DMAA-DES (1:9, 2:8, 3:7, 4:6, 5:5, 6:4 and 7:3) supramolecular eutectic gel are 1.47 Hz, 2.15 Hz, 1.47 Hz, 0.68 Hz, 0.14 Hz, 0.22 Hz and 2.15 Hz, respectively.

[0132] Figure 8 The rheological properties of DMAA-DES (1:9-9:1) supramolecular eutectic gel in the strain range of 0.01-10% are shown. The strain when G" is equal to G' is the phase transition stress of supramolecular eutectic gel. Figure 8As shown, it can be found that the G' of DMAA-DES (5:5 and 6:4) supramolecular eutectic gels in the strain range of 0.01 to 10% is less than G", which indicates that the viscous behavior of the gel is more significant than the elastic behavior at these ratios. The G' of DMAA-DES (7:3 and 8:2) supramolecular eutectic gels in the strain range of 0.01 to 10% is greater than G", which indicates that the gel is more inclined to exhibit elastic behavior. The gel phase transition stress of DMAA-DES (1:9, 2:8, 3:7, 4:6 and 9:1) supramolecular eutectic gels are 4.67%, 5.15%, 7.58%, 0.1% and 0.26%, respectively.

[0133] Fig. 9 The sensitivity of DMAA-DES (1:9-9:1) supramolecular eutectic gel to temperature in the temperature range of 0-50℃ is shown. The temperature when G" is equal to G' is the phase transition temperature of the supramolecular eutectic gel. It can be found that the G' of DMAA-DES (8:2 and 9:1) supramolecular eutectic gel in the range of 0-50℃ is higher than its G", which indicates that the supramolecular eutectic gels of these two ratios show good gel properties at this temperature. The G' of DMAA-DES (5:5) supramolecular eutectic gel in the range of 0-50℃ is lower than G", which indicates that the supramolecular eutectic gel at this ratio is more inclined to the liquid state. In addition, the phase transition temperatures of DMAA-DES (1:9, 2:8, 3:7, 4:6, 6:4 and 7:3) supramolecular eutectic gels are 42.5℃, 39℃, 38℃, 47℃, 45℃ and 31℃, respectively.

[0134] Test Example 5

[0135] Compression test of supramolecular eutectic gel DMAA-DES

[0136] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0137] Test method: In the compression test, a cylindrical supramolecular eutectic gel sample with a design diameter of 5 mm and a thickness of 2 mm was used, and the loading rate was 2 mm / min. The compressive stress was obtained from the stress-strain curve, and the compression modulus in the range of 10-20% was calculated to estimate the mechanical properties of the supramolecular eutectic gel. All tests were repeated 3 times (such as Fig.10 shown).

[0138] Result analysis:

[0139] The compression cycle test reflects the fatigue resistance of supramolecular eutectic gel. The compression strain is set to 40% of the maximum compression strain of each sample for testing. The results are shown in Fig.11 (***P<0.005). Fig.11As shown in the figure, in the initial stage of compression, the compressive strength of the supramolecular eutectic gel gradually decreases slightly. This is because the molecular chains of the supramolecular eutectic gel cannot recover in time after multiple continuous compression-unloading, and plastic deformation occurs, which reduces the compressive strength. However, after about 10 cycles of compression, the curves basically overlap, and the sample can still maintain more than 90% of the initial maximum stress, which should be related to the intermolecular interaction within the supramolecular eutectic gel. This phenomenon shows that the supramolecular eutectic gel of the present invention has good elastic recovery ability and can be used repeatedly.

[0140] Fig.12 The stress-strain curve of supramolecular eutectic gel is shown. Fig.12 As shown, it can be found that within the range of 80% of the compressive strain, the supramolecular eutectic gel of the present invention has no obvious brittle collapse, indicating that plastic deformation mainly occurs. In addition, during the entire compressive strain process, the compressive stress of the supramolecular eutectic gel increases significantly with the decrease of the DES ratio.

[0141] Fig.13 The Young's modulus of the supramolecular eutectic gel provided in Examples 2 to 4 in the strain range of 10 to 20% is shown. Fig.13 As shown, the Young's moduli of DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gels are 20.31 kPa, 51.75 kPa and 315.41 kPa, respectively.

[0142] In summary, the supramolecular eutectic gel (the mass ratio of DMAA and DES is 3:7) provided in Example 4 has good potential as a wound dressing material due to its characteristics in mechanical properties such as compression cycle performance, stress-strain characteristics and Young's modulus.

[0143] Test Example 6

[0144] Scanning electron microscopy test of supramolecular eutectic gel DMAA-DES

[0145] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0146] Test Methods: The morphology of supramolecular eutectic gel samples was characterized using field emission scanning electron microscopy. All samples used for SEM were coated with a very thin layer of gold using sputtering.

[0147] Result analysis:

[0148] Figure 14 to Figure 16 The morphology of the supramolecular eutectic gels provided in Examples 2 to 4 is shown. It can be found that irregular protrusion structures exist on the surfaces of the three supramolecular eutectic gels. Specifically, Fig.15 and Fig.16 As shown in the figure, both DMAA-DES (3:7) and DMAA-DES (2:8) supramolecular eutectic gels present a morphology similar to an "island" structure, in which the DES phase is the "sea", the surface protrusions formed are the "islands", and DMAA is wrapped on the DES surface in a thin film. However, compared with the DMAA-DES (2:8) supramolecular eutectic gel, the thin film DMAA on the surface of the DMAA-DES (3:7) supramolecular eutectic gel is more complete, with only a few cracks. In addition, as Fig.14 As shown in the figure, as the ratio of DMAA further decreases, only a small amount of film-like DMAA exists on the surface of the DMAA-DES (1:9) supramolecular eutectic gel, and the surface of the gel mainly presents a fibrous drawing shape.

[0149] Test Example 7

[0150] Ultra-depth-of-field microscopy test of supramolecular eutectic gel DMAA-DES

[0151] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0152] Test method: Use an ultra-depth-of-field microscope to observe the surface structure of supramolecular eutectic gel. Place the sample on the stage, adjust the microscope to dark field observation mode, adjust the focal length so that the surface structure can be clearly imaged, and use Z-Stack layer scanning technology to photograph the surface morphology of supramolecular eutectic gel.

[0153] Result analysis:

[0154] Figure 17 to Figure 19 The super depth images of the supramolecular eutectic gels provided in Examples 2 to 4 are shown, and it can be found that the surfaces of the three supramolecular eutectic gels are all irregular protrusion structures, which is similar to the SEM results. Specifically, Fig.18 and Fig.19 As shown in Figure 2, there are a large number of DES protrusions wrapped in thin films on the surface of DMAA-DES (2:8) and DMAA-DES (3:7) supramolecular eutectic gels. Fig.17 As shown, there are only a small amount of film-like DMAA-wrapped DES protrusions on the surface of the DMAA-DES (1:9) supramolecular eutectic gel, and at this ratio it can be observed that a small amount of DES is not wrapped by DMAA and still exists in a liquid state.

[0155] Test Case 8

[0156] X-ray diffraction test of supramolecular eutectic gel DMAA-DES

[0157] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0158] Test method: Wide-angle XRD and small-angle XRD were used to analyze the structure of the supramolecular eutectic gel provided in Examples 2 to 4. The supramolecular eutectic gel was measured at room temperature using a SmartLab SE X-ray diffractometer, with a 2θ angle rotation range of 5° to 60°, a scanning speed of 10° / min, and a step length of 0.02. The data were analyzed using Origin8.0 software.

[0159] Result analysis:

[0160] like Fig. 20 As shown, the supramolecular eutectic gels provided in Examples 2 to 4 do not show obvious crystalline diffraction peaks in the range of 5° to 60°, and only a large diffraction ring appears, which indicates that the supramolecular eutectic gels are amorphous and no crystals are precipitated.

[0161] like Fig.21 As shown, by studying the structural characteristics of the supramolecular eutectic gel at the nanoscale through small-angle XRD, no obvious crystal diffraction peaks were found in the supramolecular eutectic gel provided by Examples 2 to 4 in the range of 0.6 to 5°, indicating that the internal structure of the supramolecular eutectic gel remains relatively stable, and there is no crystal formation or structural transformation, further indicating that the supramolecular eutectic gel has good stability.

[0162] Test Example 9

[0163] Differential Scanning Calorimetry Test of Supramolecular Cocrystal Gel DMAA-DES

[0164] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0165] Test method: DSC was used to analyze the thermodynamic properties of the supramolecular eutectic gels provided in Examples 2 to 4. About 5 mg of supramolecular eutectic gel was weighed and placed in an aluminum crucible, and measured using a TA-DSC2500 differential scanning calorimeter. Nitrogen was used as the protective gas, and the temperature was raised from -80°C to 120°C at a rate of 10°C / min. The temperature at the half-height of the DSC curve was defined as the glass transition temperature (Tg).

[0166] Result analysis:

[0167] like Fig. 22As shown in the figure, the glass transition temperatures (Tg) of DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gels are -22.54°C, -24.61°C and -25.84°C, respectively. The thermal tolerances of DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gels before and after the Tg changes are 0.551 J / g·°C, 0.559 J / g·°C and 0.558 J / g·°C, respectively. At the same time, in the range of -80 to 100°C, the supramolecular eutectic gels do not have a definite melting point.

[0168] Test Example 10

[0169] Fourier Transform Infrared Spectroscopy Analysis and Test of Supramolecular Eutectic Gel DMAA-DES

[0170] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0171] Test method: FT-IR was used to study the molecular interactions before and after the formation of the supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4. The supramolecular eutectic gel solution before illumination and the supramolecular eutectic gel after illumination were pressed into thin slices with KBr, and the Fourier transform infrared spectrometer was used to measure the molecular interactions at 4000-400 cm -1 Scan within the range, scan 64 times, resolution is 4cm -1 , IR spectra were recorded using OPUS software, and data were analyzed using origin8.0 software.

[0172] Result analysis:

[0173] like Fig.23 As shown in Figure 2, the FT-IR of DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gels before and after formation undergoes significant changes. Specifically, the OH peaks on CA in the DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gels change from 3402, 3402 and 3401 cm -1 Transfer to 3433, 3436 and 3433cm -1 The C=O peaks on BE are at 1608, 1608 and 1608 cm -1 Shift to 1600, 1600 and 1601cm -1 The CO peaks on BE are from 1193, 1193 and 1193 cm -1 Transfer to 1185, 1185 and 1186cm -1 .

[0174] Test Example 11

[0175] Fourier Transform Infrared Spectroscopy Analysis and Test of Supramolecular Eutectic Gel DMAA-DES

[0176] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0177] Test method: The self-healing properties of supramolecular eutectic gel were further evaluated by macroscopic self-healing test. Specifically, the hydrogel was cut into two halves with a blade and immediately brought into contact without external force to observe the self-healing process of the hydrogel.

[0178] Result analysis:

[0179] like Fig.24 As shown, the DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gels were cut with a blade. Without applying external force, the supramolecular eutectic gels of the three ratios could achieve self-healing after 30min, 20min and 15min, respectively. And after self-healing, the cracks of the supramolecular eutectic gels gradually disappeared. In addition, the injectability of the supramolecular eutectic gel was tested: the supramolecular eutectic gel on the culture dish was sucked into the syringe for injectability investigation. Among them, the DMAA-DES (2:8 and 3:7) supramolecular eutectic gels could not be sucked into the syringe, indicating that the supramolecular eutectic gels of the two ratios were not injectable. The DMAA-DES (1:9) supramolecular eutectic gel could be re-injected from the syringe, indicating that the supramolecular eutectic gel at this ratio was injectable.

[0180] Test Example 12

[0181] Conductivity Test of Supramolecular Eutectic Gel DMAA-DES

[0182] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0183] Test method: Use LED bulb circuit to test the conductivity of supramolecular eutectic gel. In short, after connecting supramolecular eutectic gel to LED bulb circuit, observe the state of LED bulb. If LED bulb lights up, it means supramolecular eutectic gel has certain conductivity and can make the circuit conductive; if LED bulb does not light up, it may mean that the conductivity of supramolecular eutectic gel is poor. Use multimeter to detect the conductivity of supramolecular eutectic gel. First, use vernier caliper to accurately measure the height L of supramolecular eutectic gel, then fit the positive and negative ends tightly to the upper and lower surfaces of supramolecular eutectic gel and fix them with tape. Then, through linear voltammetric cycle test, measure the change curve between current and potential, and then obtain Rp through curve fitting analysis. Finally, calculate its conductivity by the following formula: σ=1 / ρ=L / Rp.

[0184] Result analysis:

[0185] like Fig.25 As shown, the LED light connected by the supramolecular eutectic gel is on. After the hydrogel is cut into two halves, the LED light goes out. After the cut hydrogels are reconnected, the LED light immediately lights up again. The conductivity of the supramolecular eutectic gels of DMAA-DES (1:9, 2:8 and 3:7) is 1.85×10 -4 S / cm, 1.37×10 -4 S / cm and 0.51×10 -4 S / cm.

[0186] Test Example 13

[0187] Strain Sensing Test of Supramolecular Eutectic Gel DMAA-DES

[0188] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Example 4.

[0189] Test method: The prepared supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4 was cut into a rectangular supramolecular eutectic gel with a length of 3 cm, a width of 1 cm, and a thickness of 5 mm. The surface was attached to the second joint of the index finger and fixed to the joint with surgical tape. The two ends of the supramolecular eutectic gel were connected to the wire and connected to the box for detecting the incoming signal. The index finger joint was slowly flexed and extended, and the index finger joint was flexed 90°. Then the index finger was slowly straightened. At this time, the electrical signal can be collected through the box and the curve of its resistance (R) changing with time (S) can be observed. The sensitivity level of the supramolecular eutectic gel used as a sensor is reflected by calculating the resistance change rate.

[0190] Result analysis:

[0191] like Fig.26As shown, (a) represents the bending of fingers at different angles; (b) represents the bending of fingers attached to the wrist at different angles; (c) represents the bending of wrist joints at different angles; (d) represents the signal monitoring of knee bending at different angles. Since the supramolecular eutectic gel has good electrical conductivity, it indicates that it may be used as a highly potential material in a variety of electronic devices or biomedical detection fields. Through the demonstration of monitoring human motion (joint bending), the DMAA-DES (3:7) supramolecular eutectic gel was installed in different parts of the volunteer's body (proximal interphalangeal joint of the index finger, wrist joint, elbow joint, and thyroid cartilage of the knee joint), and the relative resistance change value (△R / Ro) of the supramolecular eutectic gel as a sensor during mechanical stimulation of motion was recorded in real time. The results show that the DMAA-DES (3:7) supramolecular eutectic gel can detect stretching and bending at different angles. During the periodic stretching / bending process, a stable and repetitive response can be observed. Therefore, this study shows that the supramolecular eutectic gel has excellent electrical conductivity and sensitivity, and its application potential in the field of biosensors has been verified through human motion monitoring experiments.

[0192] Test Case 14

[0193] Tissue Adhesion Test of Supramolecular Cocrystal Gel DMAA-DES

[0194] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 10.

[0195] Test method: The adhesion of supramolecular eutectic gel on glass was used to preliminarily evaluate the adhesion performance of supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 10. The adhesion performance of supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 10 on various substrate surfaces (pig skin, pig bone, pig heart, pig liver and pork) was tested. In short, the supramolecular eutectic gel sample was evenly spread on a glass slide, and these substrates were placed on the glass slide. The adhesion performance of the gel was judged by observing whether the sample fell off using the inversion method.

[0196] Result analysis:

[0197] like Fig. 27As shown in the figure, DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gel can stably adhere to the glass surface. This indicates that DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gel has the potential to become an adhesive. However, DMAA-DES (4:6, 5:5, 6:4, 7:3, 8:2 and 9:1) supramolecular eutectic gel cannot be effectively adhered to the glass surface, indicating that the surface adhesion of supramolecular eutectic gels with these ratios is poor and it is difficult to use them as adhesives. Therefore, we further studied the adhesion properties of DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gel. As Fig.28 As shown in the figure, the adhesion of DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gel on various tissue surfaces. It can be found that the supramolecular eutectic gels with these three ratios have good adhesion to pig skin, pig bones, pig hearts, pork and pig liver.

[0198] Test Example 15

[0199] Overlap Adhesion Test of Supramolecular Eutectic Gel DMAA-DES

[0200] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Examples 2 to 4.

[0201] Test method: In order to compare the adhesion strength of the supramolecular eutectic gel, the lap shear adhesion test was used to determine the adhesion strength of the co-gel. On a tensile testing machine, the adhesion performance of the supramolecular eutectic gel on the surface of the glass substrate was tested at a loading rate of 10 mm / min. In short, the supramolecular eutectic gel (DMAA-DES) samples provided in Examples 2 to 4 were evenly spread on the glass surface, extruded for 3 minutes under a fixed normal load of 100 N, and then subjected to a lap shear adhesion test. The adhesion strength (Adhesion strength, T) of the supramolecular eutectic gel is the peak force (kPa) per unit area of ​​the sample during the lap adhesion test: T = F / A0; where F is the peak force applied to the sample, and A0 is the sample area, in mm 2 , each group of tests was repeated three times.

[0202] Result analysis:

[0203] like Fig.29 As shown, the binding strengths of DMAA-DES (1:9, 2:8 and 3:7) supramolecular eutectic gels are 24.3 kPa, 102 kPa and 158 kPa, respectively.

[0204] Test Case 16

[0205] Underwater Adhesion Test of Supramolecular Eutectic Gel DMAA-DES

[0206] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Example 4.

[0207] Test method: Test the adhesion performance of supramolecular eutectic gel under water. Use a glass slide to conduct an underwater adhesion test on a vial filled with water. In short, the adhesion performance of supramolecular eutectic gel to glass in different environments (water, HCl (pH = 2), KOH (pH = 10), PBS solution and saturated NaCl solution).

[0208] Result analysis:

[0209] Fig.30 Schematic diagram showing the adhesion of DMAA-DES (3:7) supramolecular eutectic gel under water. (a) represents a contact area of ​​≈4 cm for 10 mg 2 The in-plane load supported by the DMAA-DES (3:7) supramolecular eutectic gel after adhesion to the glass slide is >400g; (b) represents the adhesion study of the DMAA-DES (3:7) supramolecular eutectic gel to different materials underwater; (c) represents the underwater adhesion and leak repair study of the DMAA-DES (3:7) supramolecular eutectic gel; (d) represents the adhesion performance study of the DMAA-DES (3:7) supramolecular eutectic gel in different solvent environments.

[0210] like Fig.30 As shown in the figure, the underwater adhesion study of DMAA-DES (3:7) supramolecular eutectic gel shows that supramolecular eutectic gel has good underwater adhesion to various types of materials, including rubber, plastic, metal, wood, and glass. The adhesion study of supramolecular eutectic gel in different environments (water, HCl (pH = 2), NaOH (pH = 10), PBS solution, and saturated NaCl solution) shows that supramolecular eutectic gel can maintain good underwater adhesion in different environmental solution environments. Its oscillation experiment in different solution environments also proves this conclusion.

[0211] In order to further investigate the underwater adhesion performance of DMAA-DES (3:7) supramolecular eutectic gel, underwater leak sealing, underwater vibration and water flow impact experiments were carried out for further research. The underwater leak sealing experiment showed that the supramolecular eutectic gel can seal leaking plastic bottles and effectively seal the leakage of plastic bottles. It has ideal underwater instant adhesion and underwater in-situ leak plugging effects. The underwater vibration study showed that the supramolecular eutectic gel can still maintain good underwater adhesion to the glass after being violently shaken on the glass for 50 seconds. The water flow impact experiment showed that the supramolecular eutectic gel can still maintain good adhesion to the glass after being subjected to a high-intensity water flow impact on the glass for 120 seconds.

[0212] Test Case 17

[0213] Extreme Adhesion Test of Supramolecular Eutectic Gel DMAA-DES

[0214] Test sample: supramolecular eutectic gel (DMAA-DES) provided in Example 4.

[0215] Test method: As a material with broad application prospects, the adhesion performance of eutectic gel under different environmental conditions is crucial to its practical application. To this end, this section tests the adhesion performance of eutectic gel under extreme conditions. Test the adhesion performance of supramolecular eutectic gel under extreme conditions. In short, the adhesion performance of supramolecular eutectic gel in air at different temperature environments (-80℃, -20℃, 4℃, 25℃, 40℃, 60℃, 80℃, 100℃, 105℃ and 110℃). Secondly, the adhesion performance of supramolecular eutectic gel in water at different temperature environments (4℃, 25℃, 40℃, 60℃, 80℃ and 100℃) is investigated. The adhesion test of weights at different temperatures is carried out using supramolecular eutectic gel.

[0216] Result analysis:

[0217] Fig.31 Figure 2 shows the adhesion test of supramolecular eutectic gel under extreme conditions. (a) represents the adhesion test of supramolecular eutectic gel at 4-100℃; (b) represents the adhesion test of supramolecular eutectic gel under extreme conditions of -20℃, -80℃, 105℃ and 110℃; (c) represents the result of thermogravimetric analysis; (d) represents the result of XRD.

[0218] like Fig.31 As shown in the figure, it can be found that in the air, the eutectic gel has good adhesion performance in the temperature range of -20℃~105℃, and the adhesion performance is poor only at the temperature of -80℃. This phenomenon shows that the adhesion performance of the eutectic gel under extreme conditions is mainly controlled by its thermodynamic properties. That is, when the ambient temperature is lower than the glass transition temperature of the eutectic gel (-80℃﹤-25.84℃), the eutectic gel is mainly in an amorphous glass state, showing poor adhesion performance; when the ambient temperature is higher than the glass transition temperature of the eutectic gel (-20℃﹥-25.84℃), the eutectic gel is mainly in an amorphous high elastic state or rubber state, showing good adhesion performance.

[0219] In addition, when the temperature is high, the eutectic gel still maintains good adhesion. This shows that even at high temperatures, the eutectic gel still maintains an amorphous rubber state, and no rearrangement and crystal transformation caused by intermolecular movement occurs. This inference is consistent with the results of in-situ XRD. However, when the temperature reaches 110°C, the adhesion of the eutectic gel is poor. This phenomenon is mainly due to the destruction of the internal structure of the eutectic gel due to the high temperature, accompanied by the degradation of some components in the gel. This inference is also basically consistent with the results of in-situ XRD and thermogravimetric analysis.

[0220] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A supramolecular eutectic gel, characterized in that: The supramolecular eutectic gel is formed by polymerization of N,N-dimethylacrylamide and citric acid-betaine deep eutectic solvent.

2. The supramolecular eutectic gel according to claim 1, characterized in that: The mass ratio of the N,N-dimethylacrylamide to the citric acid-betaine deep eutectic solvent is (1-9):(9-1), preferably (1-3):(9-7), and more preferably 3:

7.

3. The supramolecular eutectic gel according to claim 1 or 2, characterized in that: The structural formula of the citric acid-betaine deep eutectic solvent is shown in Formula I below: Among them, -O and -OH are connected by hydrogen bonds.

4. A method for preparing a supramolecular eutectic gel according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: The citric acid-betaine deep eutectic solvent and N,N-dimethylacrylamide are mixed to obtain a supramolecular eutectic gel precursor solution, which is irradiated with ultraviolet light to perform a polymerization reaction to obtain the supramolecular eutectic gel.

5. The method for preparing supramolecular eutectic gel according to claim 4, characterized in that: The supramolecular eutectic gel precursor solution also includes a photoinitiator; Preferably, the photoinitiator is selected from 1-hydroxycyclohexyl phenyl ketone; Preferably, the added amount of the photoinitiator accounts for 0.5-5% of the total mass of the supramolecular eutectic gel precursor solution.

6. The method for preparing supramolecular eutectic gel according to claim 4, characterized in that: The mixing temperature is 70-80°C.

7. The method for preparing supramolecular eutectic gel according to claim 4, characterized in that: The power of the ultraviolet light is 35-45W, and the wavelength of the ultraviolet light is 360-370nm; Preferably, the ultraviolet light irradiation time is 5 to 60 seconds.

8. The method for preparing supramolecular eutectic gel according to claim 4, characterized in that: The citric acid-betaine deep eutectic solvent is prepared by the following steps: Betaine, citric acid and water are mixed to obtain a mixed solution; the mixed solution is concentrated under reduced pressure and then dried to obtain the citric acid-betaine deep eutectic solvent.

9. The method for preparing supramolecular eutectic gel according to claim 8, characterized in that: The molar ratio of betaine to citric acid is 1:(0.6-2.3); Preferably, the amount of water added accounts for 60-90% of the total mass of the mixed solution; Preferably, the temperature of the reduced pressure concentration is 50-70°C; Preferably, the drying is vacuum drying, the temperature of the vacuum drying is 45 to 55° C., and the time of the vacuum drying is 36 to 60 hours.

10. Use of the supramolecular eutectic gel according to any one of claims 1 to 3 in preparing a sealable biological tissue adhesive.

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