A kind of all-solid-state fluorinated ion gel underwater adhesive and preparation method thereof

Abstract

The present invention belongs to the field of adhesive preparation, specifically a method for preparing an all-solid-state fluorinated ion gel underwater adhesive, bistrifluoromethanesulfonyl imide anion (TFSI), due to the low polarizability and high electronegativity of its fluorinated group, has the strongest hydrophobicity among various anionic groups, can destroy the hydration layer barrier of the substrate, and effectively eliminate the interference of water molecules. Furthermore, different functional groups in the ion gel can form multiple interactions with the substrate material, such as electrostatic interaction, cation-π interaction, ion-dipole interaction, etc. to achieve underwater adhesion. Therefore, the all-solid-state ionic liquid gel adhesive can maintain long-term stable adhesion when used underwater, and can be applied to underwater motion detection, marine resource exploration, hemostatic dressings, underwater repair, etc., and is an efficient, durable underwater adhesive material with excellent environmental tolerance.

Description

Technical Field

[0001] The invention relates to the field of adhesive preparation, in particular to an all-solid-state fluorinated ion gel underwater adhesive and a preparation method thereof. Background Art

[0002] Adhesives are important and indispensable materials in aerospace, biomedicine, electronics and other fields. They are widely used in many emerging fields, such as biointerface electrodes, implantable devices, wound dressings, wearable sensors and repair work. At present, most adhesives on the market can only achieve adhesion in air environments, and achieving strong adhesion underwater and in wet environments is still a huge challenge. Water molecules can form a hydration layer on the surface of the substrate, preventing the adhesive from contacting the substrate, thereby greatly reducing or even eliminating the bonding strength of the adhesive, greatly limiting its scope of application.

[0003] Gel materials are polymer materials with a porous network structure. They will not dissolve when immersed in water for a long time. This unique property lays the foundation for their application in underwater adhesion. Inspired by nature, a series of hydrogels with underwater adhesion have been prepared. For example, inspired by the adhesive protein of marine mussels, a hydrogel adhesive for underwater application was designed using catechol groups and hydrophobic polymers. However, typical problems such as pH sensitivity, loss of adhesion due to oxidation, and low bonding strength hinder the practical application of adhesives. In addition, most hydrogel materials are subject to their inherent limitations and will inevitably swell when used in high humidity or water environments.

[0004] Therefore, in order to solve the above problems, an all-solid-state fluorinated ion gel underwater adhesive and a preparation method thereof are proposed. Summary of the invention

[0005] Based on the above problems, we proposed an all-solid-state ion gel adhesive based on polymerizable fluorinated ionic liquid, which is a highly efficient, durable underwater adhesive material with excellent environmental tolerance.

[0006] The technical solution adopted by the present invention to solve the technical problem is: the all-solid-state fluorinated ion gel underwater adhesive and the preparation method thereof described in the present invention comprise the following steps:

[0007] S1. Dissolve 60 mmol 1-vinylimidazole and 20 mmol 1,1,1,2,2-pentafluoro-4-iodobutane in anhydrous toluene at room temperature and stir at 90°C for 3 days;

[0008] S2. After cooling, the upper phase was removed, and the lower iodine ion liquid phase was washed three times with ethyl acetate. Then, the iodine ion liquid was dissolved in acetone, and 1.2 equivalents of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was added for anion exchange, and stirred for 18 hours;

[0009] S3, remove the solvent acetone by rotary evaporation, dissolve in dichloromethane, wash with water several times, and when the AgNO3 test result of the aqueous phase is negative, dry the organic phase over MgSO4, and finally dry in vacuum to obtain 3- (3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid (FIL) monomer;

[0010] S4, mixing the monomer hexafluorobutyl acrylate and the comonomer 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid uniformly to obtain an ion gel precursor solution;

[0011] S5, adding photoinitiator 2,2-diethoxyacetophenone;

[0012] S6. Pour the uniformly mixed liquid into a mold, and prepare a fully solid ion gel by ultraviolet light-induced free radical polymerization for 6-8 hours.

[0013] Preferably, in step S4, the ionic liquid monomer accounts for 10%-50% of the total monomer molar ratio.

[0014] Preferably, the amount of the photoinitiator in step S5 accounts for 3% of the total molar amount of the monomers.

[0015] Preferably, different functional groups in the all-solid-state ion gel can form multiple interactions with the substrate material, including electrostatic interaction, cation-π interaction, and ion-dipole interaction.

[0016] Preferably, the all-solid-state ion gel based on polyionic liquid is completely composed of a polymer network and mobile ions, does not contain a liquid component, can have the strong mechanical properties of a polymer, and does not have the risk of ionic liquid leakage.

[0017] Preferably, the all-solid-state ion gel is used for underwater motion detection, marine resource exploration, biomedical applications and underwater repair.

[0018] The present invention is beneficial in that:

[0019] 1. Different positive and negative charge groups in ionic liquids can give ionic liquid gels different properties. The bis(trifluoromethanesulfonyl imide) anion (TFSI-), due to the low polarizability and high electronegativity of its fluorinated group, has the strongest hydrophobicity among various anionic groups, which can destroy the hydration layer barrier of the substrate and effectively eliminate the interference of water molecules. Furthermore, different functional groups in ionic gels can form a variety of interactions with the substrate material, such as electrostatic interactions, cation-π interactions, ion-dipole interactions, etc. to achieve underwater adhesion;

[0020] 2. All-solid-state ion gel based on polyionic liquid is completely composed of polymer network and mobile ions, does not contain liquid components, can have the strong mechanical properties of polymer, and will not have the risk of leakage. Therefore, all-solid-state ion liquid gel adhesive can maintain long-term stable adhesion when used underwater, and can be used in underwater motion detection, marine resource exploration, biomedical applications and underwater repair, etc. It is an efficient, durable and environmentally tolerant underwater adhesive material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 This is a schematic diagram of the structure of the all-solid-state fluorinated ion gel synthesized by the present invention;

[0023] Figure 2 A and B are FTIR images of the ionic liquid monomer FIL and the all-solid-state fluorinated ion gel Ionogel-30 prepared in Example 4 in the wavelength range of 1400-1300 cm-1 and 1100-950 cm-1, respectively;

[0024] Figure 3 The stress-strain curve of the all-solid-state fluorinated ion gel prepared in Example 2-6;

[0025] Figure 4 This is a graph showing the underwater adhesion of the all-solid-state fluorinated ion gel prepared in Example 2-6 on a glass substrate;

[0026] Figure 5 This is a graph showing the underwater adhesion strength of the all-solid-state fluorinated ion gel prepared in Example 3 on different substrate materials;

[0027] Figure 6This is a graph showing the adhesion strength of the all-solid-state fluorinated ion gel prepared in Example 3 in deionized water, 1M HCl, 1M NaOH, and 1M NaCl solutions. DETAILED DESCRIPTION

[0028] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention are not necessarily the same as those obtained by ordinary technicians in this field.

[0029] The embodiments all belong to the protection scope of the present invention.

[0030] Embodiment 1

[0031] A fully solid fluorinated ion gel underwater adhesive and a preparation method thereof, the specific preparation method is as follows:

[0032] Step 1: 60 mmol 1-vinylimidazole and 20 mmol 1,1,1,2,2-pentafluoro-4-iodobutane were dissolved in anhydrous toluene at room temperature and stirred at 90°C for 3 days.

[0033] Step 2: After cooling, the upper phase was removed and the lower iodine ion liquid phase was washed three times with ethyl acetate. Then, the iodine ion liquid was dissolved in acetone, and 1.2 equivalents of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was added for anion exchange and stirred for 18 hours.

[0034] Step 3: Remove the solvent acetone by rotary evaporation, dissolve in dichloromethane, wash with water several times, and when the AgNO3 test result of the aqueous phase is negative, dry the organic phase over MgSO4 and finally dry in vacuum to obtain 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid (FIL) monomer.

[0035] Step 4: Evenly mix the monomer hexafluorobutyl acrylate and the comonomer 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid to obtain an ion gel precursor solution;

[0036] Step 5: Adding photoinitiator 2,2-diethoxyacetophenone;

[0037] Step 6: Pour the evenly mixed liquid into a mold and prepare a fully solid ion gel by ultraviolet light-induced free radical polymerization for 6-8 hours.

[0038] See also Figure 3As can be seen from the figure, the ion-dipole interaction, hydrogen bond interaction and fluorine effect formed inside the ion gel make its mechanical strength reach 0.75MPa, while maintaining a tensile strain of 2000%. It has excellent mechanical properties;

[0039] See also Figure 4 As can be seen from the figure, based on the hydrophobic effect of the bis(trifluoromethanesulfonyl)imide anion (TFSI-) in the ionic liquid, the hydration layer can be destroyed, so that the interaction between the ion gel and the substrate material is not disturbed. As a result, the ion gel still maintains a high adhesion under water;

[0040] See also Figure 5 ,It can be seen from the figure that the prepared ion gel adhesive can adhere to the surfaces of different substrates such as glass, aluminum plate, iron plate, PMMA plate, PET plate, PP plate, etc. underwater, and has strong adhesion, and the adhesion strength can be as high as 500KPa;

[0041] See also Figure 6 ,As can be seen from the figure, the adhesion strength of the ion gel adhesive in strong acid, strong alkali and salt solution is only slightly lower than that in water, which makes the adhesive applicable to a variety of harsh environments.

[0042] Embodiment 2

[0043] 4.02g of hexafluorobutyl acrylate monomer and 0.98g of 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid monomer were mixed evenly, and then 0.12g of 2,2-diethoxyacetophenone was added. Finally, the mixed liquid was poured into a mold and free radical polymerization reaction occurred under ultraviolet light for 6 hours to prepare a fully solid fluorinated ion gel adhesive, called Ionogel-10.

[0044] Embodiment 3

[0045] 3.22g of hexafluorobutyl acrylate monomer and 1.78g of 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid monomer were mixed evenly, and then 0.11g of 2,2-diethoxyacetophenone was added. Finally, the mixed liquid was poured into a mold and free radical polymerization reaction occurred under ultraviolet light for 6 hours to prepare a fully solid fluorinated ion gel adhesive, called Ionogel-20.

[0046] Embodiment 4

[0047] 2.57 g of hexafluorobutyl acrylate monomer and 2.53 g of 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole

[0048] The bis(trifluoromethanesulfonyl)imide ionic liquid monomer was mixed evenly, and then 0.10 g of 2,2-diethoxyacetophenone was added.

[0049] The evenly mixed liquid was poured into a mold, and under ultraviolet light, a free radical polymerization reaction occurred for 6 hours to prepare a fully solid fluorinated ion gel adhesive, called Ionogel-30.

[0050] See also Figure 2 As can be seen from the figure, the antisymmetric stretching vibration peak of S=O in the pure ionic liquid monomer TFSI- appears at 1347cm-1, and blue-shifts to 1351cm-1 in the ion gel. In addition, the peak of the NS bond in the ionic liquid is at 1052cm-1, and blue-shifts to 1056cm-1 in the ion gel. This proves that the imidazolium cation and the trifluoromethyl group form an ion-dipole interaction inside the ion gel, which contributes to the formation of a three-dimensional network structure inside the ion gel and is beneficial to the improvement of mechanical properties.

[0051] Embodiment 5

[0052] 2.02g of hexafluorobutyl acrylate monomer and 2.98g of 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid monomer were mixed evenly, and then 0.09g of 2,2-diethoxyacetophenone was added. Finally, the mixed liquid was poured into a mold and free radical polymerization reaction occurred under ultraviolet light for 6 hours to prepare a fully solid fluorinated ion gel adhesive, called Ionogel-40.

[0053] Embodiment 6

[0054] 1.56g of hexafluorobutyl acrylate monomer and 3.44g of 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid monomer were mixed evenly, and then 0.08g of 2,2-diethoxyacetophenone was added. Finally, the mixed liquid was poured into a mold and free radical polymerization reaction occurred under ultraviolet light for 6 hours to prepare a fully solid fluorinated ion gel adhesive, called Ionogel-50.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing an all-solid-state fluorinated ion gel underwater adhesive, characterized in that : Includes the following steps: S1, 60mmol1-vinyl imidazole and 20mmol1,1,1,2,2-pentafluoro-4-iodobutane were dissolved in anhydrous toluene at room temperature and stirred at 90°C for 3 days; S2, after cooling, the upper phase was removed, the lower iodine ion liquid phase was washed three times with ethyl acetate, then the iodine ion liquid was dissolved in acetone, 1.2 equivalents of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was added for anion exchange, and stirred for 18h; S3, remove the solvent acetone by rotary evaporation, dissolve in dichloromethane, wash with water several times, when the AgN03 of the aqueous phase, the test result is negative, dry the organic phase on MgS04, and finally dry in vacuum to obtain 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid FIL monomer; S4, the monomer hexafluorobutyl acrylate, the copolymer monomer 3-(3,3,4,4,4-pentafluorobutyl)-1-vinylimidazole bistrifluoromethanesulfonyl imide ionic liquid are mixed evenly to obtain an ion gel precursor solution; S5, adding photoinitiator 2,2-diethoxyacetophenone; S6. Pour the uniformly mixed liquid into a mold, and prepare a fully solid ion gel by ultraviolet light-induced free radical polymerization for 6-8 hours.

2. The method for preparing an all-solid-state fluorinated ion gel underwater adhesive according to claim 1, characterized in that : In step S4, the ionic liquid monomer accounts for 10%-50% of the total monomer molar ratio.

3. The method for preparing an all-solid-state fluorinated ion gel underwater adhesive according to claim 1, characterized in that : The amount of the photoinitiator in step S5 accounts for 3% of the total molar amount of the monomers.

4. The method for preparing an all-solid-state fluorinated ion gel underwater adhesive according to claim 1, characterized in that Different functional groups in the all-solid-state ion gel can form multiple interactions with the substrate material, including electrostatic interaction, cation-π interaction, and ion-dipole interaction.

5. The method for preparing an all-solid-state fluorinated ion gel underwater adhesive according to claim 1, characterized in that The all-solid-state ion gel based on polyionic liquid is completely composed of a polymer network and movable ions, does not contain a liquid component, can have the strong mechanical properties of a polymer, and does not have the risk of ionic liquid leakage.

6. The method for preparing an all-solid-state fluorinated ion gel underwater adhesive according to claim 1, characterized in that The all-solid-state ion gel is used in underwater motion detection, marine resource exploration, biomedical applications and underwater repair.

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