Optically switched supramolecular fluorescent polymers, their preparation methods, and their anti-counterfeiting applications in water.

Abstract

This invention discloses a photosensitive supramolecular fluorescent polymer, its preparation method, and its anti-counterfeiting application in water, using trifluoroethyl methacrylate, hexafluorobutyl acrylate, 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate, 4 This polymer was prepared by a simple one-step free radical copolymerization method using 1,1-(acryloyloxy)butyl3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxide benzo[b]thiophene-3-yl)cyclopent-1-en-1-yl)-2-methylbenzo[b]thiophene-6-carboxylate 1,1-dioxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator-819) as raw materials. The polymer exhibits excellent multicolor light-switching performance, high stretch ratio, high self-healing efficiency, strong substrate adhesion, and antifouling properties, especially demonstrating excellent stability under strong acid, strong alkali, and high salt environments. The synthetic route is simple, and it has great application potential in underwater anti-counterfeiting and encryption technologies.

Description

Technical Field

[0001] This invention belongs to the field of chemical material preparation and application, specifically relating to a light-switching supramolecular fluorescent polymer, its preparation method, and its anti-counterfeiting application in water. Background Technology

[0002] Currently, with the rapid development of society, anti-counterfeiting measures for various devices have become increasingly important. This is especially true as the marine economy develops, making the creation of highly secure underwater anti-counterfeiting labels essential to prevent unauthorized imitation or copying and avoid unnecessary economic losses. Due to the non-destructive and spatially controllable nature of light, integrating photochromic molecules into polymer systems to construct photo-switching fluorescent polymers and applying them to the field of anti-counterfeiting labels is a research hotspot (Mater. Horiz., 2022, 9, 1984-1991; Eur. Polym. J., 2022, 178, 111487.). Recently reported photo-switching fluorescent polymers are mainly based on nanoparticles, thin films, and hydrogels (Chem. Rev., 2021, 121, 9243-9358; Adv. Mater., 2015, 27, 2722-2727; Chem. Rev., 2020, 120, 7642-7707.). However, polymer nanoparticle systems exhibit poor mechanical properties, and these materials also face various problems in harsh underwater environments (acids, alkalis, or seawater). Hydrogels also exhibit abnormal expansion or contraction in acidic, alkaline, or high-concentration salt solutions, resulting in poor stability. These drawbacks greatly limit their application as underwater anti-counterfeiting tags. Therefore, there is an urgent need to develop photosensitive fluorescent polymers with good overall performance, including photosensitive switching properties, antifouling properties, and self-healing capabilities, to expand their applications in humid environments and even seawater.

[0003] Furthermore, although supramolecular materials composed of supramolecular interactions (such as hydrogen bonds, ionic interactions, host-guest interactions, coordination complexes, hydrophobic associations, π-π stacking interactions, and dipole-dipole interactions) exhibit many outstanding properties, such as processability, self-healing ability, and recyclability, their stability and self-healing performance in strong acid, strong alkali, and high-salt environments are insufficient to meet practical application requirements. Currently, the dipole-dipole interaction supramolecular system being developed not only meets the above advantages but also exhibits significant stability and self-healing ability in harsh aquatic environments. Therefore, this high-performance optical switching polymer can be better applied to anti-counterfeiting, especially in harsh environments where it has unparalleled advantages.

[0004] Therefore, inventing a novel anti-counterfeiting photosensitive supramolecular fluorescent polymer for harsh underwater environments that is simple, low-cost, has excellent processing, antifouling properties, superior self-healing properties, and photosensitive polymorphic fluorescence capabilities has significant practical implications and application prospects. Summary of the Invention

[0005] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide a light-switching supramolecular fluorescent polymer, its preparation method, and its anti-counterfeiting application in water. The light-switching molecule is prepared according to existing technology (Sci. China Mater., 2023, 66, 1949-1958. CN202210548000.X). Further application research shows that the anti-counterfeiting label prepared from this light-switching supramolecular fluorescent polymer not only exhibits reversible multicolor fluorescent switching performance under different alternating ultraviolet and visible light irradiation, but also demonstrates excellent tensile properties, high self-healing efficiency, strong substrate adhesion, and anti-fouling properties. Importantly, it exhibits excellent stability and self-healing properties under strong acid, strong alkali, and high salt environments.

[0006] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0007] 1. Preparation of light-switching supramolecular fluorescent polymers:

[0008] (1) Trifluoroethyl methacrylate, hexafluorobutyl acrylate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (photoinitiator-819), 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophene-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophene-6-yl) 4-Oxybutyrate, 4-(acryloyloxy)butyl 3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxide benzo[b]thiophene-3-yl)cyclopent-1-en-1-yl)-2-methylbenzo[b]thiophene-6-carboxylate 1,1-dioxide were mixed and ultrasonically dissolved in a molar ratio of 1:1:0.02:0~0.006:0~0.012.

[0009] (2) The solution prepared in step (1) was injected into a reaction cell consisting of a pair of glass plates spaced 2 mm apart and polymerized for 1 hour under visible light (460 nm, 40 mW per square centimeter).

[0010] (3) After the reaction in step (2) is completed, the polymerized sample is dissolved in 8 mL of dichloromethane, precipitated and centrifuged in 20 mL of petroleum ether, and the precipitate is dried to obtain a photochromic photo-switching supramolecular fluorescent polymer.

[0011] (4) The above polymer is heated in an 80°C oven and cut and shaped using a custom aluminum alloy mold to finally obtain a photochromic light-switching supramolecular fluorescent polymer. Under the irradiation of two different ultraviolet lights and two different visible lights, it can achieve reversible fluorescence changes between two or three states: no fluorescence, red fluorescence, and green fluorescence.

[0012] The structure of the prepared optically switched supramolecular fluorescent polymer is shown below:

[0013]

[0014] Where a / b / c / d = 1 / 1 / 0~0.006 / 0~0.012.

[0015] Furthermore, when the aforementioned light-switching supramolecular fluorescent polymers are applied to anti-counterfeiting labels, for example, different light-switching supramolecular fluorescent polymers are attached to the desired surface in a certain arrangement. When stimulated by light of different wavelengths in the air or underwater, their fluorescence undergoes a reversible switch, thereby enabling the identification of genuine and counterfeit samples and achieving the purpose of anti-counterfeiting.

[0016] The optically switched supramolecular fluorescent polymer described in this invention can be directly fabricated into anti-counterfeiting labels on desired surfaces, or it can be applied to special surfaces using a heat-adhesion method. Furthermore, it can be applied to anti-counterfeiting of high-value-added underwater devices or items such as diving masks and fabrics.

[0017] Furthermore, the aforementioned light-switching supramolecular fluorescent polymer achieves stable photoluminescence color change and self-healing in extreme water environments such as high salt, acid, or alkaline conditions.

[0018] The self-healing efficiency of the optically switched supramolecular fluorescent polymer described in this invention is as high as 80%.

[0019] Compared to existing polymer membranes and hydrogel systems, which are prone to instability and deformation due to swelling under extreme conditions such as acids and alkalis, the polymer prepared in this invention exhibits excellent stability in water over long periods.

[0020] This invention utilizes dipole-dipole interactions, which are resistant to strong acids, alkalis, and high salt concentrations underwater, thus exhibiting excellent self-healing properties even in extremely harsh environments. Furthermore, compared to ordinary anti-counterfeiting labels, where scratches and damage are irreversible and shorten lifespan, our invention leverages the abundant dipole-dipole interactions within the polymer system to achieve superior self-healing properties. Even if worn or broken during use, the label can be restored to its original condition thanks to its powerful self-healing capabilities.

[0021] The carbonyl groups and dipole-dipole interactions in this invention result in strong adhesion to various substrates, with an adhesion strength greater than 3.5 N / cm². This strong adhesion ensures that the material can be applied to a variety of complex surfaces.

[0022] Due to its excellent adhesion, this invention has a wide range of applications. It can also be applied to anti-counterfeiting of underwater diving clothing, etc. For example, we use a customized mold to process the prepared polymer into a designed pattern. Since the polymer has a very low glass transition temperature, it can be simply heated and then pressed tightly onto the surface of the diving clothing, etc., to realize an anti-counterfeiting mark applied to the diving clothing.

[0023] Furthermore, the aforementioned anti-counterfeiting label has excellent hydrophobic properties, with a water contact angle of 115°.

[0024] When anti-counterfeiting labels are applied in high humidity and high fog environments, their excellent waterproof performance ensures that their adhesion and stability will not be reduced due to long-term water contact.

[0025] Furthermore, the light-switching supramolecular fluorescent polymer exhibits excellent anti-fouling properties. Therefore, when used as an anti-counterfeiting label, it will not become ineffective due to contamination.

[0026] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0027] (1) In this invention, since both trifluoroethyl methacrylate and hexafluorobutyl acrylate in the polymer matrix have trifluoromethyl groups as strong hydrophobic groups, the prepared light-switching supramolecular fluorescent polymer has excellent hydrophobic properties and can be applied to underwater anti-counterfeiting under extreme and harsh conditions such as strong acids, alkalis and high salt, thus expanding the application environment of fluorescent polymers in the field of anti-counterfeiting.

[0028] (2) The light-switching supramolecular fluorescent polymer prepared by the present invention has excellent self-healing properties, good self-cleaning and adhesion properties without crosslinking agents compared with previous fluorescent polymers. This makes it more widely applicable in encryption applications and has great advantages in scale-up synthesis and actual production applications.

[0029] (3) Compared with the previous fluorinated polymers, the optical switching supramolecular fluorescent polymer prepared by the present invention not only has excellent self-healing properties, but also can realize polymorphic fluorescent switching changes, making the material applicable to anti-counterfeiting encryption and other fields.

[0030] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0032] Figure 1 Differential scanning calorimetry (DSC) results of the prepared optically switched supramolecular fluorescent polymer.

[0033] Figure 2 The fluorescence emission spectra of the prepared light-switching supramolecular fluorescent polymer during the fluorescence resonance energy transfer process under different external light conditions are shown.

[0034] Figure 3 This image illustrates the stable photochromic effect of the prepared light-switching supramolecular fluorescent polymer under extremely harsh environments (pH=1, pH=14, saturated saline).

[0035] Figure 4 The image shows the antifouling performance of the prepared light-switching supramolecular fluorescent polymer.

[0036] Figure 5 An application diagram of a butterflyfish-shaped anti-counterfeiting label made from the prepared light-switching supramolecular fluorescent polymer.

[0037] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0039] Example 1: Preparation of a light-switching supramolecular fluorescent polymer 1:

[0040] 1.68 g of trifluoroethyl methacrylate, 2.36 g of hexafluorobutyl acrylate, 0.1694 g of photoinitiator-819, and 0.0413 g of 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate were ultrasonically mixed and injected into... In a reaction chamber consisting of a pair of glass plates spaced 2 mm apart, the glass plates were clamped together to prevent air leakage. The mixture was polymerized for 1 hour under visible light irradiation (460 nm, 40 mW / min). The polymerized sample was dissolved in 8 mL of dichloromethane, precipitated in 20 mL of petroleum ether, and centrifuged. After drying the precipitate, a photo-switching supramolecular fluorescent polymer 1 was obtained. When irradiated alternately between 365 nm and 525 nm, it can achieve reversible switching between no fluorescence and red fluorescence.

[0041] Example 2: Preparation of a light-switching supramolecular fluorescent polymer 2:

[0042] 1.68 g of trifluoroethyl methacrylate, 2.36 g of hexafluorobutyl acrylate, 0.1694 g of photoinitiator-819, 0.0413 g of 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate, and 4-(acryloyloxy)butyl3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxidebenzo[b]thiophen-3-yl)cyclopent-1-en-1-yl)-2- 0.0211 g of methylbenzo[b]thiophene-6-carboxylate 1,1-dioxide was ultrasonically mixed and injected into a reaction chamber consisting of a pair of glass plates spaced 2 mm apart. The glass plates were clamped to prevent air leakage. The mixture was polymerized for 1 hour under visible light irradiation (460 nm, 40 mW / min). The polymerized sample was dissolved in 8 mL of dichloromethane, precipitated in 20 mL of petroleum ether, and centrifuged. After drying the precipitate, a photo-switching supramolecular fluorescent polymer 2 was obtained. When irradiated alternately between 254 nm, 365 nm, 460 nm, and 525 nm, it can reversibly switch between three states: no fluorescence, red fluorescence, and green fluorescence.

[0043] Example 3: Preparation of a light-switching supramolecular fluorescent polymer 3:

[0044] 1.68 g of trifluoroethyl methacrylate, 2.36 g of hexafluorobutyl acrylate, 0.1694 g of photoinitiator-819, 0.0413 g of 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate, and 4-(acryloyloxy)butyl3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxidebenzo[b]thiophen-3-yl)cyclopent-1-en-1-yl)-2- 0.0281 g of methylbenzo[b]thiophene-6-carboxylate 1,1-dioxide was ultrasonically mixed and injected into a reaction chamber consisting of a pair of glass plates spaced 2 mm apart. The glass plates were clamped to prevent air leakage. The mixture was polymerized for 1 hour under visible light irradiation (460 nm, 40 mW / min). The polymerized sample was dissolved in 8 mL of dichloromethane, precipitated in 20 mL of petroleum ether, and centrifuged. After drying the precipitate, a photo-switching supramolecular fluorescent polymer 3 was obtained. When irradiated alternately between 254 nm, 365 nm, 460 nm, and 525 nm, it can reversibly switch between three states: no fluorescence, red fluorescence, and green fluorescence.

[0045] Example 4: Preparation of a light-switching supramolecular fluorescent polymer 4:

[0046] 1.68 g of trifluoroethyl methacrylate, 2.36 g of hexafluorobutyl acrylate, 0.1694 g of photoinitiator-819, 0.0413 g of 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate, and 4-(acryloyloxy)butyl3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxidebenzo[b]thiophen-3-yl)cyclopent-1-en-1-yl)-2-methyl 0.0421 g of 1,1-dioxide of benzo[b]thiophene-6-carboxylate was ultrasonically mixed and injected into a reaction chamber consisting of a pair of glass plates spaced 2 mm apart. The glass plates were clamped to prevent air leakage. The mixture was polymerized for 1 hour under visible light irradiation (460 nm, 40 mW / cm²). The polymerized sample was dissolved in 8 mL of dichloromethane, precipitated in 20 mL of petroleum ether, and centrifuged. After drying the precipitate, a photo-switching supramolecular fluorescent polymer 4 was obtained. When irradiated alternately between 254 nm, 365 nm, 460 nm, and 525 nm, it can reversibly switch between three states: no fluorescence, red fluorescence, and green fluorescence.

[0047] Example 5: Preparation of a light-switching supramolecular fluorescent polymer 5:

[0048] 1.68 g of trifluoroethyl methacrylate, 2.36 g of hexafluorobutyl acrylate, 0.1694 g of photoinitiator-819, 0.0413 g of 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate, and 4-(acryloyloxy)butyl3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxidebenzo[b]thiophen-3-yl)cyclopent-1-en-1-yl)-2- 0.0632 g of methylbenzo[b]thiophene-6-carboxylate 1,1-dioxide was ultrasonically mixed and injected into a reaction chamber consisting of a pair of glass plates spaced 2 mm apart. The glass plates were clamped to prevent air leakage. The mixture was polymerized for 1 hour under visible light irradiation (460 nm, 40 mW / min). The polymerized sample was dissolved in 8 mL of dichloromethane, precipitated in 20 mL of petroleum ether, and centrifuged. After drying the precipitate, a photo-switching supramolecular fluorescent polymer 5 was obtained. When irradiated alternately between 254 nm, 365 nm, 460 nm, and 525 nm, it can reversibly switch between three states: no fluorescence, red fluorescence, and green fluorescence.

[0049] Example 6: Preparation of a light-switching supramolecular fluorescent polymer 6:

[0050] 1.68 g of trifluoroethyl methacrylate, 2.36 g of hexafluorobutyl acrylate, 0.1694 g of photoinitiator-819, 0.0413 g of 4-(acryloyloxy)butyl4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate, and 4-(acryloyloxy)butyl3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxidebenzo[b]thiophen-3-yl)cyclopent-1-en-1-yl)-2- 0.0842 g of methylbenzo[b]thiophene-6-carboxylate 1,1-dioxide was ultrasonically mixed and injected into a reaction chamber consisting of a pair of glass plates spaced 2 mm apart. The glass plates were clamped to prevent air leakage. The mixture was polymerized for 1 hour under visible light irradiation (460 nm, 40 mW / min). The polymerized sample was dissolved in 8 mL of dichloromethane, precipitated in 20 mL of petroleum ether, and centrifuged. After drying the precipitate, a photo-switching supramolecular fluorescent polymer 6 was obtained. When irradiated alternately between 254 nm, 365 nm, 460 nm, and 525 nm, it can reversibly switch between three states: no fluorescence, red fluorescence, and green fluorescence.

[0051] Example 7: Preparation of a light-switching supramolecular fluorescent polymer 7:

[0052] 1.68 g of trifluoroethyl methacrylate, 2.36 g of hexafluorobutyl acrylate, 0.1694 g of photoinitiator-819, and 0.0842 g of 4-(acryloyloxy)butyl3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxide benzo[b]thiophene-3-yl)cyclopent-1-en-1-yl)-2-methylbenzo[b]thiophene-6-carboxylate, 1,1-dioxide were ultrasonically mixed and injected into a... In a reaction chamber composed of glass plates spaced 2 mm apart, the glass plates were clamped to prevent air leakage. The mixture was polymerized for 1 hour under visible light irradiation (460 nm, 40 mW / min). The polymerized sample was dissolved in 8 mL of dichloromethane, precipitated in 20 mL of petroleum ether, and centrifuged. After drying the precipitate, a photo-switching supramolecular fluorescent polymer 7 was obtained. It can achieve reversible switching between no fluorescence and green fluorescence when irradiated alternately between 254 nm and 460 nm.

[0053] Example 8: Differential scanning calorimetry (DSC) results of the prepared optically switched supramolecular fluorescent polymers 1, 4, and 7.

[0054] Figure 1 These are differential scanning calorimetry (DSC) results for the polymers prepared in Examples 1, 4, and 7. From... Figure 1As can be seen, the glass transition temperature of the light-switching supramolecular fluorescent polymer 1 is 19.82℃; the glass transition temperature of the light-switching supramolecular fluorescent polymer 4 is 21.02℃; and the glass transition temperature of the light-switching supramolecular fluorescent polymer 7 is 20.07℃. This low glass transition temperature ensures that the material has excellent processability.

[0055] Example 9: Testing the fluorescence resonance energy transfer spectra of the light-switching supramolecular fluorescent polymer 4 prepared in Example 4 under different external light modulation.

[0056] Figure 2 This describes the fluorescence resonance energy transfer process of the light-switching supramolecular fluorescent polymer film prepared in Example 4, controlled at 254 nm and 525 nm. Figure 2 As can be seen, under full irradiation (10 minutes) with a 254 nm UV lamp, the polymer film exhibits a small emission peak at 475 nm for 4-(acryloyloxy)butyl 3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxide benzo[b]thiophen-3-yl)cyclopent-1-en-1-yl)-2-methylbenzo[b]thiophen-6-carboxylate 1,1-dioxide, while a higher emission peak for 4-(acryloyloxy)butyl 4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate ester appears at 650 nm. Immediately after irradiation with 525 nm visible light, the emission signal of 4-(acryloyloxy)butyl 3-(3,3,4,4,5,5-hexafluoro-2-(2-methyl-1,1-dioxide benzo[b]thiophen-3-yl)cyclopent-1-en-1-yl)-2-methylbenzo[b]thiophen-6-carboxylate 1,1-dioxide continuously increased and gradually red-shifted, reaching a maximum emission peak at 500 nm, with a fluorescence signal value nineteen times that of the original. Meanwhile, the emission peak signal value of 4-(acryloyloxy)butyl 4-(2-methyl-3-(2-(2-methylbenzo[b]thiophen-3-yl)-4-oxo-5,6-2H-4H-thiaran[2,3-)b]thiaran-3-yl)benzo[b]thiophen-6-yl)-4-oxobutyrate at 650 nm decreased significantly.

[0057] Example 10: Stress-strain test of the self-healing process of the optically switched supramolecular fluorescent polymer 4 prepared in Example 4 under an extremely harsh environment (saturated saline solution):

[0058] The prepared optically switched supramolecular fluorescent polymer 4 was processed into two sets of samples of the same size (length × width × height = 10 × 5 × 2 mm). One set was directly subjected to a tensile test at a tensile rate of 10 mm per minute. The other set was cut along the middle and then spliced ​​together along the cut surface. After self-healing at room temperature for 24 hours, the self-healed polymer was stretched. The results of the two were compared, and the self-healing efficiency was calculated to be 80%, proving that it has excellent self-healing performance under extreme conditions.

[0059] Example 11: A demonstration of the stable photochromic effect of the prepared light-switching supramolecular fluorescent polymer under extremely harsh environments (pH=1, pH=14, saturated saline).

[0060] Take the light-switching supramolecular fluorescent polymer 4 prepared in Example 4, such as... Figure 3 As shown, the polymer was processed into 3×3×3 mm cubes using a custom-made PTFE mold and placed in pH=1 (HCl), pH=7 (pure water), pH=14 (NaOH), saturated saline solution, and seawater, respectively. After soaking for one week, the polymer was removed and irradiated with 254 nm UV light. Under fluorescent light, the color of the polymer block changed from colorless to red. Under 365 nm UV light, its fluorescence changed from non-fluorescent to red. Subsequently, after irradiation with 525 nm visible light, the color of the polymer block changed from red to yellow under fluorescent light, and under 365 nm UV light, its fluorescence changed from red to green. This demonstrates that its photochromic ability and reversible fluorescence switching ability were not affected. This indicates that the polymer has a stable photochromic ability under extremely harsh environments (pH=1, pH=14, saturated saline solution, seawater).

[0061] Example 12: Adhesion performance test of the prepared optically switched supramolecular fluorescent polymer on various substrates.

[0062] The light-switching supramolecular fluorescent polymer 4 prepared in Example 4 was placed on a smooth and flat glass plate surface for 5 days. Then, it was subjected to a tensile test using a universal testing machine. At a tensile rate of 10 mm / min, the polymer broke when stretched to 15 times its original length, rather than the adhered part detaching from the glass surface. This indicates that the adhesion energy of the polymer is greater than the fracture energy, and its maximum adhesion strength is 3.5 N / cm², which shows excellent adhesion performance.

[0063] Example 13: Contact angle test of the prepared optically switched supramolecular fluorescent polymer.

[0064] The optically switched supramolecular fluorescent polymer 4 prepared in Example 4 was processed by pressure with a glass plate to form a sample with a smooth surface. Five microliters of water droplets were attached to the sample surface, and the contact angle was measured to be 115 degrees using a contact angle meter, proving that the polymer has excellent hydrophobic properties.

[0065] Example 14: Antifouling effect test of the prepared light-switching supramolecular fluorescent polymer.

[0066] The optically switched supramolecular fluorescent polymer 4 prepared in Example 4 was processed into a cuboid using a mold, such as... Figure 4 As shown, after being immersed in mud and black ink for a week and then rinsed with water, no dirt residue remained on its surface. The fluorescence switching effect was observed under different light sources. Initially, the photo-switching supramolecular fluorescent polymer 4 was in a non-fluorescent state. When irradiated with 254 nm ultraviolet light, it turned into a red fluorescent state; irradiation with 460 nm visible light then returned it to its initial non-fluorescent state. Irradiation with 254 nm followed by 525 nm visible light caused it to switch to a green fluorescent state. Irradiation with 365 nm ultraviolet light caused it to switch from green to red fluorescent, but irradiation with 460 nm visible light returned it to its initial non-fluorescent state. This demonstrates a complete and reversible fluorescence change. Furthermore, after immersing in a dirty environment for a week, no residue remained on the surface, and the fluorescence change was unaffected, proving that the photo-switching supramolecular fluorescent polymer has excellent anti-fouling properties.

[0067] Example 15: Application diagram of the prepared light-switching supramolecular fluorescent polymer used to make a butterfly-shaped anti-counterfeiting label.

[0068] The polymer solids obtained in Examples 1, 2, 3, 4, 5, 6, and 7 were respectively cut using a custom aluminum alloy mold to obtain butterflyfish-shaped parts of the light-switching supramolecular fluorescent polymers 1-7. For example... Figure 5As shown, the butterflyfish-shaped anti-counterfeiting label was assembled underwater along the interface. After 24 hours, a complete butterflyfish-shaped label was obtained. Utilizing its adhesive properties, it was adhered to a glass plate. Initially, it was non-fluorescent underwater. After being irradiated with 365 nm ultraviolet light, the tail and body of the butterflyfish emitted red fluorescence, which could be clearly observed underwater. Then, when irradiated with 254 nm ultraviolet light, the tail and body remained red, but the head emitted green fluorescence, presenting a green head, red body, and tail. Next, when irradiated with 525 nm visible light, the red emission at the tail and body was turned off, but green emission was observed, while the green emission at the head remained unaffected, presenting a green head and body, with the tail showing no fluorescence. Finally, when irradiated with 460 nm visible light, the green emission in the head and body was turned off, and the entire fish returned to its initial non-fluorescent state. This demonstrates a reversible fluorescence change process. The results show that this optically switched supramolecular fluorescent polymer can be used in the production of underwater anti-counterfeiting labels.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a photoswitchable supramolecular fluorescent polymer, characterized in that, The method comprises the following steps: Step (1), trifluoroethyl methacrylate, hexafluorobutyl acrylate, phenyl bis (2, 4, 6-trimethyl benzoyl) phosphine oxide (light initiator 819), 4- (acryloyloxy) butyl 4- (2-methyl-3- (2- (2-methyl benzene [b] thiophene-3-yl) -4-oxo-5, 6-2H-4H-thiopyran [2, 3-) b] thiopyran-3-yl) benzene [b] thiophene-6-yl) -4-oxobutyric acid, 4- (acryloyloxy) butyl 3- (3, 3, 4, 4, 5, 5-hexafluoro-2- (2-methyl-1, 1-dioxobenzene [b] thiophene-3-yl) cyclopent-1-ene-1-yl) -2-methylbenzene [b] thiophene-6-carboxylate 1, 1-dioxide are mixed in the molar ratio of 1:1:0.02:0~0.006:0~0.012, and ultrasonic dissolution is carried out; Step (2), the solution prepared in step (1) is injected into a reaction cell composed of a pair of glass plates with a spacing of 2 mm, and polymerization is carried out under the irradiation of visible light with a wavelength of 460 nm and a power of 40 mW per minute for 1 hour; Step (3), after the reaction in step (2) is completed, the sample formed by polymerization is dissolved in 8 ml of dichloromethane, and then precipitated in 20 ml of petroleum ether and centrifuged, and the precipitate is dried to obtain a photochromic light switch supramolecular fluorescent polymer.

2. The photochromic light switch supramolecular fluorescent polymer prepared by the method of claim 1 has the following structural formula: ； wherein a / b / c / d=1 / 1 / 0~0.006 / 0~0.

012.

3. The photochromic light switch supramolecular fluorescent polymer prepared by the method of claim 1 is used in anti-counterfeiting.

4. Use according to claim 3, characterized in that, The photochromic light switch supramolecular fluorescent polymer is prepared into a label and then attached or adhered to a required surface by heating.

5. Use according to claim 3 or 4, characterized in that, The prepared label is attached to diving goggles, swimwear, and textile clothing items for use in high-salt, acidic, or alkaline water environments.

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