Thermally-driven color-changing gel as well as preparation method and application thereof
By introducing organic ligands, AIE molecules and metal ions into thermally driven color-changing gels, combined with FRET cascade energy transfer, the problems of reversibility and multicolorability of existing encryption materials are solved, time-dependent encryption and anti-counterfeiting functions are realized, and information security is enhanced.
Patent Information
- Application Number
- CN202510489221.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-18
- Publication Date
- 2025-07-22
AI Technical Summary
Existing AIE-based encryption materials have shortcomings in reversibility, fluorescence multicolorability and color discrimination, and it is difficult to meet the needs of dynamic information encryption and anti-counterfeiting.
By introducing organic ligand C3-Phe, AIE molecules, bio-based polymer hyaluronic acid and metal ions into the heat-driven color-changing gel, the gel material is self-assembled by π-π stacking, hydrogen bonding and metal coordination, and a FRET cascade energy transfer system is constructed to achieve temperature and time-dependent fluorescence changes.
It significantly enhances the fluorescence performance and reversibility of the material, realizes multi-color fluorescence regulation, provides time-dependent encryption and anti-counterfeiting functions, has anti-copy and self-destruct characteristics, and improves information security.
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Figure CN120346745A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of functional thermochromic gel materials, and particularly relates to a heat-driven color-changing gel and its preparation method and application. Background Art
[0002] With the increasing demand for information security, traditional static encryption technologies have become difficult to meet the increasingly complex anti-counterfeiting requirements. Dynamic encryption materials have become a research hotspot in the field of information security due to their time-dependent, multi-factor authentication, and anti-copying characteristics. Fluorescent materials, due to their unique optical properties, including high sensitivity, fast responsiveness, and complex optical signal output capabilities, have shown great potential in the field of dynamic information encryption and anti-counterfeiting. In particular, aggregation-induced emission (AIE) materials, with their significantly enhanced fluorescence in the aggregated state, provide the possibility for constructing high-contrast encryption systems. However, existing AIE-based encryption materials still suffer from problems such as poor reversibility, insufficient color distinguishability, or dependence on chemical stimuli, which limit their reliability in practical applications.
[0003] Supramolecular gels, with their dynamic reversible non-covalent interaction networks, provide an ideal platform for constructing intelligent responsive materials. These materials are usually driven by weak interactions such as hydrogen bonds, π-π stacking, and metal coordination to self-assemble, and have stimulus responsiveness, tunability, and good biocompatibility. Research has shown that supramolecular gels can effectively anchor AIE molecules and significantly enhance their fluorescence properties by providing a rigid environment. For example, Zhou et al. reported the dynamic regulation of the gel network structure and the aggregation state of AIE molecules using temperature changes, achieving the dynamic regulation of the emission intensity and fluorescence color of AIE molecules (RSC Adv., 2020, 10, 7118 - 7124); Tian et al. reported the regulation of the emission color of AIE molecules in supramolecular gels using trifluoroacetic acid (J. Phys. Chem. C 2021, 125, 21270 - 21276). In addition, the highly ordered structure of supramolecular gels provides ideal conditions for constructing a fluorescence resonance energy transfer (FRET) system, which is conducive to achieving multi-color fluorescence output. Nevertheless, existing technologies still have difficulty in simultaneously meeting the functional requirements such as high reversibility, time-dependent fluorescence transition, and multi-level security encryption. Summary of the Invention
[0004] Aiming at the deficiencies of the existing technology, the present invention provides a heat-driven color-changing gel and its preparation method and application, which solve the shortcomings of the existing technology such as the addition of chemical substances affecting recyclability and the poor multi-color property or fluorescence color distinguishability of fluorescence.
[0005] To achieve the above objectives, the present invention is realized through the following technical solutions:
[0006] The present invention discloses a preparation method of a thermally driven color-changing gel. An organic ligand, an AIE molecule, a bio-based polymer, and a metal ion are mixed to obtain a thermally driven color-changing gel material at room temperature.
[0007] The organic ligand is C3-Phe, the bio-based polymer is hyaluronic acid, the AIE molecule is any one of 4,4′-(1,2-divinylene-1,2-diyl)dibenzoic acid, 4,4',4”,4'-(ethene-1,1,2,2-tetrayl)tetrabenzoic acid, tetrakis[4-(3,5-dicarboxyphenyl)]tetraphenylethene, 1,1,2-triphenyl-2-(4-formylphenyl)ethene, tetrakis(4-pyridylphenyl)ethene, tetrakis[4-(4'-carboxyphenyl)phenyl]ethene, and 4,4'-(2,2-diphenylethene-1,1-diyl)dibenzoic acid, and the metal ion is any one of samarium ion, europium ion, dysprosium ion, calcium ion, copper ion, barium ion, terbium ion, europium ion, and aluminum ion.
[0008] Preferably, the degree of polymerization of the hyaluronic acid is 20-200.
[0009] Preferably, the final concentration of the organic solution of the organic ligand is 3-20 mmol / L, the final concentration of the bio-based polymer is 0.1 wt%-2 wt%, the final concentration of the metal ion is 4-10 mmol / L, and the final concentration of the AIE molecule in the mixed solution of the organic ligand and the AIE molecule is 1-5 mmol / L.
[0010] Preferably, the molar ratio of the organic ligand to the AIE molecule is 100:1-10:1.
[0011] Preferably, the organic ligand is mixed with an organic solution, and the organic solvent is any one of DMSO, DMF, ethanol, and methanol;
[0012] The aqueous solution of the bio-based polymer is mixed with the mixed solution of the organic ligand and the AIE molecule, and then mixed with the poor solvent of the organic ligand and the aqueous solution of the metal ion. The poor solvent is distilled water.
[0013] Preferably, the volume ratio of the poor solvent to the organic solvent is 9:1-1:9.
[0014] Preferably, a chemical dye is added to the mixed system of the organic ligand, the AIE molecule, the bio-based polymer, and the metal ion. The chemical dye is one or more of 4,7-bis(thiophen-2-yl)benzo-[2,1,3]-thiadiazole, rhodamine B, sulfonyl rhodamine B, and sulforhodamine 101.
[0015] Preferably, the concentration of the chemical dye is 5×10 -4-5×10 -2 mmol / L.
[0016] Correspondingly, a thermally driven color-changing gel prepared by the above-mentioned preparation method.
[0017] Correspondingly, an application of a thermally driven color-changing gel prepared by the above-mentioned preparation method in time-dependent encryption and anti-counterfeiting.
[0018] The present invention has the following beneficial effects:
[0019] 1. By introducing excellent AIE molecules, bio-based polymers, metal ions, and chemical dyes into the thermally driven color-changing gel material system, the present invention utilizes the π-π stacking interaction, hydrogen bond, and coordination interaction with metal ions among the organic ligand (C3-Phe), AIE molecules, and bio-based polymers. The molecules self-assemble to form a gel material with thermochromic properties through these interactions. This gel material exhibits significant thermochromic properties and reversibility, solving the problems in the prior art such as the influence of added chemical substances on recyclability and the poor polychromaticity or distinguishable fluorescence colors of fluorescence.
[0020] 2. The present invention proposes a supramolecular gel system based on AIE. This system utilizes the multiple interactions of the C3-symmetric gelator C3-Phe, HA, and metal ions (such as Al 3+ ) to construct a stable gel network and anchors AIE molecules (such as TPE-CA) to enhance their fluorescence properties. By reversibly regulating the gel-sol transition through temperature stimulation, the time-dependent change of fluorescence is achieved. Furthermore, by introducing a FRET cascade energy transfer system (such as using DBT and RhB as acceptors), the dynamic regulation of multicolor fluorescence is realized. This material exhibits excellent time-dependent thermochromic properties and reversibility, providing a new solution for the development of highly secure dynamic encryption and anti-counterfeiting technologies.
[0021] 3. Under the condition of doping with AIE molecules, the present invention utilizes the coordination interaction between the organic ligand and metal ions, the π-π interaction between organic ligand molecules, the coordination interaction between the bio-based polymer and metal ions, and the coordination interaction between AIE molecules and metal ions, as well as the hydrogen bond interaction between AIE molecules, bio-based polymers, and organic ligands to self-assemble and form this thermochromic gel material. On the one hand, this thermochromic gel material anchors AIE molecules in a rigid environment, significantly enhancing the luminescence performance of the material; on the other hand, through the synergistic effect of the above multiple weak interactions (including π-π stacking, hydrogen bond, and metal coordination interactions), the gel material is endowed with significant thermal response characteristics: when heated, the gel network gradually dissociates, resulting in the decrease of fluorescence intensity over time until complete quenching; after cooling and replenishing water, the gel network can be reconstructed, and the fluorescence performance can be completely restored with cyclic reversibility.
[0022] Compared with the undoped C3-Phe / HA / Al 3+ TPE-CA solution, the gel material of the preferred embodiment of the present invention, C3-Phe / TPE-CA / HA / Al 3+ not only has its fluorescence intensity increased by as much as 27 times, but also its quantum yield has increased by more than 30 times.
[0023] 4. The thermally driven color-changing gel provided by the present invention overcomes the shortcomings that the current addition of chemical substances affects recyclability, or the polychromaticity or distinguishable fluorescence colors are poor, and enhances its reversibility and recyclability. Moreover, it can be obtained only by mixing a mixture of an organic ligand and an AIE molecule with a biobased polymer (such as hyaluronic acid), a chemical dye, and metal ions at room temperature, and the preparation process is simple and controllable.
[0024] 5. When constructing the FRET platform, DBT and RhB are added as the primary and secondary energy transfer acceptors respectively to construct a cascaded energy transfer system to achieve multicolor fluorescent gels.
[0025] 6. The thermoresponsive gel encryption system provided by the present invention realizes multi-level dynamic information decryption through temperature-time bivariate regulation. Gels with different fluorescence colors are arranged in an orderly manner to form the initial information carrier, showing a stepwise color evolution under different heating durations. Among them, the gel color change serves as the time key, and any incorrect decryption of the intermediate state will interrupt the verification process. Compared with traditional static encryption, this system has three advantages: (1) Using the heating duration as a dynamic variable to achieve encryption in the time dimension; (2) Constructing spatial information bits through color gradient changes; (3) The water-adding reversible property enables the carrier to be reused. This temperature-time-space collaborative encryption mechanism effectively resists brute force cracking and provides a new paradigm for high-security information protection. Description of the Drawings
[0026] Figure 1 For C3-Phe / HA / Al 3+ , C3-Phe / TPE-CA / HA / Al 3+ Comparison diagram of the luminescence spectra of different fluorescence intensities in the gel state and only TPE-CA in the solvent;
[0027] Figure 2 For C3-Phe / HA / Al 3+ Fluorescence intensity spectrum of the gel after changing the type of AIE molecule added therein;
[0028] Figure 3 Fluorescence intensity of C3-Phe / TPE-CA / HA after adding different metal ions;
[0029] Figure 4It is C3-Phe / TPE-CA / HA / Al 3+ The dry gel electron microscopy image;
[0030] Figure 5 It is the fluorescence emission spectrum of the gel formed by C3-Phe in DMSO;
[0031] Figure 6 It is the fluorescence emission spectrum of the gel formed by C3-Phe in DMF;
[0032] Figure 7 It is C3-Phe / TPE-CA / HA / Al 3+ The gel color change of / DBT at 85°C for different times, and the fluorescence color change after quenching and adding water;
[0033] Figure 8 It is C3-Phe / TPE-CA / HA / Al 3+ The gel color change of / DBT / RhB at 85°C for different times, and the fluorescence color change after quenching and adding water;
[0034] Figure 9 It is C3-Phe / TPE-CA / HA / Al 3+ / DBT / RhB is added dropwise to a 5×5 microplate, and information encryption and decryption applications are carried out according to the gel color change at 85°C for different times. Detailed implementation manners
[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0036] If not specifically specified, the technical means used in the implementation examples are conventional means well known to those skilled in the art.
[0037] The present invention discloses a preparation method of a thermally driven color-changing gel. An organic ligand, an AIE molecule, a bio-based polymer, and metal ions are mixed to obtain a thermally driven color-changing gel material at room temperature. Specifically: the organic ligand and the AIE molecule are mixed, then the bio-based polymer is added, and then it is mixed with a poor solvent of the organic ligand. Finally, metal ions are added. The above mixed solution is added dropwise while vortexing. After vortexing evenly, it is left to stand for 5-10 minutes to obtain a thermally driven color-changing gel material.
[0038] Among them, the organic ligand is C3-Phe, and the final concentration of the organic solution of the organic ligand is 3-20 mmol / L. The organic ligand is mixed with the organic solution, and the organic solvent is any one of DMSO, DMF, ethanol, and methanol.
[0039] The biobased polymer is hyaluronic acid (HA), the degree of polymerization of the hyaluronic acid is 20-200, and the final concentration is 0.1 wt%-2 wt%. During the preparation process, the aqueous solution of the biobased polymer is mixed with the mixture of the organic ligand and the AIE molecule, and then the poor solvent of the organic ligand and the aqueous solution of the metal ion are added for mixing. The poor solvent is distilled water, and the volume ratio of the poor solvent to the organic solvent is 9:1 to 1:9. The mass-volume concentration of the biobased polymer is 0.1%-0.8%. The volume ratio of the aqueous solution of the biobased polymer to the mixture of the organic ligand, the AIE molecule, and the metal ion is 7:3 to 4:6. The volume ratio of the poor solvent to the mixture of the organic ligand, the AIE molecule, the biobased polymer, and the metal ion is 6:4-3:7.
[0040] The AIE molecule is any one of 4,4′-(1,2-distyryl-1,2-diyl)dibenzoic acid (TPE-CA), 4,4',4”,4'-(ethene-1,1,2,2-tetrayl)tetrabenzoic acid, tetrakis[4-(3,5-dicarboxyphenyl)]tetraphenylethylene, 1,1,2-triphenyl-2-(4-formylphenyl)ethylene, tetrakis(4-pyridylphenyl)ethylene, tetrakis[4-(4'-carboxyphenyl)phenyl]ethylene, and 4,4'-(2,2-diphenylethene-1,1-diyl)dibenzoic acid. The final concentration of the AIE molecule in the mixture of the AIE molecule and the organic ligand is 1-5 mmol / L. The molar ratio of the organic ligand to the AIE molecule is 100:1-10:1. The AIE molecule is mixed with the organic solvent, and the organic solvent is any one of DMSO, DMF, ethanol, and methanol.
[0041] The metal ion is any one of samarium ion, europium ion, dysprosium ion, calcium ion, copper ion, barium ion, terbium ion, europium ion, and aluminum ion, and the final concentration of the metal ion is 4-10 mmol / L.
[0042] Furthermore, the temperature for the thermally driven color change of the thermally driven color-changing gel prepared by the present invention is 50-85 °C, and the heating time is 5-90 min.
[0043] Among them, the structural formulas of C3-Phe and TPE-CA are as follows:
[0044]
[0045] Furthermore, based on the reversible response characteristics of the thermally driven color-changing gel prepared according to the present invention, the present invention further constructs a cascade fluorescence resonance energy transfer (FRET) system. A chemical dye is added to the mixed system of the organic ligand, AIE molecule, biobased polymer and metal ion. The chemical dye is one or more of 4,7-bis(thiophen-2-yl)benzo-[2,1,3]-thiadiazole (DBT), rhodamine B (RhB), sulforhodamine B (SRG) and sulforhodamine 101 (SR101). The concentration of the chemical dye is 5×10 -4 -5×10 -2 mmol / L.
[0046] As one of the embodiments, the cascade fluorescence resonance energy transfer (FRET) system further constructed by the present invention uses TPE-CA as the energy donor, and 4,7-bis(thiophen-2-yl)benzo-[2,1,3]-thiadiazole (DBT) and rhodamine B (RhB) as the primary and secondary energy acceptors respectively. By precisely regulating the energy transfer efficiency between the components, temperature-dependent multicolor fluorescence conversion is achieved. In particular, due to the different temperature responses of TPE-CA, DBT and RhB, the system can exhibit time-dependent fluorescence color gradual change and quenching behavior, and this process is completely reversible. And the invented thermally driven color-changing gel material can be used for time-dependent encryption and anti-counterfeiting, and has the advantages of information self-destruction, multiple verification and anti-copying, which can greatly guarantee information security. Specifically: it can be applied to a multi-dimensional color code encryption and anti-counterfeiting system for dynamic fluorescence color-changing technology, and realizes multi-level security verification through time-temperature dual response, and has characteristics such as anti-copying, self-destruction and reversible recovery.
[0047] Specifically: Using TPE-CA as the energy donor and 4,7-bis(thiophen-2-yl)benzo-[2,1,3]-thiadiazole (DBT) as the primary energy acceptor. The preparation process is as follows: C3-Phe and TPE-CA are mixed at a molar ratio of 100:1 - 10:1. The final concentration of the organic solution of C3-Phe is 3 - 20 mmol / L, and the final concentration of TPE-CA is 1 - 5 mmol / L. DBT is mixed with the mixed solution of C3-Phe and TPE-CA, and the final concentration of DBT is 5×10 -4 -5×10 -2 mmol / L; after mixing the aqueous solution of HA with the above-mentioned mixture, distilled water as the poor solvent and an aqueous solution of Al 3+ are added and then mixed. The organic solution of DBT is any one of DMSO, DMF and ethanol. The final concentration of HA is 0.1 wt% - 2 wt%, and the final concentration of Al 3+ is 4 - 10 mmol / L.
[0048] Using rhodamine B (RhB) as the secondary energy acceptor. The preparation process is as follows: Mix C3-Phe and TPE-CA in a molar ratio of 100:1 - 10:1, and the final concentration of the organic solution of C3-Phe is 3 - 20 mmol / L; Mix DBT with the mixed solution of C3-Phe and TPE-CA, and the final concentration of DBT is 5×10 -4 -5×10 -2 mmol / L; Mix the aqueous solution of HA with the above-mentioned mixed solution and then add rhodamine B (RhB) for mixing; The final concentration of the aqueous solution of rhodamine B (RhB) is 5×10 -4 -5×10 -2 mmol / L; Then add the poor solvent distilled water and the aqueous solution of Al 3+ to mix with the above mixed solution. The final concentration of HA is 0.1 wt% - 2 wt%, and the final concentration of Al 3+ is 4 - 10 mmol / L.
[0049] The present invention will be further described below in conjunction with specific embodiments.
[0050] Example 1
[0051] A thermally driven color-changing gel, and its specific preparation steps are as follows:
[0052] Material (1): Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 0.38 mL of DMSO, and then add 0.1 ml of HA and 0.485 mL of H2O and mix evenly. Then add 15 μL of 0.5 mol / L Al 3+ , and after mixing the above solution evenly and standing for 5 - 15 min, a gel-like substance is formed, which is the C3-Phe / HA / Al 3+ hydrogel.
[0053] Material (2): Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 10 μL of 0.1 mol / L of TPE-CA and vortex evenly, then add 0.37 mL of DMSO, and then add 0.1 ml of HA and 0.485 mL of H2O and mix evenly. Then add 15 μL of 0.5 mol / L Al 3+ , and after mixing the above solution evenly and standing for 5 - 15 min, a gel-like substance is formed, which is the C3-Phe / HA / Al 3+ / TPE-CA gel.
[0054] Material (3): After vortexing 10 μL of 0.1 mol / L TPE-CA evenly, add 0.49 mL of DMSO, and then add 0.5 mL of H2O and mix evenly to obtain a mixed solution containing only TPE-CA.
[0055] Comparative Example 1
[0056] The emission spectra comparison of TPE-CA in the gel formed by C3-Phe of the present invention with C3-Phe / HA / Al alone 3+ gel and TPE-CA in the solvent.
[0057] Prepare the following 3 materials according to the steps of Example 1 above.
[0058] Material 1: C3-Phe / HA / Al provided by the present invention 3+ Hydrogel, the organic solvent is DMSO, and the final concentration of Al 3+ is 7.5 mmol / L, the final concentration of C3-Phe is 4.8 mmol / L, select 0.2 wt% of HA with a total volume of 1 mL, and prepare it according to the method described in Material (1) of Example 1.
[0059] Material 2: C3-Phe / TPE-CA / HA / Al hydrogel provided by the present invention 3+ The organic solvent is DMSO or DMF, the final concentration of TPE-CA is 1 mmol / L, the metal ion is Al 3+ with a final concentration of 7.5 mmol / L, the final concentration of C3-Phe is 4.8 mmol / L, select 0.2 wt% of HA with a total volume of 1 mL, and prepare it according to the method described in Material (2) of Example 1.
[0060] Material 3: An aqueous solution of DMSO as the organic solvent of the present invention, the final concentration of TPE-CA is 1 mmol / L, and the total volume is 1 mL, which is prepared according to the method described in Material (3) of Example 1.
[0061] Test the fluorescence of the above 3 materials in a sealed quartz cuvette with a fluorescence spectrometer. After testing with the fluorescence spectrometer, the fluorescence emission spectra of TPE-CA in the gel formed with C3-Phe / HA / Al 3+ and in the solvent alone are seen Figure 1 . From Figure 1 it can be seen that TPE-CA can cause the gel to have strong fluorescence in the gel, while the fluorescence intensity of the original gel is extremely weak.
[0062] Example 2 Influence of AIE molecular type on gel fluorescence
[0063] The gel preparation method is the same as that of Material 2 in Example 1, with all other conditions being exactly the same. Only the types of AIE molecules are changed. The four types of AIE molecules are: 4,4'-(1,2-diphenylethylene-1,2-diyl)dibenzoic acid, 4,4',4'',4'-(ethene-1,1,2,2-tetrayl)tetrabenzoic acid, tetrakis[4-(3,5-dicarboxyphenyl)]tetraphenylethylene, 1,1,2-triphenyl-2-(4-formylphenyl)ethene, tetrakis(4-pyridylphenyl)ethylene, tetrakis[4-(4'-carboxyphenyl)phenyl]ethylene, 4,4'-(2,2-diphenylethylene-1,1-diyl)dibenzoic acid.
[0064] Another set of solutions containing only AIE molecules was prepared. The preparation method was the same as that of Material 3 in Example 1. After testing with a fluorescence spectrometer, the effects of different types of AIE molecules on the gel light emission are shown in Figure 2 . Observe and compare whether different AIE molecules will affect the fluorescence intensity.
[0065] The experimental results show that when the AIE molecule is 4,4'-(1,2-diphenylethylene-1,2-diyl)dibenzoic acid, the addition of the AIE molecule significantly enhances the fluorescence performance of the gel system, mainly due to the spatial confinement effect of the gel network on the selected TPE-CA and the synergistic effect between the two. Compared with the other AIE molecules, its anchoring effect also improves the photostability of TPE-CA, making it exhibit more excellent fluorescence performance and application potential in the gel system.
[0066] Example 3 Influence of different solvent ratios on gel formation
[0067] A thermally driven color-changing gel material, and its specific preparation steps are as follows:
[0068] Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 10 μL of 0.1 mol / L TPE-CA and vortex evenly, then add 0.17 - 0.57 mL of DMSO, and then add 0.1 mL of 0.2 wt% HA and mix evenly with 0.185 - 0.585 mL of H2O. After that, add 15 μL of 0.5 mol / L Al 3+ , after mixing the above solutions evenly and standing for 5 - 15 min, a gel-like substance is formed, which is the C3-Phe / HA / Al 3+ / TPE-CA gel.
[0069] Example 4 Influence of metal ion types on gel formation
[0070] The gel preparation method was the same as that of Material 2 in Example 1, with all other conditions being exactly the same. Only the type of metal ion was changed (without affecting gel formation), and whether different rare earth ions formed gels was observed and compared. The results are shown in Table 1. The types of metal ions used in Table 1 were: samarium chloride, europium chloride, dysprosium chloride, calcium chloride, copper chloride, barium chloride, terbium nitrate, aluminum nitrate, zinc chloride, manganese chloride, iron chloride, cadmium chloride. The results showed that gels could form after adding 9 types of metal ions.
[0071] Table 1 Influence of Metal Ion Types on Gel Formation
[0072] Metal type Samarium chloride Europium chloride Dysprosium chloride Calcium chloride Copper chloride Barium chloride Terbium nitrate Aluminum nitrate Gel formation state Gel formation Gel formation Gel formation Gel formation Gel formation Gel formation Gel formation Gel formation Metal type Terbium chloride Zinc chloride Manganese chloride Iron chloride Cadmium chloride Lithium chloride Cobalt chloride Gel formation state Gel formation No gel formation No gel formation No gel formation No gel formation No gel formation No gel formation
[0073] Example 5 Influence of Metal Ion Types on Fluorescence Intensity of Gels
[0074] The gel preparation method was the same as that of Material 2 in Example 1, with all other conditions being exactly the same. Only the type of metal ion was changed. After testing with a fluorescence spectrometer, the influence of metal ion types on gel light emission is shown in Figure 3 . Figure 3 It shows that under the same conditions, whether different metal ions would affect the fluorescence intensity was observed and compared. The types of metal ions used were: samarium chloride, europium chloride, dysprosium chloride, calcium chloride, copper chloride, barium chloride, terbium nitrate, europium nitrate, aluminum nitrate. The results showed that when gels could form after adding metal ions, the addition of aluminum ions promoted stronger fluorescence intensity of the gels.
[0075] Comparative Example 2
[0076] TPE-CA and C3-Phe, HA, Al 3+ Comparison of emission spectra of gels formed in different mixed solvents and with different solvent ratios.
[0077] Finally, the following 2 materials were prepared.
[0078] Material 1: The C3-Phe / TPE-CA / HA / Al 3+ gel provided by the present invention, the organic solvent was an aqueous solution of DMSO, the final concentration of TPE-CA was 1 mmol / L, the final concentration of Al 3+ was 7.5 mmol / L, the final concentration of C3-Phe was 4.8 mmol / L, 0.2 wt% of HA was selected, with a total volume of 1 mL, and it was prepared by the method described in Example 3 with different ratios of DMSO:H2O (3:7 - 6:4, v / v). Figure 4 For the prepared C3-Phe / TPE-CA / HA / Al 3+ gel electron microscopy picture.
[0079] Material 2: The C3-Phe / TPE-CA / HA / Al provided by the present invention3+ Aggregation-induced emission gel, the organic solvent is an aqueous solution of DMF, with different solvent ratios (DMF: water = 5:5 - 3:7, v / v), the final concentration of TPE-CA is 1 mmol / L, Al 3+ The final concentration is 7.5 mmol / L, the final concentration of C3-Phe is 4.8 mmol / L, 0.2 wt% of HA is selected, and the total volume is 1 mL. The preparation process is the same as in Example 3.
[0080] The fluorescence of the above two materials was tested by a fluorescence spectrometer in a sealed quartz cuvette. After being tested by the fluorescence spectrometer, the fluorescence emission spectra of the metal gels formed by C3-Phe / TPE-CA / HA / Al 3+ in different solvents are shown in Figure 5 and Figure 6 . From Figure 5 and Figure 6 , it can be seen that for the gel formed by C3-Phe / TPE-CA / HA / Al 3+ in DMSO and water solvents, the best solvent ratio is DMSO: H2O = 5:5.
[0081] Example 6
[0082] Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 10 μL of a 0.1 mol / L DMSO solution of TPE-CA and mix well by shaking. After mixing evenly, add 1 - 100 μL of the dye DBT and 0.27 - 0.37 mL of DMSO, then add 0.1 mL of HA and 0.385 mL of H2O and mix well. Then add 15 μL of 0.5 mol / L Al 3+ . After mixing the above solution evenly and standing for 5 - 15 min, a gel-like substance is formed, which is the thermally driven color-changing gel of the present invention.
[0083] Example 7
[0084] Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 10 μL of a 0.1 mol / L DMSO solution of TPE-CA and mix well by shaking. After mixing evenly, add 20 μL of the dye DBT and 0.35 mL of DMSO, then add 0.1 mL of HA and 1 - 50 μL of RhB and mix well. Then add 0.335 - 0.385 mL of H2O and mix well. Then add 15 μL of 0.5 mol / L Al 3+ . After mixing the above solution evenly and standing for 5 - 15 min, a gel-like substance is formed, which is the thermally driven color-changing gel of the present invention.
[0085] Example 8 Effect of Temperature on Luminescence Performance of the Gel after the First Construction of the FRET Platform
[0086] The gel prepared in Example 6 was placed in an 85°C oven and left standing for 0 - 60 min for fluorescence testing of the gel. The fluorescence intensity of the gel was measured at intervals of time at 85°C. The following only shows the example of 10 μL DBT, and the results are shown in Table 2. The results indicate that for the thermochromic gel prepared for the first energy resonance transfer, the fluorescence intensity of the gel decreases after heating for different periods of time.
[0087] Table 2 Effect of Temperature on Luminescence Intensity of the Gel of the Invention
[0088]
[0089]
[0090] Example 9 Effect of Temperature on Luminescence Performance of the Gel after the Second Construction of the FRET Platform
[0091] The gel prepared in Example 7 was placed in an 85°C oven and left standing for 0 - 60 min for fluorescence testing of the gel. The fluorescence intensity of the gel was measured at intervals of time at 85°C. The following only shows the examples of 10 μM DBT and 20 μM RhB, and the results are shown in Table 3. The results indicate that for the thermochromic gel prepared for the second energy resonance transfer, the fluorescence intensity of the gel decreases after heating for different periods of time.
[0092] Table 3 Effect of Temperature on Luminescence Intensity of the Gel of the Invention
[0093] Heating time / min 0 15 35 60 Wavelength / nm 579 579 579 590 Fluorescence intensity (a.u.) 1245 651 158 45
[0094] Example 10 Effect of Adding Distilled Water to the Quenched Gel on Luminescence Performance
[0095] Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 10 μL of a DMSO solution of 0.1 mol / L TPE-CA and mix well by shaking. After mixing evenly, add 1 - 100 μL of the dye DBT and 0.27 - 0.37 mL of DMSO, then add 0.1 mL of HA and 0.385 mL of H2O and mix well. Then add 15 μL of 0.5 mol / L Al 3+ , and after mixing the above solution evenly and leaving it standing for 5 - 15 min, a gel-like substance is formed, which is the thermochromic gel of the present invention.
[0096] The gel was placed in an 85°C oven and left standing for 60 min, after which the fluorescence of the gel was quenched. After adding distilled water dropwise into the gel, the fluorescence intensity recovered, and its color change was asFigure 7 , only the case of 10 μM DBT is shown below, and the results are shown in Table 4. The results indicate that adding distilled water dropwise into the quenched gel can restore the fluorescence intensity of the gel.
[0097] Table 4 Influence of water environment on the luminescence intensity of the gel of the present invention
[0098] Water dropping order Before water dropping After water dropping Wavelength / nm 600 550 Fluorescence intensity (a.u.) 77 790
[0099] Example 11
[0100] Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 10 μL of a DMSO solution of 0.1 mol / L TPE-CA and mix well by shaking. After mixing evenly, add 20 μL of the dye DBT and 0.35 mL of DMSO, then add 0.1 mL of HA and 1 - 50 μL of RhB and mix evenly. After that, add 0.335 - 0.385 mL of H2O and mix evenly, and then add 15 μL of 0.5 mol / L Al 3+ , after mixing the above solution evenly and standing for 5 - 15 min, a gel-like substance is formed, which is the thermally driven color-changing gel of the present invention.
[0101] Place the gel in an oven at 85 °C and let it stand for 60 min, then the fluorescence of the gel is quenched. After adding distilled water dropwise into the gel, the fluorescence intensity is restored, and its color change is as Figure 8 , only the cases of 10 μM DBT and 20 μM RhB are shown below, and the results are shown in Table 5. The results indicate that adding distilled water dropwise into the quenched gel can restore the fluorescence intensity of the gel.
[0102] Table 5 Influence of water environment on the luminescence intensity of the gel of the present invention
[0103] Water dropping order Before water dropping After water dropping Wavelength / nm 590 580 Fluorescence intensity (a.u.) 45 1201
[0104] Example 12
[0105] Dissolve 3 mg of C3-Phe in 0.12 mL of DMSO, then add 10 μL of a DMSO solution of 0.1 mol / L TPE-CA and mix well by shaking. After mixing evenly, add 1 - 100 μL of the dye DBT and 0.27 - 0.37 mL of DMSO, then add 0.1 mL of HA and 0.385 mL of H2O and mix evenly, and then add 15 μL of 0.5 mol / L Al 3+, after mixing the above solutions evenly, drop them into the microplate in sequence to form a 5×5 table, and let it stand for 5 - 15 min to form a gel-like substance, which is the thermally driven color-changing gel of the present invention. Place it in an oven at 85°C and heat it for different times. The gel in each cell changes color over time at 85°C, and information encryption and decryption are performed on it. The results are as Figure 9 shown. The results show that the gel has good temperature responsiveness.
[0106] The embodiments described above are only descriptions of the preferred modes of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.
Claims
1. A preparation method of a thermally driven color-changing gel, characterized in that: Mix an organic ligand, an AIE molecule, a bio-based polymer, and metal ions to obtain a thermally driven color-changing gel material at room temperature; The organic ligand is C3-Phe, the bio-based polymer is hyaluronic acid, the AIE molecule is any one of 4,4′-(1,2-divinylene-1,2-diyl)dibenzoic acid, 4,4',4”,4'-(ethene-1,1,2,2-tetrayl)tetrabenzoic acid, tetrakis[4-(3,5-dicarboxyphenyl)]tetraphenylethylene, 1,1,2-triphenyl-2-(4-formylphenyl)ethene, tetrakis(4-pyridinophenyl)ethene, tetrakis[4-(4'-carboxyphenyl)phenyl]ethene, and 4,4'-(2,2-diphenylethene-1,1-diyl)dibenzoic acid, and the metal ion is any one of samarium ion, europium ion, dysprosium ion, calcium ion, copper ion, barium ion, terbium ion, europium ion, and aluminum ion.
2. The preparation method according to claim 1, characterized in that: The degree of polymerization of the hyaluronic acid is 20 - 200.
3. The preparation method according to claim 2, wherein: The final concentration of the organic solution of the organic ligand is 3 - 20 mmol / L, the final concentration of the bio-based polymer is 0.1 wt% - 2 wt%, the final concentration of the metal ion is 4 - 10 mmol / L, and the final concentration of the AIE molecule in the mixed solution of the organic ligand and the AIE molecule is 1 - 5 mmol / L.
4. The preparation method according to claim 3, characterized in that: The molar ratio of the organic ligand to the AIE molecule is 100:1 - 10:
1.
5. The preparation method according to claim 3, characterized in that: Mix the organic ligand with an organic solution, and the organic solvent is any one of DMSO, DMF, ethanol, and methanol; Mix the aqueous solution of the bio-based polymer with the mixed solution of the organic ligand and the AIE molecule, and then add a poor solvent of the organic ligand and an aqueous solution of the metal ion for mixing, and the poor solvent is distilled water.
6. The preparation method according to claim 5, characterized in that: The volume ratio of the poor solvent to the organic solvent is 9:1 - 1:
9.
7. The preparation method according to any one of claims 1 to 6, characterized in that: Add a chemical dye to the mixed system of the organic ligand, the AIE molecule, the bio-based polymer, and the metal ion, and the chemical dye is one or more of 4,7-bis(thiophen-2-yl)benzo-[2,1,3]-thiadiazole, rhodamine B, sulfonyl rhodamine B, and sulforhodamine 101.
8. The preparation method according to claim 7, characterized in that: The concentration of the chemical dye is 5×10 -4 -5×10 -2 mmol / L.
9. A thermally driven color-changing gel prepared by the preparation method according to any one of claims 1 - 8.
10. Application of a thermally driven color-changing gel prepared by the preparation method according to any one of claims 1 - 8 in time-dependent encryption and anti-counterfeiting.