Preparation method and application of photoactivated deoxidizing gel

Abstract

The preparation method specifically comprises the following steps: (1) respectively preparing mother liquor containing a photosensitizer and mother liquor containing an annihilation agent by taking tetrahydrofuran as a solvent; (2) heating and volatilizing the prepared mother liquor containing the photosensitizer and the annihilation agent, then adding a polymeric monomer and a photochemical deoxygenization organic medium, then adding a photoinitiator, heating and stirring the obtained mixed system to enable solids to be fully dissolved in an organic phase so as to prepare a gel precursor; and (3) irradiating the prepared gel precursor by ultraviolet light or visible light to carry out crosslinking reaction. According to the preparation method provided by the invention, photochemical deoxidizing media PEG, DMSO and TMSO are taken as organic solvent matrixes and are crosslinked with multiple groups of polymer monomers (such as PEGDA and HEA) to form a gel network, and the gel system with up-conversion emission performance in the air environment is successfully prepared. In addition, the photo-activated deoxidizing gel prepared by the method can be successfully applied to information encryption and anti-counterfeiting technologies.

Description

Technical Field

[0001] The present invention relates to the technical field of gel, in particular to a preparation method and application of a photoactivated oxygen-removing gel. Background Art

[0002] Photoactivated oxygen-scavenging TTA-UC gel is a gel material that can remove oxygen through a photochemical reaction under illumination and exhibits enhanced triplet-triplet annihilation upconversion (TTA-UC) processes. TA-UC technology has attracted increasing attention due to its broad application prospects in various fields, including photovoltaics, biomedicine, photocatalysis, organic light-emitting diodes (OLEDs), 3D printing, and sensing technology.

[0003] Efficient TTA-UC processes are typically performed in solution phase because liquids allow for rapid diffusion of excited molecules. However, one of the key factors in achieving TTA-UC in liquid phase is the anaerobic capacity of the support medium. The oxygen sensitivity of upconversion systems necessitates the search for suitable supports.

[0004] Polymer gel is a three-dimensional cross-linked polymer network and solvent (such as water) [1] , organic solvents [2] or ionic liquids [3] ) is a soft material composed of polymer chains. Its characteristic is that the polymer chains form a cross-linked structure through chemical bonds (covalent bonds) or physical effects (such as hydrogen bonds, van der Waals forces, etc.), which can absorb and retain a large amount of solvent to form a semi-solid system between solid and liquid. Polymer gels are used in biomedicine. [4] , flexible electronics [5, 6] Polymer network design and its influence on gel properties have been widely studied in various fields.

[0005] Polyethylene glycol PEG400, dimethyl sulfoxide (DMSO), and tetramethylene sulfoxide (TMSO), as organic photochemical oxygen scavenging media with a certain viscosity, can serve as a gel matrix and crosslink with other polymers to form an organic photochemical oxygen scavenging gel. The gel network structure effectively blocks oxygen and reduces its diffusion. Unlike the extremely low diffusion in a pure solid state, the semi-solid nature ensures proper diffusion and collision of molecules within the gel. This polymer gel is an ideal carrier for the upconversion dual component, enabling efficient upconversion in air.

[0006] like Figure 21 As shown, Wang et al. [7]Using polyethylene glycol 400 (PEG400) as an organic solvent, rapidly cross-linked HEMA-PEG gels were prepared, which exhibited high stretchability and toughness, rapid self-healing, and long-term stability. Depending on the molecular weight and fraction of PEG, the PEG gels had tensile strengths ranging from 0.22 to 41.3 MPa, strains at break ranging from 12% to 4336%, moduli ranging from 0.08 to 352 MPa, and toughness ranging from 2.89 to 56.23 MJ m -3 Finally, the rapid self-healing of HEMA-PEG gel was demonstrated, and a self-healing pneumatic actuator was fabricated by 3D printing.

[0007] Dowon Team [8] Several groups of photosensitive resins were prepared for fast and high-resolution visible light 3D printing, one of which was an ink component mixed with 2-hydroxyethyl acrylate and triethylene glycol diacrylate.

[0008] However, the above studies all have the disadvantages of complex preparation methods and high production costs. Therefore, it is very necessary to develop a method for preparing light-activated oxygen-scavenging gel that is easy to operate.

[0009] References are as follows: [1]ZHANG Y, TAN Y, LAO J, et al. Hydrogels for Flexible Electronics[J]. ACS Nano, 2023, 17(11): 9681-93. [2] LIN W, SONG H, QI H, et al. Controllable Structure Design of anOrganic Gel-Infused Porous Surface for Efficient Anti- and De-icing [J]. Langmuir, 2024, 40(48): 25717-27. [3] ZHANG S, WANG F, PENG H, et al. Flexible Highly SensitivePressure Sensor Based on Ionic Liquid Gel Film [J]. ACS Omega, 2018, 3(3):3014-21. [4] GAMBOA J, PAULO-MIRASOL S, ESTRANY F, et al. Recent Progress inBiomedical Sensors Based on Conducting Polymer Hydrogels [J]. ACS Applied BioMaterials, 2023, 6(5): 1720-41. [5] CHU Y, FAN Q, CHAI C, et al. “Water-in-Deep Eutectic Solvent” GelElectrolytes Synergistically Controlled by Solvation Regulation and GelationStrategies for Flexible Electronic Devices [J]. ACS Applied Materials&Interfaces, 2023, 15(9): 12088-98. [6] ZHU A, XU Q, HUANG J, et al. Fabrication of Gelatin-Derived GelElectrolyte Using Deep Eutectic Solvents through In Situ Derivatization andCrosslinking Strategy for Supercapacitors and Flexible Sensors [J]. ACSApplied Materials&Interfaces, 2023, 15(35): 41483-93. [7] WANG Z, CUI H, LIU M, et al. Tough, Transparent, 3D-Printable,and Self-Healing Poly(ethylene glycol)-Gel (PEGgel) [J]. Advanced Materials,2022, 34(11): 2107791. [8] AHN D, STEVENS LM, ZHOU K, et al. Rapid High-Resolution VisibleLight 3D Printing [J]. ACS Central Science, 2020, 6(9): 1555-63. Summary of the Invention

[0010] The purpose of the present invention is to provide a preparation method and application of a photoactivated oxygen-scavenging gel.

[0011] In order to achieve the above object, the solution of the present invention is: A method for preparing a photoactivated oxygen-scavenging gel comprises the following steps: (1) Using tetrahydrofuran as solvent, prepare mother solutions containing photosensitizer and annihilator respectively; (2) adding the mother solution containing the photosensitizer and the annihilator prepared in step (1) dropwise together and heating to volatilize, then adding the polymerization monomer and the photochemical deoxygenated organic medium, and then adding the photoinitiator, heating and stirring the resulting mixed system to fully dissolve the components in the organic phase, and preparing a gel precursor; (3) The gel precursor prepared in step (2) is irradiated with ultraviolet light or visible light to undergo a cross-linking reaction to obtain the photoactivated deoxygenating gel.

[0012] Preferably, the photosensitizer in step (1) is selected from one of tetraphenylbenzoporphyrin platinum or octaethylporphyrin platinum.

[0013] Preferably, the annihilation agent in step (1) is selected from one of 9,10-bis(phenylethynyl)anthracene, 9,10-diphenylanthracene or 9,10-bis[(triisopropylsilyl)ethynyl]anthrylbenzene.

[0014] Preferably, the polymerizable monomer in step (2) is composed of one or a combination of two or more of hydroxyethyl acrylate, polyethylene glycol diacrylate 400, 2-hydroxyethyl methacrylate or acrylic acid.

[0015] Preferably, the photochemical deoxygenation organic medium in step (2) is composed of one or a combination of two or three of polyethylene glycol 400, dimethyl sulfoxide or tetramethylene sulfoxide.

[0016] Preferably, the photoinitiator in step (2) is a liquid photoinitiator.

[0017] The photoactivated oxygen-scavenging gel prepared by the above method is a triplet-triplet annihilation upconversion material; the gel is composed of a photosensitizer, an annihilation agent, a gel polymer matrix and a photochemical oxygen-scavenging organic medium.

[0018] Preferably, the gel polymer matrix can be formed by in-situ reaction of polymerizable monomers and photoinitiators.

[0019] Application of the light-activated oxygen-scavenging gel prepared by the above method in information encryption.

[0020] The application of the light-activated deoxidizing gel prepared by the above method in anti-counterfeiting.

[0021] The principle of the preparation method of the photoactivated oxygen-scavenging gel provided by the present invention is as follows: The method provided by the present invention is to prepare a polymer organic gel carrier suitable for upconversion dual components, and then further refine the ratio of the crosslinker and the photoactivated deoxygenating solvent in the gel network to achieve upconversion luminescence in an air environment; this is because the TTA-UC process usually relies on energy transfer between the photosensitizer and the luminescent agent, but oxygen will quench the triplet excited state, thereby inhibiting the upconversion efficiency. The photoactivated deoxygenating gel prepared by the method provided by the present invention can consume oxygen through photochemical reactions, reducing the quenching of triplet states by oxygen, thereby improving the TTA-UC efficiency. Specifically, the method provided by the present invention uses photochemical deoxygenating media PEG, DMSO, and TMSO as organic solvent matrices, and crosslinks with multiple groups of polymer monomers (such as PEGDA and HEA) to form a gel network, successfully achieving upconversion emission in an air environment.

[0022] The gain effects of the present invention are as follows: 1. The raw materials used in the preparation method of the photoactivated oxygen-scavenging gel provided by the present invention are cheap and easily available. A gel system with upconversion performance can be quickly prepared through a simple reaction, which has the advantages of simple operation and low cost.

[0023] 2. The preparation method of the photoactivated oxygen-scavenging gel provided by the present invention uses photochemical oxygen-scavenging media PEG, DMSO, and TMSO as organic solvent matrices, which are cross-linked with multiple groups of polymer monomers (such as PEGDA and HEA) to form a gel network, successfully preparing a gel system with upconversion emission properties in an air environment.

[0024] 3. The method provided by the present invention uses a HEA-TMSO gel precursor containing PEGDA400 as the ink base to prepare three inks with different components. These inks are distributed at specific dot positions in the pattern and a photoinitiator is used to trigger the rapid polymerization of the gel under ultraviolet or visible light irradiation conditions. Different encrypted information is revealed under light with wavelengths of 532 nm and 350 nm. The luminescent information persists for a long time and has stable properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1This is a graph showing the excitation power dependence of the upconversion emission intensity of the HEMA-PEG-1 gel provided by the present invention.

[0026] Figure 2 This is a threshold diagram of the up-conversion emission intensity of the HEMA-PEG-1 gel provided by the present invention.

[0027] Figure 3 This is a graph of the upconversion quantum efficiency of the HEMA-PEG-1 gel provided by the present invention.

[0028] Figure 4 This is a graph showing the variation of emission intensity with excitation power density in the HEMA-PEG-2 gel system provided by the present invention.

[0029] Figure 5 This is a graph showing the upconversion efficiency of the HEMA-PEG-2 gel system provided by the present invention.

[0030] Figure 6 This is the up-conversion spectrum of the HEMA-PEG-3 gel system provided by the present invention.

[0031] Figure 7 This is a graph showing the excitation power dependence of the upconversion emission intensity of the HEMA-PEG-3 gel system provided by the present invention.

[0032] Figure 8 This is a threshold diagram of the up-conversion emission intensity of the HEMA-PEG-3 gel system provided by the present invention.

[0033] Figure 9 This is a graph of the upconversion quantum efficiency of the HEMA-PEG-3 gel system provided by the present invention.

[0034] Figure 10 The emission curves of the HEA-PEG-1 gel system provided by the present invention after irradiation with a 532 nm light source for 1 minute and 5 minutes after polymerization are shown.

[0035] Figure 11 These are the absorption and emission spectra of PtOEP and DPA in DMSO of the HEA-DMSO-1 gel system provided by the present invention.

[0036] Figure 12 This is the absorption and emission spectra of the HEA-DMSO-1 gel system provided by the present invention.

[0037] Figure 13 This is a threshold diagram of the up-conversion emission intensity of the HEA-DMSO-1 gel system provided by the present invention.

[0038] Figure 14This is a graph of the upconversion quantum efficiency of the HEA-DMSO-1 gel system provided by the present invention.

[0039] Figure 15 This is a photoluminescence curve diagram of the HEA-TMSO-1 gel system provided by the present invention.

[0040] Figure 16 This is a graph showing the excitation power dependence of the emission intensity of the HEA-TMSO-1 gel system provided by the present invention.

[0041] Figure 17 This is a threshold diagram of the up-conversion emission intensity of the HEA-TMSO-1 gel system provided by the present invention.

[0042] Figure 18 This is a graph of the upconversion quantum efficiency of the HEA-TMSO-1 gel system provided by the present invention.

[0043] Figure 19 This is a pattern of application of the HEA-TMSO-1 gel system provided by the present invention in information encryption.

[0044] Figure 20 This is a pattern of application of the HEA-TMSO-1 gel system provided by the present invention in anti-counterfeiting.

[0045] Figure 21 Schematic diagram of the hydrogel and PEG gel structures. DETAILED DESCRIPTION

[0046] The present invention will be described in detail below with reference to the accompanying drawings and examples. It should also be understood that the following examples are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. The specific mass, reaction time, temperature, process parameters, etc. in the examples are only examples within the appropriate ranges, and any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention fall within the scope of protection of the present invention.

[0047] Example 1 The steps for preparing HEMA-PEG gel are as follows: (1) Using tetrahydrofuran (THF) as solvent, the mother solutions of tetraphenylbenzoporphyrin platinum (PtTPBP) and 9,10-bis(phenylethynyl)anthracene (BPEA) were prepared with concentrations of 1×10 -3 mol / L and 1×10 -2 mol / L; (2) The PtTPBP mother solution (0.2 mL) and BPEA mother solution (4 mL) prepared in step (1) were respectively added dropwise to the same sample bottle, heated to volatilize tetrahydrofuran, and then 2-hydroxyethyl methacrylate (HEMA), acrylic acid and polyethylene glycol 400 (PEG) were added in a volume ratio of 1:1:2 (a total of 10 mL), and then a liquid photoinitiator 2-hydroxy-2-methylpropiophenone (300 mg) was added; heated and stirred to fully dissolve each component in the mixed organic phase to prepare a gel precursor; the concentrations of PtTPBP and BPEA in the obtained gel precursor were 2×10 -5 mol / L and 4×10 -3 mol / L; (3) The gel precursor prepared in step (2) is subjected to ultraviolet light irradiation for cross-linking reaction to obtain the photoactivated deoxygenated gel, and the obtained gel is recorded as HEMA-PEG-1.

[0048] The upconversion performance of the prepared gel was characterized as follows: (1) Up-conversion power threshold: A HEMA-PEG-1 gel system containing the upconversion components of the photosensitizer platinum tetraphenylbenzoporphyrin (PtTPBP) and the annihilator 9,10-bis(phenylethynyl)anthracene (BPEA) was illuminated with a 635 nm laser. The excitation power density was continuously varied through an attenuator. The power density was measured using a laser power meter, allowing for the measurement and recording of multiple spectra of upconversion intensity as a function of excitation power density. The data were then processed to generate a logarithmic plot of emission intensity versus laser power density. The intersection of the extended fitted curves with slopes of 2 and 1 was the power threshold for the upconversion system.

[0049] (2) Upconversion quantum yield The upconversion relative quantum yield was calculated using the method provided in the literature (TN Singh-Rachford, A. Nayak, ML Moro-Small, S. Goeb, MJ Therien and FN Castellano, J. Am. Chem. Soc., 2010, 132, 14203). The reference solution for the 635 nm excitation system was a methanol solution of methylene blue, while the reference solution for the 532 nm excitation system in subsequent examples was an aqueous solution of rhodamine 6G. The fluorescence emission peak of the reference solution was carefully aligned with the maximum upconversion emission peak of the upconversion organogel under the same excitation power density. Multiple spectra of the upconversion intensity as a function of excitation power density were measured and recorded by rotating the attenuator. The absorbance of the test and reference samples was measured using a UV-2600 UV-visible absorption spectrometer, and the absorbance at the excitation wavelength was recorded. The refractive index of both samples was measured using an Abbe refractometer.

[0050] The HEMA-PEG-1 gel network is formed by cross-linking 2-hydroxyethyl methacrylate, acrylic acid, and polyethylene glycol 400. To test the upconversion performance of this gel, a fiber optic spectrometer can be used to record the spectrum of the upconversion intensity as a function of the excitation light power density.

[0051] The characterization results are as follows: like Figure 1 As shown in the figure, the upconversion fluorescence peak around 520 nm and the phosphorescence peak around 770 nm of HEMA-PEG-1 gel are enhanced with the increase of the excitation light power density. Figure 2 The power threshold for obtaining HEMA-PEG-1 gel is 139.5 mW / cm 2 ; Using methanol solution of methylene blue as reference solution, Figure 3 The calculated upconversion quantum efficiency of the system is 0.3% (maximum value is 50%).

[0052] Example 2 The preparation steps of HEMA-PEG gel were similar to those in Example 1, except that 9,10-bis(phenylethynyl)anthracene in step (1) was replaced with 9,10-bis[(triisopropylsilyl)ethynyl]anthracene (TIPS-Ac); the concentrations of PtTPBP and TIPS-Ac in the obtained gel precursor were 2×10 -5 mol / L and 1×10 -3 mol / L; the remaining steps were the same as in Example 1; the obtained gel was recorded as HEMA-PEG-2.

[0053] The specific steps for characterizing the upconversion performance of HEMA-PEG-2 refer to Example 1, and the characterization results are as follows: Figure 4 Figure 3 is a graph showing the variation of emission intensity with excitation power density in the HEMA-PEG-2 gel system. The upconversion emission peak of this system is mainly located at 470 nm, and the phosphorescence peak of PtTPBP is located near 770 nm. Figure 5 This is the upconversion efficiency diagram of the system. From the diagram, we can calculate that the upconversion quantum efficiency of the system is 0.6% (the maximum value is 50%).

[0054] Example 3 The preparation steps of HEMA-PEG gel were similar to those in Example 1, except that the tetraphenylbenzoporphyrin platinum in step (1) was replaced by octaethylporphyrin platinum (PtOEP), and 9,10-bis(phenylethynyl)anthracene was replaced by 9,10-diphenylanthracene (DPA); the amount of the photoinitiator 2-hydroxy-2-methylpropiophenone in step (2) was changed to 0; the concentrations of PtOEP and DPA in the obtained gel precursor were 1×10 -5 mol / L and 3×10 -3 mol / L; the ultraviolet light in step (3) was changed to green light; the remaining steps were the same as in Example 1; the obtained gel was recorded as HEMA-PEG-3.

[0055] The specific steps for characterizing the upconversion performance of HEMA-PEG-3 refer to Example 1, except that the excitation light source was changed from 635 nm to 532 nm; the characterization results are as follows: No photoinitiator is required in the HEMA-PEG-3 gel system, and the precursor organic phase can be cross-linked into a gel using green light irradiation. Figure 6 This is the upconversion spectrum of the HEMA-PEG-3 gel system. It can be seen from the figure that the highest upconversion peak is at 440 nm and the phosphorescence peak of the photosensitizer is near 645 nm. Figure 7 The excitation power dependence diagram of the upconversion emission intensity of the system is shown in the figure. It can be seen from the figure that at 10.2 mW / cm 2 to 296.8 mW / cm 2 Within the range of excitation light power density, the upconversion intensity changes in a positive correlation. Figure 8 The excitation power threshold diagram of the system shows that there is an intersection of the linear fitting lines with a slope of 1.94 (close to 2) and a slope of 0.86 (close to 1) in the system, which indicates that the system transitions from the weak annihilation state to the strong annihilation state at this time, and the upconversion power threshold is 80.9 mW / cm 2 . Figure 9This is the upconversion efficiency diagram of the system. From the diagram, we can calculate that the upconversion quantum efficiency of the system is 3% (the maximum value is 50%).

[0056] Example 4 The steps for preparing HEA-PEG gel are as follows: (1) Using tetrahydrofuran (THF) as solvent, the mother solutions of octaethylporphyrin platinum (PtOEP) and 9,10-diphenylanthracene (DPA) were prepared respectively. The concentration of PtOEP was 1×10 -3 mol / L, the concentration of DPA was 1×10 -2 mol / L; (2) The PtOEP mother liquor (0.5 mL) and DPA mother liquor (10 mL) prepared in step (1) were respectively added dropwise to the same sample bottle, heated to evaporate the solvent, and then hydroxyethyl acrylate (HEA) and PEG400 were added in a volume ratio of 1:2 (a total of 9 mL), and then 1 mL PEGDA400 (1 wt%) was added, and heated and stirred to fully dissolve each component in the organic phase medium to prepare a gel precursor; (3) The gel precursor prepared in step (2) is subjected to green light irradiation for cross-linking reaction to obtain the photoactivated deoxygenated gel; the obtained gel is designated as HEA-PEG-1.

[0057] The specific steps for characterizing the upconversion performance of HEA-PEG-1 refer to Example 1, except that the excitation light source was changed from 635 nm to 532 nm; the characterization results are as follows: Figure 10 The emission curves of the HEA-PEG-1 gel system after irradiation with a 532 nm light source for 1 minute and 5 minutes after polymerization. It can be seen from the figure that: in the first minute of irradiation, the upconversion fluorescence peak and phosphorescence peak in the black emission curve of the system are both high; when the irradiation is continued for 5 minutes, the red emission curve decreases significantly, which may be due to photodegradation in the system; therefore, no further characterization was performed.

[0058] Example 5 The preparation steps of HEA-DMSO gel were similar to those in Example 4, except that the PEG400 matrix in step (2) was replaced by DMSO; the resulting gel was designated HEA-DMSO-1.

[0059] The specific steps for characterizing the upconversion performance of HEA-DMSO-1 refer to Example 1, except that the excitation light source was changed from 635 nm to 532 nm; the characterization results are as follows: Figure 11 The absorption and emission spectra of PtOEP and DPA in DMSO are shown in Figure 11 The red solid line and the red dotted line are the absorption and emission spectra of the photosensitizer PtOEP, respectively. It shows a typical Soret band absorption peak at 380 nm, an absorption Q band at 530 nm, and a strong red emission peak at 645 nm. The blue solid line and the dotted line are the absorption and emission spectra of the annihilator DPA, respectively. The maximum absorption characteristic peak is located at 370 nm, and the fluorescence emission peak is around 420 nm. Figure 12 The absorption and emission spectra of HEA-DMSO-1 gel system are shown in Figure 2. In addition, the concentration of photosensitizer PtOEP was 1.3×10 - 5 mol / L, the concentration of annihilator DPA was 2×10 -3 mol / L HEA-DMSO-1 gel system was used to characterize the upconversion performance. Figure 13 As shown in the figure, the excitation power threshold of the system can be tested to be 36.4 mW / cm 2 . Figure 14 This is the upconversion efficiency diagram of the system. From the diagram, we can calculate that the upconversion quantum efficiency of the system is 3.7% (the maximum value is 50%).

[0060] Example 6 The preparation steps of HEA-TMSO gel were similar to those in Example 4, except that the PEG400 matrix in step (2) was replaced by TMSO; the resulting gel was designated HEA-TMSO-1.

[0061] The specific steps for characterizing the upconversion performance of HEA-TMSO-1 refer to Example 1, except that the excitation light source was changed from 635 nm to 532 nm; the characterization results are as follows: Figure 15 Figure 2 is the photoluminescence curve of HEA-TMSO-1 gel. It can be seen from the figure that under the excitation of 532 nm light source, the upconversion emission peak is much higher than the phosphorescence peak. This phenomenon indicates that the triplet-triplet energy transfer rate between the photosensitizer and the annihilator in this system is higher, and the energy is more easily transferred to the annihilator molecules, resulting in stronger emission. Figure 16 The emission intensity of the system is dependent on the excitation power. It can be seen from the figure that at 5.10 mW / cm 2 to 130.57 mW / cm 2 Within the range of excitation light source power density, the upconversion intensity still shows a positive correlation. Figure 17 The threshold diagram of the up-conversion emission intensity of the system is shown in the figure. It can be seen from the figure that at 11.2 mW / cm 2At this point, the linear fitting line with a slope of 1.95 (close to 2) turns into a linear fitting line with a slope of 1.16 (close to 1), indicating that when the excitation light is higher than this threshold, the system is in a high-efficiency annihilation state. Figure 18 This is the upconversion efficiency diagram of the system. From the diagram, we can calculate that the upconversion quantum efficiency of the system is 5.5% (the maximum value is 50%).

[0062] Example 7 The specific steps for applying the HEA-TMSO gel system in information encryption are as follows: According to the method provided in Example 6, a HEA-TMSO gel precursor is prepared and used as a patterned ink. An appropriate amount of photoinitiator is added to the gel precursor, and then the gel is rapidly polymerized under ultraviolet irradiation. After the ink contacts the substrate, it does not spread too much to affect the resolution of the pattern. Inks with three different components (1. The gel contains only DPA, 2. The gel contains only PtOEP, 3. The gel contains both PtOEP and DPA) are prepared. A mask sticker (3cm×2cm) in the shape of a "crown" is attached to a PET substrate. The point on the top of the crown and the arc at the bottom of the crown are composed of ink containing only the photosensitizer (PtOEP). The left half of the "crown" is composed of an ink containing an upconversion dual component (containing PtOEP and DPA), and the right half is composed of an ink containing only the annihilator (DPA) component. The ink can be cross-linked into a gel by irradiating with an ultraviolet flashlight for 10 seconds. As Figure 19 (a) is the pattern obtained using ultraviolet irradiation. From the figure, it can be observed that the middle point on the top of the crown and the bottom of the crown both emit red (645 nm) phosphorescence of the photosensitizer; the upconversion ink in the middle left half emits blue light. This is because the concentration of DPA is 200 times that of PtOEP, resulting in strong blue emission; the middle right half also emits blue fluorescence of DPA. Figure 19 (b) The pattern obtained by irradiating with green light. Observed through a green light filter, the top and bottom arcs of the crown both emit red (645 nm) phosphorescence from PtOEP, the left half emits upconverted blue-violet light, and the DPA in the right half cannot absorb green light, so it does not emit light.

[0063] Example 8 The specific steps for applying the HEA-TMSO gel system in anti-counterfeiting are as follows: A HEA-TMSO gel precursor was prepared according to the method provided in Example 6 and used as a patterning ink. The ink was then dropped onto a flexible substrate with evenly distributed pits. The pits were small, so the ink had to be added to a syringe and dripped into the pits using a syringe needle. Simultaneously, a UV flashlight was used to illuminate the pits. The ink droplets within the pits rapidly crosslinked and solidified, preventing them from spreading to adjacent pits and affecting the overall dot pattern. In this example, a dot matrix with seven rows and five columns was designed, measuring approximately 2 cm x 1.5 cm. The number "3" in the center of the pattern was composed of an upconversion two-component ink. The two leftmost dots of the "3" were composed of an ink containing only DPA. The remaining two inner dots and the surrounding mask portion were composed of an ink containing only PtOEP. Figure 20 (a) is the gel pattern observed under natural light. Figure 20 (b) is the pattern observed under ultraviolet light. The outer part and two points emit red light from the photosensitizer, and the middle part shows a blue number "8". Figure 20 (c) shows the pattern observed under green light. The center shows the blue-purple number "3" emitted by the upconversion ink, while the outer mask and two dots emit red light. Different information can be observed under UV and green light modes. The gel system can still observe digital information after 10 minutes of continuous illumination.

Claims

1. A method for preparing a photoactivated oxygen-scavenging gel, characterized in that: The specific steps include: (1) Using tetrahydrofuran as solvent, prepare mother solutions containing photosensitizer and annihilator respectively; (2) adding the mother solution containing the photosensitizer and the annihilator prepared in step (1) dropwise together and heating to volatilize, then adding the polymerization monomer and the photochemical deoxygenated organic medium, and then adding the photoinitiator, heating and stirring the resulting mixed system to fully dissolve the components in the organic phase, and preparing a gel precursor; (3) The gel precursor prepared in step (2) is irradiated with ultraviolet light or visible light to undergo a cross-linking reaction to obtain the photoactivated deoxygenating gel.

2. The method for preparing the light-activated oxygen-scavenging gel according to claim 1, wherein: The photosensitizer described in step (1) is selected from one of tetraphenylbenzoporphyrin platinum or octaethylporphyrin platinum.

3. The method for preparing the light-activated oxygen-scavenging gel according to claim 1, wherein: The annihilation agent in step (1) is selected from one of 9,10-bis(phenylethynyl)anthracene, 9,10-diphenylanthracene or 9,10-bis[(triisopropylsilyl)ethynyl]anthrylbenzene.

4. The method for preparing the light-activated oxygen-scavenging gel according to claim 1, wherein: The polymerization monomer in step (2) is composed of one or a combination of two or more of hydroxyethyl acrylate, polyethylene glycol diacrylate 400, 2-hydroxyethyl methacrylate or acrylic acid.

5. The method for preparing the light-activated oxygen-scavenging gel according to claim 1, wherein: The photochemical deoxygenation organic medium in step (2) is composed of one or a combination of two or three of polyethylene glycol 400, dimethyl sulfoxide or tetramethylene sulfoxide.

6. The method for preparing the light-activated oxygen-scavenging gel according to claim 1, wherein: The photoinitiator described in step (2) is a liquid photoinitiator.

7. The photoactivated oxygen scavenging gel prepared by the method according to any one of claims 1 to 6, characterized in that: The gel is a triplet-triplet annihilation up-conversion material; the gel consists of a photosensitizer, an annihilation agent, a gel polymer matrix and a photochemical deoxygenation organic medium.

8. The light-activated oxygen-scavenging gel according to claim 7, characterized in that: The gel polymer matrix can be formed by in-situ reaction of polymerizable monomers and photoinitiators.

9. Use of the photoactivated oxygen scavenging gel prepared by the method according to any one of claims 1 to 6 or the photoactivated oxygen scavenging gel according to claims 7 to 8 in information encryption.

10. Use of the photoactivated oxygen scavenging gel prepared by the method according to any one of claims 1 to 6 or the photoactivated oxygen scavenging gel according to claims 7 to 8 in anti-counterfeiting.

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