Method for temperature monitoring and anti-counterfeiting by using photo-thermal orthogonal regulation of color-changing fluorescent polymer hydrogel

Abstract

The application discloses a method for applying photo-thermal orthogonal regulation color-changing fluorescent polymer hydrogel to temperature monitoring and anti-counterfeiting, using phase change materials, thermochromic molecules and photochromic molecules as raw materials, a series of photo-thermal orthogonal regulation color-changing fluorescent polymer capsules are prepared by adopting an emulsion-solvent evaporation method, then the prepared capsules are dispersed in hydrogel to prepare photo-thermal orthogonal regulation color-changing fluorescent polymer hydrogel, and the prepared hydrogel is used for temperature monitoring and anti-counterfeiting under photo-thermal orthogonal regulation after arrangement and combination. The prepared color-changing fluorescent polymer hydrogel has fast photoresponsivity and thermal responsivity, excellent light switching performance and high fluorescent contrast, a relatively narrow temperature response interval, temperature response sensitivity, and a simple preparation process, and has great application potential in the fields of data encryption, anti-counterfeiting and temperature monitoring.

Description

Technical Field

[0001] This invention belongs to the field of chemical materials technology, specifically, it relates to a method for applying photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogels to temperature monitoring and anti-counterfeiting. Background Technology

[0002] With rapid economic development, the development of more advanced anti-counterfeiting methods has become increasingly important. However, most luminescent materials used for anti-counterfeiting still have shortcomings: First, most luminescent materials used for anti-counterfeiting typically exhibit monochromatic light, and the information they can store is relatively limited; second, many currently developed color-changing multi-response anti-counterfeiting materials are sequentially triggered responses, making it difficult to achieve orthogonal control without interference; third, the processability of most luminescent materials used for anti-counterfeiting is poor. Therefore, developing an orthogonally controlled, processable anti-counterfeiting material has become particularly important.

[0003] Stimulus-responsive fluorescent polymer hydrogels can fluoresce in response to external stimuli (such as light, temperature, ions, pH, etc.), finding wide applications in sensing, encryption, and anti-counterfeiting. Hydrogels with high brightness and high fluorescence contrast serve as excellent carriers for stimulus-responsive fluorescent materials, retaining the optical properties of fluorescent materials while possessing the excellent processability of hydrogels. They also offer advantages such as being environmentally friendly, pollution-free, simple to operate, and requiring no complex equipment. Light, as a clean, non-contact stimulus, is widely used in stimulus-responsive fluorescent polymer hydrogels, effectively addressing the shortcomings of many anti-counterfeiting materials. However, single stimulation methods cannot meet practical needs. Therefore, introducing new stimulation methods to achieve reversible transitions between color-changing fluorescence can enhance anti-counterfeiting effects. Thus, combining non-contact temperature as a stimulus response method with photoresponse can construct novel orthogonally modulated color-changing fluorescent materials.

[0004] While much research has focused on thermally or photoresponsive materials and has achieved information encryption and anti-counterfeiting, the challenge remains in realizing photothermal orthogonally modulated stimulus-responsive materials and achieving encryption and anti-counterfeiting through the synergistic effect of temperature and photoresponse.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a method for applying photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel to temperature monitoring and anti-counterfeiting. The preparation of the photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel is divided into two steps: First, photo-thermal orthogonally regulated color-changing fluorescent polymer capsules are prepared according to the microcapsule preparation technology reported in Angew. Chem. Int. Ed. 2016, 55, 15044-15048. Then, the photo-thermal orthogonally regulated color-changing fluorescent polymer capsules are dispersed into the hydrogel according to the method reported in patent (CN113999476 B) to obtain a photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel. The prepared polymer hydrogel retains the excellent performance of the polymer capsules in color-changing fluorescence emission under light and heat stimulation, and can be used for temperature monitoring and anti-counterfeiting.

[0007] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0008] Using existing technology, various fluorescent polymer capsules were prepared via emulsion-solvent evaporation. These capsules were then dispersed in hydrogels to prepare a series of photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogels. Different arrangements and combinations of these hydrogels were used as multiple integrated temperature monitoring and anti-counterfeiting units, which were then applied to both temperature monitoring and anti-counterfeiting applications.

[0009] 1. The preparation of the integrated temperature monitoring and anti-counterfeiting unit a includes the following steps:

[0010] (1.1) Eicosane, 7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dianitron (TPA-DCPP) and 2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one (DTE) were dissolved in 2 mL of dichloromethane at a mass ratio of 2:0.0005~0.002:0.01~0.02, and the oil phase was obtained by ultrasonic dissolution.

[0011] (1.2) Polyvinyl alcohol and sodium dodecyl sulfonate were added to 8 mL of distilled water at a mass ratio of 0.2-0.4:0.03-0.07 and dissolved by ultrasonication to obtain an aqueous phase.

[0012] (1.3) Mix the oil phase and water phase and stir for 10 to 15 minutes.

[0013] (1.4) Then emulsify by sonication for 15-25 minutes using an ultrasonic cell disruptor.

[0014] (1.5) After emulsification, the solvent dichloromethane was removed by vacuum rotary evaporation at 25°C to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer capsules.

[0015] (1.6) Methacrylamide, acrylamide, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine, and sodium dodecyl sulfonate were dissolved in 1 mL of water at a mass ratio of 2.55:2~3:0.05~0.1:0.1~0.2:0.005~0.01. 0.25 mL of the above polymer capsules were added, and the mixture was polymerized at 65 °C for 1 h to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel CPs-1, which can be used as an integrated unit for temperature monitoring and anti-counterfeiting.

[0016] 2. The preparation of the integrated temperature monitoring and anti-counterfeiting unit b includes the following steps:

[0017] (2.1) n-Octadecane, 7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dianitron (TPA-DCPP) and 2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one (DTE) were dissolved in 2 mL of dichloromethane at a mass ratio of 2:0.0005~0.002:0.01~0.02, and the oil phase was obtained by ultrasonic dissolution.

[0018] (2.2) Polyvinyl alcohol and sodium dodecyl sulfonate were added to 8 mL of distilled water at a mass ratio of 0.2-0.4:0.03-0.07 and dissolved by ultrasonication to obtain an aqueous phase.

[0019] (2.3) Mix the oil phase and water phase and stir for 10 to 15 minutes.

[0020] (2.4) Then emulsify by sonication for 15-25 minutes using an ultrasonic cell disruptor.

[0021] (2.5) After emulsification, the solvent dichloromethane was removed by vacuum rotary evaporation at 25°C to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer capsules.

[0022] (2.6) Methacrylamide, acrylamide, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine, and sodium dodecyl sulfonate were dissolved in 1 mL of water at a mass ratio of 2.55:2~3:0.05~0.1:0.1~0.2:0.005~0.01. 0.25 mL of the above polymer capsules were added, and the mixture was polymerized at 65 °C for 1 h to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel CPs-2, which can be used as an integrated temperature monitoring and anti-counterfeiting unit b.

[0023] 3. The preparation of the integrated temperature monitoring and anti-counterfeiting unit c includes the following steps:

[0024] (3.1) Docosane, 7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dianitron (TPA-DCPP) and 2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one (DTE) were dissolved in 2 mL of dichloromethane at a mass ratio of 2:0.0005~0.002:0.01~0.02, and the oil phase was obtained by ultrasonic dissolution.

[0025] (3.2) Polyvinyl alcohol and sodium dodecyl sulfonate were added to 8 mL of distilled water at a mass ratio of 0.2-0.4:0.03-0.07 and dissolved by ultrasonication to obtain an aqueous phase.

[0026] (3.3) Mix the oil phase and water phase and stir for 10 to 15 minutes.

[0027] (3.4) Then emulsify by sonication for 15-25 minutes using an ultrasonic cell disruptor.

[0028] (3.5) After emulsification, the solvent dichloromethane was removed by vacuum rotary evaporation at 25°C to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer capsules.

[0029] (3.6) Methacrylamide, acrylamide, N,N'-methylenebisacrylamide, ammonium persulfate, tetramethylethylenediamine, and sodium dodecyl sulfonate were dissolved in 1 mL of water at a mass ratio of 2.55:2~3:0.05~0.1:0.1~0.2:0.005~0.01. 0.25 mL of the above polymer capsules were added, and the mixture was polymerized at 65 °C for 1 h to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel CPs-3, which can be used as an integrated unit for temperature monitoring and anti-counterfeiting.

[0030] 4. The temperature monitoring and anti-counterfeiting integrated unit a, temperature monitoring and anti-counterfeiting integrated unit b, and temperature monitoring and anti-counterfeiting integrated unit c are arranged and combined for temperature monitoring and anti-counterfeiting. They can be attached to the item whose temperature needs to be monitored to monitor its temperature, and at the same time, they exhibit color-changing fluorescence after being irradiated with ultraviolet light, thereby realizing the anti-counterfeiting application.

[0031] The structural formulas of 7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dianitronitrile (TPA-DCPP) and 2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one (DTE) mentioned in steps 1-3 are shown in the appendix. Figure 8 The preparation process of the aforementioned color-changing fluorescent polymer capsules is shown in the appendix. Figure 9 As shown, the preparation process of the color-changing fluorescent polymer hydrogel is detailed in the appendix. Figure 10As shown.

[0032] This invention employs an emulsion-solvent evaporation technique to mix an oil phase and an aqueous phase, emulsify them using ultrasound, and then remove the solvent by rotary evaporation to prepare a photo-thermal orthogonally regulated color-changing fluorescent polymer capsule. The polymer capsule uses PVA as its shell, and the capsule cavity contains a phase change material (eicosane, n-docoane, or n-docosane), a thermochromic dye (7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dianitron (TPA-DCPP), and a photochromic dye (2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one (DTE). Then, using a traditional hydrogel preparation method, the prepared photo-thermal orthogonally regulated color-changing fluorescent polymer capsules were introduced into the hydrogel system. The resulting hydrogel not only retained the excellent photo-thermal orthogonally regulated color-changing fluorescent properties of the polymer capsules, but also had the advantages of excellent processability, simple operation, and no need for complex equipment.

[0033] The photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel of this invention achieves color change primarily through the following steps: 1) When the temperature is raised to the melting point of the long-chain alkane, the polymer hydrogel changes from colorless fluorescence to green fluorescence; 2) Subsequently, irradiation with 365nm ultraviolet light results in enhanced red fluorescence and weakened green fluorescence due to fluorescence resonance energy transfer, exhibiting an intermediate state of yellow fluorescence; 3) Lowering the temperature below the melting point causes the polymer hydrogel to change from yellow fluorescence to red fluorescence; 4) Irradiation with 525nm visible light returns it to its initial non-fluorescent state. It is noteworthy that all four processes are reversible. Therefore, through these four processes, the hydrogel achieves reversible switching between four states of fluorescence—non-fluorescence, green, yellow, and red—through photo-thermal orthogonal regulation.

[0034] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0035] (1) Based on the principle of fluorescence resonance energy transfer (FRET), the present invention uses capsules prepared by emulsion-solvent evaporation technology to disperse in hydrogels to prepare color-changing fluorescent polymer hydrogels. Compared with conventional hydrogels, these hydrogels can achieve dual stimulation response to light and heat, and exhibit reversible switching between four states of fluorescence: no, green, yellow and red.

[0036] (2) The hydrogel prepared by the present invention has better processability than polymer capsules, and the preparation steps are simple and pollution-free.

[0037] (3) The polymer hydrogel prepared in this invention exhibits rapid and reversible polymorphic fluorescence switching characteristics under orthogonal control of light and heat, with a narrow temperature response range and obvious fluorescence contrast. Because it can realize reversible switching between polymorphic fluorescence, and has a rapid and sensitive temperature response, and combines the light response and thermal response into the same hydrogel system, it has very important prospects in the field of temperature monitoring and anti-counterfeiting integration.

[0038] (4) This invention simplifies and modularizes each temperature monitoring and anti-counterfeiting integrated unit, making it faster and more convenient to use. It also has significant advantages in amplification synthesis and actual production applications.

[0039] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0040] 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:

[0041] Figure 1 The image shows the thermo-response fluorescence spectrum of the typical polymer hydrogel CPs-2.

[0042] Figure 2 The photoresponse fluorescence spectrum of the typical polymer hydrogel CPs-2 prepared is shown.

[0043] Figure 3 The photocycle diagram is for the typical polymer hydrogel CPs-2 prepared.

[0044] Figure 4 The thermal cycling diagram shows the typical polymer hydrogel CPs-2 prepared.

[0045] Figure 5 The thermal response diagram of the prepared polymer hydrogel CPs-1.

[0046] Figure 6 The thermal response diagram of the prepared polymer hydrogel CPs-3.

[0047] Figure 7 The photo-thermal orthogonally modulated color-changing fluorescent polymer hydrogels (CPs-1, CPs-2 and CPs-3) are used for integrated temperature monitoring and anti-counterfeiting.

[0048] Figure 8 It is a TPA-DCPP and DTE structure.

[0049] Figure 9 This describes the preparation process of color-changing fluorescent polymer capsules.

[0050] Figure 10 This describes the preparation process of a color-changing fluorescent polymer hydrogel.

[0051] 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

[0052] 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.

[0053] Example 1: Preparation of temperature monitoring and anti-counterfeiting integrated unit a, the specific steps are as follows:

[0054] 0.2 g of n-eicosane, 0.0001 g of 7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dianitron, and 0.0015 g of 2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one were weighed and dissolved in 2 mL of dichloromethane to obtain the oil phase. 0.03 g of polyvinyl alcohol and 0.005 g of sodium dodecyl sulfonate were weighed and ultrasonically dissolved in 8 mL of water to obtain the aqueous phase. The oil and aqueous phases were mixed and stirred for 10 min, then emulsified using a cell disruptor for 20 min. After emulsification, the solution was placed at 25 °C and the solvent dichloromethane was removed by vacuum rotary evaporation to obtain the polymer capsule solution. Weigh out 0.255g of methacrylamide, 0.213g of acrylamide, 0.0092g of N,N'-methylenebisacrylamide, 0.0137g of ammonium persulfate, and 0.005g of sodium dodecyl sulfonate, dissolve them in 1mL of water, add 0.25mL of polymer capsule solution, mix well, and then add 0.000775g of tetramethylethylenediamine. Pour the mixed solution into a mold to prepare a color-changing fluorescent polymer hydrogel CPs-1 with photo-thermal orthogonal regulation, which can be used as an integrated temperature monitoring and anti-counterfeiting unit a.

[0055] Example 2: Preparation of the integrated temperature monitoring and anti-counterfeiting unit b, the specific steps are as follows:

[0056] 0.2 g of n-docosahexanes, 0.0001 g of 7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dionitrile, and 0.0015 g of 2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one were weighed and dissolved in 2 mL of dichloromethane to obtain the oil phase. 0.03 g of polyvinyl alcohol and 0.005 g of sodium dodecyl sulfonate were weighed and dissolved in 8 mL of water by ultrasonication to obtain the aqueous phase. The oil and aqueous phases were mixed and stirred for 10 min, then emulsified using a cell disruptor for 20 min. After emulsification, the solution was placed at 25 °C and the solvent dichloromethane was removed by vacuum rotary evaporation to obtain the polymer capsule solution. Weigh out 0.255g of methacrylamide, 0.213g of acrylamide, 0.0092g of N,N'-methylenebisacrylamide, 0.0137g of ammonium persulfate, and 0.005g of sodium dodecyl sulfonate, dissolve them in 1mL of water, add 0.25mL of polymer capsule solution, mix well, and then add 0.000775g of tetramethylethylenediamine. Pour the mixed solution into a mold to prepare a color-changing fluorescent polymer hydrogel CPs-2 with photo-thermal orthogonal regulation, which can be used as an integrated temperature monitoring and anti-counterfeiting unit b.

[0057] Example 3: Preparation of the integrated temperature monitoring and anti-counterfeiting unit c, the specific steps are as follows:

[0058] 0.2 g of n-dodecane, 0.0001 g of 7,10-bis(4-(diphenylamino)phenyl)dibenzo[f,h]quinoxaline-2,3-dionitrile, and 0.0015 g of 2,3-bis(2-methylbenzo[b]thiophene-3-yl)-5,6-dihydro-4H-thiophene[2,3-b]thiopyran-4-one were weighed and dissolved in 2 mL of dichloromethane to obtain the oil phase. 0.03 g of polyvinyl alcohol and 0.005 g of sodium dodecyl sulfonate were weighed and dissolved in 8 mL of water by ultrasonication to obtain the aqueous phase. The oil and aqueous phases were mixed and stirred for 10 min, then emulsified using a cell disruptor for 20 min. After emulsification, the solution was placed at 25 °C and the solvent dichloromethane was removed by vacuum rotary evaporation to obtain the polymer capsule solution. Weigh out 0.255g of methacrylamide, 0.213g of acrylamide, 0.0092g of N,N'-methylenebisacrylamide, 0.0137g of ammonium persulfate, and 0.005g of sodium dodecyl sulfonate, dissolve them in 1mL of water, add 0.25mL of polymer capsule solution, mix well, and then add 0.000775g of tetramethylethylenediamine. Pour the mixed solution into a mold to prepare a color-changing fluorescent polymer hydrogel CPs-3 with photothermal orthogonal regulation, which can be used as an integrated temperature monitoring and anti-counterfeiting unit 3.

[0059] Example 4: Thermal response fluorescence test of typical polymer hydrogel CPs-2.

[0060] The prepared polymer hydrogel CPs-2 was subjected to thermal response testing, with tests conducted at 1°C intervals until the fluorescence intensity no longer changed. Figure 1 As shown in (A) and (B), from 25℃ to 37℃, the green fluorescence intensity remains essentially constant with increasing temperature. However, upon further heating, the fluorescence intensity changes significantly, and after reaching 45℃, further heating no longer increases the fluorescence intensity. Figure (B) provides a clearer view of the green fluorescence change at 518nm. These results indicate that the hydrogel exhibits an extremely narrow temperature response range and is highly sensitive to temperature changes.

[0061] Example 5: Photoresponse fluorescence test of typical polymer hydrogel CPs-2.

[0062] The photoresponse was tested while maintaining the temperature at 45℃. After irradiation with 365nm ultraviolet light for a certain period, spectral measurements were performed until the fluorescence no longer changed after ultraviolet irradiation. Then, irradiation with 525nm visible light was conducted, and spectral measurements were performed at regular intervals until the fluorescence returned to its initial state. Figure 2 As shown in (A) and (B), when the temperature was kept constant at 45°C and the photoresponse was tested, the green fluorescence of the polymer hydrogel CPs-2 gradually decreased and the red fluorescence gradually increased due to the FRET effect after irradiation with 365 nm ultraviolet light. Combined with Figure (D), it can be seen that after about 2 minutes of ultraviolet light irradiation, the emission at 518 nm decreased to its lowest value; subsequently, after about 4 minutes of visible light irradiation, the fluorescence intensity returned to its initial maximum value, indicating that the polymer hydrogel has a rapid photoresponse.

[0063] Example 6: Photocycling test of typical polymer hydrogel CPs-2.

[0064] The hydrogel CPs-2 was kept at 45°C and alternately irradiated with 365nm ultraviolet light and 525nm visible light. The fluorescence was cyclically tested, with the minimum value at 518nm after 365nm ultraviolet irradiation and the maximum value at 518nm after 525nm visible light irradiation. From this cycle, its photo-switching performance was tested. Figure 3 As can be seen, the polymer hydrogel CPs-2 can remain essentially unchanged after 17 cycles of alternating irradiation with 365nm ultraviolet light and 525nm visible light, which indicates that the polymer hydrogel CPs-2 has excellent light-switching cycling performance.

[0065] Example 7: Thermal cycling test of typical polymer hydrogel CPs-2.

[0066] After the hydrogel CPs-2 was kept at 25℃ and 45℃ to maintain temperature stability, fluorescence testing was performed. The thermal cycling performance of the hydrogel was then tested by continuously alternating cycles at 25℃ and 45℃. Figure 4 As can be seen, the polymer hydrogel CPs-2 can remain unchanged after 100 cycles of alternating temperature changes of 25℃ and 45℃, which indicates that the polymer hydrogel CPs-2 has excellent thermal cycling performance.

[0067] Example 8: Thermal response diagram of polymer hydrogel CPs-1

[0068] The main difference between polymer hydrogels CPs-1 and typical polymer hydrogels CPs-2 lies in the different phase change materials, resulting in a change in the temperature response range. Therefore, the temperature response of polymer hydrogel CPs-1 was tested. The temperature of polymer hydrogel CPs-1 was increased by 1°C each time until the fluorescence intensity at 518 nm remained constant. Figure 5 As can be seen, within the temperature range of 20-32℃, the fluorescence intensity remains essentially constant with increasing temperature. However, upon further temperature increases, the fluorescence intensity significantly increases until reaching 39℃, after which the fluorescence intensity remains essentially constant. These results indicate that the polymer hydrogel CPs-1 exhibits an extremely narrow temperature response range and is highly sensitive to temperature changes.

[0069] Example 9: Thermal response diagram of polymer hydrogel CPs-3

[0070] The polymer hydrogel CPs-1 was tested by increasing the temperature by 1°C until the fluorescence intensity at 518 nm remained constant. From Figure 6 As can be seen, within the temperature range of 30-42℃, the fluorescence intensity remains essentially constant with increasing temperature. However, upon further temperature increases, the fluorescence intensity significantly increases until reaching 46℃, after which the fluorescence intensity remains essentially constant. These results indicate that the polymer hydrogel CPs-1 exhibits an extremely narrow temperature response range and is highly sensitive to temperature changes.

[0071] Example 10: An experiment integrating temperature monitoring and anti-counterfeiting, the specific steps of which are as follows:

[0072] like Figure 7As shown, polymer capsules containing n-eicosane were dispersed in a precursor solution of hydrogel, poured into region 1 of the mold, and polymerized at 65°C to obtain polymer hydrogel CPs-1. Subsequently, polymer capsules containing n-docosahexanes were dispersed in the precursor solution of hydrogel, poured into region 2 of the mold, and polymerized at 65°C to obtain polymer hydrogel CPs-2. Finally, polymer capsules containing n-docosahexanes were dispersed in the precursor solution of hydrogel, poured into region 3 of the mold, and polymerized at 65°C to obtain polymer hydrogel CPs-3. This combination yielded a clover model capable of temperature monitoring and anti-counterfeiting, which was then attached to a baby bottle. When the temperature exceeds 43℃, all clover petals will exhibit a green fluorescence, indicating a relatively high temperature. When the temperature is between 39-42℃, the green fluorescence of the petals in area 3 disappears, representing a suitable temperature for infant feeding. When the temperature is between 32-38℃, the green fluorescence of the petals in area 2 disappears, indicating a slightly low temperature. When the temperature is below 31℃, the green fluorescence of the petals in area 1 disappears, indicating a temperature that is too cold for an infant. In addition, as... Figure 7 In section B, when the petals are irradiated with ultraviolet light, all the petals undergo a fluorescent color change. Therefore, the results show that the polymer hydrogel can be well applied to temperature monitoring and anti-counterfeiting integration.

[0073] 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 applying photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogels to temperature monitoring and anti-counterfeiting, characterized in that, Includes the following steps: Step 1, Preparation of temperature monitoring and anti-counterfeiting integrated unit a: Using n-eicosane as the phase change material, a photo-thermal orthogonally regulated color-changing fluorescent polymer capsule was prepared by emulsion-solvent evaporation method. The polymer capsule was dispersed in the hydrogel mother liquor and polymerized to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel CPs-1, which served as the temperature monitoring and anti-counterfeiting integrated unit a. Step 2, Preparation of temperature monitoring and anti-counterfeiting integrated unit b: Using n-dodecane as the phase change material, a photo-thermal orthogonally regulated color-changing fluorescent polymer capsule was prepared by emulsion-solvent evaporation method. The polymer capsule was dispersed in the hydrogel mother liquor and polymerized to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel CPs-2, which served as the temperature monitoring and anti-counterfeiting integrated unit b. Step 3, Preparation of temperature monitoring and anti-counterfeiting integrated unit c: Using n-dodecane as the phase change material, a photo-thermal orthogonally regulated color-changing fluorescent polymer capsule was prepared by emulsion-solvent evaporation method. The polymer capsule was dispersed in the hydrogel mother liquor and polymerized to obtain photo-thermal orthogonally regulated color-changing fluorescent polymer hydrogel CPs-3, which served as the temperature monitoring and anti-counterfeiting integrated unit c. Step 4: After arranging and combining the integrated temperature monitoring and anti-counterfeiting unit a, integrated temperature monitoring and anti-counterfeiting unit b, and integrated temperature monitoring and anti-counterfeiting unit c, they are used for temperature monitoring and anti-counterfeiting.

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