CN117511534A

CN117511534A - Multicolor adjustable response type gel fluorescent material, preparation method, using method, regulating method and application thereof

Info

Publication number: CN117511534A
Application number: CN202311202095.0A
Authority: CN
Inventors: 周琪; 代傲; 黄泓皓; 王欣楠
Original assignee: Zhengzhou University
Current assignee: Zhengzhou University
Priority date: 2023-09-18
Filing date: 2023-09-18
Publication date: 2024-02-06

Abstract

The invention belongs to the technical field of functional materials, and discloses a multicolor adjustable response type gel fluorescent material, which takes rare earth europium ion-2, 6-pyridine dicarboxylic acid compound as a red fluorescent group, 5-aminosalicylic acid as a blue-green fluorescent group and gelatin as a gel matrix; under the excitation of ultraviolet light, the fluorescent color of the responsive gel fluorescent material presents red, pink white, bluish or bluish green. The gel material provided by the invention not only introduces two luminescent centers, but also has stimulus responsiveness, and can convert the fluorescent color of the gel between red, pink, white, light blue and blue-green by changing the concentration of each component, changing the wavelength of excitation light and adding one or more of acid or metal ions.

Description

Multicolor adjustable response type gel fluorescent material, preparation method, using method, regulating method and application thereof

Technical Field

The invention belongs to the technical field of functional materials, and relates to a multicolor adjustable response type gel fluorescent material, a preparation method, a use method, a regulation and control method and application thereof.

Background

In recent years, information storage, encryption and information security technologies have been widely used in the fields of daily life, economy and military. With the rapid development of information science and technology, the demand for information storage materials with good storage capacity and high safety is more and more urgent. Various techniques such as laser holography, nano humidity sensing, radio frequency identification, etc. have been applied to the fields of storage and encryption. However, these methods are often complex, inconvenient to use, and expensive, which limits their wide application in the field of information security.

The response type fluorescent material can realize the switching of fluorescence or the change of fluorescence color under the external stimulus, and has the potential of being applied to the fields of advanced encryption and information storage. However, the performance of the existing response fluorescent materials is difficult to meet the requirement of rapid development of information storage, and the main limitation is that a plurality of fluorescent groups are difficult to introduce and regulate. Thus, there remains a need to develop more reliable information storage materials.

The gel material has a good matrix effect, and can embed fluorescent groups such as carbon dots, quantum dots, dyes, nano particles and the like to construct a plurality of luminous centers. Meanwhile, as a soft substance material, compared with solid and liquid materials, the gel also has the characteristics of self-support, plastic shape and easy processing, so that the application is more flexible. The fluorescent groups are introduced into the gel matrix to construct the response gel fluorescent material, and the change of the properties such as fluorescence, phase state, color, mechanics and the like is regulated and controlled by external stimulus, so that the information storage and encryption capability can be greatly improved, and the information transmission safety can be remarkably improved.

However, the currently reported response type gel fluorescent material has complex preparation process, long time consumption, single luminous color, difficult regulation and control and limited application, and the multicolor adjustable response type gel fluorescent material which can be used for information storage and encryption has not been reported yet.

Disclosure of Invention

Aiming at the technical problems of complex preparation process, long time consumption, single luminous color, difficult regulation and control, limited application and the like of the traditional gel fluorescent material, the invention provides a multicolor adjustable response type gel fluorescent material, which introduces two luminous centers and has stimulus responsiveness, and can convert the fluorescent color of gel between red, pink, white, light blue and blue-green by changing the concentration of each component, changing the wavelength of exciting light and adding one or more of acid or metal ions, and the multidimensional regulation and control mode is more beneficial to the application in the information storage or encryption anti-counterfeiting field.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

in a first aspect, the invention provides a multicolor adjustable response type gel fluorescent material, wherein the response type gel fluorescent material takes rare earth europium ion-2, 6-pyridine dicarboxylic acid compound as a red fluorescent group, 5-aminosalicylic acid as a blue-green fluorescent group and gelatin as a gel matrix; under the excitation of ultraviolet light, the fluorescent color of the responsive gel fluorescent material presents red, pink white, bluish or bluish green.

According to the invention, two fluorescent groups, namely 5-aminosalicylic acid (blue green) and rare earth europium ion-2, 6-pyridine dicarboxylic acid compound (red), are introduced into a gel material, gelatin is adopted as a gel matrix, and the gel forming property and the embedding capacity of the gelatin on guest molecules are utilized, so that the light emitting property of the rare earth europium ion-2, 6-pyridine dicarboxylic acid compound and the 5-aminosalicylic acid is not influenced, and the two luminescent centers can be uniformly embedded and fixed by utilizing a network structure formed by hydrogen bonds and electrostatic interaction among molecules of the rare earth europium ion-2, 6-pyridine dicarboxylic acid compound and the 5-aminosalicylic acid, so that the stability of gel luminescence and the accurate regulation and control of various colors are facilitated.

In a second aspect, the present invention provides a method for preparing the multicolor adjustable response type gel fluorescent material, which comprises the following steps:

1) Dissolving 2, 6-pyridine dicarboxylic acid in an organic solvent to obtain an organic solution of 2, 6-pyridine dicarboxylic acid, and adding a salt solution of rare earth europium ions into the organic solution of 2, 6-pyridine dicarboxylic acid to obtain a mixed solution containing rare earth europium ions and 2, 6-pyridine dicarboxylic acid complex;

2) Dissolving 5-aminosalicylic acid in an organic solvent to obtain an organic solution containing 5-aminosalicylic acid;

3) Under the heating condition, uniformly mixing a mixed solution containing rare earth europium ions and a 2, 6-pyridine dicarboxylic acid compound, an organic solution containing 5-aminosalicylic acid and an aqueous solution of gelatin, and then cooling to room temperature to obtain the multicolor adjustable response type gel fluorescent material.

In one embodiment, the organic solvent is selected from one of N, N-dimethylformamide, dimethyl sulfoxide, methanol, ethanol, acetonitrile or acetone.

In one technical scheme, the concentration of europium ions in the rare earth europium ion salt solution is 1-100 mmol/L, and the concentration of 2, 6-pyridine dicarboxylic acid in the 2, 6-pyridine dicarboxylic acid organic solution is 1-600 mmol/L; the volume ratio of the salt solution of rare earth europium ions to the organic solution of 2, 6-pyridine dicarboxylic acid is 1:1 to 3.

In one technical scheme, the concentration of the 5-aminosalicylic acid in the organic solution containing the 5-aminosalicylic acid is 1-100 mu mol/L; the volume ratio of the organic solution containing 5-aminosalicylic acid to the mixed solution containing rare earth europium ions and 2, 6-pyridine dicarboxylic acid compound is 1-3: 1.

in one technical scheme, the concentration of the gelatin in the aqueous solution of the gelatin is 10-30wt%; the volume ratio of the gelatin aqueous solution to the mixed solution containing rare earth europium ions and 2, 6-pyridine dicarboxylic acid compound is 1-5: 1.

when the gel material is prepared, firstly, rare earth europium salt solution and 2, 6-pyridine dicarboxylic acid are mixed according to a certain proportion and concentration, then, under the heating condition, the rare earth europium salt solution and 5-aminosalicylic acid organic solution are respectively added into gelatin aqueous solution to be uniformly mixed, and the addition sequence can not be changed at will. If the rare earth europium salt solution is mixed with the 5-aminosalicylic acid organic solution, the rare earth europium salt solution and the 2, 6-pyridine dicarboxylic acid can not form a compound, and the gel has no red fluorescence. The 5-aminosalicylic acid has amino, carboxyl and hydroxyl which can be coordinated with rare earth europium ions to form a compound, but the excitation state energy level of the 5-aminosalicylic acid and the rare earth europium ions is not matched, and energy transfer cannot be carried out. That is, the order of addition was changed, and the resulting gel material was unable to undergo color conversion under ultraviolet light excitation.

In the experimental process of the invention, other polymer gels such as agarose gel, chitosan gel and alginic acid gel are adopted as gel matrixes, but the experimental results cannot be well realized, and gel fluorescence cannot be well converted. Thus, gelatin is preferred for the gel matrix.

Other rare earth ions with better luminous performance, such as terbium ions, dysprosium ions and samarium ions, are also tried in the experimental process of the invention. However, under the same conditions, the green fluorescence emitted by terbium ions coincides with the blue-green fluorescence of 5-aminosalicylic acid, the color of the gel has less change, and the gel material prepared from dysprosium ions and samarium ions has no fluorescence of rare earth ions. Therefore, the rare earth ions are preferably europium ions, and the prepared gel material has various fluorescent color changes.

Other fluorescent dyes which do not need to be synthetically modified are tried in the experimental process of the invention, but the experimental result can not be well realized, and gel fluorescence can not be well converted. Therefore, the preferred blue-green luminescence center is 5-aminosalicylic acid. The multicolor regulation and control of the gel material is based on the change of fluorescence of two different colors, and the fluorescent color of the gel can not be regulated and controlled due to the fact that the luminous center and the gel matrix are replaced at will.

In conclusion, the preparation process control of the gel material is particularly critical, and the conditions of the types, the concentration, the proportion, the feeding sequence and the like of the raw materials have great influence on the gel formation and the gel formation performance. The invention can successfully prepare the multicolor adjustable response type gel fluorescent material by selecting proper gel matrix and fluorescent group and controlling specific preparation conditions and technological parameters.

In a third aspect, the present invention provides a method of using the above-described multi-color tunable responsive gel fluorescent material, the responsive gel fluorescent material being used in one or more of the following environments:

1) Under the excitation of 220-380 nm ultraviolet light, the fluorescent color of the responsive gel fluorescent material presents red, pink white, light blue or bluish green;

2) When the gel fluorescent material is used under the heating condition, the responsive gel fluorescent material is converted into a solution state, and the luminous performance of the gel fluorescent material is unchanged;

3) When acid or metal ions exist in the use environment, the phase state of the responsive gel fluorescent material is unchanged, but the red fluorescence of the responsive gel fluorescent material is weakened under the excitation of ultraviolet light.

In one technical scheme, the heating temperature is 45-100 ℃; the acid is hydrochloric acid, and the concentration of the acid is 0.01-1 mol/L when in use; the metal ion is Cu ²⁺ The concentration of metal ions is 0.1-1.6 mmol/L when in use.

The gel material prepared by the invention can quench gel red fluorescence after acid or metal ions are added. Other acids such as acetic acid, phosphoric acid, acetic acid, other metal ions such as Zn were tried during the experiment ²⁺ 、Fe ³⁺ 、Co ²⁺ 、Mn ²⁺ 、Cd ²⁺ However, the experimental results are not well realized, and gel fluorescence is not well converted. Thus, the acid is preferably hydrochloric acid and the metal ion is preferably Cu ²⁺ 。

In a fourth aspect, the present invention provides a method for controlling the multicolor adjustable responsive gel fluorescent material, which is implemented by one or more of the following modes:

1) Changing the dosage ratio of rare earth europium ion-2, 6-pyridine dicarboxylic acid compound and 5-aminosalicylic acid, or changing the concentration of one or more of rare earth europium ion, 2, 6-pyridine dicarboxylic acid or 5-aminosalicylic acid, and regulating the fluorescent color of the responsive gel fluorescent material;

2) Changing the wavelength of the excited ultraviolet light, and regulating and controlling the fluorescent color of the responsive gel fluorescent material;

3) Adding HCl and/or Cu with different concentrations into gel system ²⁺ The fluorescent color of the responsive gel fluorescent material is regulated.

The maximum excitation wavelength of two fluorophores in the gel material is 100nm different, and the energy transfer between 2, 6-pyridine dicarboxylic acid and rare earth europium ion can be interrupted by acid or metal ion, so that the concentration of each component is changed, the wavelength of the excitation light is changed, acid (hydrochloric acid) or metal ion (Cu) is added ²⁺ ) One or more of these three ways can control the fluorescence color of the gel to switch between red, pink, white, bluish and bluish-green.

In a fifth aspect, the invention also provides an application of the multicolor adjustable response type gel fluorescent material in information storage, encryption or anti-counterfeiting.

Compared with the prior art, the invention has the beneficial effects that:

(1) The gel material provided by the invention not only introduces two luminescent centers, but also has stimulus responsiveness, and can convert the fluorescent color of the gel between red, pink, white, light blue and blue-green by changing the concentration of each component, changing the wavelength of excitation light and adding one or more of acid or metal ions.

(2) The fluorescent groups adopted by the invention are antibacterial drugs and rare earth, and the invention has the advantages of high safety, good stability, high fluorescence intensity, long luminescence life, high quantum yield and the like, the gel matrix is gelatin, the biological safety is high, the embedding effect is good, the performance of the luminescent groups is not influenced, and the safety of information encryption is increased.

(3) The preparation method is simple, only a plurality of solutions are required to be uniformly mixed, the required materials are common and easy to obtain, the complex processes of chemical modification, synthesis and the like are not required, and the gel has excellent mechanical properties and processability, so that the application range of the material is widened.

Drawings

FIG. 1 is a scanning electron microscope image of the gel fluorescent material prepared in example 8.

FIG. 2 is a photograph showing fluorescence of the gel fluorescent material prepared in example 9 under ultraviolet light (254 nm+365 nm) irradiation.

FIG. 3 is a photograph of the gel fluorescent material prepared in example 10 after being prepared into a heart shape, a five-pointed star shape and a leaf shape, and irradiated with sunlight and ultraviolet light (254 nm, 365nm, 254nm+365 nm).

FIG. 4 is a photograph of the gel fluorescent material prepared in example 11 under irradiation of sunlight and ultraviolet light (254 nm, 365nm, 254nm+365 nm) before and after heating.

FIG. 5 is a photograph of the gel fluorescent material prepared in example 12 under irradiation of sunlight and ultraviolet light (254 nm, 365nm, 254nm+365 nm) before and after addition of HCl.

Fig. 6 is a photograph of the encryption and decryption process for the digital code stored in the gel sheet array of example 13.

FIG. 7 is a photograph showing the encryption and decryption process of pattern information stored in a gel according to example 14, and multiple encryption and decryption using HCl based thereon.

Detailed Description

The following examples are illustrative of the present invention and are not intended to limit the scope of the invention. The technical means used in the examples are conventional means well known to those skilled in the art unless otherwise indicated. The test methods in the following examples are conventional methods unless otherwise specified.

Example 1

100. Mu.L of 0.1mol/L aqueous europium chloride solution was taken in a test tube, followed by adding 200. Mu.L of 0.1mol/L dimethyl sulfoxide solution of 2, 6-pyridinedicarboxylic acid and mixing well. At 60 ℃, adding the mixed solution and 100 mu L of dimethyl sulfoxide solution of 0.1 mmol/L5-aminosalicylic acid into 1mL of 15wt% gelatin aqueous solution, uniformly mixing, and cooling to room temperature to form yellow gel-like substance, namely the multicolor adjustable response type gel fluorescent material.

Example 2

100. Mu.L of 0.1mol/L aqueous europium chloride solution was taken in a test tube, followed by addition of 300. Mu.L of 0.1mol/L dimethyl sulfoxide solution of 2, 6-pyridinedicarboxylic acid and mixing well. At 60 ℃, adding the mixed solution and 100 mu L of dimethyl sulfoxide solution of 0.1 mmol/L5-aminosalicylic acid into 1mL of 15wt% gelatin aqueous solution, uniformly mixing, and cooling to room temperature to form yellow gel-like substance, namely the multicolor adjustable response type gel fluorescent material.

Example 3

100. Mu.L of 0.1mol/L aqueous europium chloride solution was taken in a test tube, followed by adding 200. Mu.L of 0.1mol/L dimethyl sulfoxide solution of 2, 6-pyridinedicarboxylic acid and mixing well. At 60 ℃, adding the mixed solution and 200 mu L of dimethyl sulfoxide solution of 0.1 mmol/L5-aminosalicylic acid into 1mL of 15wt% gelatin aqueous solution, uniformly mixing, and cooling to room temperature to form yellow gel-like substance, namely the multicolor adjustable response type gel fluorescent material.

Example 4

100. Mu.L of 0.1mol/L aqueous europium chloride solution was taken in a test tube, followed by adding 200. Mu.L of 0.1mol/L dimethyl sulfoxide solution of 2, 6-pyridinedicarboxylic acid and mixing well. At 60 ℃, adding the mixed solution and 100 mu L of dimethyl sulfoxide solution of 0.1 mmol/L5-aminosalicylic acid into 1mL of 20wt% gelatin aqueous solution, uniformly mixing, and cooling to room temperature to form yellow gel-like substance, namely the multicolor adjustable response type gel fluorescent material.

Example 5

100. Mu.L of 0.1mol/L aqueous europium chloride solution was taken in a test tube, followed by adding 200. Mu.L of 0.1mol/L dimethyl sulfoxide solution of 2, 6-pyridinedicarboxylic acid and mixing well. At 60 ℃, adding the mixed solution and 200 mu L of dimethyl sulfoxide solution of 0.1 mmol/L5-aminosalicylic acid into 1mL of 20wt% gelatin aqueous solution, uniformly mixing, and cooling to room temperature to form yellow gel-like substance, namely the multicolor adjustable response type gel fluorescent material.

Example 6

100. Mu.L of 0.1mol/L aqueous europium chloride solution was taken in a test tube, followed by addition of 300. Mu.L of 0.1mol/L dimethyl sulfoxide solution of 2, 6-pyridinedicarboxylic acid and mixing well. At 60 ℃, adding the mixed solution and 100 mu L of dimethyl sulfoxide solution of 0.1 mmol/L5-aminosalicylic acid into 1mL of 20wt% gelatin aqueous solution, uniformly mixing, and cooling to room temperature to form yellow gel-like substance, namely the multicolor adjustable response type gel fluorescent material.

Example 7

100. Mu.L of 0.1mol/L aqueous europium chloride solution was taken in a test tube, followed by addition of 300. Mu.L of 0.1mol/L dimethyl sulfoxide solution of 2, 6-pyridinedicarboxylic acid and mixing well. At 60 ℃, adding the mixed solution and 200 mu L of dimethyl sulfoxide solution of 0.1 mmol/L5-aminosalicylic acid into 1mL of 20wt% gelatin aqueous solution, uniformly mixing, and cooling to room temperature to form yellow gel-like substance, namely the multicolor adjustable response type gel fluorescent material.

Example 8

FIG. 1 is an electron microscope image of the gel fluorescent material of the present example. The gel is shown in figure 1 as an intertwined network.

Example 9 fluorescent color of gel Material under ultraviolet light excitation

Experimental materials

Raw materials: the rare earth salt is europium chloride, the concentration of rare earth europium ions is 100, 50, 10, 5, 2 and 1mmol/L respectively, the concentration of 2, 6-pyridine dicarboxylic acid is 200, 100, 20, 10, 4 and 2mmol/L respectively, the concentration of 5-aminosalicylic acid is 1, 2, 5, 10, 50 and 100 mu mol/L, the concentration of gelatin is 15wt% respectively, and the organic solvent is dimethyl sulfoxide. Six gel fluorescent materials were prepared in the same manner as in example 1, with a total volume of 1mL. The concentrations of the components in the six gel fluorescent materials are shown in table 1.

TABLE 1 concentration of the components in the six gel fluorescent materials obtained in example 9

(II) Experimental methods

The above gel fluorescent material was subjected to ultraviolet light (254 nm+365 nm), and the result is shown in FIG. 2. As can be seen from fig. 2, by adjusting the component concentration of the fluorescent groups, the fluorescent color of the gel material may appear red, pink, white, bluish or bluish green.

Example 10 modification of wavelength of ultraviolet light excitation to control fluorescence color of gel fluorescent Material

Experimental materials

Materials: the rare earth salt is europium chloride, the concentration of rare earth europium ions is respectively 20, 10 and 5mmol/L, the concentration of 2, 6-pyridine dicarboxylic acid is respectively 40, 20 and 10mmol/L, the concentration of 5-aminosalicylic acid is respectively 2 mu mol/L, the organic solvent is dimethyl sulfoxide, the concentration of gelatin is 15wt%, and the total volume is 1mL.

(II) experimental method: three gel fluorescent materials were prepared as in example 1. The concentrations of the components in the three gel fluorescent materials are shown in table 2. And making each gel into heart shape, five-pointed star shape and leaf shape by using mould, and placing each shape into sunlight and ultraviolet light (254 nm, 365nm and 254nm+365 nm).

TABLE 2 concentration of the components in the three gel fluorescent materials obtained in example 10

The fluorescent color of the gel fluorescent material is shown in figure 3 after being excited by ultraviolet light (254 nm, 365nm and 254nm+365 nm). As can be seen from FIG. 3, the gel fluorescent material is yellow in sunlight, red in 254nm ultraviolet light, blue in 365nm ultraviolet light, and pink or pink in 254nm+365nm ultraviolet light. This is because the rare earth europium ion-2, 6-pyridine dicarboxylic acid complex in the gel fluorescent material can emit red fluorescence under 254nm ultraviolet excitation. Under the excitation of 365nm ultraviolet light, the 5-aminosalicylic acid in the gel fluorescent material emits blue fluorescence. Under the common excitation of 254nm ultraviolet light and 365nm ultraviolet light, the color of the gel becomes pink or pink after the red fluorescence and the green fluorescence with different intensities are mixed, which indicates that the gel can regulate the fluorescence color of the gel fluorescent material by changing the wavelength of the excited ultraviolet light.

Example 11 response of gel fluorescent Material to temperature

Experimental materials

Materials: the rare earth salt is europium chloride, the concentration of rare earth europium ions is 20mmol/L, the concentration of 2, 6-pyridine dicarboxylic acid is 40mmol/L, the concentration of 5-aminosalicylic acid is 10 mu mol/L, the concentration of gelatin is 15wt%, and the total volume of the organic solvent is 1.5mL.

(II) experimental method: a gel was prepared according to the procedure of example 1, heated at 60℃and after it had been converted to a solution, placed under sunlight and UV light (254 nm, 365nm, 254nm+365 nm) and the gel fluorescent material before heating was used as a control.

The gel fluorescent material before heating and the solution material after heating are respectively excited by ultraviolet light (254 nm, 365nm and 254nm+365 nm), and the fluorescent color of the gel fluorescent material is shown in figure 4. As can be seen, the gel turns into a solution state after heating, but is still yellow under sunlight, and the fluorescence under ultraviolet light is not changed obviously. Under the heating condition, the hydrogen bond and the electrostatic action among gelatin molecules are broken, the network structure of gelatin is broken, and the gel is converted into a solution state, so that the gel fluorescent material has response to temperature.

Example 12 gel Material vs. HCl and/or Cu ²⁺ Response to (2)

Experimental materials

Materials: the rare earth salt is europium chloride, the concentration of rare earth europium ions is 20mmol/L, the concentration of 2, 6-pyridine dicarboxylic acid is 40mmol/L, the concentration of 5-aminosalicylic acid is 10 mu mol/L, the concentration of gelatin is 15wt%, the organic solvent is dimethyl sulfoxide, the total volume is 1.5mL, and the organic solvent is 0.1mol/L HCL solution and 0.1mol/L copper chloride aqueous solution.

(II) experimental method: according to the method of example 1, 100. Mu.L of HCL solution, 100. Mu.L of copper chloride aqueous solution, and 50. Mu.L of each of HCL solution and copper chloride aqueous solution were added during the preparation of the gel, and the mixture was uniformly mixed, cooled to room temperature to form a gel, and then placed under sunlight and ultraviolet light (254 nm, 365nm, 254nm+365 nm), to obtain three kinds of gel fluorescent materials, and the gel fluorescent materials without adding acid or metal ions were used as a control.

The gel fluorescent material without adding acid or metal ions and the gel fluorescent material with adding HCL solution are respectively excited by ultraviolet light (254 nm, 365nm, 254nm+365 nm), the fluorescent color of the gel fluorescent material is shown in figure 5, and the fluorescent color of the gel fluorescent material with adding copper chloride aqueous solution and simultaneously with the HCL solution and the copper chloride aqueous solution under the ultraviolet light is the same as that of figure 5. As can be seen, the gel was added with HCl or Cu ²⁺ After that, the fluorescent dye is yellow under sunlight, but the red fluorescence under 254nm ultraviolet light is quenched, and the fluorescent dye has no obvious influence on the blue fluorescence under 365nm ultraviolet light. In HCl or Cu ²⁺ In the presence of the compound, the energy transfer between the 2, 6-pyridine dicarboxylic acid and rare earth europium ions is interrupted, the red fluorescence of the gel is quenched, and the gel fluorescent material is proved to be specific to HCl and Cu ²⁺ Has responsiveness.

Example 13 gel Material application for information storage, encryption

Experimental materials

Materials: the concentration of rare earth europium ions is 20mmol/L, the concentration of 2, 6-pyridine dicarboxylic acid is 40mmol/L, the concentration of 5-aminosalicylic acid is 2 mu mol/L, the organic solvent is dimethyl sulfoxide, the rare earth salt is europium chloride, the concentration of gelatin is 15wt%, and the total volume is 1mL. Three gel fluorescent materials were prepared as in example 1. The concentrations of the components in the three gel fluorescent materials are shown in table 3.

TABLE 3 concentration of the components in the three gel fluorescent materials obtained in EXAMPLE 12

(II) experimental method: three gel fluorescent materials were prepared into 3 gel sheet arrays, digital codes were stored in the arrays, and then decrypted under ultraviolet light (254 nm, 365nm, 254nm+365 nm), and the results are shown in fig. 6.

As can be seen from fig. 6, the gel array can read the number "438" under 254nm uv light, the encrypted number "888" under 365nm uv light, and the number "110" under 254nm+365nm uv light, and the two numbers are combined to obtain the complete password information, which indicates that the gel fluorescent material can be applied to information storage and encryption.

Example 14 application of gel fluorescent Material to multidimensional storage and encryption of information

Experimental materials

Materials: the rare earth salt is europium chloride, the concentration of rare earth europium ions is 5mmol/L respectively, the concentration of 2, 6-pyridine dicarboxylic acid is 10mmol/L respectively, the concentration of 5-aminosalicylic acid is 2 mu mol/L, the organic solvent is dimethyl sulfoxide, the concentration of gelatin is 15wt%, and the total volume is 1mL.0.1mol/L HCL solution, 0.1mol/L copper chloride aqueous solution. Two gel fluorescent materials were prepared as in example 1. The concentrations of the components in the two gel fluorescent materials are shown in Table 4.

TABLE 4 concentration of the components in the two gel fluorescent materials obtained in example 13

(II) experimental method: preparing two gel fluorescent materials into a jade shape, storing pattern information in gel, and adopting HCl or Cu on the basis ²⁺ The letter codes were stored in the gel and then decrypted by uv light (254 nm, 365nm, 254nm +365 nm) respectively, as shown in figure 7.

As can be seen from FIG. 7, the original jade-shaped gel fluorescent material can read red heart-shaped patterns under 254nm ultraviolet light, can not read pattern information under 365nm ultraviolet light, and can read white heart-shaped patterns under 254nm+365nm ultraviolet light. By HCl or Cu ²⁺ After re-encryption, the gel fluorescent material can read the letter U under 254nm or 254nm+365nm ultraviolet light, which indicates that the gel fluorescent material can be applied to multidimensional storage and encryption of information.

The above-mentioned embodiments are merely preferred embodiments of the present invention, which are not intended to limit the scope of the present invention, and other embodiments can be easily made by those skilled in the art through substitution or modification according to the technical disclosure in the present specification, so that all changes and modifications made in the principle of the present invention shall be included in the scope of the present invention.

Claims

1. The multicolor adjustable response type gel fluorescent material is characterized in that the response type gel fluorescent material takes rare earth europium ion-2, 6-pyridine dicarboxylic acid compound as a red fluorescent group, 5-aminosalicylic acid as a blue-green fluorescent group and gelatin as a gel matrix; under the excitation of ultraviolet light, the fluorescent color of the responsive gel fluorescent material presents red, pink white, bluish or bluish green.

2. The method for preparing the multicolor adjustable response type gel fluorescent material as set forth in claim 1, which is characterized by comprising the following steps:

3. The method according to claim 1, wherein the organic solvent is one selected from the group consisting of N, N-dimethylformamide, dimethyl sulfoxide, methanol, ethanol, acetonitrile and acetone.

4. The method according to claim 1, wherein the concentration of europium ions in the rare earth europium ion salt solution is 1 to 100mmol/L, and the concentration of 2, 6-pyridinedicarboxylic acid in the organic solution of 2, 6-pyridinedicarboxylic acid is 1 to 600mmol/L; the volume ratio of the salt solution of rare earth europium ions to the organic solution of 2, 6-pyridine dicarboxylic acid is 1: 1-3.

5. The method according to claim 1, wherein the concentration of 5-aminosalicylic acid in the organic solution containing 5-aminosalicylic acid is 1 to 100. Mu. Mol/L; the volume ratio of the organic solution containing 5-aminosalicylic acid to the mixed solution containing rare earth europium ions and the 2, 6-pyridine dicarboxylic acid compound is 1-3: 1.

6. the method according to claim 1, wherein the concentration of gelatin in the aqueous solution of gelatin is 10 to 30wt%; the volume ratio of the gelatin aqueous solution to the mixed solution containing rare earth europium ions and the 2, 6-pyridine dicarboxylic acid compound is 1-5: 1.

7. the method of using a multi-color tunable responsive gel fluorescent material of claim 1, wherein said responsive gel fluorescent material is used in one or more of the following environments:

1) Under the excitation of 220-380 nm ultraviolet light, the fluorescent color of the responsive gel fluorescent material presents red, pink white, bluish or bluish green;

8. The method of use according to claim 1, wherein the heating temperature is 45-100 ℃; the acid is hydrochloric acid, and the concentration of the acid is 0.01-1 mol/L when in use; the metal ion is Cu ²⁺ The concentration of metal ions is 0.1-1.6 mm when in useol/L。

9. The method for regulating and controlling a multicolor adjustable response type gel fluorescent material as claimed in claim 1, wherein the method is realized by one or more of the following modes:

10. The use of the multi-color tunable responsive gel fluorescent material of claim 1 for storage, encryption or anti-counterfeiting of information.