CN109721743B - A color-changing anti-counterfeiting material based on MoS2 quantum dots and preparation method thereof - Google Patents

Abstract

The invention provides a color-changing anti-counterfeiting material based _on MoS2 quantum dots and a preparation method thereof. The structural color area was formed in the glass tube; (c ₎ the acrylamide prepolymerization solution uniformly dispersed with MoS2 quantum dots was prepared, and the acrylamide prepolymerization solution was placed in the capillary glass tube through the capillary effect; (d) the capillary glass tube was in Perform gelation in an incubator in an oxygen-free environment; (e) after the gelation is completed, dissolve the capillary glass tube and nano-silica microspheres with hydrofluoric acid, take out the gel and soak it in deionized water to remove the residual hydrogen After the hydrofluoric acid is removed, the color-changing anti-counterfeiting material is obtained. The anti-counterfeiting material of the invention is a color-changing anti-counterfeiting material with high stability index, small color pollution, wider discoloration range, faster recovery and stronger applicability, and its comprehensive performance is significantly better than the existing color-changing anti-counterfeiting materials.

Description

A color-changing anti-counterfeiting material based on MoS2 quantum dots and preparation method thereof

technical field

The invention relates to the technical field of color-changing anti-counterfeiting materials, in particular to a color-changing anti-counterfeiting material based _on MoS2 quantum dots and a preparation method thereof.

Background technique

There are many contemporary anti-counterfeiting materials and technologies, but with the development of science and technology, contemporary forgery and counterfeiting are also produced on the background of productivity improvement and scientific and technological development. degree of discrimination. Therefore, anti-counterfeiting materials must be superior, and change from "the road is one foot high, the magic height is one zhang" to "the devil is one foot high and the road is one zhang high". That is to say, a new type of anti-counterfeiting material whose anti-counterfeiting ability is much higher than the existing technology has a very broad market space and a very large market demand. According to relevant data, in recent years, the relevant state departments have increased financial support for new anti-counterfeiting materials. The annual output value of the global anti-counterfeiting market has reached 500 billion US dollars, and the annual output value of the domestic anti-counterfeiting market has also reached more than 100 billion yuan. In general, the research and development of new anti-counterfeiting materials has encountered a once-in-a-lifetime opportunity. Based on the present, we urgently need a new material to break through the existing technical bottleneck of anti-counterfeiting materials.

A research team at the Leibniz Institute for Polymer Research in Germany has developed a special graphene coating that changes color when it deforms or breaks. The researchers believe that the coatings they prepared, or products similar to them, have some promise for industrial applications. However, the effectiveness of the coating in revealing the degree of deformation and cracking of the material remains to be tested, and whether the coating can adapt to the harsh environment in the real world is not yet clear. Color-changing anti-counterfeiting materials for application environments have become an important research topic.

SUMMARY OF THE INVENTION

One of the objectives of the present invention is to provide a color-changing anti-counterfeiting material based on MoS ₂ quantum dots to solve the problem of unsatisfactory comprehensive performance of the existing anti-counterfeiting materials.

The second purpose of the present invention is to provide a preparation method of a color-changing anti-counterfeiting material based on MoS ₂ quantum dots.

One of the objects of the present invention is achieved through the following technical solutions: a color-changing anti-counterfeiting material, which is prepared by the following method:

(a) Monodisperse nano-silica microspheres in ethanol to obtain nano-silica microsphere dispersion;

(b) Entering the nano-silica microsphere dispersion into the capillary glass tube, and evaporating ethanol naturally, so that the nano-silica microspheres form a structural color area in the capillary glass tube;

(c) Preparation of acrylamide prepolymerization solution uniformly dispersed with _MoS2 quantum dots, so that the acrylamide prepolymerization solution enters the capillary glass tube with the structural color region through capillary effect;

(d) gelling the capillary glass tube containing the acrylamide prepolymerization solution prepared in step (c) in an oxygen-free environment in a thermostat;

(e) After the gel is completed, the capillary glass tube and the nano-silica microspheres are dissolved with hydrofluoric acid, the gel is taken out and soaked in deionized water, and the residual hydrofluoric acid is removed to obtain a color-changing anti-counterfeiting material.

In step (b):

The nano-silica microsphere dispersion liquid enters the capillary glass tube through the capillary effect, and then the capillary glass tube is placed horizontally to make the ethanol in the capillary glass tube evaporate completely, and the nano-silica microspheres form in the capillary glass tube. Structural color areas; or

The nano-silica microsphere dispersion liquid is placed in an open container, and the capillary glass tube is inserted into the container longitudinally. The ethanol in the container and in the capillary glass tube was naturally evaporated completely, and the nano-silica microspheres formed a structural color area in the capillary glass tube at the same time.

In step (c), the preparation process of the acrylamide prepolymerization solution is as follows:

Take polyethylene glycol diacrylate in a glassware, then add N-isopropylacrylamide and N,N'-methylenebisacrylamide to the glassware and dissolve, then add MoS ₂ quantum dot dispersion, Then add N,N,N',N'-tetramethylethylenediamine and ammonium persulfate solution with a mass fraction of 5.0%, and finally put the glassware in an ice bath and ultrasonically mix evenly to obtain acrylamide prepolymerization solution ; Wherein, the mass ratio of the N-isopropylacrylamide added and N,N'-methylene bisacrylamide is 30: 1, and the consumption ratio of N-isopropylacrylamide and polyethylene glycol diacrylate is It is 3g:15~20mL, N-isopropylacrylamide:N,N,N',N'-tetramethylethylenediamine:ammonium persulfate solution=3g:100~130uL:260~290uL.

In step (c), the MoS ₂ quantum dot dispersion liquid refers to a dispersion liquid using MoS ₂ quantum dots as a solute and N-methylpyrrolidone as a solvent, wherein the lateral size of the MoS ₂ quantum dots is 1-10 nm, so The concentration of the MoS ₂ quantum dot dispersion liquid is 1 mg/mL, and the MoS ₂ quantum dot dispersion liquid: N-isopropylacrylamide=4~6mL: 3g.

In step (a), the diameter of the monodispersed nano-silica microspheres is 251 nm; in step (b), the diameter of the capillary glass tube is 10 mm and the length is 10 cm; in step (d), propylene The capillary glass tube of the amide prepolymerization solution was put into a plastic bag, the air in the plastic bag was exhausted and nitrogen gas was filled, and then the plastic bag was sealed and placed in a thermostat at 27°C for gelation.

The second object of the present invention is achieved through the following technical solutions: a preparation method of a color-changing anti-counterfeiting material, comprising the following steps:

(a) Monodisperse nano-silica microspheres in ethanol to obtain nano-silica microsphere dispersion;

(b) Entering the nano-silica microsphere dispersion into the capillary glass tube, and evaporating ethanol naturally, so that the nano-silica microspheres form a structural color area in the capillary glass tube;

(c) Preparation of acrylamide prepolymerization solution uniformly dispersed with _MoS2 quantum dots, so that the acrylamide prepolymerization solution enters the capillary glass tube with the structural color region through capillary effect;

(d) gelling the capillary glass tube containing the acrylamide prepolymerization solution prepared in step (c) in an oxygen-free environment in a thermostat;

(e) After the gel is completed, the capillary glass tube and the nano-silica microspheres are dissolved with hydrofluoric acid, the gel is taken out and soaked in deionized water, and the residual hydrofluoric acid is removed to obtain a color-changing anti-counterfeiting material.

In step (b):

The nano-silica microsphere dispersion liquid enters the capillary glass tube through the capillary effect, and then the capillary glass tube is placed horizontally to make the ethanol in the capillary glass tube evaporate completely, and the nano-silica microspheres form in the capillary glass tube. Structural color areas; or

The nano-silica microsphere dispersion liquid is placed in an open container, and the capillary glass tube is inserted into the container longitudinally. The ethanol in the container and in the capillary glass tube was naturally evaporated completely, and the nano-silica microspheres formed a structural color area in the capillary glass tube at the same time.

In step (c), the preparation process of the acrylamide prepolymerization solution is as follows:

Take polyethylene glycol diacrylate in a glassware, then add N-isopropylacrylamide and N,N'-methylenebisacrylamide to the glassware and dissolve, then add MoS ₂ quantum dot dispersion, Then add N,N,N',N'-tetramethylethylenediamine and ammonium persulfate solution with a mass fraction of 5.0%, and finally put the glassware in an ice bath and ultrasonically mix evenly to obtain acrylamide prepolymerization solution ; Wherein, the mass ratio of the N-isopropylacrylamide added and N,N'-methylene bisacrylamide is 30: 1, and the consumption ratio of N-isopropylacrylamide and polyethylene glycol diacrylate is It is 3g:15~20mL, N-isopropylacrylamide:N,N,N',N'-tetramethylethylenediamine:ammonium persulfate solution=3g:100~130uL:260~290uL.

In step (c), the MoS ₂ quantum dot dispersion liquid refers to a dispersion liquid using MoS ₂ quantum dots as a solute and N-methylpyrrolidone as a solvent, wherein the lateral size of the MoS ₂ quantum dots is 1-10 nm, so The concentration of the MoS ₂ quantum dot dispersion liquid is 1 mg/mL, and the MoS ₂ quantum dot dispersion liquid: N-isopropylacrylamide=4~6mL: 3g.

In step (a), the diameter of the monodispersed nano-silica microspheres is 251 nm; in step (b), the diameter of the capillary glass tube is 10 mm and the length is 10 cm; in step (d), propylene The capillary glass tube of the amide prepolymerization solution was put into a plastic bag, the air in the plastic bag was exhausted and nitrogen gas was filled, and then the plastic bag was sealed and placed in a thermostat at 27°C for gelation.

The anti-counterfeiting material of the invention is a color-changing anti-counterfeiting material with high stability index, small color pollution, wider discoloration range, faster recovery and stronger applicability, and its comprehensive performance is significantly better than the existing color-changing anti-counterfeiting materials. The preparation method provided by the invention is simple, easy to operate, and has good operability, and the prepared color-changing anti-counterfeiting material based on MoS ₂ quantum dots has good performance. The present invention uses MoS ₂ quantum dots to make the anti-counterfeiting material more excellent in performance, unique in structure, and has broad application prospects.

Description of drawings

Figure 1 is a picture of monodispersed nano-silica microspheres taken under a scanning electron microscope. The diameter of the monodisperse nano-silica microspheres is 251 nm.

FIG. 2 is a schematic diagram of drawing an acrylamide prepolymerization solution by the capillary effect of a capillary glass tube. In the figure, 1 denotes a capillary glass tube having a structural color region, 2 denotes an open glass vessel, and 3 denotes an acrylamide prepolymerization solution.

FIG. 3 is a picture taken by the Mshot microscope camera MD50 of the color-changing anti-counterfeiting material based on MoS ₂ quantum dots prepared in Example 2.

FIG. 4 is a schematic diagram of the photobending phenomenon of the color-changing anti-counterfeiting material based on MoS ₂ quantum dots prepared in Example 2 under the illumination of the epi-illumination system of the Mshot metallographic microscope MJ33.

5 is a picture taken by the Mshot microscope camera MD50 when the color-changing anti-counterfeiting material based on MoS ₂ quantum dots prepared in Example 2 is illuminated by the epi-illumination system of the Mshot metallographic microscope MJ33 when the structural color is blue-shifted.

FIG. 6 is a comparison diagram of the stability index investigation of the materials prepared in Example 2 and Comparative Example 1. FIG.

FIG. 7 is a comparative graph of the investigation of the maximum bending angle of the materials prepared in Example 2 and Comparative Example 1. FIG.

Detailed ways

The following examples are used to further illustrate the present invention in detail, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

Example 1 Fabrication of capillary glass tubes with structural color regions

As shown in FIG. 1 , the nano-silica microspheres used in the present invention are monodisperse nano-silica microspheres with a diameter of 251 nm that are commercially available, and are dispersed in water. Centrifuge it in a centrifuge at a speed of 4000 r/min for 5 minutes, then use a dropper to suck out the water, then centrifuge again, and suck out the water again. The ethanol is dispersed in ultrasonic wave (ultrasonic dispersing time is about 1h) until it is completely dispersed and there is no deposition, thus the nano-silica microsphere dispersion liquid of the present invention is obtained.

Place the nano-silica microsphere dispersion in an open glass container, insert the capillary glass tube into the container longitudinally, and the nano-silica microsphere dispersion will enter the capillary glass tube through the capillary effect, and keep standing to make the container The ethanol in the inner and capillary glass tubes is naturally evaporated completely, and the nano-silica microspheres form structural color regions in the capillary glass tubes through self-assembly; or

After the nano-silica microsphere dispersion enters the capillary glass tube through the capillary effect, the capillary glass tube is taken out and left to stand horizontally, so that the ethanol in the capillary glass tube is naturally evaporated, and the nano-silica microspheres are in physical sedimentation and Structural color regions are formed in the capillary glass tube under the action of agglomeration.

The structural color area formed above is a striped or other patterned area formed by nano-silica microspheres on the inner wall of the capillary glass tube. The diameter of the capillary glass tube is 10mm and the length is 10cm. Silica microspheres are easily dissolved by hydrofluoric acid; after a structural color area is formed on the inner wall of the capillary glass tube, it is stored for later use.

Example 2 Preparation of color-changing anti-counterfeiting materials based on MoS ₂ quantum dots

(1) Prepare a glass vessel with a lid for holding the acrylamide prepolymerization solution. Wipe the inner surface of the glassware with absorbent cotton dipped in acetone and anhydrous ethanol in turn, wipe off the dust and other small particles attached to the surface, and preliminarily remove the oil on the surface, and then put the glassware in acetone and use ultrasonic waves. After cleaning for 10 min, put it in alcohol for 10 min with ultrasonic cleaning, then take it out with a clip, put it in deionized water and ultrasonically clean it for 5 min, and finally take it out from deionized water and dry it with N ₂ .

(2) Preparation of acrylamide prepolymerization solution:

Take 1 mL of polyethylene glycol diacrylate (average molecular weight 600) in the glassware of step (1), and use an analytical balance to weigh 0.15 g of N-isopropylacrylamide (NIPAM, AR content 98%) and 0.005 g of N,N'-methylenebisacrylamide (BIS) was added to polyethylene glycol diacrylate, respectively, and then 0.3 mL of MoS ₂ quantum dot dispersion was added. Then, 6.5uL of N,N,N',N'-tetramethylethylenediamine (TEMED, 99%) and 14.5uL of ammonium persulfate solution (5% by mass) were added by pipette. Among them, the MoS ₂ quantum dot dispersion liquid refers to the dispersion liquid using MoS ₂ quantum dots as a solute and N-methylpyrrolidone as a solvent, the lateral size of the MoS ₂ quantum dots is 1~10 nm, and the concentration of the MoS ₂ quantum dot dispersion liquid is 1 mg/mL. It should be noted that ammonium persulfate solution is the initiator, and N,N,N',N'-tetramethylethylenediamine (TEMED) is the catalyst, which catalyzes ammonium persulfate to generate free radicals, thereby accelerating the polymerization of acrylamide gels, The amount of N,N,N',N'-tetramethylethylenediamine (TEMED, 99%) and ammonium persulfate solution should be strictly controlled. If the amount is too small, the gelation process will become abnormally slow or even no gelation. , a large amount will cause the pre-polymerization solution just prepared to complete the gel in a glass vessel. Shake the glassware to initially disperse the substances, and then ultrasonically mix in an ice bath for 1 h until the prepared prepolymer solution is completely and uniformly mixed without stratification. The temperature of the ultrasonic mixing process should be strictly controlled, and the prepolymerization solution will rapidly coagulate into a solid if the temperature is slightly higher.

(3) Gel in anaerobic environment:

As shown in Figure 2, using the capillary effect of the capillary glass tube, the acrylamide prepolymerization solution was placed into the capillary glass tube prepared in Example 1, and the liquid level in the capillary glass tube was higher than the glass container. The prepolymerized solution was allowed to fill the entire area with structural color. After that, the capillary glass tube filled with the prepolymerization solution was placed in a petri dish. Take a plastic bag, squeeze out all the air in it (oxygen will stop free radical binding and thus inhibit the gel), push the petri dish into the plastic bag, fill the plastic bag with nitrogen, and seal it with tape . Put the sealed plastic bag into an incubator, keep the temperature at 27°C, and gel for 10h. After completing the gel, cut the plastic bag, take out the petri dish, soak the capillary glass tube in hydrofluoric acid until the glass is completely dissolved, remove the gel with tweezers, soak in deionized water for 10 minutes, change the water, and soak again. After three soaks, the gel was removed and stored in deionized water. The prepared gel is shown in Figure 3. The acrylamide gel is cylindrical, the radius of the bottom surface is consistent with the capillary glass tube used, and its length can be adjusted artificially, and the formed structural color is dispersed on the outer surface of the cylinder.

Comparative Example 1 Preparation of color-changing anti-counterfeiting materials based on graphene oxide

(1) Prepare a glass vessel with a lid for holding the acrylamide prepolymerization solution. Wipe the inner surface of the glassware with absorbent cotton dipped in acetone and anhydrous ethanol in turn, wipe off the dust and other small particles attached to the surface, and preliminarily remove the oil on the surface, and then put the glassware in acetone and use ultrasonic waves. After cleaning for 10 min, put it in alcohol for 10 min with ultrasonic cleaning, then take it out with a clip, put it in deionized water and ultrasonically clean it for 5 min, and finally take it out from deionized water and dry it with N ₂ .

(2) Preparation of acrylamide prepolymerization solution:

Take 1ml of polyethylene glycol diacrylate (average molecular weight 600) in a glass vessel, add 0.15g of N-isopropylacrylamide (NIPAM, AR content 98%) and 0.005g of N,N'-sulfite Methylbisacrylamide (BIS), followed by 0.3 ml of graphene oxide in water (2 mg/ml). Then add 6.5ul of N,N,N',N'-tetramethylethylenediamine (TEMED, 99%) and 14.5ul of ammonium persulfate solution (mass fraction 5%), shake the vessel to make various substances preliminary Disperse, and then ultrasonically mix in an ice bath for 1 hour until the prepared pre-polymerization solution is completely and uniformly mixed without delamination.

(3) Gel in anaerobic environment:

Using the capillary effect of the capillary glass tube, the acrylamide prepolymerization solution was put into the capillary glass tube prepared in Example 1, and the liquid level in the capillary glass tube was higher than the glass container. The prepolymerized solution was allowed to fill the entire area with structural color. After that, the capillary glass tube filled with the prepolymerization solution was placed in a petri dish. Take a plastic bag, squeeze out all the air in it (oxygen will stop free radical binding and thus inhibit the gel), push the petri dish into the plastic bag, fill the plastic bag with nitrogen, and seal it with tape . Put the sealed plastic bag into an incubator, keep the temperature at 27°C, and gel for 10h. After completing the gel, cut the plastic bag, take out the petri dish, soak the capillary glass tube in hydrofluoric acid until the glass is completely dissolved, remove the gel with tweezers, soak in deionized water for 10 minutes, change the water, and soak again. Finally, the gel was swollen in hydrazine monohydrate solution (0.33 M) to reduce the graphene oxide dispersed in the gel network. After two days, remove the gel and place it in deionized water for two more days.

Example 3 Performance test

Because of the incorporation of MoS ₂ quantum dots, the acrylamide gel is endowed with some special properties. As shown in Figure 4, the material made in Example 2 is placed on an optical microscope with an optical camera (Mshot Mingmei microscope MJ33, Mshot Mingmei microscope camera MD50), and the light source of the microscope is turned on (the light comes from Mshot Mingmei microscope). Epi-illumination system of phase microscope MJ33), after irradiating the material for a period of time, the material will bend toward the light source like a sunflower. At the same time of bending, the camera MD50 was used to capture the area of the material with structural color periodically, and it was found that when the material was bent to the light, it also had the color change phenomenon of the illuminated structural color area. After a large number of experimental observations and data analysis, it is found that this is a phenomenon of structural color regional blue shift. Because the color-changing anti-counterfeiting material based _on MoS ₂ quantum dots has excellent photothermal conversion efficiency, when illuminated, it will cause the material to undergo reversible light bending, and the change of structure will indirectly lead to the change of structural color. With special microstructure, the structural color will have a blue shift phenomenon. The specific phenomenon is shown in Figure 5. The numbers 1 to 9 in Figure 5 correspond to the bending of the material at 2°, 4°, 6°, 8°, and 10°, respectively. , 12°, 14°, 16°, 18°. And it can be seen from Figure 5 that some structural colors are shifted to invisible wavelengths due to blue shift, resulting in the disappearance of structural colors. Using this phenomenon, we can make dynamic anti-counterfeiting barcodes with photochromic capability.

The discoloration rates of the MoS ₂ quantum dot-based discoloration anti-counterfeiting material prepared in Example 2 and the material prepared in Comparative Example 1 were compared. When irradiated with high-power light, because the power of the light itself is too high, the photothermal conversion ability of the material will be saturated, and the difference between different raw material concentrations of the same material will be amplified. In order to highlight the different properties of the material itself, We use low-power light for irradiation. At this time, it can be considered that the required ability of photothermal conversion is determined by the light power, and the different performances between materials are determined by the doping substances. Take dozens of the above two materials respectively, and the length of each one is 6.5mm, and irradiate with low-power light (the light comes from the epi-illumination system of Mshot Mingmei phase microscope MJ33), in order to ensure the difference of the experiment Only on the premise of the incorporated substances, we monitor the bending rates of the two materials in real time and calculate their stability indices. Using multiple measurements of multiple materials to finally obtain a representative mean value, a general stability index of the two materials can be obtained.

In order to describe the anti-interference ability of the material, and express the stability of the material reasonably and clearly in the coordinate system. We propose a stability index, expressed as:

in,

represents the instantaneous rate of bending of the hydrogel fibers toward the light source, and represents the bending angle of the hydrogel fibers in time.

The results of the material stability index are shown in Figure 6. We can clearly compare that the stability index of the color-changing anti-counterfeiting material based on MoS ₂ quantum dots is significantly higher than that of the material prepared in Comparative Example 1. These two materials have strong discoloration ability and degree of discrimination. Today, when imaging technology and color analysis have been so developed, we can easily identify the structural color changes of materials. Therefore, materials with high stability index should be ours. Preferred. Because of the high stability index, the stronger its ability to resist environmental light source pollution, the higher its anti-counterfeiting accuracy. Furthermore, in real life, we need to complete the function of anti-counterfeiting detection in a short time, so the light source should be replaced with a high-power infrared light source, but it is inevitable that there will be a certain error in the irradiation time and power of the light source and the ideal situation. , and materials with high stability index have a good effect on reducing the influence of this inevitable error, which can greatly improve the accuracy of anti-counterfeiting detection while ensuring efficiency.

The maximum bending angle of the color-changing anti-counterfeiting material based on MoS ₂ quantum dots prepared in Example 2 and the material prepared in Comparative Example 1 was tested, and the results are shown in Figure 7 . The maximum bending angle of the two materials was measured using the same light source (light from the epi-illumination system of the Mshot Mingmei phase microscope MJ33). The color-changing anti-counterfeiting material based _on MoS2 quantum dots has a maximum bending angle of 19.6 degrees, while the maximum bending angle of the material prepared in Comparative Example 1 is 40 degrees. Because the discoloration of this color-changing anti-counterfeiting material is still derived from the change of structure, we cannot interfere with its bending. The smaller the maximum bending angle, the smaller the required space range when bending, and the stronger the reversibility of bending, and the faster the recovery speed of structural color. Moreover, the smaller the bending angle, the smaller the maximum occupied volume in actual anti-counterfeiting applications, the stronger the plasticity, and the easier it is to be widely used in many fields.

The color-changing anti-counterfeiting material based on MoS ₂ quantum dots prepared in Example 2 is also different from the color-changing anti-counterfeiting material based on reduced graphene oxide in Comparative Example 1 in terms of discoloration range and phenomenon. The initial structural color we used is formed by 251nm monodisperse nano-silica microspheres, and the initial structural color is only red. When we illuminate the material (the light comes from the epi-illumination system of the Mshot Mingmei microscope MJ33), the color of the material's structural color gradually changes from red to green, and then the structural color turns to the invisible light part, as shown in Figure 5. In contrast, the graphene oxide-based color-changing anti-counterfeiting material in Comparative Example 1 only changes from red to green when its initial structural color has only one color (such as red), and does not change from structural color to invisible light. . That is to say, the color-changing anti-counterfeiting material based on MoS ₂ quantum dots prepared by us has a wider color-changing range, and thus has a stronger ability to store hidden encoded information, and is expected to replace the current black and white barcodes in the future.

During color analysis, it was found that the color-changing anti-counterfeiting material of Comparative Example 1 had color contamination because graphene oxide was tan. The color-changing anti-counterfeiting material based on MoS ₂ quantum dots has relatively little color pollution, so its structural color accuracy is stronger, and the color distinction of structural color is also stronger.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the described embodiments, and any other changes, modifications, substitutions, and combinations made without departing from the spirit and principle of the present invention , simplification, all should be equivalent replacement modes, and are all included in the protection scope of the present invention.

Claims (6)

1. A color-changing anti-counterfeiting material, wherein the color-changing anti-counterfeiting material is prepared by the following method: (a) Monodisperse nano-silica microspheres in ethanol to obtain nano-silica microsphere dispersion; (b) Entering the nano-silica microsphere dispersion into the capillary glass tube, and evaporating ethanol naturally, so that the nano-silica microspheres form a structural color area in the capillary glass tube; (c) Prepare an acrylamide pre _- polymerization solution with MoS2 quantum dots uniformly dispersed, so that the acrylamide pre-polymerization solution enters the capillary glass tube with the structural color region through the capillary effect; the preparation process of the acrylamide pre-polymerization solution is as follows : Take polyethylene glycol diacrylate in a glassware, then add N-isopropylacrylamide and N,N'-methylenebisacrylamide to the glassware and dissolve, then add MoS ₂ quantum dot dispersion, Then add N,N,N',N'-tetramethylethylenediamine and ammonium persulfate solution with a mass fraction of 5.0%, and finally put the glassware in an ice bath and ultrasonically mix evenly to obtain acrylamide prepolymerization solution ; Wherein, the mass ratio of the N-isopropylacrylamide added and N,N'-methylene bisacrylamide is 30: 1, and the consumption ratio of N-isopropylacrylamide and polyethylene glycol diacrylate is It is 3g: 15~20mL, N-isopropylacrylamide: N,N,N',N'-tetramethylethylenediamine: ammonium persulfate solution=3g: 100~130uL: 260~290uL; The MoS ₂ quantum dot dispersion liquid refers to a dispersion liquid using MoS ₂ quantum dots as a solute and N-methylpyrrolidone as a solvent, wherein the lateral size of the MoS ₂ quantum dots is 1-10 nm, and the MoS ₂ quantum dots are dispersed The concentration of the liquid is 1mg/mL, MoS ₂ quantum dot dispersion liquid: N-isopropylacrylamide=4~6mL:3g; (d) gelling the capillary glass tube containing the acrylamide prepolymerization solution prepared in step (c) in an oxygen-free environment in a thermostat; (e) After the gel is completed, the capillary glass tube and the nano-silica microspheres are dissolved with hydrofluoric acid, the gel is taken out and soaked in deionized water, and the residual hydrofluoric acid is removed to obtain a color-changing anti-counterfeiting material. 2. The color-changing anti-counterfeiting material according to claim 1, wherein in step (b): The nano-silica microsphere dispersion liquid enters the capillary glass tube through the capillary effect, and then the capillary glass tube is placed horizontally to make the ethanol in the capillary glass tube evaporate completely, and the nano-silica microspheres form in the capillary glass tube. Structural color areas; or The nano-silica microsphere dispersion liquid is placed in an open container, and the capillary glass tube is inserted into the container longitudinally. The ethanol in the container and in the capillary glass tube was naturally evaporated completely, and the nano-silica microspheres formed a structural color area in the capillary glass tube at the same time. 3 . The color-changing anti-counterfeiting material according to claim 1 , wherein in step (a), the diameter of the monodispersed nano-silica microspheres is 251 nm; in step (b), the diameter of the capillary glass tube is 251 nm . is 10mm and the length is 10cm; in step (d), put the capillary glass tube containing the prepolymerized solution of acrylamide into a plastic bag, exhaust the air in the plastic bag and fill with nitrogen, and then seal the plastic bag and place it side by side Gels were performed in an incubator at 27°C. 4. a preparation method of discoloration anti-counterfeiting material, is characterized in that, comprises the following steps: (a) Monodisperse nano-silica microspheres in ethanol to obtain nano-silica microsphere dispersion; (b) Entering the nano-silica microsphere dispersion into the capillary glass tube, and evaporating ethanol naturally, so that the nano-silica microspheres form a structural color area in the capillary glass tube; (c) Prepare an acrylamide pre _- polymerization solution with MoS2 quantum dots uniformly dispersed, so that the acrylamide pre-polymerization solution enters the capillary glass tube with the structural color region through the capillary effect; the preparation process of the acrylamide pre-polymerization solution is as follows : Take polyethylene glycol diacrylate in a glassware, then add N-isopropylacrylamide and N,N'-methylenebisacrylamide to the glassware and dissolve, then add MoS ₂ quantum dot dispersion, Then add N,N,N',N'-tetramethylethylenediamine and ammonium persulfate solution with a mass fraction of 5.0%, and finally put the glassware in an ice bath and ultrasonically mix evenly to obtain acrylamide prepolymerization solution ; Wherein, the mass ratio of the N-isopropylacrylamide added and N,N'-methylene bisacrylamide is 30: 1, and the consumption ratio of N-isopropylacrylamide and polyethylene glycol diacrylate is It is 3g: 15~20mL, N-isopropylacrylamide: N,N,N',N'-tetramethylethylenediamine: ammonium persulfate solution=3g: 100~130uL: 260~290uL; The MoS ₂ quantum dot dispersion liquid refers to a dispersion liquid using MoS ₂ quantum dots as a solute and N-methylpyrrolidone as a solvent, wherein the lateral size of the MoS ₂ quantum dots is 1-10 nm, and the MoS ₂ quantum dots are dispersed The concentration of the liquid is 1mg/mL, MoS ₂ quantum dot dispersion liquid: N-isopropylacrylamide=4~6mL:3g; (d) gelling the capillary glass tube containing the acrylamide prepolymerization solution prepared in step (c) in an oxygen-free environment in a thermostat; (e) After the gel is completed, the capillary glass tube and the nano-silica microspheres are dissolved with hydrofluoric acid, the gel is taken out and soaked in deionized water, and the residual hydrofluoric acid is removed to obtain a color-changing anti-counterfeiting material. 5. The method for preparing a color-changing anti-counterfeiting material according to claim 4, wherein in step (b): The nano-silica microsphere dispersion liquid enters the capillary glass tube through the capillary effect, and then the capillary glass tube is placed horizontally to make the ethanol in the capillary glass tube evaporate completely, and the nano-silica microspheres form in the capillary glass tube. Structural color areas; or The nano-silica microsphere dispersion liquid is placed in an open container, and the capillary glass tube is inserted into the container longitudinally. The ethanol in the container and in the capillary glass tube was naturally evaporated completely, and the nano-silica microspheres formed a structural color area in the capillary glass tube at the same time. 6 . The method for preparing a color-changing anti-counterfeiting material according to claim 4 , wherein in step (a), the diameter of the monodispersed nano-silica microspheres is 251 nm; in step (b), the capillary glass The diameter of the tube is 10 mm and the length is 10 cm; in step (d), the capillary glass tube containing the prepolymerized solution of acrylamide is put into a plastic bag, the air in the plastic bag is exhausted and nitrogen is filled, and then the plastic bag is filled with nitrogen. Seal and place in an incubator at 27°C for gelation.

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