A multi-modal fluorescent anti-counterfeiting material with photochromism and a preparation method thereof

Abstract

The application discloses a kind of multi-modal fluorescence anti-counterfeiting materials with photochromic and preparation method thereof, the material has multicolor photoluminescence, dynamic long afterglow and reversible photochromic characteristics: under the excitation of 254nm, the luminescence color can gradually change from blue to red, and the afterglow color gradually changes; only red fluorescence is emitted under the excitation of 365nm, and the duration of red afterglow is greater than or equal to 1 hour; it becomes brown after irradiation by 254nm ultraviolet light, and can recover to the initial color under the condition of 450nm blue light irradiation, white light irradiation or heating. The application makes the luminescence gradually change from blue to red, adapts to more anti-counterfeiting scenes, has wide application prospect in the field of multi-modal anti-counterfeiting, has simple preparation process operation, low raw material and equipment cost, is environment-friendly, the product has stable chemical properties, and is suitable for popularization and use.

Description

Technical Field

[0001] This invention relates to the field of fluorescent anti-counterfeiting materials technology, and in particular to a multimodal fluorescent anti-counterfeiting material with photochromic properties and its preparation method. Background Technology

[0002] Fluorescent anti-counterfeiting technology has attracted much attention due to its advantages such as high visibility, multiple color options, high throughput, and low design cost. Compared to common single-mode static fluorescent materials, fluorescent materials with long-persistence luminescence characteristics can exhibit unique properties such as long lifetime, multi-color emission, and dynamic changes by controlling the photon release process, making them ideal multi-mode anti-counterfeiting materials. To improve the security of anti-counterfeiting labels, traditional single-mode fluorescent materials are gradually being upgraded to luminescent materials with multi-mode emission capabilities. These long-persistence materials provide rich identification information, covering emission color, intensity (spatial dimension), and luminescence lifetime (temporal dimension). Materials with single components effectively overcome the complexity of composite structures and material mixing, as well as the low efficiency problems caused by performance mismatch and physicochemical incompatibility.

[0003] However, most single-component multimode luminescent materials currently exhibit only monochromatic emission. Color changes can only be achieved by adjusting the doping of the luminescent centers or changing their concentration in the multicomponent material, limiting the achievement of higher levels of anti-counterfeiting functionality in both spatial and temporal dimensions. A more effective solution is to use single-component long-persistence materials whose emission color changes depend on the excitation light source. These materials can exhibit different colors of emission under excitation light of different wavelengths. In addition to photoluminescence and afterglow emission modes, afterglow phosphors often exhibit multiple excitation emission modes, meaning that additional external physical stimuli (such as thermal, mechanical, chemical, or optical excitation) can further enhance anti-counterfeiting capabilities. Nevertheless, the development and research of dynamic multicolor long-persistence materials remain limited. Therefore, achieving dynamic multicolor emission with multimode response in a single material remains a pressing technical challenge to be overcome.

[0004] Furthermore, photochromic materials are a class of photoresponsive materials whose color change is due to the capture of charge carriers generated by photoexcitation, leading to the formation of metastable color-changing centers. In recent years, these materials have received widespread attention for their potential applications in anti-counterfeiting, information encryption and storage, optical switches, and smart windows. In anti-counterfeiting applications of photochromic materials, the materials must meet the following key criteria: 1) strong color contrast to ensure effective readout, high signal-to-noise ratio, and resolution; 2) high photoresponse rate for real-time writing and reading; and 3) excellent fatigue resistance and chemical / thermal stability to ensure long-term cycle life. However, to date, photochromic phosphor materials with high color contrast and easily reversible properties remain relatively scarce. To improve the photochromic performance of phosphor materials, researchers typically employ various strategies, such as introducing volatile elements into the composition design, high-temperature sintering, and activated ion doping, aiming to increase the concentration of vacancy defects (including cation vacancies and oxygen vacancies) to form more color centers, thereby enhancing photochromic performance. Nevertheless, preparing phosphor materials with excellent photochromic properties remains a challenging task.

[0005] To achieve multimode luminescence in a single material, trivalent rare earth ions (Ln) 3+ Due to its rich 4f n Energy levels and characteristic peak emissions are often considered key activators for designing commercial materials. However, the high cost and singular emission modes of rare earth elements greatly limit their industrial applications. Therefore, research on rare earth-free, tunable emission, long-afterglow materials has attracted widespread attention in recent years. Copper is an essential trace element involved in many important metabolic processes in the human body. In phosphor materials, Cu... 2+ Ions typically undergo dd transitions via the Jahn-Teller effect, resulting in near-infrared emission. Cu 2 + There are few reports on visible light emission of Cu. 2+ Visible light emission typically originates from the matrix conduction zone to Cu. 2+ 3d orbitals or from excited state Cu 2+ Electron transitions to the valence band. Therefore, changing the type of matrix can alter the properties of Cu. 2+ The emission covers a wide color range from blue to red. Based on this, Cu can be achieved by adjusting the band gap of the matrix. 2+ Multicolor emission doped with phosphor. We chose Sr 0.97 Zn 0.03 Ga 1.94 Al 0.06O4 (SZGA) matrix is ​​a wide-bandgap semiconductor material with multiple cation sites and abundant coordination environments. This provides diverse options for activator ion doping and ample opportunities for further design and introduction of cation or oxygen vacancies. Therefore, the SZGA matrix shows great potential in achieving excellent long afterglow and photochromic properties. Currently, regarding Cu... 2+ The luminescence properties of doped SZGA have not yet been reported.

[0006] Currently, single-component multimode luminescent materials have significant limitations in anti-counterfeiting applications: First, they lack flexibility in color control. Traditional materials are mostly limited to monochromatic emission, requiring adjustments to the doping concentration of the luminescent center or reliance on multi-component systems to achieve color changes, making it difficult to achieve dynamic and highly complex anti-counterfeiting functions in the spatiotemporal dimensions. Second, existing photochromic phosphor materials generally have performance defects, especially materials that combine high color contrast with simple reversible color-changing characteristics, which are still scarce. This severely restricts their practical application in the field of multimode fluorescent anti-counterfeiting. Summary of the Invention

[0007] The purpose of this invention is to solve existing problems by proposing a photochromic multimodal fluorescent anti-counterfeiting material and its preparation method. To achieve the above objectives, the present invention adopts the following technical solution: This invention has the following general formula: A 1-x-z A' x M 2-y M' y O4:zCu 2+ ; Wherein, A and A' are selected from one or more of Mg, Zn, Ca, Sr, and Ba, and A and A' are not repeated; M and M' are independently selected from one or more of Ga, Al, In, Sc, and Y, and M and M' are not repeated; the doping amount satisfies: 1mol%≤x≤20mol%, 1mol%≤y≤20mol%, 0mol%≤z≤4mol%. The material exhibits multicolor photoluminescence, dynamic long afterglow, and reversible photochromic properties: under 254nm excitation, the emission color can gradually change from blue to red, and the afterglow color gradually changes; under 365nm excitation, it only emits red fluorescence, and the red afterglow lasts for ≥1 hour; after being irradiated with 254nm ultraviolet light, it turns brown, and can be restored to its initial color under 450nm blue light irradiation, white light irradiation, or heating conditions.

[0008] Furthermore, A is Sr, and A' is Zn.

[0009] Furthermore, M represents Ga, and M' represents Al.

[0010] Furthermore, M and / or M' may be partially substituted with one or more of La, Gd, and Lu, with a substitution ratio of 0.5 mol% ≤ substitution amount ≤ 40 mol%.

[0011] Furthermore, the duration of the red afterglow under 365nm excitation is ≥1 hour, and the emission peak position under 254nm excitation can be red-shifted from 451nm to 650nm.

[0012] In another aspect, a method for preparing the multimodal fluorescent anti-counterfeiting material includes the following steps: (1) Take a copper source, an A-containing metal source, an A'-containing metal source, an M-containing metal source and an M'-containing metal source, mix them and grind them once to obtain a raw material mixture, wherein the molar ratio of the oxide corresponding to the A-containing metal source to the carbonate corresponding to the A' metal source is (0.99-0.76):(0.01-0.2); or any combination of the carbonate corresponding to the A metal and the nitrate corresponding to the A' metal, or the combination of the nitrate corresponding to the A metal and the acetate corresponding to the A' metal, and the molar ratio of the carbonate corresponding to the A metal and the nitrate corresponding to the A' metal is (0.99-0.76):(0.01-0.2), and the molar ratio of the nitrate corresponding to the A metal and the acetate corresponding to the A' metal is (0.99-0.76):(0.01-0.2); (2) The raw material mixture is calcined at 1000~1500℃ for 1~24 hours, cooled to room temperature, and then ground twice to obtain a calcined mixture; (3) The calcined mixture is calcined at 1000~1500℃ for 3~24 hours, cooled and then ground three times to obtain the multimodal fluorescent anti-counterfeiting material.

[0013] Further, in step (1), the copper source is selected from one or more of copper oxides, carbonates, halides, oxalates, acetates or nitrates; the A-containing metal source, the A'-containing metal source, the M-containing metal source and the M'-containing metal source are each independently selected from one or more of the corresponding element's oxides, halides, carbonates, nitrates, oxalates, citrates or acetates.

[0014] Furthermore, the molar ratio of the A-containing metal source to the A'-containing metal source is (0.99~0.76):(0.01~0.2), and the molar ratio of the M-containing metal source to the M'-containing metal source is (1.99~1.8):(0.01~0.2).

[0015] Furthermore, the apparatus for the first, second, and third grinding was an agate mortar, and the grinding time was 5 to 120 minutes.

[0016] Furthermore, the calcination temperature in step (2) is 1400℃ and the calcination time is 6 hours, and the calcination temperature in step (3) is 1400℃ and the calcination time is 6 hours.

[0017] Compared with the prior art, the beneficial effects of this invention are as follows: The multimode fluorescent anti-counterfeiting material provided by this invention uses a compound with a monoclinic crystal structure as a matrix, and is made of environmentally friendly Cu. 2+ Ions are the luminescent centers. Compared with existing fluorescent anti-counterfeiting technologies, the fluorescent anti-counterfeiting material of this invention has significant advantages: First, it integrates multi-mode anti-counterfeiting functions, with a single matrix possessing multi-color photoluminescence, multi-color long afterglow (afterglow color gradually changes under 254 nm excitation, and red afterglow lasts for more than 1 hour under 365 nm excitation), and reversible photochromism (the material color turns brown under 254 nm irradiation, and can be restored by 450 nm light or heating), resulting in richer anti-counterfeiting layers; second, it offers higher anti-counterfeiting security, with reversible photochromism providing an additional layer of protection, making complex dynamic anti-counterfeiting modes difficult to imitate; third, its luminescence is adjustable, with Cu... 2+ Doping allows the luminescence to gradually change from blue to red, making it suitable for more anti-counterfeiting scenarios and showing broad application prospects in the field of multi-mode anti-counterfeiting. Furthermore, the preparation process of this multi-mode fluorescent anti-counterfeiting material is simple, with low raw material and equipment costs, environmentally friendly, and the product has stable chemical properties, making it suitable for widespread use. Attached Figure Description

[0018] Figure 1 This is the X-ray diffraction (XRD) spectrum of the multimode fluorescent anti-counterfeiting material prepared in Example 1 of the present invention. Figure 2 The different Cu prepared in Example 1 of this invention 2+ Emission spectra of multimode fluorescent anti-counterfeiting materials with ion-doped concentrations under common 254nm and 365nm excitation light sources; Figure 3 The different Cu prepared in Example 1 of this invention 2+ Afterglow spectra of multimode fluorescent anti-counterfeiting materials with ion-doped concentrations after irradiation by common 254nm and 365nm excitation light sources, respectively. Figure 4 The diffuse reflectance spectrum, grayscale value, and photochromic photograph of the multimode fluorescent anti-counterfeiting material prepared in Example 1 of this invention after being subjected to 254nm light irradiation, 450nm photobleaching, and 523K heating fading in 10 reversible alternating cycles are shown. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Example 1 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 1 hour. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a highly significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0021] Example 2 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 1 hour. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.8 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0022] Example 3 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 24 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.9 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a highly significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0023] Example 4 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1000℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.4 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits slightly significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0024] Example 5 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1500℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.5 hours. Figure 3 Furthermore, upon irradiation with 254nm ultraviolet light, the material exhibits visible photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0025] Example 6 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 3 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.7 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0026] Example 7 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 24 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.8 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0027] Example 8 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1000℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.4 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits slightly significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0028] Example 9 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.99-z):0.01:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.99- z Cu z Zn 0.01 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.1 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a subtle photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0029] Example 10 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.8-z):0.2:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.8- z Cu z Zn 0.2 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.2 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a subtle photochromic behavior, with the powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0030] Example 11 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.995:0.005:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.99 Al 0.01 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.4 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0031] Example 12 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.95:0.1:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.8 Al 0.2 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.3 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a weak photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0032] Example 13 The raw materials were BaCO3 (99.99%), MgO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1500℃ for 24 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1500℃ for 24 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Ba. 0.97- z Cu z Mg 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.4 hours. Figure 3 Furthermore, upon irradiation with 254nm ultraviolet light, the material exhibits visible photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0033] Example 14 The raw materials were BaCO3 (99.99%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Ba. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.7 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0034] Example 15 The raw materials were BaCO3 (99.99%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1500℃ for 24 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1500℃ for 24 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Ba. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.4 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits slightly significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0035] Example 16 The raw materials were SrCO3 (99.95%), ZnO (99.99%), In2O3 (99.999%), Sc2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 In 1.94 Sc 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.3 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a weak photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0036] Example 17 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Y2O3 (99.999%), Ga2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1500℃ for 24 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1500℃ for 24 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Y 1.94 Ga 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.2 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a subtle photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0037] Example 18 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for about 5 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.8 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0038] Example 19 The raw materials were SrCO3 (99.95%), ZnO (99.99%), Ga2O3 (99.999%), Al2O3 (99.999%), and CuO (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 120 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain a multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97- z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 1 hour. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits a highly significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0039] Example 20 The raw materials were Sr(NO3)2 (99.95%), Zn(NO3)2 (99.99%), Ga(NO3)3 (99.999%), Al(NO3)3 (99.999%), and Cu(NO3)2 (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for approximately 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97-z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.7 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0040] Example 21 The raw materials were Sr(CH3COO)2 (99.95%), Zn(CH3COO)2 (99.99%), Ga(CH3COO)3 (99.999%), Al(CH3COO)3 (99.999%), and CH3COOCu (99.99%), with a molar ratio of (0.97-z):0.03:0.97:0.03:z (0≤z≤0.04). The raw materials were weighed according to this ratio, mixed evenly in an agate mortar, and ground for about 30 minutes. Then, the mixture was placed in an alumina crucible and calcined at 1400℃ for 6 hours. The sample after the first calcination was removed, ground and mixed again, and then placed back into the alumina crucible for further calcination at 1400℃ for 6 hours. After natural cooling, the sample was removed and carefully ground to obtain the multi-mode fluorescent anti-counterfeiting material. The obtained multi-mode fluorescent anti-counterfeiting powder, along with Cu... 2+ As the ion doping concentration increases, the powder color gradually changes from white to reddish-brown, with the molecular formula Sr. 0.97-z Cu z Zn 0.03 Ga 1.94 Al 0.06 O4 (0≤z≤0.04). Figure 1 The prepared sample shows to be a single, pure phase. Under a 254 nm excitation source, the material exhibits a broad emission peak of 300–800 nm. With Cu… 2+ With increasing doping concentration, the emission color gradually transitions from blue to yellow, and finally to red, with the emission peak position shifting from 451 nm to 650 nm. When the excitation source is switched to 365 nm, the material emits only red fluorescence. Figure 2 After the 254nm excitation source was turned off, the afterglow color of the material changed sequentially from blue to yellow and then to red; however, after the 365nm excitation source was turned off, the afterglow only appeared red, and the decay time exceeded 0.6 hours. Figure 3 Furthermore, after irradiation with 254nm ultraviolet light, the material exhibits significant photochromic behavior, with its powder color changing from white to brown. This color change process is reversible under irradiation with 450nm blue light, white light, or heating conditions, and can be restored to its initial white state. Figure 4 In summary, by combining Cu 2+ By leveraging the tunable luminescence and long afterglow properties of ions, as well as reversible photochromic behavior, this invention achieves the functional integration of multicolor luminescence, long afterglow, and dynamic photochromism in a single matrix, constructing complex dynamic anti-counterfeiting patterns and demonstrating the broad application prospects of this material in the field of multimode fluorescent anti-counterfeiting.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A photochromic multimodal fluorescent anti-counterfeiting material, characterized in that, It has the following general formula: A 1-x-z A' x M 2- y M' y O4:zCu 2+ ; Wherein, A and A' are selected from one or more of Mg, Zn, Ca, Sr, and Ba, and A and A' are not repeated; M and M' are independently selected from one or more of Ga, Al, In, Sc, and Y, and M and M' are not repeated; the doping amount satisfies: 1mol%≤x≤20mol%, 1mol%≤y≤20mol%, 0mol%≤z≤4mol%. The material exhibits multicolor photoluminescence, dynamic long afterglow, and reversible photochromic properties: under 254nm excitation, the emission color can gradually change from blue to red, and the afterglow color gradually changes; under 365nm excitation, it only emits red fluorescence, and the red afterglow lasts for ≥1 hour; after being irradiated with 254nm ultraviolet light, it turns brown, and can be restored to its initial color under 450nm blue light irradiation, white light irradiation, or heating conditions.

2. The multimodal fluorescent anti-counterfeiting material according to claim 1, characterized in that, A is Sr, and A' is Zn.

3. The multimodal fluorescent anti-counterfeiting material according to claim 1, characterized in that, M stands for Ga, and M' stands for Al.

4. The multimodal fluorescent anti-counterfeiting material according to claim 1, characterized in that, M and / or M' may be partially substituted with one or more of La, Gd, and Lu, with a substitution ratio of 0.5 mol% ≤ substitution amount ≤ 40 mol%.

5. The multimodal fluorescent anti-counterfeiting material according to claim 1, characterized in that, The duration of red afterglow under 365nm excitation is ≥1 hour, and the emission peak position under 254nm excitation can be redshifted from 451nm to 650nm.

6. A method for preparing the multimodal fluorescent anti-counterfeiting material according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Take a copper source, an A-containing metal source, an A'-containing metal source, an M-containing metal source and an M'-containing metal source, mix them and grind them once to obtain a raw material mixture, wherein the molar ratio of the oxide corresponding to the A-containing metal source to the carbonate corresponding to the A' metal source is (0.99-0.76):(0.01-0.2); or any combination of the carbonate corresponding to the A metal and the nitrate corresponding to the A' metal, or the combination of the nitrate corresponding to the A metal and the acetate corresponding to the A' metal, and the molar ratio of the carbonate corresponding to the A metal and the nitrate corresponding to the A' metal is (0.99-0.76):(0.01-0.2), and the molar ratio of the nitrate corresponding to the A metal and the acetate corresponding to the A' metal is (0.99-0.76):(0.01-0.2); (2) The raw material mixture is calcined at 1000~1500℃ for 1~24 hours, cooled to room temperature, and then ground twice to obtain a calcined mixture; (3) The calcined mixture is calcined at 1000~1500℃ for 3~24 hours, cooled and then ground three times to obtain the multimodal fluorescent anti-counterfeiting material.

7. The method according to claim 6, characterized in that, In step (1), the copper source is selected from one or more of copper oxides, carbonates, halides, oxalates, acetates or nitrates; the A-containing metal source, the A'-containing metal source, the M-containing metal source and the M'-containing metal source are each independently selected from one or more of the corresponding element's oxides, halides, carbonates, nitrates, oxalates, citrates or acetates.

8. The method according to claim 6, characterized in that, The molar ratio of the metal source containing A to the metal source containing A' is (0.99~0.76):(0.01~0.2), and the molar ratio of the metal source containing M to the metal source containing M' is (1.99~1.8):(0.01~0.2).

9. The method according to claim 6, characterized in that, The apparatus used for the first, second, and third grinding was an agate mortar, and the grinding time was 5 to 120 minutes.

10. The method according to claim 6, characterized in that, The calcination temperature in step (2) is 1400℃ and the calcination time is 6 hours. The calcination temperature in step (3) is 1400℃ and the calcination time is 6 hours.

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