阅读说明：本技术 具有多模态发光的尖晶石材料、制备方法及荧光防伪应用 (Spinel material with multi-modal luminescence, preparation method and fluorescent anti-counterfeiting application ) 是由 朱琦 司特 于 2021-06-10 设计创作，主要内容包括：本发明属于材料科学领域,涉及具有多模态发光的尖晶石材料、制备方法及荧光防伪应用。本发明的尖晶石荧光粉的化学表达式为Zn-(1-)-xAl-(2-2y-2z)O-4:xMn～(2+),yCr～(3+),zSi～(4+),其中0.0005≤x≤0.01,0.0005≤y≤0.01,0.1≤z≤0.6。该荧光粉中Mn～(2+)和Cr～(3+)离子为两种不同的发光中心,作用为产生绿色和红色两种不同的光发射。Si～(4+)离子的作用是调节Mn～(2+)和Cr～(3+)离子相对含量的电荷调节剂。本发明采用传统的高温固相法,根据化学计量比称量实验所需的原料,原料包括ZnO、Al-2O-3、Cr-2O-3、MnCO-3、SiO-2,并将混合料充分研磨并进行煅烧。本发明所制备的荧光材料具有多模动态发光的潜力,能输出可调谐的动态多色辐射、可变换的可见光和近红外信号、可改变的可见光和近红外长余辉信号。此外,由于其成本低廉,工艺简单,因而有利于广泛应用于荧光防伪领域。(The invention belongs to the field of material science, and relates to a spinel material with multi-modal luminescence, a preparation method and a fluorescent anti-counterfeiting application. The chemical expression of the spinel fluorescent powder is Zn 1‑ x Al 2‑2y‑2z O 4 :xMn 2+ ,yCr 3+ ,zSi 4+ Wherein x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6. Mn in the phosphor 2+ And Cr 3+ Ions are two distinct luminescent centers and function to produce two distinct light emissions, green and red. Si 4+ The function of the ions is to regulate Mn 2+ And Cr 3+ A charge control agent in ionic relative content. The invention adopts the traditional high-temperature solid phase method, and raw materials required by the experiment are weighed according to the stoichiometric ratio, wherein the raw materials comprise ZnO and Al 2 O 3 、Cr 2 O 3 、MnCO 3 、SiO 2 And mixing the mixture fullyGrinding and calcining. The fluorescent material prepared by the invention has the potential of multimode dynamic luminescence, and can output tunable dynamic multicolor radiation, switchable visible light and near infrared signals, and changeable visible light and near infrared long afterglow signals. In addition, the cost is low, and the process is simple, so the fluorescent anti-counterfeiting ink is beneficial to being widely applied to the field of fluorescent anti-counterfeiting.)

1. A spinel material with multi-modal luminescence is characterized in that the spinel material has a chemical expression of Zn_{1- x}Al_2-2y-2zO₄:xMn²⁺,yCr³⁺,zSi⁴⁺Wherein x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6.

2. A method of preparing a spinel material having multi-modal luminescence according to claim 1, comprising the steps of:

step 1: firstly, according to the stoichiometric ratio of spinel material, ZnO and Al as experimental raw materials are mixed₂O₃、SiO₂、Cr₂O₃、MnCO₃Weighing and grinding to uniformly mix the mixture;

step 2: pre-sintering the mixture;

and step 3: grinding the pre-sintered powder again and calcining;

and 4, step 4: and grinding the calcined powder again to prepare the spinel material with multi-modal luminescence.

3. The method for preparing the alloy material according to claim 2, wherein the pre-sintering temperature in the step 2 is 800 ℃ to 1000 ℃.

4. The preparation method according to claim 2, wherein the pre-sintering time in the step 2 is 2 to 10 hours.

5. The method according to claim 2, wherein the calcination temperature in step 3 is 1100 to 1600 ℃.

6. The preparation method of claim 2, wherein the calcination time in step 3 is 8-21 h.

7. The preparation method according to claim 2, wherein the pre-sintering temperature in step 2 is 1000 ℃ and the pre-sintering time is 8 hours.

8. The method according to claim 2, wherein the calcination temperature in step 3 is 1250 ℃ and the calcination time is 14 hours.

9. Use of a spinel material having multimodal luminescence according to claim 1 as a fluorescent security material.

Technical Field

The invention belongs to the field of material science, and particularly relates to anti-counterfeiting fluorescent powder made of a spinel material with multi-modal luminescence, and a preparation method and application thereof.

Background

Counterfeiting is a long standing global problem, and the products being counterfeited are of a wide variety, including currency, brand-name goods, official documents, passports, pharmaceuticals, and the like. Counterfeiting the production and sale of goods involves as much as billions of dollars each year, which is a huge loss to the economy of any country, and also poses immeasurable risks to the safety and health of consumers worldwide. In recent decades, many security technologies such as radio frequency identification, isotope tracking, and fluorescence anti-counterfeiting have been developed to prevent counterfeiting. In the technologies, the fluorescent anti-counterfeiting method has the advantages of low production cost, simple and convenient design, environmental protection, difficult imitation and the like, has obvious advantages and application prospects, is an ideal means for fighting counterfeiters, and is most widely used for anti-counterfeiting. However, the traditional fluorescent anti-counterfeiting material generally shows monochromatic light emission under a fixed excitation mode, and is more and more easily imitated by counterfeiters, but if the fluorescent materials with different colors are simply mixed, the material can generate uneven dispersibility, and the performance can be greatly reduced. For this reason, it is necessary to develop a multi-level security material having various light emitting characteristics in a single host material. The multilevel anti-counterfeiting material is difficult to copy and has higher anti-counterfeiting safety, so that the preparation of the anti-counterfeiting fluorescent powder with multiple fluorescence modes is very important.

In recent years, in order to improve the anti-counterfeiting security level of the fluorescent powder, researchers have made a lot of efforts to develop different anti-counterfeiting modes of the fluorescent material, such as a multi-wavelength light response mode, a long afterglow mode, and the like. Although these materials have substantially improved the level of security of the material, the difficulty is to combine different security modes in the same substrate material. The multi-mode fluorescent material has extremely high anti-counterfeiting level, and can hardly be repeatedly engraved by counterfeiters, so the multi-mode fluorescent material has wide application prospect in the anti-counterfeiting field.

Is different from expensive rare earth ions and relatively low in cost²⁺And Cr³Activated phosphors have become a focus of research in recent years. Is currently being directed to ZnA1₂O₄In the study of spinel system, in Chinese patent networkDiscloses a device based on ZnA1₂O₄The light color of the substrate can be adjusted, and the preparation method and the application thereof (grant date: No. 18/2/2020, application No. 201910975985.2). However, the invention only has a multi-wavelength light response mode, does not have multi-mode luminescence such as a long afterglow mode and the like, and is not applied to the field of fluorescence anti-counterfeiting.

As mentioned above, not yet at ZnA1₂O₄As a matrix, with Mn²⁺And Cr³⁺Ions are two different luminescent centers, with Si⁴⁺Ion as regulating Mn²⁺And Cr³⁺The multi-mode fluorescent anti-counterfeiting material of the charge regulator with the relative ion content is reported.

Disclosure of Invention

The invention provides a preparation method of ZnA1₂O₄As a matrix, with Mn²⁺And Cr³⁺Ion as luminescent center, Si⁴⁺Ion as regulating Mn²⁺And Cr³⁺The method for preparing the multi-mode fluorescent anti-counterfeiting material of the charge regulator with the relative ion content successfully synthesizes Zn by adopting a high-temperature solid phase method_1-xAl_2-2y-2zO₄:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) anti-counterfeiting fluorescent powder.

The technical scheme of the invention is as follows:

ZnAl with multimode luminescent spinel material₂O₄:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) as follows:

step 1: firstly, according to the stoichiometric ratio of spinel material, ZnO and Al as experimental raw materials are mixed₂O₃、SiO₂、Cr₂O₃、MnCO₃Weighing and grinding to uniformly mix the mixture;

step 2: pre-sintering the mixture;

and step 3: grinding the pre-sintered powder again and calcining;

and 4, step 4: and grinding the calcined powder again to prepare the spinel material with multi-modal luminescence.

Further, the pre-sintering temperature in the step 2 is 800-1000 ℃, and the pre-sintering time is 2-10 h.

Further, the calcining temperature in the step 3 is 1100-1600 ℃, and the calcining time is 8-21 h.

Preferably, the presintering temperature is 1000 ℃ and the presintering time is 8 h. The calcining temperature is 1250 ℃, and the calcining time is 14 h.

The invention has the beneficial effects that:

zn is successfully synthesized by the traditional high-temperature solid-phase reaction method_1-xAl_2-2y-2z:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) anti-counterfeiting fluorescent powder. The fluorescent powder is highly sensitive to components, excitation wavelength and detection time, so that by changing the test conditions, the fluorescent powder can output tunable dynamic multi-color radiation, switchable visible light and near infrared signals and changeable visible light long afterglow and near infrared long afterglow signals. In addition, the cost is low, and the process is simple, so the fluorescent anti-counterfeiting ink is beneficial to being widely applied to the field of fluorescent anti-counterfeiting.

Drawings

FIG. 1 is a diagram of Zn production in examples 1 to 3 of the present invention_1-xAl_2-2y-2z:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) an experimental flow schematic diagram of the anti-counterfeiting fluorescent powder;

FIG. 2 is a diagram of Zn production in examples 1 to 3 of the present invention_1-xAl_2-2y-2z:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) the XRD pattern of the anti-counterfeiting fluorescent powder;

FIG. 3 is a Zn prepared in examples 1 to 3 of the present invention_1-xAl_2-2y-2z:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) under the excitation of 244nm wavelength; (b) PL profile under 410nm wavelength excitation;

FIG. 4 is a Zn prepared in examples 1 to 3 of the present invention_1-xAl_2-2y-2z:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) under the monitoring of the wavelength of 503 nm; (b) a long afterglow spectrum under the monitoring of 708nm wavelength;

FIG. 5 is a Zn prepared in examples 1 to 3 of the present invention_1-xAl_2-2y-2z:xMn²⁺,yCr³⁺,zSi⁴⁺(x is more than or equal to 0.0005 and less than or equal to 0.01, y is more than or equal to 0.0005 and less than or equal to 0.01, and z is more than or equal to 0.1 and less than or equal to 0.6) the CIE color coordinate spectrum of the anti-counterfeiting fluorescent powder.

Detailed Description

The following detailed description of the embodiments of the invention refers to the accompanying drawings.

The chemical reagents used in the examples of the present invention are analytical grade products.

Example 1(x ═ 0.01, y ═ 0.01, z ═ 0.1)

Firstly, weighing 8mmol of experimental raw materials ZnO and Al according to the stoichiometric ratio₂O₃、SiO₂、Cr₂O₃、MnCO₃0.6446g, 0.726g, 0.0096g, 0.0122g and 0.0092g respectively. Grinding for 40 minutes to uniformly mix the mixture, pre-burning for 8 hours in a box furnace at 1000 ℃, then grinding for 40 minutes, putting the sample into the box furnace, calcining for 14 hours at 1250 ℃, grinding for 30 minutes to obtain Zn_0.99Al_1.78O₄:0.01Mn²⁺,0.01Cr³⁺,0.1Si⁴⁺Anti-counterfeiting fluorescent powder.

Zn_0.99Al_1.78O₄:0.01Mn²⁺,0.01Cr³⁺,0.1Si⁴⁺The experimental preparation flow chart of the fluorescent powder is shown in fig. 1, the XRD diffraction pattern is shown in fig. 2, the PL pattern under different wavelength excitation is shown in fig. 3, and the long afterglow pattern under different wavelength monitoring is shown in fig. 4. The CIE color coordinate spectra under different wavelength excitation are shown in fig. 5.

As can be seen from fig. 2: zn_0.99Al_1.78O₄:0.01Mn²⁺,0.01Cr³⁺,0.1Si⁴⁺Diffraction peak of phosphor and ZnAl₂O₄The standard card (JCPDS No #82-1043) fits well, indicating that its crystal structure is ZnAl₂O₄Likewise, no impurity phases are present. From the figure3, the following steps are known: spinel Zn when excited by UV light of wavelength 244nm_0.99Al_1.78O₄:0.01Mn²⁺,0.01Cr³⁺,0.1Si⁴⁺The phosphor exhibits a typical relatively weak narrow-band green emission (Mn) at 503nm²⁺Of ions⁴T₁(G)→⁶A₁(S) transition), and a very strong Cr-containing layer located at-709 nm³⁺Ion(s)²E→⁴A₂Near infrared broadband emission caused by the transition. When excited by ultraviolet light with the wavelength of 410nm, the fluorescent powder only has strong Cr at 709nm³⁺Ion(s)²E→⁴A₂Near infrared broadband emission caused by the transition. As can be seen from fig. 4: zn_0.99Al_1.78O₄:0.01Mn²⁺,0.01Cr³⁺,0.1Si⁴⁺The fluorescent powder presents green long afterglow under the monitoring of 503nm and near infrared long afterglow under the monitoring of 708 nm. As can be seen from fig. 5: zn_0.99Al_1.78O₄:0.01Mn²⁺,0.01Cr³⁺,0.1Si⁴⁺The phosphor had CIE color coordinates (0.1769, 0.5213) at 244nm and (0.6448, 0.3452) at 410 nm.

Example 2(x ═ 0.001, y ═ 0.001, z ═ 0.3)

Firstly, weighing 8mmol of experimental raw materials ZnO and Al according to the stoichiometric ratio₂O₃、SiO₂、Cr₂O₃、MnCO₃0.6505g, 0.5702g, 0.2884g, 0.0012g and 0.001g respectively. Grinding for 40 minutes to uniformly mix the mixture, pre-burning for 8 hours in a box furnace at 1000 ℃, then grinding for 40 minutes, putting the sample into the box furnace, calcining for 14 hours at 1250 ℃, grinding for 30 minutes to obtain Zn_0.999Al_1.398O₄:0.001Mn²⁺,0.001Cr³⁺,0.3Si⁴⁺Anti-counterfeiting fluorescent powder.

As can be seen from fig. 2: zn_0.999Al_1.398O₄:0.01Mn²⁺,0.001Cr³⁺,0.3Si⁴⁺Diffraction peak of phosphor and ZnAl₂O₄Standard card (JCPDS No #82-1043) fits well, explainIts crystal structure and ZnAl₂O₄Likewise, no impurity phases are present. As can be seen from fig. 3: spinel Zn when excited by UV light of wavelength 244nm_0.999Al_1.398O₄:0.01Mn²⁺,0.001Cr³⁺,0.3Si⁴⁺The phosphor exhibits a typical relatively strong narrow-band green emission (Mn) at 503nm²⁺Of ions⁴T₁(G)→⁶A₁(S) transition), and relatively strong Cr at 709nm³⁺Ion(s)²E→⁴A₂Near infrared broadband emission caused by the transition. When excited by ultraviolet light with the wavelength of 410nm, the fluorescent powder only has strong Cr at 709nm³⁺Ion(s)²E→⁴A₂Near infrared broadband emission caused by the transition. As can be seen from fig. 4: zn_0.999Al_1.398O₄:0.01Mn²⁺,0.001Cr³⁺,0.3Si⁴⁺The fluorescent powder presents green long afterglow under the monitoring of 503nm and near infrared long afterglow under the monitoring of 708 nm. As can be seen from fig. 5: zn_0.999Al_1.398O₄:0.01Mn²⁺,0.001Cr³⁺,0.3Si⁴⁺The phosphor had CIE color coordinates (0.1768, 0.5612) at 244nm and (0.6609, 0.3312) at 410 nm. Zn printed on ceramic substrate_0.999Al_1.398O₄:0.01Mn²⁺,0.001Cr³⁺,0.3Si⁴⁺The fluorescent powder is white under natural illumination; the color is bright green under the real-time excitation of 254nm ultraviolet light; under the real-time excitation of 254nm ultraviolet light, a near-infrared night vision device is used for observing that the fluorescent powder presents bright near-infrared luminescence; bright red under 365nm ultraviolet light excitation; when the 254nm ultraviolet excitation source is removed, the fluorescent powder presents bright green long afterglow under natural light, and presents bright near infrared long afterglow luminescence in the shooting of a near infrared night vision device. Imagine that Zn is_0.999Al_1.398O₄:0.01Mn²⁺,0.001Cr³⁺,0.3Si⁴⁺The fluorescent powder is applied to two-dimensional code anti-counterfeiting, the two-dimensional code can show obvious color changing effect under different excitation conditions, and after excitation is stoppedThe visible light long afterglow and the near infrared long afterglow can be presented simultaneously, so that the two-dimensional code anti-counterfeiting level can be greatly improved, and the method has a wide application prospect in the two-dimensional code anti-counterfeiting field.

Example 3(x ═ 0.0005, y ═ 0.0005, z ═ 0.6)

Firstly, weighing 8mmol of experimental raw materials ZnO and Al according to the stoichiometric ratio₂O₃、SiO₂、Cr₂O₃、MnCO₃0.6508g, 0.2989g, 0.5768g, 0.0012g and 0.0005g, respectively. Grinding for 40 minutes to uniformly mix the mixture, pre-burning for 8 hours in a box furnace at 1000 ℃, then grinding for 40 minutes, putting the sample into the box furnace, calcining for 14 hours at 1250 ℃, grinding for 30 minutes to obtain Zn_0.9995Al_0.799O₄:0.0005Mn²⁺,0.0005Cr³⁺,0.6Si⁴⁺Anti-counterfeiting fluorescent powder.

As can be seen from fig. 2: zn_0.9995Al_0.799O₄:0.0005Mn²⁺,0.0005Cr³⁺,0.6Si⁴⁺Diffraction peak of phosphor and ZnAl₂O₄The standard card (JCPDS No #82-1043) fits well, indicating that its crystal structure is ZnAl₂O₄Likewise, no impurity phases are present. As can be seen from fig. 3: spinel Zn when excited by UV light of wavelength 244nm_0.9995Al_0.799O₄:0.0005Mn²⁺,0.0005Cr³⁺,0.6Si⁴⁺The phosphor exhibits a typical relatively strong narrow-band green emission (Mn) at 503nm²⁺Of ions⁴T₁(G)→⁶A₁(S) transition), and relatively weak Cr at 709nm³⁺Ion(s)²E→⁴A₂Near infrared broadband emission caused by the transition. When excited by ultraviolet light with the wavelength of 410nm, the fluorescent powder only has relatively weak Cr at 709nm³⁺Ion(s)²E→⁴A₂Near infrared broadband emission caused by the transition. As can be seen from fig. 4: zn_0.9995Al_0.799O₄:0.0005Mn²⁺,0.0005Cr^{3 +},0.6Si⁴⁺The fluorescent powder presents green long afterglow under the monitoring of 503nmAnd the nano-particles show near-infrared long afterglow at 708nm monitoring. As can be seen from fig. 5: zn_0.9995Al_0.799O₄:0.0005Mn²⁺,0.0005Cr³⁺,0.6Si⁴⁺The phosphor had CIE color coordinates (0.2347, 0.4403) at 244nm and (0.6848, 0.3108) at 410 nm.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.