High-brightness piezoelectric mechanical luminescent material, method for preparing same, and use thereof

Abstract

The application discloses a high-brightness piezoelectric mechanical luminescent material with a chemical formula of LiNbO3:0.01Pr,xZn and a preparation method and application thereof, wherein 0

Description

Technical fields:

[0001] This invention relates to the field of luminescent materials technology, specifically to a high-brightness piezoelectric mechanical luminescent material, its preparation method, and its application. Background technology:

[0002] Mechatronics refers to the property of quantitatively converting mechanical energy into light energy under mechanical stimulation, which includes crushing, friction, impact, compression, stretching, bending, twisting, and ultrasound. Mechatronic materials with piezoelectric effect can realize the energy conversion of electrical energy to mechanical energy to light energy, and can be applied to fields such as triboluminescent anti-counterfeiting ink, flexible wearable materials, pressure detection sensors, disease monitoring and structural flaw detection (see, for example: HUANG ZF, et al. Smartmechanoluminescent phosphors: a review of strontium-aluminate-based materials, properties, and their advanced application technologies[J]. Adv. Sci., 2023, 10(3): 2204925-1-44. XU CN, et al. Direct view of stress distribution in solid bymechanoluminescence[J]. Appl. Phys. Lett., 1999, 74(17): 2414-2416.). Currently reported mechanoluminescent materials can be divided into three categories: organic, inorganic, and organic-inorganic hybrid materials. Organic mechanoluminescent materials are more diverse, but suffer from drawbacks such as complex and cumbersome synthesis processes, low luminous efficiency, poor thermal stability, and insufficient optical stability. Organic-inorganic hybrid mechanoluminescent materials exhibit poor interfacial compatibility, low material stability, and difficulty in simultaneously optimizing mechanical flexibility and luminescent performance, hindering their effective utilization. Inorganic mechanoluminescent materials suffer from limited material variety and low luminous intensity. Currently, relatively few piezoelectric inorganic mechanoluminescent materials have been discovered that possess high luminous intensity, long-term storage capability, and good repeatability. Therefore, there is an urgent need to develop more novel and stable piezoelectric inorganic mechanoluminescent materials. Summary of the Invention:

[0003] The purpose of this invention is to provide a high-brightness piezoelectric mechanical luminescent material, its preparation method, and its application.

[0004] This invention is achieved through the following technical solutions:

[0005] A high-brightness piezoelectric mechanical luminescent material with the chemical formula LiNbO3:0.01Pr,xZn, wherein 0<x≤0.02, preferably 0.001≤x≤0.01, and most preferably x is 0.005.

[0006] The high-brightness piezoelectric mechanical luminescent material is composed of Li₂CO₃, Nb₂O₅, and Pr₆O₃ with a purity greater than 99.9%. 11 It is prepared by high-temperature solid-state method using ZnO as raw material. The preparation method includes the following steps: the raw materials are dried in an oven at 60-100℃ for 4-6 hours. The raw materials are accurately weighed according to the required mass fraction of components in the chemical formula LiNbO3:0.01Pr,xZn and poured into an agate mortar. The mixture is ground for 15-20 minutes with anhydrous ethanol as the medium. Then, the mixed raw materials are placed in an oven at 60-100℃ and dried for 5 minutes. The dried raw materials are calcined at 1000-1100℃ for 6-8 hours. After naturally cooling to room temperature, the mixture is ground again for 3-5 minutes to obtain the final product.

[0007] The material prepared by this invention has high brightness, long-term storage capability, and repeatable mechanoluminescence properties. It exhibits mechanoluminescence emission after 10 minutes of sunlight irradiation or 60 seconds of 365nm ultraviolet radiation during the period from 12:00 to 16:00. The luminescence intensity is 100% higher than that of the undoped Zn sample LiNbO3:0.01Pr. It still exhibits mechanoluminescence emission after being placed in a dark room for 30 days without the need for further irradiation. It also has good repeatability. Under sunlight irradiation or 365nm ultraviolet radiation during the period from 12:00 to 16:00, the mechanoluminescence intensity can recover to its initial state, and the repeatability can be maintained for 5 cycles.

[0008] Therefore, this invention also protects the application of the high-brightness piezoelectric mechanical luminescent material, as a mechanical luminescent material used as a stress distribution visualization material, or as an optical anti-counterfeiting material such as an anti-tamper label.

[0009] In application, a high-brightness piezoelectric mechanical luminescent material is composited with a resin. The resin includes epoxy resin, etc.

[0010] A mechanoluminescent composite material includes the high-brightness piezoelectric mechanoluminescent material and a resin. The resin includes epoxy resin, etc.

[0011] The beneficial effects of this invention are as follows:

[0012] 1) The material prepared by this invention has high brightness and long-term storage properties of mechanoluminescence. The mechanoluminescence intensity is 100% stronger than that of the undoped Zn sample LiNbO3:0.01Pr. It still emits mechanoluminescence after being placed in a dark room for 30 days, and the process does not require re-irradiation.

[0013] 2) The material prepared by the present invention has good repeatability of mechanoluminescence properties. Under the re-irradiation of sunlight or 365nm ultraviolet light, the mechanoluminescence intensity can be restored to the initial state and can maintain repeatability for 5 cycles.

[0014] 3) The preparation process of this invention is simple.

[0015] In summary, the preparation process of this invention is simple, and the prepared material has high brightness, can be stored for a long time, and has repeatable mechanoluminescence properties. It can be used as a mechanoluminescent material for stress distribution visualization or as an optical anti-counterfeiting material such as an anti-tamper label. Attached image description:

[0016] Figure 1 XRD patterns of LiNbO3:0.01Pr,xZn (x=0, 0.005, 0.01, 0.015) prepared in Examples 1-3 and Comparative Example 1;

[0017] Figure 2 Mechanoluminescence spectra of LiNbO3:0.01Pr,xZn (x=0, 0.005, 0.01, 0.015) prepared in Examples 1-3 and Comparative Example 1;

[0018] Figure 3 The image shows the mechanoluminescence changes of the LiNbO3:0.01Pr,xZn (x=0.005) sample prepared in Example 1 after 60s of 365nm ultraviolet light irradiation over 5 cycles.

[0019] Figure 4 The image shows the changes in mechanoluminescence of the LiNbO3:0.01Pr,xZn (x=0.005) sample prepared in Example 1 after 10 min of sunlight irradiation over 5 cycles.

[0020] Figure 5 The image shows the changes in mechanoluminescence of LiNbO3:0.01Pr,xZn (x=0, 0.005, 0.01) prepared in Examples 1-2 and Comparative Example 1 after 30 days.

[0021] Figure 6 Amplitude curves of LiNbO3:0.01Pr,xZn (x=0.005, 0.01) prepared in Examples 1-2;

[0022] Figure 7 The image is a luminescent image of the composite sample prepared in Example 1, consisting of LiNbO3:0.01Pr,0.005Zn material and epoxy resin, after the letters "M" and "L" were written on the surface with a glass rod. Detailed implementation method:

[0023] The following is a further description of the invention, but not a limitation thereof.

[0024] Example 1: Preparation and application of LiNbO3:0.01Pr,0.005Zn

[0025] Step 1) The raw materials used are Li2CO3 (99.99% purity), Nb2O5 (99.99% purity), and Pr6O. 11 Both ZnO (purity 99.9%) and ZnO (purity 99.99%) were dried in an oven at 70°C for 6 hours.

[0026] Step 2) According to the required mass fraction of components in the chemical formula LiNbO3:0.01Pr,xZn (x=0.005), accurately weigh the raw materials and put them into an agate mortar. Grind them for 15 minutes with anhydrous ethanol as the medium. Then, put the mixed raw materials into an oven at 70℃ and dry them for 5 minutes.

[0027] Step 3) Sinter the dried product at 1080℃ for 8 hours, cool it naturally to room temperature, and then grind it again for 5 minutes to obtain a mechanoluminescent material of LiNbO3:0.01Pr,xZn (x=0.005) that can be stored for a long time and has good repeatability.

[0028] The sample prepared in Example 1 was subjected to XRD testing, and the test results are as follows: Figure 1 As shown, LiNbO3:0.01Pr,0.005Zn is a single-phase material, which matches the standard card (PDF#85-2456). No other impurity phases or secondary phases are generated, proving that LiNbO3:0.01Pr,0.005Zn was successfully prepared.

[0029] In addition, to characterize the mechanoluminescence, the prepared material needs to be composited with epoxy resin using a mold to obtain a mechanoluminescent composite material. The composite steps are as follows:

[0030] Step 1) Prepare the epoxy resin mixture. Pour 3g of epoxy resin A (TJ 2221A, Truly (Suzhou) Materials Technology Co., Ltd.) and 1g of epoxy resin B (TJ 2221B, Truly (Suzhou) Materials Technology Co., Ltd.) into a petri dish at a mass ratio of 3:1. Stir with a glass rod to make it evenly mixed and without the generation of bubbles.

[0031] Step 2) Weigh 1.5g of the mechanoluminescent material powder from Example 1 above, add it to the mold, press it lightly, and spread it evenly on the bottom of the polytetrafluoroethylene mold (25mm inner diameter);

[0032] Step 3) Add the mixed epoxy resin mixture into the mold and let it stand at room temperature for 3 minutes;

[0033] Step 4) Place the settled material in a 70℃ oven for 4 hours, then demold to obtain the bulk mechanoluminescent composite material.

[0034] To demonstrate that LiNbO3:0.01Pr,0.005Zn possesses mechanoluminescent properties, mechanoluminescence spectroscopy was performed. The test results are as follows: Figure 2 As shown, the bulk mechanoluminescent composite material prepared in Example 1 exhibits Pr under the application of a mechanical force of 30N. 3+ The material exhibits a characteristic emission band, with a maximum emission band at 616 nm. Test results show that the material of this invention displays an immediate and strong mechanoluminescence signal.

[0035] To demonstrate the repeatability of the mechanoluminescence properties of LiNbO3:0.01Pr,0.005Zn, a mechanoluminescence cyclic test was conducted. The test results are as follows: Figure 3 As shown, the bulk mechanoluminescent composite material prepared in Example 1 was irradiated with 365nm ultraviolet light for 60s once before testing, and a mechanical force of 30N was applied. The mechanoluminescence spectrum was tested continuously for 5 cycles. In addition, before each test, it was irradiated with 365nm ultraviolet light for 60s, and a mechanical force of 30N was applied. The mechanoluminescence spectrum was tested continuously for 5 cycles. The test results showed that under 5 consecutive test cycles, when the 365nm ultraviolet light was not irradiated again during the test, the mechanoluminescence intensity showed a gradual decreasing trend. When the 365nm ultraviolet light was irradiated again before each test, the mechanoluminescence intensity could be restored to the initial value. The material of the present invention showed good repeatability of mechanoluminescence performance.

[0036] To demonstrate the repeatability of the mechanoluminescence properties of LiNbO3:0.01Pr,0.005Zn, a mechanoluminescence cyclic test was conducted. The test results are as follows: Figure 4 As shown, the bulk mechanoluminescent composite material prepared in Example 1 was irradiated with sunlight for 10 minutes before testing, and a mechanical force of 30N was applied. The mechanoluminescence spectrum was tested for 5 consecutive cycles. In addition, before each test, it was irradiated with sunlight for 10 minutes and a mechanical force of 30N was applied. The test results showed that under 5 consecutive test cycles, when sunlight was not applied again during the test, the mechanoluminescence intensity showed a gradual decreasing trend. When sunlight was applied again for 10 minutes before each test, the mechanoluminescence intensity could be restored to the initial value. The material of the present invention showed good repeatability of mechanoluminescence performance.

[0037] To demonstrate that the mechanoluminescence of LiNbO3:0.01Pr,0.005Zn can be stored for a long period, mechanoluminescence tests were conducted after different storage times. The test results are as follows: Figure 5As shown, the bulk mechanoluminescent composite material prepared in Example 1 was only irradiated with 365nm ultraviolet light for 60s in the first test. The test was conducted in a dry dark room environment. As the storage time increased, the mechanoluminescence intensity showed a significant attenuation trend. After 30 days of storage, a mechanical force of 30N was applied, and a significant mechanoluminescence signal could still be generated, which was visible to the naked eye. The material of the present invention showed good mechanoluminescence performance after long-term storage.

[0038] To demonstrate the piezoelectricity of the LiNbO3:0.01Pr,0.005Zn material, amplitude curve tests were conducted. The test results are as follows: Figure 6 As shown, the material prepared in Example 1 exhibits a typical butterfly amplitude curve under the influence of an external electric field, with an amplitude of 73.16 pm when a voltage of 9V is applied. The material of this invention possesses piezoelectric properties.

[0039] After the LiNbO3:0.01Pr,0.005Zn material prepared in Example 1 of this invention was composited with epoxy resin, the letters "M" and "L" were written on the surface of the composite sample using a glass rod. The luminescent image is as follows. Figure 7 As shown, this demonstrates its value as a material for visualizing stress distribution.

[0040] Example 2: Preparation and application of LiNbO3:0.01Pr,xZn (x=0.01):

[0041] Referring to Example 1, the difference is that the required component mass fraction in step 2) satisfies the chemical formula LiNbO3:0.01Pr,xZn (x=0.01).

[0042] The sample prepared in Example 2 was subjected to XRD testing, and the test results are as follows: Figure 1 As shown, this proves that the LiNbO3:0.01Pr,0.01Zn material was successfully prepared.

[0043] The mechanoluminescence testing method for LiNbO3:0.01Pr,0.01Zn, a piezoelectric mechanoluminescent material that can be stored for a long time and is reproducible, is the same as in Example 1.

[0044] The composite material prepared in Example 2 exhibits Pr under the application of a mechanical force of 30N. 3+ The material exhibits a characteristic emission band, with a maximum emission band at 616 nm. Test results show that the material of this invention displays a significant mechanoluminescence signal. The test results are as follows: Figure 2 As shown. Figure 5The figure shows the changes in mechanoluminescence over different storage times. As the storage time increases, the mechanoluminescence intensity shows a significant decreasing trend. After 30 days of storage, applying a mechanical force of 30N still produces a noticeable mechanoluminescence signal. The material of this invention exhibits good mechanoluminescence performance after long-term storage. The material prepared in Example 2, under the action of an external electric field, shows a typical butterfly amplitude curve. When a voltage of 9V is applied, the amplitude is 74.62 pm, exhibiting piezoelectric characteristics. The test results are as follows... Figure 6 As shown, the test method is the same as in Example 1.

[0045] Example 3: Preparation and application of LiNbO3:0.01Pr,xZn (x=0.015):

[0046] Referring to Example 1, the difference lies in that the required component mass fraction in step 2) satisfies the chemical formula LiNbO3:0.01Pr,xZn (x = 0.015). XRD analysis was performed on the sample prepared in Example 3, and the results are as follows... Figure 1 As shown, this proves that the LiNbO3:0.01Pr,0.015Zn material was successfully prepared.

[0047] LiNbO 3: The mechanoluminescence testing method for 0.01Pr and 0.015Zn piezoelectric mechanoluminescent materials that are long-term storable and reproducible is the same as that in Example 1.

[0048] The composite material prepared in Example 3 exhibits Pr under the application of a mechanical force of 30N. 3+ The material exhibits a characteristic emission band, with a maximum emission band at 616 nm. Test results show that the material of this invention displays a significant mechanoluminescence signal. The test results are as follows: Figure 2 As shown, the testing method is the same as in Example 1.

[0049] To investigate the effect of Zn doping amount on the brightness, storage properties, and reproducibility of mechanoluminescent materials, materials were prepared using Comparative Example 1.

[0050] Comparative Example 1: Preparation method of LiNbO3:0.01Pr

[0051] Referring to Example 1, the difference lies in that the required component mass fraction in step 2) satisfies the chemical formula LiNbO3:0.01Pr,xZn (x=0). XRD analysis was performed on the sample prepared in Comparative Example 1, and the results are as follows: Figure 1 As shown, this proves that the LiNbO3:0.01Pr material was successfully prepared.

[0052] The composite material prepared in Comparative Example 1 exhibits Pr under the application of a mechanical force of 30 N. 3+The material exhibits a characteristic emission band, with a maximum emission band at 616 nm. Test results show that the material of this invention displays a relatively weak mechanoluminescence signal. The test results are as follows: Figure 2 As shown, the testing method is the same as in Example 1. Figure 5 The figure shows the changes in mechanoluminescence over different storage times. As the storage time increases, the mechanoluminescence intensity shows a significant decreasing trend. After 30 days of storage, a mechanical force of 30N was applied, and the mechanoluminescence signal was detected to be weak and difficult to observe with the naked eye. The mechanoluminescence performance of LiNbO3:0.01Pr is difficult to detect after long-term storage.

[0053] In the above embodiments, the sample prepared in Example 1 exhibits the strongest mechanoluminescence brightness, can be stored for a long time, and after 30 days of storage, the mechanoluminescence signal is strong and observable with the naked eye, showing good repeatability. Therefore, the preferred value is 0.001≤x≤0.01, and the most preferred value is x=0.005.

Claims

1. The chemical formula is LiNbO3: 0.01Pr, x Zn high-brightness piezoelectric mechanical luminescent materials, among which... 0.001≤ x ≤0.01; The high-brightness piezoelectric mechanical luminescent material is composed of Li2CO3, Nb2O5, and Pr6O with a purity greater than 99.9%. 11 It is prepared by high-temperature solid-state method using ZnO as raw material.

2. The high-brightness piezoelectric mechanical luminescent material according to claim 1, characterized in that, The preparation method includes the following steps: All raw materials are dried in an oven at 60-100℃ for 4-6 hours, according to the chemical formula LiNbO3: 0.01Pr. x Accurately weigh the required Zn components into an agate mortar and grind them for 15-20 minutes using anhydrous ethanol as the medium. Then, place the well-mixed raw materials in an oven at 60-100℃ and dry them for 5 minutes. After drying, calcine the raw materials at 1000-1100℃ for 6-8 hours, and after naturally cooling to room temperature, grind them again for 3-5 minutes to obtain the Zn product.

3. The method for preparing the high-brightness piezoelectric mechanical luminescent material according to claim 1, characterized in that, Includes the following steps: All raw materials were dried in an oven at 60-100℃ for 4-6 hours, according to the chemical formula LiNbO3: 0.01Pr. x Accurately weigh the required Zn components into an agate mortar and grind them for 15-20 minutes using anhydrous ethanol as the medium. Then, place the well-mixed raw materials in an oven at 60-100℃ and dry them for 5 minutes. After drying, calcine the raw materials at 1000-1100℃ for 6-8 hours, and after naturally cooling to room temperature, grind them again for 3-5 minutes to obtain the Zn product.

4. The application of the high-brightness piezoelectric mechanical luminescent material according to claim 1, characterized in that, It can be used as a mechanoluminescent material for stress distribution visualization or for optical anti-counterfeiting of tamper-evident labels.

5. The application according to claim 4, characterized in that, High-brightness piezoelectric mechanical light-emitting material and resin composite.

6. The application according to claim 5, characterized in that, The resin is epoxy resin.

7. A mechanoluminescent composite material, comprising the high-brightness piezoelectric mechanoluminescent material of claim 1 and a resin.

8. The mechanoluminescent composite material according to claim 7, characterized in that, The resin is epoxy resin.

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