Self-recovery force-induced luminescent borate, and preparation method and application thereof
By regulating trivalent cations, self-recovery force electroluminescent borate materials without pre-irradiation were prepared, which solved the problem of insufficient self-restoration ability of existing materials, and achieved wide-band red-light-near-infrared adjustable emission and low-cost industrial production.
Patent Information
- Application Number
- CN202311673370.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-07
- Publication Date
- 2025-06-10
AI Technical Summary
Existing powerful electroluminescent materials lack self-restoration ability and require ultraviolet pre-radiation treatment. Their electroluminescent intensity gradually decays after mechanical stimulation, making it difficult to achieve long-term stable luminescence.
By regulating trivalent cations, a self-recovery force electroluminescent borate material M1-xBO3:xCr3+ without pre-irradiation was prepared, and the high-temperature solid phase reaction was sintered in one-step method to achieve red-light-near-infrared adjustable emission in the wide spectrum band.
The force-luminescent material that can recover without pre-irradiation is realized, and can present a wide spectrum band red light-near-infrared adjustable emission in the range of 600 to 1050 nm, broadening the practical application field and reducing production costs.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of mechanoluminescent materials, and specifically to a self-recovery mechanoluminescent borate, a preparation method thereof, and an application thereof. Background Art
[0002] With the intensification of the global energy crisis and environmental pollution, how to achieve green, energy-saving, and environmental protection is a common concern globally, and finding new natural energy is the key to solving this problem. Therefore, the efficient collection, conversion, and utilization of new energy are of great significance. Mechanoluminescent materials can convert mechanical stimuli acting on the materials into light energy, and can utilize a large amount of surplus mechanical energy, which is a new type of energy with great potential. Due to the low luminescence threshold of elastic mechanoluminescent materials, they are linearly related to the amplitude of external mechanical stimuli (such as force magnitude, loading speed, elongation rate, etc.), and can be self-recovered in a specific environment, thus having broad application prospects. In recent years, researchers have effectively improved the intensity, sensitivity, and thermal stability of mechanoluminescence, reduced the mechanoluminescence threshold, and achieved full coverage of mechanoluminescence from visible light to near-infrared light by regulating matrix components and crystal structures, changing doping ions and their contents, ion blending, and heterojunctions. With the improvement of mechanoluminescence characteristics, its applications have expanded from simple stress sensing at the beginning to many fields such as non-destructive testing, structural flaw detection, anti-counterfeiting encryption, flexible devices, disease monitoring, lighting display, stress recording, etc.
[0003] Although great progress has been made in the development of mechanoluminescent materials, they still face many difficulties and challenges. Most of the currently reported mechanoluminescent materials do not have self-recovery ability and need to be pre-irradiated with ultraviolet light, which greatly limits their practical applications. Generally, under the influence of mechanical stimuli, the mechanoluminescence intensity of this kind of material will gradually decay until it cannot be detected, and at this time, it is necessary to continuously restore mechanoluminescence by means of irradiation and charging. Therefore, it is urgent to further explore new mechanoluminescent matrices, especially self-recovery near-infrared mechanoluminescent matrices. The currently known inorganic mechanoluminescent matrices mainly focus on aluminates, sulfides, sulfur oxides, etc. Borates have advantages such as low price and simple structure. So far, no self-recovery mechanoluminescent materials based on chromium ion-activated borate matrices have been reported. Summary of the Invention
[0004] The purpose of the present invention is to provide a self-recovery mechanoluminescent borate, a preparation method thereof, and an application thereof. The borate is a self-recovery type mechanoluminescent material that does not require pre-irradiation, and wide-spectrum red-light to near-infrared tunable emission can be achieved by regulating trivalent cations; its preparation method adopts high-temperature solid-phase reaction and is fired in one step, with low cost, simple preparation conditions, and convenient for mass production.
[0005] The present invention is implemented as follows:
[0006] A self - recovering stress - induced luminescent borate with the general expression formula of M 1-x BO 3 :xCr 3+ , where M is Sc, Lu, Ga or In, and x = 1 - 5%.
[0007] Preferably, the value of x is x = 1 - 2%. More preferably, x = 2%.
[0008] The preparation method of the above - mentioned self - recovering stress - induced luminescent borate is as follows:
[0009] a. Weigh the oxides of M, chromium oxide and boric acid according to the molar ratio of each element in the chemical general formula M 1-x BO 3 :xCr 3+ , where boric acid is in an excess of 50%, M is Sc, Lu, Ga or In, and x = 1 - 5%;
[0010] b. Mix the weighed raw materials and grind them evenly to obtain a mixture;
[0011] c. Calcinate the mixture at high temperature to obtain the self - recovering stress - induced luminescent borate M 1-x BO 3 :xCr 3+ .
[0012] Preferably, in step c, when M is Ga, the mixture is calcined at 850 °C for 10 hours; when M is Sc, Lu or In, the mixture is calcined at 1250 °C for 10 hours.
[0013] Preferably, in step a, the value of x is x = 1 - 2%.
[0014] The present invention synthesizes the MBO 3 :Cr 3+ material (M is Sc, Lu, Ga or In), and finds that it shows self - recovering near - infrared stress - induced luminescence under multiple stress stimulations. By regulating the matrix composition, its stress - induced luminescence phenomenon can be broadened to the range of 600 - 1050 nm, presenting a wide - band red - light to near - infrared tunable emission.
[0015] The present invention also provides the application of a self - recovering stress - induced luminescent borate MBO 3 :Cr 3+ in the fields of non - destructive testing technology, structural flaw detection, anti - counterfeiting encryption, flexible devices, disease monitoring, lighting display, stress recording, etc.
[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0017] (1) Without using rare earth as the luminescence center and without using harsh preparation conditions. Under atmospheric pressure, using inexpensive Cr 3+ as the activator, a mechanoluminescent material that does not require pre-irradiation and has immediate self-recovery of luminescence is prepared, which is convenient for industrial mass production.
[0018] (2) Compared with most of the existing mechanoluminescent materials, the mechanoluminescence of MBO 3 :Cr 3+ has the self-recovery property and does not require any pre-irradiation treatment.
[0019] (3) It can achieve broadband mechanoluminescence with adjustable red-light to near-infrared in the range of 600 - 1050 nm, which is beneficial to broadening the actual application fields.
[0020] (4) The near-infrared mechanoluminescent phosphor of the present invention has its main emission peak measured in the first biological window, and can be used as a near-infrared light source for non-destructive testing. Moreover, we know that broadband near-infrared emission mechanoluminescence is very rare. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 Powder X-ray diffraction spectra of samples of ratios (1)-(8) in Example 1.
[0022] Figure 2 Mechanoluminescence spectra of samples of ratios (1)-(8) in Example 1.
[0023] Figure 3 Integrated intensity of the mechanoluminescence spectrum of the sample of ratio (4) in Example 1 under 15 mechanical forces.
[0024] Figure 4 Powder X-ray diffraction spectra of samples of ratios (1)-(6) in Example 2.
[0025] Figure 5 Mechanoluminescence spectra of samples of ratios (1)-(6) in Example 2.
[0026] Figure 6 Transmission spectrum of the sample of ratio (4) in Example 2 through the solution, difference between the calculated mechanoluminescence spectrum of the sample of ratio (4) in Example 2 and the transmission spectrum of the solution. DETAILED DESCRIPTION OF THE INVENTION
[0027] The luminescent material of the present invention is a near-infrared mechanoluminescent borate, and its general expression formula is M 1-x BO 3 :xCr 3+ , the activating ion is Cr 3+ , and its crystal structure belongs to the trigonal system; Cr 3+ replaces M in the crystal 3+, M is Sc, Lu, Ga or In; x represents the substitution rate, where x = 0 - 5%. The Cr of the present invention 3+ activated borate can exhibit broadband emission in the range of 600 - 1050 nm.
[0028] The following are the preparation methods of several specific chromium-doped borate luminescent materials to further explain the technical solution of the present invention.
[0029] Example 1
[0030] This example is the preparation of the luminescent material Sc 1-x Cr x BO 3 by the high-temperature solid-phase method, and the specific preparation process is as follows:
[0031] Since boric acid will volatilize during the calcination process, boric acid is in an excess of 50%. Weigh each raw material according to the molar ratio of each element. Specifically: weigh the raw material compounds of scandium oxide, chromium oxide (analytical pure), and boric acid (analytical pure) according to the stoichiometric ratio of Sc 3+ :Cr 3+ :B + = 1 - x:x:1.5, a total of 8 groups, and the ratios are as follows:
[0032] (1) Sc 3+ :Cr 3+ :B + = 1:0:1.5, corresponding to x = 0%, weigh Sc 2 O 3 0.2759 g, H 3 BO 3 (AR) 0.3586 g;
[0033] (2) Sc 3+ :Cr 3+ :B + = 0.99:0.01:1.5, corresponding to x = 1%, weigh Sc 2 O 3 0.2731 g, Cr 2 O 3 (AR) 0.0030 g, H 3 BO 3 (AR) 0.3586 g;
[0034] (3) Sc 3+ :Cr 3+ :B + = 0.985:0.015:1.5, corresponding to x = 1.5%, weigh Sc 2 O 3 0.2717 g, Cr2 O 3 (AR) 0.0046 g, H 3 BO 3 (AR) 0.3586 g;
[0035] (4) Sc 3+ : Cr 3+ : B + = 0.98:0.02:1.5, corresponding to x = 2%, weighing Sc by molar ratio 2 O 3 0.2703 g, Cr 2 O 3 (AR) 0.0061 g, H 3 BO 3 (AR) 0.3586 g;
[0036] (5) Sc 3+ : Cr 3+ : B + = 0.975:0.025:1.5, corresponding to x = 2.5%, weighing Sc by molar ratio 2 O 3 0.2689 g, Cr 2 O 3 (AR) 0.0076 g, H 3 BO 3 (AR) 0.3586 g;
[0037] (6) Sc 3+ : Cr 3+ : B + = 0.97:0.03:1.5, corresponding to x = 3%, weighing Sc by molar ratio 2 O 3 0.2675 g, Cr 2 O 3 (AR) 0.0091 g, H 3 BO 3 (AR) 0.3586 g;
[0038] (7) Sc 3+ : Cr 3+ : B + = 0.95:0.05:1.5, corresponding to x = 5%, weighing Sc by molar ratio 2 O 3 0.2620 g, Cr 2 O 3 (AR) 0.0152 g, H 3 BO 3 (AR) 0.3586 g;
[0039] (8)Sc 3+ :Cr 3+ :B + = 0.93:0.07:1.5, corresponding to x = 7%, weighed Sc according to the molar ratio 2 O 3 0.2565 g, Cr 2 O 3 (AR)0.0213 g, H 3 BO 3 (AR)0.3586 g;
[0040] Grind evenly to obtain a mixture; calcine the mixture at 1250 °C for 10 hours, and grind it after cooling to obtain a near-infrared luminescent material.
[0041] Figure 1 Powder X-ray diffraction spectra of the samples of the ratios (1)-(8) in Example 1. The spectra were measured using a Bruker D8 Advance X-ray diffractometer with a test voltage of 40 kV, a test current of 40 mA, and Cu-Kɑ radiation selected. It can be seen from Figure 1 that X-ray diffraction analysis shows that the samples of ratios (1)-(8) are ScBO 3 phase, belonging to the trigonal crystal system. The doping of Cr does not affect the formation of the crystal phase. As the Cr content (x value) increases, the relative intensity of the X-ray diffraction peaks of the samples does not show an obvious change, mainly because the ionic radii of and in the six-coordination are very close.
[0042] Figure 2 Force-induced luminescence spectra of the samples of the ratios (1)-(8) in Example 1. A QEPro fiber optic spectrometer from Ocean Optics, USA was used, with a data acquisition integration time of 800 ms and a scanning step of 1 nm. It can be seen from Figure 2 that for the samples of the ratios (2)-(7) in Example 1 under stress (the magnitude of the force is 50 N and the time of force application is 2 s), a force-induced luminescence peak with a peak at 788 nm appears, corresponding to the 3+ ion of 4 T 2 → 4 A 2 transition; due to the absence of Cr 3+ , for the sample of the ratio (1) in Example 1 under stress (the magnitude of the force is 50 N and the time of force application is 2 s), there is no force-induced luminescence phenomenon; due to the luminescence quenching caused by the excessive concentration of Cr 3+ , the luminescence of the sample of the ratio (8) is very weak.
[0043] Figure 3The integrated intensity of the mechanoluminescence spectrum of the sample with the formulation (4) in Example 1 under 15 mechanical forces (the magnitude of each force is 50 N, and the action time of each force on the sample is 2 s; one spectrum is obtained for each force application); an Ocean Optics QEPro fiber spectrometer from the United States was used, the data acquisition integration time was 800 ms, and the scanning step was 1 nm. As can be seen from Figure 3 it, under 15 mechanical stimulation cycles, its mechanoluminescence intensity can achieve a certain degree of self-recovery (self-recovery means that the luminescence intensity obtained from one force application is equivalent to that obtained from the next force application, and no pre-irradiation is required between one force application and the next).
[0044] Example 2
[0045] This example is for the preparation of the luminescent material M 0.98 Cr 0.02 BO 3 , where M = Lu, Ga, Sc, In, Gd, Y. The specific preparation process is as follows:
[0046] Since boric acid volatilizes during the calcination process, boric acid is in an excess of 50%. Weigh each raw material according to the molar ratio of each element. Weigh the oxide of M (lutetium oxide, gallium oxide, scandium oxide, indium oxide, gadolinium oxide, yttrium oxide), chromium oxide (analytical pure), and boric acid (analytical pure) compound raw materials according to the stoichiometric ratio of M 3+ :Cr 3+ :B + = 0.98:0.02:1.5. There are a total of 6 groups, as follows:
[0047] (1) Lu 3+ :Cr 3+ :B + = 0.98:0.02:1.5. Weigh 0.7799 g of Lu 2 O 3 , 0.0061 g of Cr 2 O 3 (AR), and 0.3586 g of H 3 BO 3 (AR) according to the molar ratio;
[0048] (2) Ga 3+ :Cr 3+ :B + = 0.98:0.02:1.5. Weigh 0.3674 g of Ga 2 O 3 , 0.0061 g of Cr 2 O 3 (AR), and 0.0061 g of H 3 BO 3(AR) 0.3586 g;
[0049] (3) Sc 3+ : Cr 3+ : B + = 0.98:0.02:1.5, weigh Sc according to the molar ratio 2 O 3 0.2703 g, Cr 2 O 3 (AR) 0.0061 g, H 3 BO 3 (AR) 0.3586 g;
[0050] (4) In 3+ : Cr 3+ : B + = 0.98:0.02:1.5, weigh In according to the molar ratio 2 O 3 0.5442 g, Cr 2 O 3 (AR) 0.0061 g, H 3 BO 3 (AR) 0.3586 g;
[0051] (5) Gd 3+ : Cr 3+ : B + = 0.98:0.02:1.5, weigh Gd according to the molar ratio 2 O 3 0.7105 g, Cr 2 O 3 (AR) 0.0061 g, H 3 BO 3 (AR) 0.3586 g;
[0052] (6) Y 3+ : Cr 3+ : B + = 0.98:0.02:1.5, weigh Y according to the molar ratio 2 O 3 0.4426 g, Cr 2 O 3 (AR) 0.0061 g, H 3 BO 3 (AR) 0.3586 g;
[0053] Grind evenly to obtain a mixture; calcine the mixtures (1), (3), (4), (5), and (6) at 1250 °C for 10 hours, and calcine the mixture (2) at 850 °C for 10 hours. After cooling, grind to obtain the near-infrared luminescent material.
[0054] Figure 4 Powder X-ray diffraction spectra of the samples of formulations (1)-(6) of Example 2. The spectra were measured using a Bruker D8 Advance X-ray diffractometer at a test voltage of 40 kV, a test current of 40 mA, and using Cu-Kɑ radiation. It can be seen from Figure 4 that X-ray diffraction analysis shows that the sample of formulation (1) is the LuBO 3 phase, the sample of (2) is the GaBO 3 phase, the sample of (3) is the ScBO 3 phase, the sample of (4) is the InBO 3 phase, the sample of (5) is the GdBO 3 phase, the sample of (6) is the YBO 3 phase. The doping of Cr has no effect on the formation of the crystal phase.
[0055] Figure 5 Mechanoluminescence spectra of the samples of formulations (1)-(6) of Example 2 were measured using an Ocean Optics QEPro fiber optic spectrometer in the United States. The data acquisition integration time was 800 ms and the scanning step size was 1 nm. It can be seen from Figure 5 that for samples (1)-(4) under stress (the magnitude of the applied force is 50 N and the time of force application is 2 s), near-infrared tunable mechanoluminescence in the range of 600-1050 nm is achieved, corresponding to the 3+ E→ 2 A 4 and 2 T 4 → 2 A 4 transitions of Cr 2 ions; for samples (5) and (6) under stress (the magnitude of the applied force is 50 N and the time of force application is 2 s), there is no mechanoluminescence phenomenon.
[0056] The present invention also provides an application of the above-mentioned near-infrared mechanoluminescent material in non-destructive testing, including the following steps:
[0057] A glass tube containing different solutions is used as the loading force on the ML film. The emitted ML signal is collected by a spectrometer after passing through the solution, and then the chemical composition of the object to be detected is obtained by analyzing the absorption spectrum of the solution to be detected.
[0058] Among them, the near-infrared mechanoluminescent material is placed at the bottom of the solution glass tube, and the added near-infrared mechanoluminescent material is In 0.98 Cr 0.02 BO 3, specifically: After grinding and mixing the sample of formulation (4) in Example 2, it was incorporated into PDMS. The mass ratio of the phosphor to PDMS was 1:1. After mixing and stirring for 2 min, it was poured into a mold and dried in an oven at 70 °C for 50 min, and then taken out of the mold. The bottom of a glass tube containing different solutions was used to scratch In 0.98 Cr 0.02 BO 3 thin film, and the transmitted spectrum absorbed by the solution was collected.
[0059] Some common solutions in the laboratory and daily life were selected as the solutions to be detected to demonstrate the potential of the self-recovery force-induced luminescence material in the detection of near-infrared solutions, which were: ethanol, deionized water, ethyl acetate, cyclohexane, acetone, and methanol.
[0060] Figure 6 The transmitted spectrum of the sample of formulation (4) in Example 2 through different solutions, and the difference between the calculated force-induced luminescence spectrum of the sample of formulation (4) in Example 2 and the transmitted spectrum of the solution. An Ocean Optics QEPro fiber spectrometer in the United States was used, with a data acquisition integration time of 800 ms and a scanning step size of 1 nm. When the sample of formulation (4) in Example 2 was under stress (the magnitude of the force was 50 N and the acting time of the force was 2 s), force-induced luminescence with a peak at 806 nm occurred. Since different solutions have specific absorption peaks in the near-infrared region, the qualitative detection of the solution type can be realized by using the difference in the force-induced luminescence intensity before and after the sample passes through the solution. It was found in the experiment that the peak position of the difference in the force-induced luminescence intensity before and after the sample passed through ethanol was 905 nm, and the absorption peak belonged to the third overtone of the methyl C-H stretching vibration; the peak position of the difference in the force-induced luminescence intensity before and after the sample passed through deionized water was 960 nm, and the absorption peak belonged to the second overtone of the O-H stretching vibration; the peak position of the difference in the force-induced luminescence intensity before and after the sample passed through ethyl acetate was 899 nm, and the absorption peak belonged to the third overtone and the third combination frequency of the methyl C-H stretching vibration; the peak position of the difference in the force-induced luminescence intensity before and after the sample passed through cyclohexane was 920 nm, and the absorption peak belonged to the third overtone and the third combination frequency of the methylene C-H stretching vibration; the peak position of the difference in the force-induced luminescence intensity before and after the sample passed through acetone was 890 nm, and the absorption peak belonged to the third overtone and the third combination frequency of the methyl C-H stretching vibration; the peak position of the difference in the force-induced luminescence intensity before and after the sample passed through methanol was 910 nm, and the absorption peak belonged to the third overtone of the methyl C-H stretching vibration. The results proved the potential application of the near-infrared force-induced luminescence borate of the present invention in analyzing the types of solutions with specific absorption signals.
[0061] The principle of the present invention is as follows: Crystallographic data shows that ScBO 3 belongs to the trigonal crystal system, and the space group is lattice parameters and Z = 6. When the coordination number (CN) is equal to 6, Cr3+ The effective ionic radius of is close to that of Sc 3+ ( CN = 6), and much larger than that of B 3+ ( CN = 6). From the perspective of coordination number and the corresponding ionic radius, Cr 3+ is more inclined to replace Sc 3+ . Since Cr 3 with a 3d 3+ electronic configuration has luminescence properties that are very sensitive to changes in the crystal field in the host, tunable emission is achieved through local crystal field engineering by fully replacing the Sc 3+ sites with Lu 3+ , Ga 3+ , and In 3+ . Since the ionic radii of Y 3+ ( CN = 6) and Gd 3+ ( CN = 6) are much larger than that of Cr 3+ , they are not suitable for Cr 3+ to replace, so the ML phenomenon is not observed.
[0062] The above embodiments are all preferred embodiments of the present invention. However, the embodiments of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.
Claims
1. A self - recovering stress - induced luminescent borate, characterized in that, Its general expression formula is M 1-x BO 3 :xCr 3+ , where M is Sc, Lu, Ga or In; x = 1% - 5%.
2. The self - recovering stress - induced luminescent borate according to claim 1, characterized in that, the value range of x is x = 1% - 2%.
3. A preparation method of a self - recovering stress - induced luminescent borate, characterized by including the following steps: a. Weigh the oxides of M, chromium oxide, and boric acid according to the molar ratios of the elements in the chemical formula M 1-x BO 3 :xCr 3+ wherein the boric acid is in an excess of 50%, M is Sc, Lu, Ga, or In; x = 1% - 5%; b. Mix the weighed raw materials and grind them evenly to obtain a mixture; c. Calcinate the mixture at a high temperature to obtain a self-restoring force-induced luminescent borate M 1-x BO 3 :xCr 3+ .
4. The preparation method of a self - recovering stress - induced luminescent borate according to claim 3, characterized in that, in step c, when M is Ga, calcine the mixture at 850 °C for 10 hours; when M is Sc, Lu or In, calcine the mixture at 1250 °C for 10 hours.
5. The preparation method of a self - recovering stress - induced luminescent borate according to claim 3, characterized in that, in step a, the value range of x is x = 1% - 2%.
6. The application of the self - recovering stress - induced luminescent borate according to any one of claims 1 - 2 and the self - recovering stress - induced luminescent borate prepared by the method according to any one of claims 3 - 5 in non - destructive testing, structural flaw detection, anti - counterfeiting encryption, flexible devices, disease monitoring, lighting display, stress recording.